气候变化对北江流域径流影响的模拟研究

通过构建北江流域SWAT分布式水文模型,以北江流域13个雨量站10年逐月降水量及北江流域干流石角水文站同步逐月流量数据为输入条件进行水文模型参数率定,应用气候情景设置方法研究了北江流域在降水和气温等不同气候变化条件下径流量的变化规律。研究表明:气温变化1℃对年径流量及其年内分配的影响变化均在1%以内。降水量变化对年径流量影响十分显著,降水量变化10%对年径流量的影响变化可达到15%,而对径流年内分配的影响变化在1%以内,影响较小。随着气温下降和降水量的增加,枯季径流量占年内分配比例均有所上升,枯水期来水量提高,有利于流域城乡供水安全和生态用水安全。

Simulative study on impact of climate change on runoff within Beijiang River Basin

Through establishing SWAT distributed hydrological model of Beijiang River Basin and taking monthly precipitation of 10 years from 13 precipitation stations within the river basin as well as the synchronized monthly flowrate data from Shijiao Hydrological Station on the main stream of Beijiang River Basin as the inputs of the hydrological model for rating of the parameters for the hydrological model， the changing law of the runoff under various climate conditions of precipitation and temperature in Beijiang River Basin is studied with the method for setting the climate scenarios. The study shows that under the impact from the temperature change of 1%， the changes of both the annual runoff and its distribution within a year are 1%. The impact from the change of precipitation on the annual runoff is quite significant; i.e. under the impact from the precipitation change of 10%， the change of the annual runoff can reach to 15%， and nevertheless， the change of the annual distribution of precipitation is within 1% with less impact. Following with decrease of temperature and increase of precipitation， the proportion of the runoff in dry season within the annual distribution of runoff is increased to a certain extent along with the increase of the inflow， which is favorable for both the safety of urban and rural water supply and the safety of ecological water demand within the basin.