Holocene Landscape and climate change in northern Arizona

1. Holocene Landscape Evolution, Sediment Flux, and Climate Change in Drylands of the southwestern Colorado Plateau

Diana Anderson 
The overall objective of this work is to understand and quantify changes in Holocene sediment flux in various landscape elements in the semiarid lands of northeastern Arizona.

Research is being conducted to assess prehistoric, historic and modern landscape change, and involves developing alluvial chronologies in selected stream reaches, analyzing sequential landscape images in the context of changing historical precipitation regimes, and establishing of baseline surveys of stream and hillslope morphometry.

Understanding the long-term variability of sediment flux will contribute to a better understanding of landscape changes that might occur during future low amplitude climate change.

2. Holocene Fluvial Geomorphology in Forested Ecosystems of Northern Arizona

Studies related to developing a long-term (Holocene) record of sediment flux in the ponderosa pine ecosystem of northern Arizona continue with two main foci.

One is to understand the relationship between debris flows, fire, climate, and land use in complex terrain in the ponderosa pine forest during the latest Pleistocene through the Holocene.

The second focus area is to build a Holocene chronology of stream activity through mapping, describing and dating stream and alluvial fan deposits and analyzing these chronologies in the context of Holocene climate changes.

This information will help to provide land managers with a better understanding of the long-term natural variability in sediment flux in local forested ecosystems.

3. The Northern Arizona Mesonet

The Northern Arizona Mesonet (NAM) is a network of sixteen wireless, solar-powered weather stations located throughout northeastern Arizona that upload thirteen measured and calculated parameters automatically to a web server every 2 minutes.

The network was initiated in 2003 through a partnership between NAU and the National Weather Service, and most of the stations were established as part of ABOR-sponsored teacher professional development opportunities to enhance technology-based physical science education. Nine of the stations are in the Flagstaff area and seven are in rural and tribal communities.

NAM data is utilized by the National Weather Service, secondary school teachers and the general public. The establishment of weather stations at arid and semiarid Colorado Plateau sites will provide an opportunity to estimate sand flux using standard equations that incorporate wind speed, wind duration, and local soil texture.

Simple dust collectors will eventually be added to selected stations to quantify dust flux and to determine dust composition. In addition to eolian sediment flux, the stations will also provide data on rainfall intensity, closely linked to arroyo incision.