宁夏清水河流域水沙变化特点分析

Analysis on the characteristics of flow and sediment variation in Qingshuihe River basin of Ningxia

  • 摘要: 为搞清清水河流域不同时期、年际及年内水沙变化特点,以清水河流域固原、韩府湾和泉眼山3个水文站长系列实测水沙资料为基础,采用实测资料统计分析方法对水沙量进行系统分析,并利用Mann-Kendall突变检验方法确定了各站年水沙突变点年份。研究表明:与长时期相比,近期2010—2015年除泉眼山站水量增加6.2%外,其他各站水沙量均减少,水沙减少范围分别为58.8%~65.7%和64.3%~94.4%,沙量减幅大于水量减幅。清水河流域年水量的58.5%~65.6%和年沙量的85.6%~89.4%都集中在汛期,年际间水沙丰枯悬殊。各站年径流量和输沙量突变时间存在差异性,各站水沙量近期呈减少趋势。同时也对影响清水河流域水沙条件变化的降雨量、坡面水土保持措施、水库运用和淤地坝建设等因素进行了初步分析。

     

    Abstract: In order to achieve the variant quantity characteristics of flow and sediment in the Qingshuihe River basin in different time periods, including flood and non-flood seasons, inter annual and intra seasonal periods, the variation process of flow and sediment volume is analyzed systematic with the method of applied statistics for filed data. The long-series measured materials contain the flow and sediment data gained at three hydrological stations, namely, Guyuan, Hanfuwan and Quanyanshang sites. The change-point analysis of hydrological time series is implemented with Mann-Kendall method for obtaining the mutation year for each hydrological station. The results indicate that the mutation time of each station is asynchronous for annual runoff and sediment load. Moreover, the amount of water and sediment at each station is decreasing in recent years. Compared with the tendency in the long term, the water volume increased by 10% in 2010−2015 at Quanyanshang station and decreased at other stations. The range of water and sediment reduction is 58.8%~65.7% and 64.3%~94.4%, respectively. 58.5%~65.6% of annual water volume and 85.6%~89.4% of annual sediment volume occur in the flood seasons in the Qingshuihe River basin. The distinction of water and sediment in wet seasons and dry seasons is significant for inter-annual periods. A preliminary analysis is underway for the factors affecting discharge and sediment supply, including rainfall, slope soil-water conservation engineering, reservoir operation mode and silt arrester construction.

     

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