气候变化对南水北调中线工程水源区与受水区降水丰枯遭遇的影响

Effects of Climate Change on Synchronous-Asynchronous Encounter Probability of Rich-Poor Precipitation between Water Source Area and Water Receiving Areas in the Middle Route of South-to-North Water Transfer Project

运用Copula方法构建南水北调中线工程水源区与各受水区汛期、非汛期及全年降水量的联合分布,并基于IPCC第四次评估报告中大气环流模式的降水结果,用所建模型探讨了气候变化情景下,南水北调中线工程水源区与受水区丰枯遭遇的变化。结果表明,从汛期来看,汉唐(汉江水源区-唐白河受水区)和汉海(汉江水源区-海河受水区)遭遇的丰枯同步频率呈增加趋势,不同排放情景下分别增加3.34%～16.48%和2.56%～8.21%,而汉黄(汉江水源区-黄河受水区)遭遇的丰枯同步频率呈减小趋势,不同排放情景下减小-1.97%～9.57%;从非汛期来看,汉唐和汉海遭遇的丰枯同步频率呈减小趋势,不同排放情景下分别减小-0.21%～9.42%和0.99%～5.54%,而汉黄遭遇的丰枯同步频率呈增加趋势,不同排放情景下增加1.79%～13.28%;从全年尺度来看,汉唐、汉黄和汉海遭遇的丰枯同步频率基本均呈减小趋势,不同排放情境下分别减小-2.88%～10.97%、-1.28%～5.05%和-2.33%～7.01%。

The Copula theory was used to construct the joint distribution of precipitation in the flood seamn, the dry sea ran, and the whole year between the water source area and the water receiving areas in the middle route of the South-to- North Water Transfer Project. The effect of climate change on the synchronous - asynchronous encounter probability of rich - poor precipitation was analyzed based on the General Circulation Models （GCMs） outputs in the IPCC Fourth Assessment Report （IPCC AR4）. The results show that on the flood season scale, the synchronous frequency of both rich and poor exhibits increasing tendency in the Han- Tang （Hanjiang Water Source Area- Tangbaihe Water Receiving Area） encounter and Han- Hai （Hanjiang Water Source Area- Hai River Water Receiving Area） encounter, and the values are 3. 34%- 16.48% and 2.56%- 8. 21%, respectively, under different emission scenarios; while the syn chronous frequency of both rich and poor exhibits decreasing tendency in Han- Huang （Hanjiang Water Source Ar ea- Yellow River Water Receiving Area） encounter, the value is in the range of --1.97%- 9.57% under different emission scenarios. On the dry season scale, the synchronous frequency of both rich and poor in the Han - Tang en counter and Han- Hai encounter decreases about -0.21%- 9.42% and 0. 99%- 5.54%, respectively, while that in Han- Huang encounter increases about 1.79%- 13. 28%. On the annual scale, the synchronous frequency of both rich and poor exhibits decreasing tendency in all the three encounters, and the values for the Han- Tang, Han - Huang, and HanHai encounters decrease about --2. 88%- 10. 97%, 1.28%- 5.05%, and --2. 33%- 7.01%, respectively.