CCSM3模式下汉江流域设计暴雨计算

分析气候变化对降雨频率的影响,有助于水利工程的设计和规划。根据大气环流模式CCSM3的结果,结合IPCC第四次评估报告中给出的SRA1B、SRA2和SRB1三种排放情景,利用随机天气发生器LARS-WG生成汉江流域20个站点2020s时期逐日降雨资料,通过线性矩方法计算各个站点的百年一遇设计暴雨值,并通过克里金方法插值至整个汉江流域。结果表明,百年一遇设计暴雨值在汉江流域呈现由下游向上游逐渐递减的特征没有明显改变,SRA1B和SRA2情景下,最大设计暴雨值出现在流域出口处的武汉站;三种排放情景下,百年一遇最大设计暴雨值都有所增加,SRA1B情景和SRA2情景下都有40mm左右的增幅;SRA2和SRB1情景下,上游地区的设计暴雨值则有减小的趋势。

Estimation of design storm in Han River basin with CCSM3 model

This study applied a LARS-WG weather generator and a general circulation model CCSM3 to simulate synthetic weather data under the SRA1B,SRA2 and SRB1 scenarios from IPCC.Design storms of 100 years return period at 20 stations in the Han River basin for the period of 2020s were calculated using the P-Ⅲ curve and the L-moment approach,and the design storms of the whole basin were interpolated with Kriging method.Results show that the design storms in this basin tend to decrease from the downstream to upstream.Under SRA1B and SRA2,the largest design storms will occur at Wuhan station.Relative to the existing conditions,the largest design storms in 2020s will be greater in all the three scenarios.They will be increased by about 40mm under SRA1B and SRA2,while under SRA2 and SRB1 they will be decreased in the upstream.