气候和土地利用变化对潮白河流域径流变化的定量影响

为量化气候和土地利用变化对流域径流的影响,该文以华北土石山区潮白河流域为研究对象,利用AWY(annual water yield)模型及分离评判法定量分析了1956-2010年气候和土地利用变化对流域年径流的影响。结果表明:研究时段内,潮白河流域年降水量和年径流量呈显著下降趋势;流域年径流量在1979年发生减少突变;气候变化是潮河、白河流域年径流减少的主要原因,贡献率分别为59.3%和93.5%;土地利用变化贡献率相对较小,分别为40.7%和6.5%;不同土地利用类型对流域年径流变化的影响差异较大:林地对径流变化贡献率平均达到67%,耕地和草地分别为18%和15%,水域、未利用地因所占面积比例小,与流域年径流变化相关性并不显著。研究结果可为流域内水土资源规划及管理提供参考。

Quantitative effects of climate variations and land-use changes on annual streamflow in Chaobai river basin

In order to make the quantitative analysis of the impacts of climate variation and land use change on annual streamflow, Chaobai River watershed located in rocky mountain area of north China was selected as research object. AWY model and separation evaluation method were applied to quantify the respective contribution of climate and land use change to annual streamflow of the area from 1956 to 2010. The results indicated that the precipitation among years presented significantly a decreasing tendency, and the annual runoff also had a significant decreasing trend with the change point occurred in 1979. Climate variations was the strongest contributor to the reduction in mean annual streamflow of Chaohe and Baihe watershed, and the contribution rate reached 59.3% and 93.5%, respectively, while the remaining caused by land-use change. The effects of different type of land-use on the reduction in annual streamflow were quite different, for instance, the contribution rates of forest land was about 67%, which was more than the farmland of 18% and the grassland of 15%. The water body and unused land, which have a small proportion and a small change ranges in this region, were not observed to have a clear impact on annual streamflow. The results provide a theoretical reference for basin water resources management and land-use planning in Chaobai river basin.