Catchment-scale soil conservation: Using climate, vegetation, and topo-hydrological parameters to support decision making and implementation

The geomorphometric analysis of watersheds provides useful quantitative information on stream hydrology and potential landscape change that can be used by soil conservation decision makers to determine areas prone to land degradation. In this study, we develop a methodology for the assessment of catchment-scale sensitivity to sediment yield using various topo-hydrological, vegetation, and climatic parameters using four multi-criteria decision making (MCDM) techniques: the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Vlse Kriterijumska Optimizacija Kompromisno Resenje (VI(OR), weighted-sum analysis (WSA), and combined factor (CF). To identify the most important factors affecting sediment yield and soil erosion, a model incorporating principle component analysis with MCDM was devised, using infiltration number (IF), drainage density (Dd), length of overland flow (Lo), channel maintenance (C), stream frequency (Fs), and ruggedness number (Rn) as indices of sediment. and erosion risk. Data from a previous study that employed the RUSLE3D model and sediment-yield field data were used to validate Lhe results. The TOPSIS model achieved the highest. correlation with the RUSLE3D results. The correlation of watershed activities to the experimental erosion and sediment. prioritization results is 032. The TOPSIS results indicate that all 23 sub-walersheds yielded moderate amounts of sediment. Based on the VIKOR method, 17.39% (78.96 km(2)) of the region was classified as having very high eroclibilily, 26.08% (241.93 km(2)) high eroclibilily, 34.78% (225.95 km(2)) moderate eroclibilily, and 2173% (105.05 km(2)) low eroclibilily. Considering the high sensitivity of Taleghan watershed to soil erosion, it is recommended that. conservation efforts be implemented lo minimize land degradation in the area. This methodology can be adapted to other regions that lack detailed topo-hydrological, vegetation, or climatic data. (C) 2019 Elsevier B.V. All rights reserved.