窟野河流域次降雨事件下水沙变化特征及其输移过程OA北大核心

[Objective]This study aims to provide significant scientific evidence for the management and regulation of water and sediment in the watersheds in coarse sand areas of the Loess Plateau by conducting an in-depth analysis of the characteristics of sediment and water dynamics and their transfer processes at the sub-rainfall event scale in the watersheds in coarse sand areas of the Loess Plateau.[Methods]Kuye River Basin in the coarse sand region of the Loess Plateau was selected as research site,water and sediment data from 160 rainfall events between 2006 and 2019 were collected.Variance analysis,sediment-rating curves,and hysteresis analysis were utilized to compare the runoff and sediment transport characteristics during sub-rainfall events in the Kuye River Basin and its sub-watersheds,to construct sediment-rating curves at the sub-rainfall event scale for each watershed,to analyze the spatial differences in the hysteresis relationship and hysteresis index of water and sediment,and to reveal the transfer processes of water and sediment in the Kuye River Basin at the sub-rainfall scale.[Results](1)There were no significant differences in runoff-related parameters among the four watersheds,but significant differences were observed in sediment-related parameters.(2)The Xinmiao watershed in the eastern upper reaches of the Kuye River showed a strong correlation between runoff and sediment,with the parameter(a)indicating the degree of external anthropogenic interference being the highest,while the Wangdaohengta watershed in the western upper reaches had a low sediment concentration and weak runoff-sediment correlation,with the parameter(b)representing the river's own sediment transport capacity being the highest.(3)The primary hysteresis pattern in the Xinmiao,Wangdaohengta and Wenjichuan watersheds was anti-clockwise,indicating that sediment originated from the upper reaches and the average value of the high sediment concentration Hysteresis Indexi(HI)was mostly negative.In contrast,the Shenmu Watershed's primary hysteresis pattern was 8-shaped pattern,indicating that sediment sources were relatively close to the watershed outlet,and the average HI value for high sediment concentration rainfall events was mostly positive.[Conclusion]The nested watersheds of the Kuye River exhibit significant spatial differences in water and sediment changes,and the sediment transport process is complex.The hysteresis patterns in different sub-watersheds reveal the spatial heterogeneity of sediment sources and transport mechanisms at rainfall event scale.