Exploring the driving effects of control factors on changes in sediment yield from a watershed perspective is of paramount importance for refined watershed management. The objective of this research is to unveil the spatiotemporal variation of sediment yield in the Coarse Sandy Hilly Catchments (CSHC) region from 1956 to 2019 and further investigate the relationship between sediment yield and driving factors. The findings revealed that the mutation years of sediment load (SL) at Toudaoguai and Longmen stations were 1986 and 1996, respectively, with annual SL declining by 66.75 % and 79.04 % after the mutation. Water and sediment discharge at Toudaoguai station exhibited more consistent fluctuations over time, while water and sediment discharge at Longmen station remained relatively consistent before 1967, followed by an entirely inconsistent trend. The spatial pattern of the annual average specific sediment yield (SSY) indicated that the northwest watersheds had a relatively higher erosion rate compared to the southeast. Over time, the SSY of each watershed exhibited a decreasing trend. The SSY showed significant negative correlations with terrace, afforestation, topographic position index (TPI), grass planting (GP), and elevation, while demonstrating significant positive correlations with rainfall indicators and runoff depth. Changes in precipitation, topography, vegetation and engineering measures accounted for 58.5 % of the variance in SSY. The total impact of precipitation on SSY change was positive (standard path coefficient (SPC) = 0.567, < 0.01), whereas the total impact of topography, vegetation measures, and engineering measures on SSY change was negative (SPC = -0.282, −0.231, and −0.087, respectively). This study quantified the impact of different types of controlling factors on sediment yield at the watershed level. The insights provided by these results can contribute to sustainable watershed management and the optimal allocation of soil and water conservation measures (SWCMs).

中文翻译：

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降水、地形和土壤保持措施决定区域尺度产沙量的时空格局

从流域角度探讨控制因素对产沙量变化的驱动作用对于流域精细化管理至关重要。本研究的目的是揭示1956年至2019年粗沙丘陵流域（CSHC）地区产沙量的时空变化，并进一步研究产沙量与驱动因素之间的关系。结果表明，头道拐站和龙门站的泥沙负荷突变年份分别为1986年和1996年，突变后年SL分别下降了66.75%和79.04%。头道拐站的水沙流量随时间波动较为一致，而龙门站的水沙流量在1967年之前保持相对稳定，随后出现完全不一致的趋势。年平均特定产沙量（SSY）的空间格局表明，西北流域的侵蚀速率相对东南部较高。随着时间的推移，各流域的SSY均呈现下降趋势。 SSY与梯田、绿化、地形位置指数（TPI）、植草面积（GP）、海拔呈显着负相关，与降雨指标、径流深度呈显着正相关。降水、地形、植被和工程措施的变化占SSY方差的58.5%。降水对SSY变化的总影响为正（标准通径系数（SPC）=0.567，<0.01），而地形、植被措施和工程措施对SSY变化的总影响为负（SPC=-0.282，-0.231） 、和-0.087，分别）。这项研究量化了不同类型的控制因素对流域水平沉积物产量的影响。这些结果提供的见解有助于可持续流域管理和水土保持措施（SWCM）的优化分配。