黄河河口-龙门区间降雨时空分布特征及其与流域产沙的关系

目的]揭示黄土高原典型多沙粗沙区河口—龙门区间降雨时空分布特征及其与流域产沙的关系,为区域水土保持规划的制定提供科学依据。方法]基于降雨和产沙模数资料,采用泰森多边形加权变差系数法、K-means聚类分析以及线性回归分析,系统研究河口—龙门区间降雨和产沙的空间变异规律。结果] 1959—2015年期间,河龙区间汛期降雨和汛期降雨侵蚀力具有相同的空间分布特征,但是汛期降雨侵蚀力表现出更强的空间变异性,两者在年内和年际时间尺度上分别表现出相同的空间分布特征,并且具有纬度地带性(p0.01)。汛期降雨和汛期降雨侵蚀力在支流尺度上的空间变异性差异不大,具有同增同减的变化趋势。结论] 1959—2015年期间,水土流失大规模治理以前,河口—龙门区间流域产沙主要受降雨的影响(p0.01),水土流失治理以后,流域产沙量锐减,降雨和流域产沙模数无显著相关关系。

Spatial and Temporal Distribution of Precipitation in Hekou-Longmen Region and Its Relationship with Sediment Yield

Objective] The temporal and spatial distribution of rainfall and its relationship with sediment yield in Hekou-Longmen region of the middle reaches of the Yellow River was studied in order to provide basis for erosion control and soil and water conservation planning. Methods] Based on the data of rainfall and sediment yield modulus, the spatial variation rules of rainfall and sediment yield in Hekou-Longmen region was systematically studied by using Tyson polygon weighted variation coefficient method, K-means clustering analysis and linear regression analysis. Results] From 1959 to 2015, the precipitation and rainfall erosivity in flood season showed the same spatial distribution characteristics, but the spatial variability of rainfall erosivity in flood season was stronger. The spatial distribution characteristics of precipitation and rainfall erosivity in flood season were the same in the annual and inter annual time scales, and they had latitude zonality (p<0.01). The spatial variability of precipitation in flood season and rainfall erosivity in flood season had little difference at tributary scale, and the variation trend was similar. Conclusion] From 1959 to 2015, before large-scale soil erosion control, sediment yield in Hekou-Longmen region was mainly affected by rainfall (p<0.01), but after soil erosion control, sediment yield in the basin decreased dramatically, and there was no significant correlation between rainfall and sediment yield modulus in the basin.