泾河长系列水沙变化规律与归因研究

近些年泾河径流量及来沙量大幅减少,在一定程度上影响到流域的水资源开发利用,为了厘清水沙减少程度及变化特征,探寻其变化背后的驱动因素,采用联合滑动t检验、距平累积曲线法和Copula等方法,从不同层面对泾河长系列水沙规律进行了研究。同时,建立分布式水文模型,分情景对泾河流域径流泥沙对气候和土地利用变化的响应进行了模拟。结果表明:气候变化对径流和泥沙减少的贡献率约为21. 20%和6. 08%;土地利用变化对径流泥沙减少的贡献率约为4. 04%和11. 08%;泾河流域径流泥沙变化除受气候变化影响外,还与土地利用(覆被)类型、面积比重等有关。研究结论表明:人为拦蓄和引水是河川径流减少的主要原因,而泥沙减少的主因除了退耕还林还草之外,通过淤地坝等水保措施直接拦沙也起到了重要作用。

Attribution analysis of long series runoff and sediment variation in Jinghe River

The runoff and sediment of Jinghe River have greatly reduced in recent years, which has affected the utilization of water resources along the bank to some extent. In order to determine the reduction degree and characteristics of runoff and sand, and to explore the driving factors, this paper studied the runoff and sediment series of Jinghe river by combining sliding T test, with Copula, Anomaly Accumulation Curve Method and other methods. Moreover, a SWAT model for Jinghe River basin was constructed based on the geographic information data of Jinghe River basin, and different scenarios were set up to study the response of runoff and sediment to climate and land use change in Jinghe River basin. The results showed that climate change contributes about 21.20% and 6.08% to runoff and sediment reduction. The land use change contributes about 4.04% and 11.08% to runoff and sediment reduction. Runoff and sediment changes in Jinghe River basin are not only the effect of climate change, but also land use and other human activities. Conclusions can be drawn that: the increasing water diversion and other water demand along the riverside is mainly count for the runoff reduced. Compared with runoff, sediment change is more sensitive to land use change, the reduction of sediment is mainly attributed to returning farmland to forest and grass, silt dam also plays an important part.