Runoff and sediment effect of the soil-water conservation measures in a typical river basin of the Loess Plateau

作者：Haiyan Yang, Taihua Wang, Dawen Yang, Zihan Yan, Jinfeng Wu, Huimin Lei · 发表于：CATENA · 年份：2024 · DOI：10.1016/j.catena.2024.108218 · 被引用次数：30 · 研究领域：Soil erosion and sediment transport、Hydrology and Watershed Management Studies、Hydrology and Sediment Transport Processes

Soil erosion and sediment transport processes, which are intimately connected with hydrological processes, strongly affect land surface morphology and earth system dynamics. Over the past 60 years, intensive Soil-Water Conservation (SWC) measures implemented on the Loess Plateau have significantly reduced sediment load and concurrently exacerbated runoff declines, while the quantitative evaluation of the effects of SWC measures remains challenging. This study develops a sediment module which simulates the hillslope and in-stream sediment processes, and then incorporates the module into a Geomorphology-Based Ecohydrological Model (GBEHM). Besides, the model also couples with an explicit representation of different types of SWC measures, including both Hillslope SWC (HSWC) and River-network SWC (RSWC) measures. The newly developed hydro-sediment model is then applied to the Kuye River basin, a typical river basin on the Loess Plateau, and used for quantifying the effects of SWC measures on river discharge and sediment load during 1982–2019. Compared with Period 1 (1982–2000), the river discharge decreased by 48.7% in Period 2 (2001–2019), while the sediment load experienced a more substantial decrease of 95.3% between the two periods. Based on the numerical experiment results, HSWC and RSWC contributed to 25.4% (58 million m 3 /yr) and 28.9% (66 million m 3 /yr) of the annual runoff decline, as well as 58.1% (36 million t/yr) and 33.9% (21 million t/yr) of the annual sediment l...