嫩江径流年内变化特征分析

Changes of annual runoff distribution in the NenJiang river

在气候变化和人类活动的影响下,嫩江径流年内分配特征也发生了一些变化,直接影响人类开发利用和生态环境建设,根据嫩江石灰窑、同盟、江桥、大赉四个水文站1956-2006年月径流资料,分析了嫩江年内分配不均匀系数、完全调节系数、集中度、集中期及变化幅度特征。结果表明：1970-1979年（石灰窑除外）无论是年内分配完全调节系数还是年内分配集中度都比较小,径流分配比较均匀。1980年后,年内分配不均匀性增加,集中度也增大。就空间而言,由上游向下游,年内分配不均匀系数逐渐减小、集中度也逐渐减小,集中期后延,嫩江流域月径流量变化幅度不大,总体来看,下游的大赉站变化幅度明显大于中、上游。且中、上游1970-1979年变化幅度较大。

With the impact of climate change and increasing intensity of human activities, the NenJiang River annual runoff distribution has changed. In this paper, the index of unevenness, concentration, and variation have been defined and calculated according to the records of runoff in the 1956 - 2006. It was revealed that;In 1970 -. 1979 the index of unevenness and concentration was lower, the runoff distribution was even. After 1980 the indexes of unevenness and concentration were higher. In the downstream the unevenness and the concentration rate were higher than the upper stream. The variation range wasnt very large. At the DaLai station which locates at the upper stream the variation range was higher than the middle and upstream. In 1970 - 1979 the variation rate was higher in the middle and the upstream.