蒙江流域降水及径流变化特征分析

Analysis of Characteristics of Precipitation and Runoff Variation of Mengjiang River Basin

分析蒙江流域降水及径流的变化特征,有利于水资源的开发利用与保护。基于蒙江流域1959～2012年降水、径流资料,应用线性倾向估计法探讨了降水和径流年际、年代变化特征;借助Mann-Kendall法、Yamamoto法、滑动t检验、小波分析法和R/S方法探讨了降水、径流的趋势性、突变性、周期性及长程相关性。结果表明,降水年际、年代间变化较小,径流年际间波动剧烈;年代间,最大年径流量出现时间一般较降水滞后3年,除1990年代,最小年径流、年降水出现时间同步,降水、径流分别呈不显著减少、不显著增加变化,这主要是由1990年以后的人类活动所致;流域降水在1975、1981年发生突变,年径流在1991年发生突变,均存在24年的主周期,未来一段时期内,降水、径流均呈偏丰状态,区域水资源形势较为乐观。研究成果可为区域水电站运行及水资源配置提供参考。

The analysis of the variation characteristics of precipitation and runoff in the Mengjiang River Basin is beneficial to the development, utilization and protection of water resources. Based on the precipitation and measured runoff data from 1959 to 2012 in the Mengjiang River Basin, this paper analyzes the inter-annual and temporal changes of precipitation and runoff by using trend line. And then the trend, the periodic, the mutation and the long-range correlation are discussed by means of Mann-Kendall, Yamamoto method, Sliding t-test, wavelet analysis and R/S analysis. The results show that the fluctuation of precipitation is insignificant, and runoff fluctuates sharply. Time of occurrence of maximum annual runoff is generally lagging behind the precipitation about three years. Except the 1990s, the occurrence time of minimum annual runoff is synchronized with annual precipitation. The precipitation has a not significant downward trend in the future, and the runoff has a not significant upward trend due to human activities. The sudden change points of precipitation existed in 1975 and 1981 while the sudden change point of runoff existed in 1991. Both precipitation and runoff have a main cycle of 24 years, and will be abundant in the future period. The regional water resources situation is optimistic. The research results can provide a reference for the operation of regional hydropower stations and the allocation of water resources.