Novel combination of analytical hierarchy process and weighted sum analysis for watersheds prioritization. A study of Ulindi catchment, Congo River Basin

Congo River Basin (CRB) is among the World's major basins and one of the least studied basins Worldwide. The few existing literature reported that its upper sub-basin is the source of large sediments which are the heart of many environmental problems. However, the severity level was not fully elucidated due to its larger area of about 1.7 million km(2). Subsequently, this opened up a gateway to further narrow the degradation level. The selected Ulindi catchment located in the upper Congo sub-basin was subdivided into 25 watersheds and the study aimed to delineate their priority for soil conservation. To achieve this, morphometric parameters prepared using Weighted Sum Analysis (WSA) together with soil loss, sediment production rate, sediment transport index, and runoff potential were considered as criteria in the Analytical Hierarchy Process (AHP). The results revealed that about 43.8% and 31.04% of the catchment experienced high and low soil degradation and respectively fall under high and low priority for soil conservation measures. The combination of AHP and WSA methods proved to be efficient for identifying sediment deposits and areas' sensitivity to degradation.