 Except for the Talysh region (1.6-2.2 km/km²), the river system density is the highest (1–2 km/km²) at 1,000-2,500 kilometers, while in the area of the Talysh mountains it peaks at 1.6-2.2 km/km² at 500–1,000 km.The average density of the river system of Azerbaijan is 0.39 km/km².The density is even lower than 0.05 km/km² in the plains.