南水北调中线水源地与受水区丰枯遭遇分析

Analysis of Wet-Dry Encounter Between Source Area and Receiving Area of the South-to-North Water Transfer Project

基于丹江口水库1954—2009年的月平均径流序列与郑州地区同时期的月平均降雨序列,采用游程理论计算了4种丰枯遭遇组合在不同游程长度下的分布概率和重现期。结果表明:在同一截取水平条件下,游程重现期随着游程长度的增加而快速增长;在同一游程长度条件下,重现期随着截取水平的增大而增长;在同一截取水平、同一游程长度的条件下,同步偏枯发生的可能性最大,其次为同步偏丰,枯丰遭遇的可能性最小。

Based on the average month- runoff series of Danjiankou Reservoir covering the period of 1954—2009 and the rainfall series of Zhengzhou Area at the same period,the theory of run was employed to calculate the distribution probability and return period of drought with given length under four different kinds of asynchronous- synchronous encounter combinations,i. e.,B（ low flow）- B,A（ ample flow）- A,A- B and B- A. The results show that when the intercept level is fixed,the return period of drought events with longer length is greater;drought return period increases as intercept level improves when the run length remains unchanged. In term of the run events with the same intercept level and run length,the B- B encounter combination is the easiest to occur,the next one is the A- A encounter combination,and B- A is the last one.