渭河流域典型水库淤积及其对径流输沙的影响

发布时间：2018-10-14 20:10

【摘要】：水库作为调节河流水沙、蓄水兴利的重要措施，在缓解我国工程性缺水的同时对河流径流和泥沙产生了重大影响。本文借助变差系数、偏态系数、Pearson相关分析、双累积曲线法以及淤积率经验模型等，系统分析渭河流域水库建设对河流径流、输沙过程的影响机制，采用水库淤积量估算方法揭示渭河流域水库蓄水拦沙对河流径流量和输沙量的影响，为水沙调度提供理论依据。结论如下：（1）严重的水土流失导致水库淤积严重。据测定，巴家嘴水库1960～2004年共淤积泥沙4.35亿t；冯家山水库1974～1993年共淤积泥沙0.93亿t；羊毛湾水库1973～2005年共淤积泥沙2187.5万t；黑河金盆水库和石头河水库淤积较少。依据水库淤积率经验模型估算得知，渭河流域46座中型水库2001～2011年淤积泥沙总量为2363.6万t。（2）从年内变化特征看，巴家嘴水库入库水沙年内分配很不均匀，水沙集中分布于7～9月，且沙量集中分布特征更明显。巴家嘴水库汛期径流量占全年的52.4%，输沙量占全年的82.2%。水库蓄水运用后使水库下游水文站径流量和输沙量年内分配趋于均匀化。水库下游沿程站点多年平均输沙量在水库修建后同水库修建前相比，其降低幅度随着离水库距离的增加而减小。毛家河站输沙量从1956～1959年的1.9195亿t，下降到1960～1987年的0.2486亿t，降幅为87.1%；杨家坪站输沙量从1956～1959年的1.1005亿t，下降到1960～1987年的0.5739亿t，降幅为47.8%；张家山站输沙量从1956～1959年的3.5468亿t，下降到1960～1987年的2.3610亿t，降幅为33.4%。（3）1950～2008年渭河流域径流量和输沙量随时间呈显著下降趋势。由渭河流域张家山、状头和华县3站径流-输沙双累积过程线知，3站输沙量均发生了趋势线变化，说明除径流量的变化对输沙量产生影响外，人类活动是渭河流域输沙量变化趋势发生改变的主要原因。同时3站径流-输沙双累积曲线的转折点同水库下闸蓄水的时间相对应。借助张家山、状头、华县3站径流-输沙双累积曲线，，对3站径流-输沙双累积曲线最后一个阶段的累积输沙量的变化进行估算，求得：2001～2008年无降水影响时张家山站累积减沙量约为4.52亿t；2003～2008年无降水影响时状头站的累积减沙量约为5.78亿t；2001～2008年无降水影响时华县站的累积减沙量约为11.24亿t。
[Abstract]:Reservoir, as an important measure to regulate river water and sediment, has great influence on river runoff and sediment while alleviating the water shortage of engineering in China. With the help of variation coefficient, skewness coefficient, Pearson correlation analysis, double accumulation curve method and sedimentation rate empirical model, this paper systematically analyzes the influence mechanism of reservoir construction on river runoff and sediment transport process in Weihe River Basin. The method of reservoir siltation estimation is used to reveal the influence of reservoir water and sediment retention on river runoff and sediment discharge in Weihe River Basin, which provides a theoretical basis for water and sediment regulation. The conclusions are as follows: (1) serious soil erosion results in serious reservoir siltation. According to the measurement, the total sedimentation of Bajiazui Reservoir is 435 million t from 1960 to 2004; the Fengjiashan Reservoir is 93 million t from 1974 to 1993; the Miao Bay Reservoir is 21.875 million t from 1973 to 2005; and the Heihe Jinpan Reservoir and the Shihe Reservoir are less. According to the empirical model of reservoir siltation rate, the total sediment accumulation of 46 middle reservoirs in Weihe River Basin from 2001 to 2011 is 23.636 million t. (2) according to the variation characteristics of the year, the distribution of water and sand in the Bajiazui Reservoir is very uneven. The distribution of water and sediment is concentrated from July to September, and the distribution of sediment volume is more obvious. The runoff of Bajiazui Reservoir in flood season accounts for 52.4 percent of the whole year, and the sediment discharge accounts for 82.2 percent of the whole year. The distribution of runoff and sediment discharge in the downstream hydrological station of the reservoir tends to be uniform after the storage and operation of the reservoir. Compared with that before the construction of the reservoir, the decrease of the average sediment discharge at the downstream of the reservoir decreases with the increase of the distance from the reservoir after the construction of the reservoir. The sediment discharge of Maojiahe Station decreased from 191.95 million t from 1956 to 1959 to 24.86 million t from 1960 to 1987, with a decrease of 87.1 t, and the sediment discharge capacity of Yangjiaping Station decreased from 110.05 million t from 1956 to 1959 to 57.39 million t from 1960 to 1987, with a decrease of 47.8 t. The sediment discharge of Zhangjiashan station decreased from 354.68 million t in 1956-1959 to 236.1 million t in 1960-1987, the decrease was 33.4T. (3) the runoff and sediment discharge of Weihe River Basin decreased significantly with time from 1950 to 2008. According to the line of the double accumulation process of runoff and sediment transport at Zhangjiashan, Xiangtou and Huaxian stations in the Weihe River Basin, the trend line changes of sediment transport amount have taken place in the three stations, which indicates that the change of runoff has an effect on sediment discharge. Human activity is the main reason for the change of sediment discharge trend in Weihe River Basin. At the same time, the turning point of the double accumulation curve of runoff and sediment transport at the three stations corresponds to the storage time of the lower sluice of the reservoir. With the aid of Zhangjiashan, Xiangtou, Huaxian three stations runoff and sediment transport double accumulation curve, the variation of cumulative sediment transport in the last stage of the runoff-sediment transport double accumulation curve at 3 stations is estimated. The results show that the accumulative sediment reduction of Zhangjiashan station is about 452 million t ~ 2003-2008 when there is no effect of precipitation from 2001 to 2008. The cumulative sediment reduction of Huaxian station is about 1.124 billion t during the period of 2001 ~ 2008 when there is no effect of precipitation on Zhangjiashan station during the period of 578 million t ~ 2001.When there is no influence of precipitation in 2001 ~ 2008, the accumulated sediment reduction of Zhangjiashan station is about 452 million t ~ 2003-2008.
【学位授予单位】：中国科学院研究生院（教育部水土保持与生态环境研究中心）
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV145

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