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为探究气候变异和土地利用变化对流域产流产沙的影响,选择位于北京密云水库上游的潮河流域,对该流域1961-2009年的年径流、年降水、年潜在蒸散发和年输沙量分别进行了非参数检验和突变点分析,结合该流域不同时期的土地利用变化情况,采用水量平衡原理,定量评价该流域土地利用和气候变异对年径流量和年输沙量变化的贡献。结果表明:该流域年径流量在1961-2009年间呈显著减少趋势,并在1999年发生突变,但年降水和潜在蒸散发没有显著变化。该流域年输沙量显著减少,且于2004年发生突变。分析表明该流域气候变异和土地利用变化对年径流量减少的贡献率分别为43.9%和56.1%,而对年输沙量减少的贡献率分别为1.95%和98.05%。土地利用变化是导致该流域年径流量减少,特别是年产沙量减少的重要原因。在全球气候变化的大背景下,通过调整流域土地利用结构、优化土地利用方式,开展以植被恢复为主体的水土流失综合治理,是实现适应性流域管理目标的根本途径。
In order to explore the impact of climate variability and land use change on runoff and sediment yield, the authors selected the Chao River basin located in the upper reaches of Miyun Reservoir in Beijing. The annual runoff, annual precipitation, annual evapotranspiration and annual sediment transport Nonparametric test and mutation point analysis were carried out respectively. According to the land use change in different periods of the basin, the principle of water balance was used to quantitatively evaluate the contribution of land use and climate variation to the annual runoff and annual sediment load changes. The results showed that the annual runoff of the basin decreased significantly from 1961 to 2009 and abruptly changed in 1999, but the annual precipitation and potential evapotranspiration did not change significantly. Annual sediment load decreased significantly in this basin, and a mutation occurred in 2004. The analysis shows that the contribution rates of climate change and land use change to annual runoff decrease are 43.9% and 56.1% respectively, while the contribution rates to the annual sediment transport decrease are 1.95% and 98.05% respectively. The change of land use is the important reason that causes the annual runoff decrease in this basin, especially the annual sediment yield. Under the background of global climate change, it is the fundamental way to achieve the goal of adaptive watershed management by adjusting the land use structure, optimizing land use patterns and implementing integrated control of soil and water loss with vegetation restoration as the main body.