Validation of land-use contributions to sediment yield using virtual sediment samples in the Alvand Basin, Kermanshah Province

methods (such as plowing along the slope), contributes the most to erosion and sediment production.This research comprehensively examines weathering indices in various land uses as sediment sources within the Alvand watershed, assessing 42 indices as new tracers, in contrast to previous studies (Derakhshan et al., 2024; Mohammadi Rayegani et al., 2019) that evaluated only a limited number of weathering indices.Geochemical properties of soil generally differentiate the surface soil based on weathering differences, which are also influenced by land use and management practices.With the high erosion rates (Derakhshan Babaei et al., 2020), approximately three-quarters of the nine geochemical elements and 42 weathering indices initially listed passed the two range-based bracket tests.This study investigates the contributions of sediment sources from various land uses based on sediment fingerprinting techniques, using weathering indices along with geochemical elements as tracers to identify and quantify the contribution of each source to sediment yield in the Alvand watershed.A total of 28 soil samples were collected from different land uses (irrigated cultivation, rainfed cultivation, and pasture) to quantify each land use's contribution using sediment fingerprinting.The results indicate that although rainfed lands cover the smallest area, they appear to produce the highest sediment yield at 53.7%, likely due to poor agricultural practices.Among the 9 geochemical elements and 42 weathering indices analyzed, the chemical element Na and the weathering index FENG were identified as the best tracers, with the strongest differentiation power for sediment sources.These findings suggest that poor land management practices, such as slope-based plowing, cultivation on steep slopes, and improper methods of preparing the land for re-cultivation, are influential factors in erosion and sediment production, which was also observed during field surveys in the study area .