New approach for qualitative sediment yield assessment of ungauged drainage basins

Abstract

The sediment yield of a drainage basin during flood events has a remarkable impact on a desert ecosystem. While sediment yield increases the destructive impact of the flood, it also influences the recovery of disturbed surfaces downslope from source areas in desert landscapes. For environmental change and flood mitigation, it is important to evaluate the sedimentary yield of drainage basins. The current study proposes a simple method to qualitatively evaluate sediment yield of ungauged drainage basins in arid and semi-arid zones. The method evaluates basin sediment yield based on a list of factors that control detaching of detritus from bedrocks and transporting it down the hill slopes and through the drainage system. Four drainage basins: Al Ahsabah, Qanunah, Yabah, and Hali located on the Saudi Arabia Red Sea coast were selected to apply and test the new approach. The Automated Geospatial Watershed Assessment Tool (AGWA) was used to evaluate the new approach. The study found that the new method has a reasonable capability to qualitatively evaluate the sedimentary yield of ungauged drainage basins.