Namaste and welcome back to the video course on Watershed Management. In module number 8, lecture number 32, we will discuss today urban drainage system. So, some of the important topics covered in this lecture includes urban flooding, disaster risk management, urban drainage system, design requirements, roadside drainage design. Some of the keywords for today's lecture urban flooding, drainage system design, risk management and roadside drain. So, as we were discussing earlier, so when we discuss about watershed management, so we are taking it as a holistic way. So, we have to see the urban areas also and then we have to see the storm water management within the watersheds and then we have to see the say later flooding and overall say the storm water management within the system. So, as we discussed in the last lecture, say the storm water system we have to we can design as separate system or combined system and then say whenever the urbanization takes place there is lot of changes to the to the watershed and the time of concentration reduces and the peak to the hydrograph, the peak of the hydrograph increases. So, like that a number of hydrological changes takes place with respect to the runoff taking place within the watershed due to the urbanization. So, due to all this as we discussed there is good chance of say increase the chance of flooding within the watershed. So, that way we have to we should appropriate flood management say planning as far as the watershed is concerned. So, somehow the the the causes of urban flooding say here I have mentioned. So, it can be as we discussed a large increase in concrete or impervious surfaces or unplanned usage of urban lands or lack of proper drainage or loss of wetlands or it can be less ground water usage or recharge, tidal effects or very heavy storms or cloud cloud burst or say like a climate change effect. So, there can be number of such causes as far as urban flooding is concerned. So, say lot of changes takes place due to the urbanization to the considered watershed. So, that way the impervious surface area increases and then wetlands will be lost many locations and then if there is no sufficient drainage or the drainage is not proper then the chances of flooding increases. So, that way we can see that in most of the urbanized watershed say there is problems of flooding. So, the problems of flooding are increasing and then we have to we should appropriate plans when we deal with the watershed management. So, now let us look into what are the things which we can do to deal with these kinds of urban flooding say on a watershed basis. So, in this slide some of the important points related to urban flood disastrous management are mentioned. So, as we discussed say to deal with these kinds of urban flooding we have to develop appropriate coping strategies and disaster reduction plans along with the greater awareness of how to reduce risk. So, that is the high priority as far as watershed development and plan circumstances. So, there can be number of strategies. So, strategies like we can go for enhanced national stage and local scale advocacy partnerships and knowledge management. So, we can get to say all the data and then come up with certain decision support systems which can say clearly say that what are the possible ways to reduce the flood say urban flooding. And then standardizing hazard risk management tools so, we can say come up with some standard management tools and methodologies and practices to reduce the risk of urban flooding. Then developing integrated and coordinated approaches so, same as far as the flooding is concerned say as we discussed in the previous lecture also it is not only simply the storm water drainage which we have to manage, but we should have look into holistic same watershed management including LID schemes or low infrastructure developments or the integrated storm water management schemes. So, like that as we discussed in the previous lecture. So, that way we have to standardize the management tools and then we can have a we can develop integrated and coordinated approaches. And then also we can incorporate learning by doing mode of operations. So, we can see that in many cities say there may be number of floods that happens earlier times. So, from that we can learn a number of lessons. Say for example, in Mumbai and July 26 2005 there was a severe flooding. So, from that we can learn many lessons and then we can implement many changes many things to the to the area considered so, that to this flood risk can be reduced. So, that way this the learning by doing mode of operations are very helpful. Then we can promote the diffusion or the documentation of best practices. So, as we discussed in the previous lecture also so, there are a number of best practices are possible. So, we can say say come up with specific documents say how we can reduce the risk as far as the urban flood flood is concerned. So, that we can go for better management practices and then this can be say communicated to various the stakeholders in going common public schools and public enterprises or the private institutions. And then also we can build appropriate communication protocols facilitating multi-platform and multilingual dissemination. So, as far as flooding is concerned say if there is any area say due to heavy rainfall or any other reason if there is an area which is flood prone then we need to have appropriate communication protocols we can develop and then the people can be want say just like advanced flood warning systems and that will be very useful to the to reduce the risk as far as the urban flood is concerned. So, whenever deal whenever we talk about the disaster risk management as far as urban flooding is concerned we have to come up with appropriate plans and then we have to come up with appropriate guidelines with previous experiences and then also we have to disseminate this information to the stakeholders and various agencies. So, that the appropriate flood warning system can be made and so, people lives and money can be saved this way. So, that way when we discuss about the urban flood disaster risk management say we have to analyze and present information in an easily understandable form for wider use by decision makers. So, whatever we are making as far as the guidelines or as far as the management plans so, it should be analyzed and presented in such a way that it is easily understandable to the decision makers or the politicians or the district authorities like that. And then we have we can encourage integrated approaches of projective mitigation based on master plan. So, each urban urbanized watershed is concerned we can come up with certain master plans and then we can have integrated approaches as far as the projective mitigation is concerned. So, that the flood risk can be reduced and then also we can encourage states to accord top priority to deal with recurring urban flooding. Say for example, government of India say as central government so, government of India can encourage states governments to give top priority as far as to deal with the urban flooding. Since when urban flooding happens say the economical loss will be very high the human loss will be very high. So, that way we should have integrated flood risk assessment plans and we have to go for disaster risk management as far as the urban flooding is concerned. So, whenever we deal with the urban flooding number of difficulties are there. So, some of the difficulties I have listed here like a comprehensive risk assessment then factoring risk in development planning coordination among different institutions lack of information sharing disintegrated investment decisions lack of consultation with stakeholders etcetera. So, like that when we look into urban flood management like whenever we look into disaster risk management say number of problems are there. So, say most of time number of agencies will be working as far as the urban flood risk assessment and management is concerned. So, we have to coordinate these agencies and then most of the time the stakeholders those who are affected by these floods they will not have sufficient information. So, we have to consult with them and then we have to disseminate the knowledge and then we have to we should have comprehensive risk assessment plan covering all the aspects with respect to the master plans as far as the urbanized water shed is concerned for the disaster risk management. So, now say we were discussing say when we deal with the urban flooding say it is always better to deal with on a water shed scale or on a catchment scale. So, that is hydrological unit is considered in the in the plans as far as the urban flooding is concerned. So, now let us discuss the urban flood management within the perspective of water shed management. So, as we discussed any planning for effective urban flood management has to take into the consideration of entire water shed. So, since a water shed is defined in such a way that it is hydrological unit wherever the we can have a single outlet where the all the runoff will be coming through a single outlet. So, that way the water shed is the best unit to look into the urban flood management. So, then that way on water shed basis we can identify the problems, causes and we can go for various remedial measures. And then also on water shed basis we can go for the preparedness and then mitigation as far as the flooding is concerned what kind of mitigation measures to be undertaken. And then also since a water shed is a hydrologic unit. So, when we look into early warning system and then communication it is always better to be on water shed basis. And then the response action also it is better to be on water shed basis since the response is concerned it is with respect to deal with the discharges taking place within a water shed or the depth of flow taking place. And then also we can go for awareness generation within the various stakeholders and that way we can develop the community capacity to deal with such kind of flood problems. And then also we can develop vulnerability maps and then risk assessment maps. So, that the total the risk or the vulnerability due to the urban flooding can be reduced very much. So, that way like a hazard mapping or flood level mapping and then we can identify the damages and then as a if any specific locations are there then we can go for insurance and risk transfer. So, that way various things are possible when we deal with the urban flood management on a water shed basis. So, it is not just like an administrative unit just like a district or a taluk or a village, but it is always better to go on a water shed basis as far as urban flood management is concerned. So, that way when we deal with the urban flood management on a water shed basis if we can develop a special decision support system which we discussed in one of the earlier lecture. So, we can develop appropriate special decision support system which we can show say the vulnerability to flooding or say the flood risk areas and then we can easily predict which of the area will be affected whenever say the water level raises to a certain level. And then so that way the decision makers can easily understand what will be happening due to say certain specified intensity of rainfall or the predicted rainfall. So, that appropriate measures management measures can be taken to save lives or to save properties. So, that way we can have an urban information system say for example, in Mumbai city after the 26th July 2005 rainfall say disaster management cell has been opened and then this cell is monitoring say with respect to the during the monsoon season how the very rainfall pattern changes or with respect to heavy rainfall what are the possibilities of flooding or what are the which are the areas which may be affected due to flooding. So, that way this disaster management cell gives information to the public media and that will be disseminated and then that way we can have appropriate managing plans. So, that way it is always better to develop an urban information system so that we can come up with appropriate plans to deal with the urban flooding problems. So, now whatever we have discussed is say the urban flooding and related courses and then what are the risk involved and then how we can manage. So, now let us discuss about the urban drainage system since drainage pattern or appropriate drainage is given then to a bigger stance the urban flooding can be reduced. So, appropriate urban drainage system is very important as far as the urban management is concerned. So, urban drainage system so drainage system generally we can categorized into major drainage systems and minor drainage systems. So, major drainage systems generally say to this comprises of open NALAs or streams and channels and natural surface drain. So, say whenever rainfall takes place in the urbanized area then this the immediately the runoff starts especially from the interior surfaces and this will be collected through minor drainage systems just like a network of underground pipes and channels. So, that is so called a minor systems and this minor system will be joining the major drainage systems just like streams, NALAs say small channels or rivers. So, this finally it will be taken to larger wells or the to the ocean directly depending upon the area. So, minor system generally we can categorize into two types like a separate and combined storm water drainage system. So, this also we have discussed in the last lecture. So, in the separate drainage system generally there is one system to convey the the storm water and another system to convey the sewage or the say as a separate sanitary sewage. So, the sanitary sewage usually underground pipes convey the wastewater from homes and business to discharge point while the storm drains which is the underground pipes or channels collect the storm water from the rainfall runoff and convey to the discharge point. So, depending upon the city or depending upon the location there may be separate systems or the combined system. So, the advantage and limitations of separate system and combined system we have discussed earlier. So, as far as urban drainage system is concerned there can be major drainage systems or the minor drainage system. So, when we look into the urban drainage processes so, we can put it in a flowchart like this. So, the the urban runoff is coming from precipitation or snow say precipitation as rain or snow and then if you consider the watershed area there some area will be same pervious area and some area will be say urbanized or impervious area. So, we should have a say using hydrologic models so, we can model this rainfall runoff by considering various processes like evaporation, infiltration, overland flow like that and then say by by using hydrologic models we can get the hydrographs so, which is the say overland flow as far as the considered hydraulic unit is concerned and then this the hydrographs which we consider that will be further this overland flow will be joined to the channels or the big drains or small drains depending upon the conditions and this say we can model through hydraulic models. So, we can be either say the the flow through on the roads or say pipe flow and so, that can be various say there can be some storage as far as road is concerned or this we were to routes and then most of time we have to identify how much will be the depth of flow and how much is their discharge passing or flooding taking place and then of course as far as the main roads are concerned number of opportunities will be there roads and drains will be there and then say the culverts will be there then inlet will be there. So, like that number of opportunities will be there roads and opportunities will be there. So, this overland flow will be passed through the the road to this to the opportunities to the major drains like drain channel or pipe and then that will be routed as drain flow and that will be the discharge which is coming to a major channel stream or river and that will be further routed. So, that way when we discuss with the urban drainage processes. So, we have to say deal with the hydrological aspects and the hydraulic aspects. So, had we we need to have a hydrological models so, which converts the precipitation to runoff. So, that can be mainly for overland flow conditions and then we should have hydraulic models which will be routing this runoff through the roads through the roadside drains through various opportunities and then through drainage channels or pipes and to the to the main drainage system or the main mahala or the streams or river. So, that is the way we have to model the urban drainage system say starting from the precipitation to the runoff to the main river or channel say through various say overland flow conditions or roads road flow on the road or the small drains pipes like that. So, this flow chart shows a typical hydraulic process as far as urban hydrology is concerned. So, now let us look into various aspects as far as stormwater drainage system is concerned. So, as we discussed say this total stormwater system can be major stormwater system or minor stormwater system major system include the small channels, mahalas and rivers minor mainly consist pipe drains or small drains open down drains. So, we should have an inventory of all this drainage system within the area which we consider. So, most of the time we can do this through a GIS platform. So, that we can identify the locations easily where is the major drainage system where are the minor systems so, like that. So, we can we should have an inventory so, as far as with respect to the watershed to enable proper hydrologic and hydraulic analysis and what so, what are say particular local locality based to enable coordinated administrative management. So, most of time administration is concerned it is administrative area will not be most of time the watershed based. So, that way say many of this local administration have to coordinate together. So, it is always better to have an inventory of the drainage system the major drainage system as well as the minor drainage system. So, as far as minor drainage systems concerned we should map this minor drainage systems clearly showing the interconnections with the major systems besides the cross connection with the sewer lines. So, say if there is any cross connection with the sewer lines for the minor storm water drainage system that should be also clearly shown and all the interconnections should be shown and then where this minor systems join the major systems also should be clearly shown. And then as far as major system is concerned we should map clearly with delineation demarcation and details of cross sections then slopes drain crossings including natural formations and manmade structures. So, all this say we should have appropriate inventory within a GIS platform. So, that say whenever we are having a flooding warning systems a flood warning system which a flooding. So, that we can easily identify which area will be flooded and what kind of appropriate measures to be taken so that we can save lives and property. So, that when appropriate inventory in a GIS platform helps to reduce the flood related problems. So, now let us look so we were discussing about the urban drainage systems. So, whenever we are going to design an appropriate urban drainage design say we have to meet with certain requirements. So, let us look into various aspects as far as the urban drainage design requirements are concerned. So, the development of an adequate and functioning drainage system based on sound hydrologic and hydrologic design principle we should have. So, we have to see the hydrologic principles. So, like rain fart runoff and then how the flood routing all takes place so that we have to get through a hydraulic design. Then design of an urban drainage system requires knowledge of the catchment area and topography, then urbanization details rainfall intensity, hydrology, hydrologics etcetera. So, the number of factors number of things we have to consider when we go for urban drainage designs like the catchment area its topography, then the rainfall details, then the hydrologics details etcetera. Then as we discussed most of the time it is always better to go for watershed or catchment as basis as far as urban drainage design is concerned. So, that way we should have the conduces of the watershed so that we can easily determine the boundaries of the watershed or the catchments for computing the directions of flow. So, as we discussed earlier based upon the conduces and then the topography details we can come up with a digital elevation model. So, this digital elevation model as shown here that indicates the flow directions and then how the if a flood type space how it will be affecting the watershed. Then say as far as rainfall is concerned another important data. So, for design of a drainage system the conventional practice is to choose an appropriate statistically relevant design storm to establish the storm water flows to be conveyed based on existing national and international practices. So, certain codes are there Indian standard codes or international standard codes. So, accordingly we should consider say how much rainfall intensity or intensity duration frequency curve say for example, depending upon the importance of the areas just like airport we need a say maximum consideration or say roads or say specified installations. So, like that we have to consider. Then we can also come up with the design storms which are generally estimated from rainfall data records for a long time and then we can come up with the intensity duration frequency curves. So, which shows the relationships between the rainfall intensity and then its possibility of occurrence. And this idea of curves need to be used to maintain design standards for new systems and then also retrofitting and replacement of all the urban drainage systems. So, that way say we have to keep on updating the idea of curves and then come up with the appropriate rainfall intensity while designing the new urban drainage systems or when we are going for retrofitting or replacement. So, idea of curves should be developed for each city based on extraction of data from the road data charts and this can be say minimum 15 minutes resolutions. So, that we can easily identify which are the locations of possible locations of flooding or what kind of say how the discharge or the flow depth will be varying within the watershed which we consider. So, now let us look into some of the important design consideration as far as urban drainage is concerned. So, some of the important say considerations like a frequency of thunderstorms. So, we should also look into additional considerations for planning future urban drainage systems and then as far as say discharge flow or design flow is concerned to protect urban areas safe management and passage of water resulting from frequent storm events like say we have to look into hydrologic design and then corresponding hydrologic design. So, we have there should be adequate capacity as far as the drainage system is concerned. So, we have to consider this design flow. Then urban drainage design most of the time our main objectives include hydrologic analysis and design to estimate the peak flow rates and the flow hydrograph for the adequate sizing and design of conveyance and quantity of control facilities. So, as I mentioned earlier we had two components one is a hydraulic design, second one is the hydraulic design. So, accordingly say the main objective is to do a hydrologic analysis and design. So, that gives the peak flow rate time to peak and all those details and then accordingly we design the drainage section and then its conveyance and then the control facilities as far as the flood movement is concerned. So, to estimate the peak flow rates say the nuance of the rainfall intensity is duration and frequency is required. So, this we can consider the historical rainfall events say for example, at least 10 years and you always say always if you can have more data like 50 years or 100 years of data we can analyze and then come up with say appropriate levels of say as far as design flow is concerned depending upon the area which we consider. Then say when we look into urban drainage design say we have to deal with the number of problems. So, like say some of the important problems are listed here like increase in rainfall intensities. So, in the last few decades you can see that many cities like Mumbai, Kolkata, then Chennai etcetera are affected by high intensity short duration rainfalls and this rainfall causes heavy flooding and large losses as far as the human life and property are consensed. So, this can be due to various reasons like cloud burst or the urban heat islands problems or climate change impacts. So, that way we have to deal with increasing rainfall intensities induced by climate change, urban heat islands or other factors which will possibly result in varying return periods for a given intensity of rainfall. And then rainfall intensity to be used for design will also depend upon the time of concentration. We have to identify how much is the time of concentration as far as the considered water shade by considering the various parameters and then if higher the catchment area higher will be the time of concentration and lower will be the design rainfall intensity. Other factors remaining the same, but we have also how to see the effects like a tidal effects say for example, in cities like Costa cities like Mumbai or Chennai are affected by the tidal effects also. So, we have to see simultaneously not only related to the rainfall runoff pattern, but also the tidal effects. As far as peak flow rates are considered we can simply use methods like rational method which is q is equal to c into i into a where a is the area of the catchment, i is the intensity of rainfall, c is the coefficient of runoff. So, this is this symbol formula we can utilize for hydrologic analysis. And then say we can say as far as this rational formula is concerned approximations based on runoff coefficient and rainfall intensity and area of catchment. So, that way we can easily do calculations and designs as far as hydrology is concerned. And then hydrology design say just like the cross section of the drainage system we can use simple equations like manning's equations or chassis equations for simple design. But whenever we are looking for the flat routing is concerned we have to go for numerical techniques and softwares like HEC, HMS or HEC RAS type of modeling tools. So, for a simple channel design we can use manning's equation like q is equal to a into r to the power 2 by 3 s to the power 1 by 2 divided by n, where n is the manning's reference coefficient, a is the area of cross section, r is the hydraulic radius and s is the slope. For computation of water level profiles in the drainage systems or channel rivers say we can go for suitable softwares for flat routing just like public domain softwares like HEC, HMS for hydrologic modeling of the watershed and then HEC RAS for river modeling or we can go for software like SWMM storm water management model for sewer drainage design. So, that way we can either go for a simple modeling models just like a rational formula or manning's equations or we can go for somewhat complex models like HEC, HMS or HEC RAS which you consider most of the physical parameters as far as the rainfall runoff is considered. So, all future storm water drainage system may be designed to taking into consideration a runoff coefficient up to C is equal to 0.95 for estimating peak discharge using the rational method. If you are using rational method, so maximum possible generally we can consider 0.95 and then say urban drainage system is concerned we also should be we should deal with the operation and maintenance. So, it is not only appropriate design and then implementation, but the operation and maintenance also very important. So, let us look into some of the important aspects as far as the operation and maintenance of the urban drainage system. So, proper operations and maintenance are crucial for any urban drainage system to be functional to the design capacity and for its durability as well. So, you can see that say whenever heavy rainfall or the monsoon takes place say for example, in India during the monsoon period of 4 to 5 months starting from June to September or October. So, we cannot do many of this maintenance during that time. So, we have to do this maintenance work before the monsoon starts. So, that way pre-monsoon desiliting a major operation maintenance activity in most of the cities and watersheds. Then a periodicity of cleaning of drains should be worked out based on the local conditions. So, as I mentioned local conditions like if there is effect of tides or other kinds of parameters which you have to consider, then we have to see whether we have to do before monsoon only or periodically we have to do and then other issues like say removal of solid base. So, you can see that many locations say the drains will be clogged due to the solid base. So, there should be suitable interventions in the drainage system like traps, trash tracks which will reduce the amount of solid base going into the storm sewers. And then also in many of the same storm drainage systems we can see that a sedimentation is a problem, silting is a problem in channels or even pipes. So, we have to see various arrangement like removal of sediments within the say drainage systems. So, sometimes hydrology also we can do this through maintaining certain minimum velocity within the drainage system or say we can also remove it manually. And then also we have to see the inlet connectivity between the major drains and then minor drains and then we have to see how the system to be worked out. And then also as far as urban drainage system is concerned some of the special considerations which we have to see as far as the watershed is concerned like low lying areas should be reserved for parks and other low important impact human activities should be only done. Then wherever unavoidable buildings in low lying areas should be constructed on steels above the high flood level or full tank level. Then for chronic flooding spots alternative locations may be explored for accommodating people staying there. And then a building should be constructed on steels after taking into account the stability of slopes and then storm water drainage system for coastal cities have to be designed taking into account the tidal variations. So, when we look into urban drainage system we have to see all these considerations like a tidal effects then low lying areas and then if any specific areas always flood prone then what kind of measures we can consider like that. So, various special considerations we have to see as far as urban drainage system design is concerned. So, now say what we are discussing is the important aspects as far as urban drainage system its considerations is designed and its requirements so that is what we are discussing. So, now say one of the important urban drainage system generally in urban areas is the roadside drainage system. So, say if we have appropriate roadside drainage system we can see that in most of the urban areas we can reduce the flooding problems to certain extent. So, as I mentioned earlier there was a heavy flooding in on 26 July 2005 in Mumbai due to cloud based effects of rainfall of about more than 940 mm in a time span of 24 hours and then also high tidal effects. So, due to this there were heavy flooding in many locations of Mumbai city and number of people died and then there was huge economic loss. So, that when then we were asked to look into the roadside drainage system as far as the Mumbai city is concerned most of the important roads of Mumbai cities are concerned. So, then we looked into various design aspects of various existing conditions as far as this Mumbai roads are concerned and then we went through all the design procedures as far as roadside drainage design is concerned and then we come up with certain guidelines. So, I will just discuss this roadside drainage design within this context of Mumbai roads which we which we redesigned few years back by considering the various rainfall conditions tidal conditions and then the the road conditions and the side conditions. So, some of the important aspects are listed here. So, as I mentioned roadside drainage integral part of urban drainage systems. So, this is actually storm drainage. So, whatever the the storm water from the nearby areas it will be mainly coming through these roadside drains and then it will be going to the to these larger drainage systems or the Nalas or Stannels. So, the storm drainage here what is happening we collect the storm water runoff then this should be away from structures and through roadway or the waterway or right of way. So, you can see that if this is a the road then we have to collect all this the the storm water coming from adjacent areas and then generally the drainage system storm water drains will be on the sides of the roads and then we have to see appropriate design as far as the roadside drainage system is concerned. So, some of the important objectives for such a design is hydrologic we have to see the hydrologic aspects like in part runoff then we have to see the hydraulic considerations like what kind of section to be given what kind of drain open drain or pipe drain so what kind of drain is to be given. So, the main objective will be minimize the flooding and then erosion to properties and then safe traffic. So, in an urban area if there is the if we can reduce the flood risk through all the roads then most of the inconveniences of course, due to urban flooding can be reduced to a larger extension. So, that way we have to see say when we design the the the roadside drain we have to see the the road layout and then various junctions, various flyovers and various natural drains coming and then wherever say the the cross drainage systems and then the directions then in the slope all these important aspects we have to consider when we look into roadside drainage design. So, as I mentioned say we have formulated the design steps so some of the important design steps we will discuss here. So, design problem and design criteria specification so we should see what kind of design we are looking for then what kind of locality whether just like a crowded place like Mumbai or a small city where not much crowd is there so accordingly we have to see the roadside drainage design. Then the system drainage area definition and preliminary layout so we should get the road layout accordingly we should go for the the drainage and then the drainage area. Then we should get the street layout total drainage then a field and office data collection so we should go to the field and then see the specific problems like the width the say whether in trees are there outcrops, utility locations etcetera then we should come up with the system layout. So, the final layout we should have then like all ditches, waterways, inlets, manholes, mains, laterals, culverts, flow direction etcetera so we have to go systematically. Then next step is hydrologic calculations so we have to identify as far as roadside road is concerned so how much water will be coming from both sides so we have to see that area and then how much is a rainfall possible and then we should go for hydrologic calculations so we may have to go for a hydrologic modeling rainfall runoff. So, flow estimations for the design frequency we have to consider so we have to see the intensity duration frequency curve or return periods which we have to consider 2 years return period or 5 years return period or 50 years return period like that. Then we have to see the street flow like a flow and spread calculations then a maximum spread gutters flow like that. Then inlet spacing and layout so like location and type of inlets, size, extra inlets etcetera then we have to see the hydraulic calculations like size of the drain, permissible velocity, slopes etcetera then various design checks like discharge, fruit number, velocity, slope like this all these parameters we have to consider as far as the roadside drainage design is concerned. So, it is not only hydrologic aspects, but also the hydraulic aspects like size of the drain, velocity, slope etcetera. So, some of the important factors which we have to consider when we go for roadside drainage design is listed here like return period of flow like 2 years return period or 5 years return period or 50 years return period. So, this depends upon the city area and then the importance of the area. Then the water spread area say like when we consider the road both sides how much area whether it is the on a watershed basis or only a strip wise both sides like a 50 meter or 100 meter both sides of the roadside. Then inlet types and spacing so how these flow is coming to the roadside drains so and then what is the spacing for that. Then longitudinal slope we have to see then cross slope then curves and gutter sections so how the curves and how the gutters how this is considered. Then roadside and median channels bridge decks flyover, shoulder gutter, median barriers, storm drains, detention storage, erosion and then what is the cost how much cost say what are the financial layout as far as whether we have to go for very expensive drainage system. So, how we can reduce the cost so all those issues we have to consider. So, these are some of the important factors which we have to consider when we deal with the drainage design. So, some of the important design considerations I have listed here like how much area should be considered for a reach. So, if this is the in the mounts which we consider then both sides how much area we have to consider. So, actual length is in between hydraulic mount to the drainage point so this is the drainage point. So, this is the hydraulic mount so how much area we have to consider. Then second issue is how much width should be considered on other side of the road drainage. Internationally roadside drain are designed to cater only road runoff, but in highly populated area like Mumbai we have to consider the runoff coming from nearby areas also. So, nearby properties or this runoff will be coming to the roadside drains. So, we have to deal that also. So, then actual width should be based on topographical survey and then the roads in Mumbai say for example, we have to see the actual area contributing to roadside since it is heavily populated and then roads are very narrow. So, that way we have to consider. Then third issue which we have to consider is designed rainfall intensity. Generally rainfall intensity with 10 year return period is considered say for important roads it should be about 50 year return period say like a roads connected to airport area like that. Then it should be based on time of concentration and then intensity duration frequency curve. So, Indian road congrats say for example, recommends time of concentration as made of two time periods. One is a time required for the rain water to flow over the road surface and enter into the drain and then time of flow in the drains. So, this is the most stated. So, this is say this is central line of the road this is the road. So, this is T 1 the time of this flow to enter to the roadside drain and then T 2 is say this say how to how much time to reach the main drain or NALA or the channel. So, that way we have to consider the time of concentration is equal to T 1 plus T 2. So, some of the important design considerations say for example, if you consider Indian road congrats in a manual number 50 say for example, Mumbai they suggest say minimum 50 mm per hour rainfall. Then the values are worked out assuming time of concentration of 30 minutes. Then rate of rainfall is 62.5 mm per hour with a return period of 2 years and then average runoff coefficient to be considered 0.6. So, these are the details as given for given in IRC 50 and then like type of surface like bituminous the runoff coefficient can be 0.8 to 0.9, impervious soil 0.44 to 0.65. So, like that depending upon the area and we can consider the runoff coefficients. Then say as far as hydraulic design is concerned if we use the Manning's equations then Manning's coefficient value we have to consider. So, if it is con gate channel then it can vary from 0.0132 to 0.017. For various surface characteristics range of N is given here this we can get from standard literature. Then next important design concerns permissible velocity in the road drains say as far as RCC drains if we consider allowable maximum velocity 6 meter per second and minimum velocity say up to say 0.30 centimeter per second and, but even the 6 meter per maximum is allowed, but restrict it is generally to 3 meter per second as per Indian Road Congress courts. Then another important aspect is width and depth. So, the width is as per the local width available for the construction of the drains. Then depth should be estimated based on Manning's formula as far as possible we can go for rectangular drains. Then economical section is the width is equal to 2 times depth and some places we may have to if we are going for open drains some places we may have to go for further pipe drains. Then as per IRCA50 minimum width of drain should not be less than 250 mm and in case of pipe the minimum diameter should not be less than 450 mm. This is as per Indian Road Congress manual number 50. Then 8th point is slope of the drains like longitudinal slope generally slope should not be less than 0.3 percent, but in flat terrain it can go up to 0.2 percent and slope is designed such a way that the flow is always in subcritical flow. So, there should not be any supercritical flow conditions so that there is any hydraulic jump can take place within the channel that may create further flooding problems. So, as per IRCA50 code minimum longitudinal gradient is 0.3 percent. Then freeboard also we have to when we go for open channel type design 0.3 meter is the in the prescribed freeboard, but say for example in a city like Mumbai flat terrain and does not allow to have more freeboards then IRCA recommends like if the bed width is less than 300 mm freeboard minimum should be 10 centimeter 300 to 900 mm 15 centimeter 900 to 1500 mm 30 centimeter and for larger size it should be 90 centimeter so like that. Then say design concentration like a type of inlet to drains so we can have either curbing lead or we can have greater inlet or we can have combined inlet. So, we should have say depending upon the terrain depending upon the location we should go for the best possible type of inlet to the drains. Then like a junction box size this should be designed as per the velocity of the water crossing the crossing or joining each other. Then as far as the NALA is concerned NALA this all these small drains what will be taking into the NALAs or the streams. So, level difference between the invert level of the maximum water level in the NALA we have to see the invert level of the drain is lower than the maximum water level in NALA then NALA water starts entering to the drains. So, then slope has to be modified and designed in such that the invert level of drains is above the maximum water level of NALA. Then connection between the main drain or either side of the road we have to see. Then points important points like design of drain draining to the creek or NALA having tidal effect. So, as I mentioned in a city like Mumbai tide is an important factor as far as spreading is concerned. So, we have to see that whether the outlet of the drain is to a creek or to a NALA whose water level rises according to the tidal level and the invert level of the drain should be above the high tidal level as seawater may enter to the drain. If possible a large size drain may be constructed which you can act as holding a pond until the high tide level. Then same we need a large quantity of data when we go for the road side drainage system design or the urban drainage design. So, some of the important data like your infalling density and runoff coefficient, area contributing to drains, then cross sectional parameters, the reduced level of the hydraulic mounts, then reduced level of the ground level, invert level of the drains. So, like this all this data required as far as the drainage design is concerned. Then key plan of the work the area like the length location of the NALA size invert level of drains at starting point and draining point, slope between the sections, other major drainage work nearby or river nearby. So, all these key plan should be available. Then detailed plan of the road like a length, location of point sources and their discharges, hydraulic mounts, reduced level of ground levels, then arrows showing the flow direction of storm water in the drains, location of draining NALA, location and size of cross drainage work, location of manholes and their sizes and any other data size specific. So, all this data detailed plan of the road and all the data should be available. Then longitudinal section drawing like a finished road level, reduced level of existing ground level, invert level of drains, wet levels, water levels of NALA, location of curbing inlet points, location and size of other point source joining the drain. So, like this. So, all this data should be available. So, when we go for integrated urban drainage system design, so including the roadside drains and then the NALA system or the channel system. So, we should have integrated drainage design plan. So, that the flood effect if any possibilities that can be reduced and then we can have a better management plans and better design, so that there is no flood problems as far as areas concerned. For today's lecture some of the important references are shown here. Then says before closing the lecture, some tutorial questions and assignment questions. Critically study the urban drainage design methodology adopted in India. Some details you can see in this websites. What are the urban drainage design practices in US, UK and India and propose better management practices for Indian cities? Then few self evaluation questions. What are the important causes of urban flooding? What are the difficulties in urban flood management? Discuss watershed based urban flood management. Describe the inventories to be taken for storm water drainage system. What are the important design consideration for urban drainage systems? What are the important data to be considered for roadside drainage design? So, all these questions you can easily answer by going through today's lecture. Then few assignment questions. What are the important strategies for urban flood disaster risk management? Illustrate various urban drainage systems. What are the important design requirements for urban drainage systems? Discuss the important design considerations for roadside drainage design. What are the important factors to be considered for roadside drainage design? So, these questions also you can answer by going through today's lecture. So, what we discussed today is urban drainage design and then say an integrated design system by considering all the aspects including the roadside drains, NALA system or the channel system. So, that we can have an effective drainage design. Thank you very much.


Let's get over to our mammoth to Tim or as we do every Tuesday and Thursday You can reach Tim folks every trading day is a great newsletter at odd or d dash oracle calm That's odd dash oracle calm Tim or what a market. How you doing? I'm doing great man yourself Well, good good. I got a couple of charts. We're kind of walk through it. Everybody's kind of worried about the gold market, so we actually going to take a Pretty big view on it. So, okay, that was weeks when you start chart one, okay, we showed this a number of times The top window is the RSI for the bullish percent index For the goldmires slash gdx ratio, right and every time the RSI of That ratio got below 30 and closed above 30 a majority of the time the bottom was then that just happened here probably in September Probably early September don't have the exact date But anyhow, all the blue lines there across the chart shows the time that signal was generated So let's look at the bigger chart of that same chart. This chart goes back to Chart number two. Okay goes back all the way back to 2008 about mid 2008. Yes, and that's kind of a rare signal But the blue line should hang out that type of signal where they are is I drop below 30 and close above 30 And I took it all the way back to 2008 and all the blue lines there Horizontal blue lines are times that signal was generated and there's which was 18 times and there's two red Lines there that the signal failed. So if you do that number You work out 80% or 89% success rate. Yeah, pretty good. Yeah. Yeah, so the odds of this making a low And this vicinity because this doesn't actually pick up the exact low But that's pick up the vicinity of a low is 89% so you really Don't really want to be bearish here Again, the other two times was coming off the 2011 major top So they didn't give a signal then 2016 that was going off of a ballistic Upward rally. I remember that rally just went right through the ceiling right then it failed but since then 2016 all those signals have been successful. So I flipped To a little another chart here and show you show where we are on the short-term basis. Is that the third John? Yeah Yeah, the third chart. Okay, cool. And The bottom window is the six to a sixty-two day average of the up-down volume percent for GDX So it measures the up-down volume of all the stocks in GDX, which is I think around 30 or 32 of them And so when it gets above zero, that's the blue shaded area is when those rallies start and sometimes they kind of hover around if you look at 2019 Right smack that January high it kind of fumbled around that zero line before the rally actually got I got going and It's kind of common But once it gets around zero it usually stays there usually doesn't go up and eject and go back down they usually hovers around that zero line was what we've kind of been doing and We got above that zero line last week now. We're a little bit below it We're pox about minus two right now and I think got up about plus five last week So we're hanging around that zero line and this is a 62-day average. So it's like three months three months. Yeah So and also I want to point out this chart When it gets down below minus 20 which it did back in July of 2000 or maybe September of 2021 that down below minus 20 again and Looks like about July 2022 and again in July to 2023 the market flip sideways for several months And 2021 when it's sideways approximately six months in 2022 when sideways for four months Currently, we've been going sideways for about three months. So in my opinion, we're still looking at a lower here I think the market Because it's down so hard is affecting pretty much all the markets. So I don't think this is a big decline I still think probably in a basing period and there's a good chance of a possible base for maybe another month and be similar to The previous times when this indicator hit below minus 20 you flip sideways several months And maybe that's what's going on here, but I don't think the market's set up now for decline from here Yeah, if we stay down here for another month and the gold market no one's ever going to buy any stocks And that's exactly what you need for a market to go higher, right?  You're certainly not making it easy. That's right They're not making it easy right now. I can tell you you know, it's interesting though Tim They are actually they are stronger than the gold contract still I mean, you know, it's interesting a few of these are actually pretty strong, you know Well, I mean they've they're back down, but you know, if you look at like an eco eagle It's like okay, man. It's back down, but not much man You know, so there's a few of them even new months, you know There's a few that just haven't backed down which is pretty positive, you know, so I think the major bottom again back to this chart here I had some other charts that gave it the a long-term buy signal last July and people which is July 2022 yeah, and if you look where we are Last July compared where we are right now to me. This is just a sideways Consolidation right that's been going on since April right and I think that's all it is I don't think we're gonna go down all the way, you know, I'm thinking still in general I think we're gonna move sideways around this, you know 28 30 area to my 27 30 area And I think that's pretty much it so yeah, see if you look at this I'm gonna put this up for the, you know listeners right now So this is pretty intense because what does happen you got to remember folks, okay? That you know Tim and I You know both big, you know white cough people also and this deal the longer that you build a cause here The bottom line the higher you can go and you know, it's interesting Tim is that, you know I get this on a monthly right now, right going all the way back to 2022 and On the monthly check this out. This is pretty intense man actually on the monthly I won't take this month, but well even if I did, you know, we went up on that September with 182 million shares in the GDX and Yeah, it's going down right now at 29 million Yeah, that that bar is huge man the bar that it's going into which is that November bar of 2021 You know, that's when the GDX went from that 24 to 28 and then that basically throw it into consolidation So there's no doubt that's going to be intriguing. So yeah and volume is basically like gas or not Yeah, it's like the energy right or gas for a car, right? And so if you get volume going up and adversely less volume going down the bigger trend is up Right, so I don't have a volume chart here, but I do have up and down volume Which will kind of works in a similar way. It's a little bit different way to look at volume But it works pretty well So the major is basically the up on compared to the down volume that bottom chart and on yes on chart three The bottom window on chart three images of the up line compared to the down point So if you notice, you know, we had a workshop move Minus 20 and that's pretty much the Josh move to downside. So stay right there folks Stay there Tim and I come right back and get hold of Tim folks at odd or ID dash oracle calm Tim and I come right back Welcome back folks Tim or Tom or brown. We do appreciate your growling and prowling when it's out here Okay, Tim. We would like to go next Yes, it's cool to number chart four. Okay This is that seven indicator and the bottom window is the cboe Equity put call ratio reading with the 21 day average The next higher window from the bottom the second window up from the bottom is the cboe equity put call ratio readings with a five day average And chart goes back to about Of mid 2014 and the red lines or the pink areas show the times when this ratio is above Uh, well a certain level actually a bullish level. So this is kind of a It measures how many puts to calls there is and others and up markets People buy more calls and puts and down markets people buy more puts and calls So this measures a five day and a 21 day average. So when it gets up Into bullish territory, which we're out right now. We actually have been for about the last Uh several weeks is usually getting close to a low This really doesn't pick out the bottom per day Or bottom The day of the bottom or anything like that it gets you in the vicinity of a low. Okay, and so so And it could be a little off but in general, it's usually pretty good when everybody has hits the sell button These indicators jump up And gives you a good clue that Uh bottoms coming up. So and we're in that bullish range right now on a three week And actually on a on a one week time frame So, uh It actually has a great history. So uh, in my opinion, this is not a bear market We're probably going into a low Uh, you know, could it be another week or two maybe But we're we're banged according to the book called ratio weeks is kind of a seminary here We're probably getting close. So now it's flipped to on a sugarcane basis to flip to five. Okay number five There we go And this is my kind of bread and butter Of panic because it works pretty well the trend Uh is actually major to see Uh advanced decline and also measures up down volume and it puts it in all in one number Uh, when the number is one everything's kind of neutral There's there's just as much up volume is down volume And it's just as much as advanced as there is decline. So it doesn't really say much But when that indicator gets above one point or around 1.2 and higher The volume's starting to hit the declining stocks And that's when that number jumps up. So it measures kind of the selling against declining stocks And it goes the other way too. It measures also when it gets down below 0.8 It tells you that uh most buying is going on on the upstock everyone's buying the same stocks. Yeah, right, right, right Yeah, so it kind of so it's a good indicator Uh to look when you have the the bottom window is a five day average of the Arms index or trend index next to one up is the 10 day the 10 days usually the better one That's two weeks of data And the peak areas there show the times When this indicator got in bullish territory and uh So basically all you know we went over this chart before but From may of 2022 until basically april of 2023 the market built a base And if you can see which is that kind of side blue area I kind of boxed in blue there. Yes And it was 365 to 390 with sport because that's where the trend On a five day and a 21 day We're reaching panic levels. So that's building a base panic happens at bottoms. That's where that base was So now we flip over to the current time frame And neither the five day or the 10 day have reached bullish uh readings yet The 10 day needs to get up to around 1.2 and the five day needs to get up around 1.5 And so Ideally what we want the market to do right now to get those two Five and 10 day trends up around into the bullish territory really showing panic You need kind of a washout move in the market. You went to trend Preferably close up around two or three which would be ideal Now tim do you do you going into a washout move tim do you use the use a closing trend or using the interday high trend? No, you'd use the clothes clothes. Okay, which makes a huge difference because like, you know yesterday He had a 0.66 So that kills everything right it's interesting and yeah kills everything Yeah, and on the clothes it closed at 0.73. Yeah, right There's a lot of bomb pickers there. I evidently and we had a you know today It would happen here folks is that today you had a high of 1.45 But yet you're only at 1.09 right now. So yeah, that's they're buying too quick Interesting that they're buying too quick. Yeah, so you really want, you know When the big what I call the puke happens those trends just explode right and when those trends explode, you know Actually explosion is probably not a one-day base.  So once you start seeing rings, you know preferably up around two even three You know, you're looking a day or two away probably for a meaningful low and that's it gets pretty good Uh picked out bottoms a day of the bottoms them on this before Nice, you know, but they're tough Yeah, no, there's no there's no There's no private audience there and everybody's kind of laughing at you Right. No, I can see that. Yeah, because it's like what's going to make it turn around I mean everything's going down You know the the vixx has quite a jump out here today to tim the tim the vixx up 253 we traded in 1943 So, I mean the last time, you know and one week it's already gone from what, uh Yeah, it's gone from 12 57 Yeah, no 13 57 That was yeah, it's kind of unusual, you know everything Uh kind of acts different and kind of different markets, you know, that's been stayed low even on That top we had in august to kind of just stay low, which is kind of rare But now we're getting the trend the trend finally, you know approaching 20 and higher And so that's helping too. He gets in the 20s and even Very seldom gets to 30, but it it does gets 30 every once a while on a kind of a wash out low So this is kind of lining up my bet Is the the bottom I think is going to be this week. Okay You know prove me wrong, you know and but there is a You know, well today's Tuesday, Wednesday, Thursday, you know, I'm thinking Thursday or Friday, you know You know the market may tip to rally Maybe tomorrow try for a bounce and if it doesn't I bet we get a wash out move going into this weekend So we'll see no you can think I can see that See enough of these when they stop momentum to the downside they usually doesn't quit Right till you get real climatic, right, right.  So the spies almost there the spies only like, uh, you know Another six points away from, you know the 420 418 area, you know, I mean where Where the cues, you know is playing catch up here. So there's no doubt it's going to get interesting here, man Yeah, I thought we you know, I didn't actually think we'd get down we you talked about this too I thought well, maybe we'll find support around this 430 area But you know the real sports down around that 420 Yeah, and when these when the market gets to support area, that's usually where all the panic really occurs So we're a little bit away from it, but I bet we hit it. I bet that trend until it explodes Well, listen tim, it's always a pleasure Look forward to having you on thursday and don't forget folks. You get hold of tim has a great newsletter at odd or d dash oracle dot com Have a great one tim. Have a safe one


So here's a strategy to have a future proof set of steps towards solo piano arrangements. Take a song of choice and do it in an accompaniment.  Transfer all that you did with two hands and make it one hand. So maybe that pattern or a simple arpeggio.


Hi everyone, Joe for jaspyscasebreaks.com. We knocked out that filler pack, that allure pack that knocks out Opiechi, Platinum 4, and 5. Those are coming up in separate videos. We're going to do the break itself first and then we'll randomize everybody's names and then the top 15 names are going to get teams in their corresponding breaks. So the top two names will get the Oilers, top name will get the Oilers number 4, second name will get the Oilers number 5, so on and so forth. But let's do the break itself first. Great, thanks everyone here for rallying around it. All the teams are available right there. And let's go. Let's roll it, randomize it 4 to 4, 8 times. 8 the hard way for names and teams, 2, 3, 4, and 8th and final time, 6, 7, and 8th and final time. Alright, here's the first half-ish of the list right here. Here's the second part right here. It's just alphabetized by team, print and rip that pack. Now Ravens Dolphins on to the background, 30s in football. Who knew? That in the third quarter, 9 minutes left in the third quarter that the Dolphins would be up 6-3. What an odd game. Tua didn't start and then Jacoby Brissette got knocked out of the game. Looked like he was going to come back. Miami coach said no, Tua's in and now the Dolphins are punting it away to the Ravens. Let's see what we've got in here. We've got Max over now, red rainbow die cut, and that'll go to Ottawa, that's going to go to Troy. Alright, now let's do the second randomizer. Let's get a clean list here, there you go, and let's roll it and randomize that list 6 and a 5, 11 times. So it's going to be the top 15 after 11 and we're just randomizing your names not the teams. Good luck. 1, 2, 3, 4, 7, 8, there's 9, 10, and 11 then final time. 6 and a 5, 11, there's 11 right there. So this group right here, thank you. Thanks for giving that a shot but no teams there. But the top half you have teams, Martin, Rick, Rick, Rick, Martin, Martin, Martin, Steven, Martin, Martin, David, Martin, Martin, David, Steven. There you go, top 15 you are in. So there you go, so we'll put rooftops next to your name so you know you won those spots in the filler. But Steven Kay, you've got the Oilers in 4, David you have the Oilers in 5, Martin with the Senors in 5, Canucks in 4, David B has the Canucks in 5, Martin with the Blackhawks in 4, Martin with the Caps in 4, Steven with the Blackhawks in 5, Martin with the Canadians in 5, the Caps in 5, and the Red Wings in 5, Rick with the Jets in 4, Flyers in 5, Panthers in 4, and Martin with the Flames in 5. There you go. Thanks for giving this a shot. Thanks for taking the risk. I'm Joe. I'll see you in the next video for the break itself. Bye-bye.


are going through them in a particular order, I would prefer to hear your ideas and your questions because much of what you see up here derives from all the good ideas that have been discussed throughout this conference in the talks and in the conversations. In fact, a lot of what you see up here is a result of those things happening at this conference because I rewrote the slides this morning. So we're going to talk about a couple of things related to host-based intrusion prevention on Windows and Unix. And I'm not going to try and define what those are. I think the community, by developing the intellectual property, will define what those are as we make advances. And I want to recognize several people for the contributions that they've made. Neal's Provost is at the University of Michigan, he's a graduate student, and he's published several tools, one of them CIS Trace that we're going to look at closely. And those are currently in OpenBSD and NetBSD. And there's code on your conference CD to support FreeBSD 5.1. And there's more code on his website to support FreeBSD 4.8. And we'll look closer at that. T7 with the Razor Team has a similar components for Windows that provide intrusion prevention. Slightly different approach in terms of the way it integrates with the system, but very similar functionality. I'd like to thank DT for suggesting this thread last year in his call for papers. There was a call for a talks on how to harden FreeBSD. Last year I gave that, and the gap analysis of that showed a real need for something that increases the integrity of the system that all of the rest of the security architecture depends on. I'd like to thank Greg Hoglund for many insights about application security and looking at application state and the code at the binary level. MD5 at the Ghetto Hackers reviewed a lot of this material about how intrusion prevention looks like firewalls in some ways. That was a great metaphor. Gotroot.net helped me find exploits such as SHH for the demo and finally FreeBSD Mall for all the free stuff that we just gave away. More about Neal's provost. He's written a tool called SysTrace. What it does is it catches system calls and alters their behavior. It supports OpenBSD and NetBSD. He's also written something called HoneyNet that supports the HoneyPipe project. And all these tools you can find on his homepage is listed right there. Okay, so in the abstract for the talk I mentioned a couple of things. Why should we care about intrusion prevention? What does it do for us? And we'll look at how it works and how it is consistent across the platform because of architectural constraints of the way kernels are put together. We'll look at some common features and talk about what's missing. So why should we care about intrusion prevention? One way to think about this is to look at an analogy of the layers of network security. So if you look at layered network security you'll find rules and routers and firewalls and services at the router level, firewall and INIT-D or TCP wrappers. And each has a distinctive performance advantage because of the kind of objects it's dealing with at the router level dealing with lower layers of the protocols and doing a lot of filtering at the firewall. If you have those rules in the router you're dealing with higher layers things that are more specific to individual sessions and at INIT-D you're looking at services that have successfully connected and the context of where they're coming from and who they're coming from. So each of those has a different specificity in terms of the context information and each has something that contributes to the performance of the next layer. So if we look at the host side there's a parallel structure there of information flowing through the app through the kernel to disk and applications explicitly use authentication methods have rules for when to allow access and when not to the kernel does the same thing enforcing permissions and the file system does as well at each layer you have different performance advantages depending on the kind of messages that are coming through and each has a distinctive advantage at the disk at the file system layer you've got access to individual objects and permissions specific to the object so in terms of specificity specificity of rules at the application you have rules that can be specific to the session or the connection or the kernel rules that are specific per system call and the file system per file or other object each of these layers depends on in a lot of cases the integrity of the other layers the file system permission assumes integrity of the application and kernel the granularity of system call permissions affects what you can do in an application so you depend on the granularity of the semantics of system calls to decide how you're going to enforce security in your application the problem is all of this depends on the integrity of the layers around a particular layer and it's very often that applications or services run as root and if that integrity is not held the architecture doesn't do you that much and this is this is compounded by advances in the various layers encryption fragmentation re-encoding all of these can prevent application layer filtering on the wire and that's why we're going to look at this in terms of the kernel being a gap and the ability to preserve integrity of the system and the application why would we do that there it's through the application that your data is going to reside there in memory and exploits are going to go through there to get to the disk so visibility in the application layer also provides the ability for better contextual discrimination when you have an incoming connection you have IP address of the client maybe a domain name once you're inside the application the application is likely going to be collecting other kinds of information about the session about what permissions have been authenticated and you can leverage that contextual information about what the application has established to enhance what you can do to block exploits so why would we need another tool to do this when we have all the other layers already we can think about this kernel level system call filtering as like we do about firewalls as an application level firewall that enhances what you do at the router and downstream what you do in TCP wrappers a lot of exploits are going to attack through service and demons and without enhancing the protection against buffer overflows and everything you do inside applications the system is going to look crunchy on the outside soft on the inside the problem is application state is very complex the state of memory disk, clients on the other hand all that contextual information allows you to write signatures that are application state specific specific to the state of the US you know within the context of a process there's all sorts of system information that you can rely on that perhaps should be consistent each time an application runs or for each session and these contextual clues that if they are consistent from run to run allows you can allow you to block from the inside of the system inside the application so let's look let's look at a specific example on free BSD how it works and what's the motivation for doing this we're going to look at an SSH exploit it's an off by one channel lookup an SSH 2.9 and it was current and all the BSDs at the time the exploit occurred and the gap analysis for this was that if we can't rely on something a hard, relatively hard application like SSH what can we rely on and what can we do to prevent exploits on something we would usually trust so the stuff being done by root is at the top of the screen the stuff being done by a client user is at the bottom so this is an example of setting up SysTrace to filter system calls for the SSH team and at the very top you see a directory that SysTrace looks in to find all the rules the rules that specify whether to permit or deny system calls the second panel we've invoked SysTrace with a capital A in order to gather all the system calls and it'll watch watch those system calls and spit out a list of what's what the application does so here on the bottom we're logged in as a user we've got SSH demon running and we run an exploit here the exploit uses exploits this channel lookup the exploit payload listens on port 11520 for a connection so that's what the payload is doing then the client side connects to that port and the payload folks say root shell and there's a message from the authors that's part of the source for the exploit so just to make sure what our context is we have a root ID and we see we're root oil group and PWD shows us we're in the root of the file system so what can we do to modify this to block that exploit well here we stop SSHD and when it exits SysTrace generates a file containing all the rules so there's the file right there user bin SSHD and we'll look at what it contains here what we'll see is a list of system calls these are all the system calls that SSHD invoked you see all names of all libraries so it gives you all the file names that it needs access to to run and down at the bottom of all the permissions you see something interesting it's invoke bin SH so that's something that SSHD you know fundamentally normally does but we can tune it a little bit by adding a condition let's change it so that it can fork a shell only if it's not root so what happens when we change that rule we'll invoke SSHD again with a minus little a that means apply these rules with a default deny policy a system call that it hadn't made the first time is going to return an error so invoke the exploit again the client side binds to port I'm sorry the payload binds to port 11.5.20 a client side connects to it it tries to fork a shell as root and a system call returns an error and they close the connection so that's the model that's the fundamental motivation for doing something like this to add another layer to the security inside the host that does a couple of things in this context we're looking at SSHD that's normally one of the most trusted applications in this instance it's an off by one error in channel lookup that's buffer overflowed and elevates the user to root it was in all the BSDs as we just mentioned before the demo what can we do if we can't rely on something as trusted as SSH what can we do to prevent this as we see and saw in the example we're doing something there specific to the payload not the injection method and that's slightly different than what's happening at other layers it's a unique way to recognize what's going on in the exploit rather than being unique to aspects of the injection but for each of those if there's contextual information that's usually consistent we can use that to form rules that narrow the footprint of the exposure of the system what kind of contextual information do we have inside the application we've got network identity of the client the IP address of the source of the connection a lot of times we have user identity either on the client system or user identity inside the application we've got application state we've got information about what was done to authenticate the connection we've got information about workflow we're in the we're in the state of the processing we are and we've got the advantage of being orthogonal to methods that are applied in other layers so MD5 suggested a look at firewall wizards discussion and they were saying that intrusive prevention basically looks like a firewall at first I thought this looked like a kid with a hammer everything looks like a nail but they have a good point you've got messages come in messages that go out and rules that decide what gets discarded in a firewall that's packets and sessions and the host by side is analogous to that you can look at it as API calls but even more fundamentally when you make a system trap when the trap occurs you've just got data sitting there this is called a number you've got a bunch of arguments there in memory so you've got a packet of information so where for the network you have packets IP packets and signatures on those host-based side when you have a trap you've got packets of syscall information so you probably wouldn't consider running on this network without a firewall would you and it's not that firewalls are the only essential thing it's that they allow you together with the other parts of the security architecture to mount an effective defense so I would look at intrusion prevention in the same way that it's not a it's not a solution in itself but it's a way to tune all the layers together to provide something effective so where is intrusion prevention going and how is it different the firewall wizards distinguish intrusion prevention from other kinds of firewalls and that they use signatures rather than rules take a lot of more state information but these aren't the same kind of rules that you might run an intrusion detection system they're more in more cases they're signatures as forms of access control so consider snort with hogwash that's the sort of signature-based firewall they're talking about and the ID&S vendors call this and gateway IDS and again that's why I don't necessarily want to try and give you a definition there's a lot of creativity going on out there and I think it's up to the community to decide what the effective boundaries between the layers are and what the effective architecture is so firewalls are complementary to routers and identity intrusion prevention can be a firewall system layer the intrusion prevention filters messages basically data, sting, and stack or memory when you just a trap interrupt and the intrusion prevention can use signatures to recognize rather than the injection method the payload the behavior of the payload so how does this work some architectural layering in windows and in unix so here's windows kernel architecture, user land it's a little bit different from unix in that they have micro kernel architecture and a few more layers at the top you've got executive services that's where most of the sys calls land first takes the traps routes the messages and you've got an NTDLL in some ways kind of like libc that takes an API call turns it into a trap that's basically what I just said in the bottom half executive services at the top a bunch of top level services that abstract away the hardware for various objects at the bottom from hardware abstraction layers end in homer right next to page up and page down okay so this is a example of linux system architecture it's similar in some ways especially the boundary between the user land and kernel they've got libc up there between the applications and the trap which is represented by the dotted line below that you've got the system call interface that interprets the information associated with the trap turns it into access to the various modules there you've got some layers but most of the layers are specific to certain kinds of resources in the case of linux and this is simply a fact of the architectural decision to use a macro kernel architecture so what are the common abstractions here we've got a common abstraction and a layer between applications in the kernel and between most of the kernel and the upper side above the trap each of these layers provides some unique contextual information while we're going to look closer at this particular boundary you can apply this principle to all the other layers this just happens to be a convenient place to do it because it's a because the method is very consistent across the various OSs so comparing this highlights the similarities you get a C library on top and something on bottom that interprets the traps and turns them back into calls to services in the kernel so even if we consider the application a black box even if we don't look at contextual information specific to an application we still have contextual information at these various levels contextual information API calls in libc where we can trap contextual information when the system calls invoked and we have trap into the system call interface and lastly at the instruction level and all of these are all these have distinct advantages so what's being done today is really something that's the tip of the iceberg we're looking at the most convenient place to apply these principles so as X points are advancing in terms of capabilities there's a lot of focus on escaping IDS or using exceptional behavior to get in and I'm somewhat delusion with IDS and this provides a way to take an entirely different approach and so you can make an approach because it's independent of the transport can be independent of the transport and independent method of ejection and it can be specific to the state or behavior of the application and the behavior of the exploit payload so in terms of gap analysis when you implement layered security a lot of the host security depends on the integrity of the OS and this assumption is made even when you have very complex or vulnerable or untrusted applications things like Netscape by E, Binds and Mail even SSH exploits are advancing just as rapidly as the defense is and those advances are often gaining capabilities to circumvent existing layers using encryption, fragmentation, re-encoding so added layers is common way to enhance protection the system call rules have a distinct advantage in terms of being specific to individual system calls and you can use them to enforce permissions but you can also use rules to alter alter system call semantics alter what the system call does and how it does it so what we saw in the example was we first invoked the SSH team to generate a set of rules to allow or disallow individual system calls so by default we invoked it once and got a list of what it normally invokes and this narrows the footprint of interaction with the system so that later on if we invoke it again and does something different that's outside of that footprint it's blocked and we can refine that in consideration with the other layers reduce the dependence of the other layers in fact we can reduce the dependence of other layers on the permissions they need for example you can rewrite bind call bind to a socket so that you can open a low low numbered port without being root and then perhaps not have to run a service as root so being out changing the semantics so that the application needs less resources is one way to move the specificity of the rules to the layer that best supports it we can also rewrite system call arguments we'll talk about that a bit more some of the implementations use pop-up dialogs similar to what a firewall does and this is a big advantage in terms of being able to generate a first draft of your rules and not have to close all the gaps immediately and it takes advantage of a default ask policy so rather than just permit, deny you've got default and ask I mean you've got to ask this allows gaps in the rules allows you to incrementally delve out the rules as you observe the behavior and allows you to interactively iteratively tune the specificity furthermore in addition to permit and deny and ask you can log exceptions exceptional calls or interesting calls divine rules for interesting calls like fork been a s H as root and this permits improved reporting also permits logging interesting contextual information so when fork been a s H occurs as root grab the client user IP domain and application state so the next couple of slides talk about how this works in practice for a lot of applications things like LS find a lot of other a lot of them use around 25 system calls really relatively heavyweight applications like browsers email clients with a rich interaction they can use up to 60 and this is out of a total of say 250 for Unix and I don't even know how many there are in windows couple thousand and as it stands most the implicate most of the current implementations are generating and using rules for filenames and in some way this duplicates file system permissions and what this suggests is that there needs to be more consideration of cross layer architecture interaction of the file system productions and assist call but it also means in terms of performance impact that is that typically there's a high performance impact on applications that make a lot of open system calls in terms of using rules that do a string match or rules that use regular expressions and with the current implementations you see relatively low impact on anything that's CPU bound what this means in term well let's look at how this fits into the rest of the system one advantage of this is that the system call filtering is completely transparent to the application so the application doesn't have to know anything about or recognize anything about the system call filtering so you can use third party applications untrusted applications caveat that is that rule creation isn't fully automated yet it's not completely transparent to the user and that's where it's really important for things to be transparent and lastly that as it stands most of the tools generate rules by observing application behavior and general large part of the advantage is being able to reduce the dependence of in other layers so zero day code there's patches for free bsd 5.1 on the conference CD neil's provost has all these they are differences between this is trace and net bsd and open bsd current for kernel and user land and free bsd 5.1 it's on the conference cd it's on neil's provost homepage and hopefully will be in free bsd current soon so here's what I believe are the current advantages of these tools you got things like chrute and jail for sandboxing system call filtering does some of the same kind of thing in terms of being able to sand reduce the footprint of an application's interaction with the system and can be tuned for the footprint of each application the current tools allow iterative and interactive rule generation a lot very similar to what firewalls do it's got some limited automated rule generation in terms of tracing past invocation as the application it's transparent to the application and allows you to tune system call permissions but more importantly system call semantics you can change the system call semantics to reduce the dependency of other layers on the security architecture on their ability to enforce permissions so it's available for free bsd 4.8 5.1 right now and you can find updated versions on my website on neil's provost website hopefully in free bsd soon the slides that you're looking at now are slightly different than what's on the cd and they will the updated slides will be on the def con sites archives and on my sites and if you like you can contact me at this email address I think that's about it wow we're way early so there's a couple other things I can talk about before the questions let me make a couple more comments we looked at the system architecture there's a common architecture of the layer between user land and kernel and this is similar at the source code level for the bsd's and similar at the binary level for windows so for for these tools in general across all these platforms there's a lot of commonality in the architecture of how you implement system call filtering you've got to have a device that allows you to set rules so something a slash dev that'll you can write rules to you've got to get the module into the kernel somehow and when the module is invoked on a particular application it's got to got to have hooks to start up grab the rules wait for an application to be invoked and it's got to catch the application as it starts up between when fork is called and when the application starts up do things like fill out the system call table and there are a couple of methods of how you do the hooking but it's always going to occur between when you create the process and when it begins to execute and there are a couple of different implementations out there are we close? okay I'm told the award ceremony is going to be held in the Apollo room rather than here and that's at four o'clock it's about 340 345 35 okay so the similarities here across all these platforms are those those junction points I just mentioned between startup of the application or between creating the application filling out the process structure and starting the application something that happens when the modules loaded and some kind of architecture for a device that applications can read or write rules to there's a couple different instances or implementations of system called tracing we looked at one sys trace there is another for free BST called serve NG serve next next generation they that varies from sys trace in a couple of ways it's a loadable kernel module but they both have to do the same kinds of things in terms of where they hook in whether it's module load or if it's a static statically compiled in the case of sys trace there's a start up routine that gets called so for each of these implementations they may plug in differently but they're basically going to plug in in the same same place same place startup of the module startup of the application and something that happens at the sys call at the time of the sys call and because we've got a couple of implementations out there I have a feeling that these things are going to evolve a lot like the way the firewalls are evolving and other tools and that there's a statement by Linux Linus Torvalds recently about people lobbying to put in other firewall implementations and he's basically said I'm not convinced which one is the best or where are we going to go so what I want to do is creating API and let them all sort it out so I think that's what I'm going to try to pursue next is create a first draft of an API get sys trace and serve next generation to plug in and then hopefully let them fight it out how we doing on time okay why don't we take questions right here oh wait Mark is there a port for this for windows or yes yeah that was there's a reference to it and the acknowledgments and it was written by one of the guys at bind view with the razor team I'm sorry to there's there's two implementations for BSD there aren't any yet for for Linux but if we use same current abstraction these modules there's no reason we can't use the same implementations in Linux windows we don't have the opportunity to implement those interfaces at source level but the windows it plugs in at the same places but it's got to muck with the kernel directly to hook in I mean muck with the binary so T7 with the razor team at bind view has a tool called SysTrace again I think the current version is 0.3 so same name but it's four windows and it's on bind views bind you to site I believe it's more or less open source license I was going to ask you in the next version of windows in Longhorn they have something called next generation windows protection services which is Palladium which is actually exactly this actually Microsoft is trapping all API calls and generating rules for them based on whether they have like a signature or something like that unique processor ID or something of that nature but what happens when a version of the software changes and they change the API calls that they do how does the BSD tools react to that do you have to regenerate all the rules if you're extremely paranoid you probably would because you'd want to close reduce as much the footprint as possible but with windows you know in practice I would imagine you would do exactly what you do with a firewall if you upgrade a client or a service you continue applying the same rules and you catch any exceptions and decide on the per exception basis whether to add rules so with the windows tool does it plug into the NTDLL.DLL or does it sit above it or it no it plugs into system trap any more questions now the Microsoft research has a detour's library which allows you to insert trampoline functions into syscalls cool for the system and the the latest messaging vulnerabilities everybody's talking about I think one guy had approved a concept using McAfee and how he could send you know this window and then you know does this take care of that problem a lot of the windowing is in the kernel and windows but it that's not the case in Unix so imagine that would be very different implemented very differently on Unix so maybe they're trying to fix it with this long horn implementation so I would imagine a lot of that would be rather than assist call filtering and library call filtering for X windows any other questions we're good alright have fun at the awards ceremony