1989~2019年黄河宁夏段支流水沙变化规律及其驱动因素

Variation of Water and Sediment in the Tributaries of Ningxia Section of Yellow River,China from 1989 to 2019 and Their Driving Factors

为明确黄河宁夏段典型支流水沙变化的主要驱动因素,基于清水河泉眼山站、红柳沟鸣沙洲站、苦水河郭家桥站实测水文资料,运用滑动平均法、Mann-Kendall突变检验和双累积曲线法分析典型流域的水沙变化趋势以及突变年份,运用累积斜率法、水文法和水保法对比分析水沙变化的驱动因素。结果表明:①1989~2019年,清水河、红柳沟和苦水河流域水沙变化均表现出减少趋势;相比来说,输沙量变化较径流量变化更显著,苦水河流域的水沙变化较清水河和红柳沟流域更显著。②人类活动在水沙变化中占据主导地位且贡献率逐渐增大;运用累积斜率法、水文法和水保法进行水沙变化归因分析,均表明人类活动是水沙变化的主要驱动因素,其中累积斜率法和水文法计算结果比较接近。③利用水保法对清水河流域进行水沙变化归因分析,发现人类活动中减水效益占据主导地位的是淤地坝和梯田,贡献率分别为42.9%、29.0%,减沙效益占据主导地位的是淤地坝,贡献率为94.5%。

In order to find the main driving factors of the variation of water and sediment in the typical tributaries of Ningxia section of Yellow River,based on the measured hydrological data at Quanyanshan station of Qingshui river,Mingshazhou station of Hongliugou river and Guojiaqiao station of Kushui river,the variation trend of water and sediment,and mutation year of the typical watershed were analyzed by the sliding average method,Mann-Kendall mutation test and double accumulation curve method;the driving factors of the variation of water and sediment were analyzed by cumulative slope method,hydrology method,and soil and water conservation method.The results show that①from 1989 to 2019,the variation of water and sediment in Qingshui river,Hongliugou river and Kushui river basins all show a decreasing trend;the variation of sediment transport is more significant than that of runoff;compared with Qingshui river and Hongliugou river basins,the variation of water and sediment in Kushui river basin is more significant.②Human activities play a leading role in the variation of water and sediment,and the contribution rate gradually increases;the cumulative slope method,hydrology method,and soil and water conservation method used in the attribution analysis of the variation of water and sediment show that human activity is the main driving factor of the variation of water and sediment,and the cumulative slope method and hydrology method have the same results.③According to the soil and water conservation method used in the attribution analysis of the variation of water and sediment in Qingshui river basin,it is found that the water reduction benefits of human activities are dominated by silt dam and terraced fields,with contribute rates of 42.9%and 29.0%,respectively;silt dam is dominant in sediment reduction,with contribute rate of 94.5%.