我国主要入海河流水沙变化分析

本文利用"中国河流泥沙公报"数据,结合各流域长系列年降水量资料,利用趋势分析和水沙双累计曲线方法相结合分析径流模数和输沙模数的变化,探讨我国主要入海河流水沙的历史变迁。数据系列至2006年,大多数数据长达50年。根据河流下游站历年水沙变化趋势,将我国主要河流大致分为3类:水量基本不变沙量降低、水量和沙量均降低、几近断流断沙。按地域看,我国淮河及其以南河流年水量无明显的改变趋势,而年沙量呈明显下降趋势;淮河以北地区河流水沙量均呈明显下降趋势,特别是黄河径流量的近10年平均值仅为多年平均值的1/3,输沙量从20世纪五、六十年代的约12亿t/a锐减至近10年的约1.6亿t/a,而海河水系的河流下游几乎是断流断沙。总体上,我国大多数河流的沙量明显下降,本文所列的10条河流下游站近10年的输沙量年平均值低于多年平均值的一半。流域降水量的变化不是河流入海水沙量的明显降低的主要原因,水沙量的降低主要是人类活动造成的。

Analysis on variation of seagoing water and sediment load in main rivers of China

The variation of runoff module and sediment transportation module in main seagoing rivers of China are analyzed according to the latest 60 years data published in the China Gazette of River Sedimentation by using tendency analysis method and based on the accumulated water-sediment relationship to investigate their historical evolution.It is found that the rivers can be classified into 3 groups:rivers with decreasing sediment transport and stable runoff, rives with greatly reduced sediment transport and decreasing runoff.The rivers located in south of the Huaihe River is not significantly varies in average annual runoff,but experienced great reduction of sediment transport.Generally,the major part of the rivers in China exhibits the characteristics of sediment decreasing.Both water and sediment are remarkably reduced in the region at the north of Huaihe River.The main cause of reduction of water and sediment is mankind activities.