通过弹性系数法及小波-神经网络模型对1959-2000年东江流域4个径流测站、28个降水测站、4个气温蒸发测站的径流、降水、气温、蒸发数据做系统分析与模拟,定量研究了气候变化及人类活动对东江流域径流量变化的贡献率。研究表明: ① 1972年是东江径流变化的变异点,1972年后东江径流较1972年前增大; ②东江流域降水增加,蒸发减少,是导致东江流域径流量增加的重要原因,气候变化对东江径流增加的贡献率约为0.27-0.77; ③人类活动主要通过土地利用方式的改变而改变产汇流过程,导致径流量变化,大型水库的建设是东江流域径流年内分配显著改变的重要驱动因素,人类活动对东江流域径流量变化的贡献率约为0.23~ 0.73,其影响从上游到下游呈减弱趋势。研究对于气候变化与人类活动影响下,东江流域水资源管理具有重要理论及现实意义。
英文摘要:
Precipitation,daily temperature and evaporation data from 28 meteorological stations and 4 evaporation stations,and daily streamflow data from 4 hydrological stations during 1959-2000 are analyzed by using the elastic coefficient method and the W-ANN model. Besides,construction of water reservoirs and land use changes are also considered in the analysis to investigate fractional contributions of climate changes and human activities as driving factors to streamflow variations. The results indicate that: ① the change point of the streamflow of the East River Basin occurred in 1972,the streamflow was larger after 1972 than before 1972; ② The increased precipitation and decreased evaporation resulted in the increase of streamflow. The fractional contribution of climate change to the increase of the streamflow is 0.27 ~ 0.77; ③ Human activities led to the increase of the streamflow via changes of land use. Mean-while,the construction of water reservoirs or hydraulic facilities tends to modify the annual distribution of the streamflow significantly. The fractional contribution of human activities to the increase of the streamflow is 0.23 ~ 0.73 and the fractional contribution decreases from the upper to the lower East River basin. This research has theoretical and practical contribution to human knowledge of the driving factors behind streamflow variations and also to the scientific water resources management of the East River basin.