大凌河流域径流演变规律分析

Analysis of Variation Characteristics of Runoff in Dalinghe River Basin

利用大凌河流域7个主要水文站资料,对大凌河近50a径流年内变化,年际变化分析,探寻年径流演变规律。结果表明:大凌河径流7月,8月占全年径流比例最大,年内分配最不均匀是1960s,2000年以后年内分配相差最小,干流3站集中度在2000年以前同步性较好,2000年新建水库后,同步性变差;年际变化上整体处于下降→显著下降→上升→显著下降的趋势,从典型站的趋势检验结果分析,大凌河径流减少趋势明显,干流凌海站突变点是1980年,支流哈巴气站在置信区间内,没有发生突变;从周期性上分析,干流的凌海站和支流的哈巴气站主周期都是26a,周期性较明显。

The evolution regularities of the monthly runoff time-series of hydro-meteorological data from 7 sta- tions distributing in different areas of Dalinghe River basin during the period of 1961--2010 were analyzed in this paper. The variation and skewness coefficients, Mann-Kendall trend test, complex Morlet wavelet and runoff concentration degree （RCD） were used to investigate the inhomogeneity, trends, cycle and concentra- tion of the monthly runoff time-series. The results demonstrated that the most runoff flow presented in July and August and the most uneven distribution within a year occurred in 1960s, respectively. The RCD syn- chronization of three stations in the main stream maintained relatively good state before some new reservoirs were built. But after the operation of these reservoirs, the RCD synchronization gradually weakened and a decrease in annual distribution differences was found after 2000. With respect to the interannual variability, all the runoff time-series from 7 stations showed a significant dropping--dropping--increasing dropping trend. Moreover, Mann-Kendall trend test proved that the runoff flow of Dalinghe River decreased obviously and the abrupt negative trend shift at Linghai station became significant around the year of 1980. Abrupt changes were not found at Habaqi station within the confidence interval. Periodic analysis via complex Morlet wavelet indicated a strong cycling was found in the runoff time-series with a 26-year main cycle from both Linghai and Habaqi.