Sub-basin prioritisation from morphometry for erosion management in an undulating rocky terrain: Validating different MCDM techniques with respect to RUSLE in the Chaka River Basin, Eastern India.

In an area like India, where a large number of people are dependent upon agriculture, soil erosion assumes the role of a silent killer. A comprehensive soil management plan requires systematic development and planning at the scale of the natural boundaries, i.e., the watersheds. These watersheds are now actively encouraged to become the planning unit for a wide range of natural resource management. Sub-basin prioritisation with respect to erosion susceptibility, therefore, has become increasingly popular in the last few decades as this helps in optimal distribution, especially in a country like India, where the availability of resources is scarce. Erosion is a complex problem wherein a large number of factors play an important role in influencing this process. Therefore, multi-criteria decision-making (MCDM) techniques are becoming more popular in this domain. However, there are a myriad of MCDM models in literature, and a proper and systematic comparison between such MCDM models may help in deciding on the best possible model in the given categories. This paper has tried to make such a comparison for morphometry-based sub-basin prioritisation in the rocky terrain of the Chaka River Basin, Eastern India. The MCDM models that have been investigated include technique for order of preference by similarity to ideal solution (TOPSIS), VlseKriterijumsk Optimizacija Kompromismo Resenje (VIKOR), multi-objective optimisation on the basis of ratio analysis (MOORA), compound factor (CF), weighted sum model (WSM), weighted product model (WPM) and weighted aggregated sum product assessment (WASPAS). These results were compared with respect to the RUSLE-based annual soil loss of the Chaka Basin with the help of the ROC curve. Results reveal that the MOORA MCDM method is the most reliable (AUC = 0.711), whereas the TOPSIS is the least authentic (AUC = 0.378). The middle domain of the Chaka Basin appears to be highly prioritised as compared to the lower domain. [ABSTRACT FROM AUTHOR]