南水北调中线水源区与受水区降水丰枯遭遇研究

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方法理论构造了南水北调中线工程水源区与各受水区汛期、非汛期及全年降雨量的联合分布,并用所建模型对水源区与各受水区的丰枯遭遇进行了研究。结果表明,用Copula方法来描述不同水文区的丰枯遭遇问题是可行的。通过分析得出以下结论:水源区与受水区丰枯同步的频率表现出由南向北递减的规律,且同枯的频率略大于同丰的频率,同平的频率最低,有利于调水的频率却表现出相反的趋势;非汛期调往各受水区的水量有限,需配合其他水利工程进行联合调度才能保证供水区的用水安全。

The Copula theory was applied to construct the joint distribution of precipitation in flood season, dry season and annual precipitation in water source area and receiving areas in the Middle Route of South-to-North Water Transfer Project. The synchronous-asynchronous encounter probability of richpoor precipitation was analyzed. The results show that synchronous frequency of both rich and poor exhibits descending tendency from south to north, and the encounter frequency of synchronous poor precipitation is slightly greater than synchronous rich precipitation, while the frequency of both normal precipitation is the smallest. The amount of water transferred to receiving areas is limited during dry season, which needs to jointly operate with other water resource projects to ensure the water security of receiving areas.