Sub-watershed prioritization for soil erosion: a combined morphometric analysis, PCA, and MCDM approach

Abstract Soil erosion is a major global environmental problem, reducing soil fertility, crop yields, and causing economic losses. To tackle this effectively, it is essential to prioritize sub-watersheds using advanced techniques that support better planning and sustainable management. In this study, the delineation of the seven sub-watersheds (SWs) was carried out using a minimum third-order stream as the threshold. This study employs an integrated approach combining morphometric analysis, multiple criteria decision-making (MCDM) including additive ratio assessment (ARAS), technique for order of preference by similarity to ideal solution (TOPSIS), multi-objective optimization by ratio analysis (MOORA), simple additive weighting (SAW), and principal component analysis (PCA) to prioritize sub-watersheds in the Potteruvagu basin. The MCDM method used weights derived from the criteria importance through intercriteria correlation (CRITIC) method. The novelty of this study lies in its innovative application of MCDM techniques, synergistically combined with morphometric analysis and PCA for soil erosion priority. These novel methodologies enable precise and accurate analyses, facilitating the creation of a unified ranking system for each sub-watershed. The results classify SW5 and SW6 as high-priority soil erosion sub-watersheds, SW1 is a medium-priority soil erosion sub-watershed, and SW2, SW3, SW4, and SW7 are ranked low-priority soil erosion sub-watersheds. The results enable targeted soil erosion management, which directly helps with sustainable development goals (SDGs) such as SDG 6 (clean water and sanitation) and SDG 15 (life on land). This new framework makes it easier to make decisions based on facts for long-term planning and protection of watersheds.