Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
Sci Total Environ. 2023 Jun 25;879:163090. doi: 10.1016/j.scitotenv.2023.163090. Epub 2023 Mar 30.
The sediment transport capacity by overland flow (T) is a key parameter in process-based soil erosion models and T variation is sensitive to changes in soil properties. This study was undertaken to investigate T variations with respect to soil properties and establish a universal relationship to predict T. The test soils were collected from typical agricultural regions (Guanzhong basin-Yangling (YL), Weibei Dry plateau-Chunhua (CH), Hilly and gully region-Ansai (AS), Ago-pastoral transition zone along the Great Wall-Yuyang (YY), and Weiriver floodplain-Weicheng (WC)) of the Loess Plateau, and subjected to 36 different combinations of slope gradients (S, 5.24-44.52 %) and flow discharge (q, 0.00033-0.00125 m s) in a hydraulic flume. The results showed that the mean T values for WC were 2.15, 1.38, 1.32, and 1.16 times greater than those for YL, CH, AS, and YY, respectively. T significantly decreased with clay content (C), mean weight diameter (MWD), and soil organic matter content (SOM). T for different soil types increased with S and q as a binary power function, and T variation was more sensitive to S than to q. Stream power (w) was the most appropriate hydraulic variable to express T for different soils. T for different soil types could be satisfactorily simulated using a quaternary power function of S, q, C, and MWD (R = 0.94; NSE = 0.94) or a ternary power function of w, C, and MWD (R = 0.94; NSE = 0.94). The new T equation can reflect the effect of soil properties on it and facilitate the development of a process-based soil erosion model.
坡面流输沙能力（T）是基于过程的土壤侵蚀模型中的一个关键参数，T 的变化对土壤性质的变化很敏感。本研究旨在调查 T 随土壤性质的变化，并建立一个通用关系来预测 T。测试土壤取自黄土高原典型农业区（关中小流域-杨陵（YL）、渭北高原-淳化（CH）、丘陵沟壑区-安塞（AS）、长城农牧交错带-榆阳（YY）、渭河流域-渭城（WC）），并在水力水槽中进行了 36 种不同坡度（S，5.24-44.52%）和流量（q，0.00033-0.00125 m s）组合的试验。结果表明，WC 的平均 T 值分别比 YL、CH、AS 和 YY 大 2.15、1.38、1.32 和 1.16 倍。T 随粘粒含量（C）、平均重量直径（MWD）和土壤有机质含量（SOM）的降低而显著减小。不同土壤类型的 T 随 S 和 q 的增加呈二元幂函数增加，T 的变化对 S 比 q 更敏感。水流功率（w）是表达不同土壤 T 的最合适的水力变量。不同土壤类型的 T 可以用 S、q、C 和 MWD 的四次幂函数（R = 0.94；NSE = 0.94）或 w、C 和 MWD 的三元幂函数（R = 0.94；NSE = 0.94）来很好地模拟。新的 T 方程可以反映土壤性质对 T 的影响，有助于基于过程的土壤侵蚀模型的发展。
