松花江流域河流泥沙及其对人类活动的响应特征

Response characteristics of sediment to human activities in the Songhua River basin

对松花江流域主要水文站输沙量变化的分析表明:51年来,嫩江除1998年发生洪水外其余年份输沙量变化不大,第二松花江输沙量表现为明显的下降趋势,松花江干流输沙量也表现为下降趋势,而松花江整个流域在1979年之前为下降趋势,1979年之后为上升趋势。松花江干流区域和第二松花江为主要的泥沙来源区,分别占整个松花江流域输沙量的72.1%和16.2%。通过对单位降雨侵蚀力输沙量的分析,松花江流域输沙量负荷的变化与流域内重大历史事件、国家政策等人为活动的变化密切相关。"大跃进"时期嫩江流域输沙量负荷显著增大,三年自然灾害时期各区段输沙量负荷都出现峰值,"文革"时期各区段输沙量负荷起伏变化比较大,改革开放特别是家庭联产承包责任制实施以后,各区段输沙量负荷都呈现显著增长的趋势,90年代自然灾害频发使输沙量负荷持续出现峰值,直至1999年退耕还林后输沙量负荷才有所下降,但此后输沙量负荷又有不同程度的增长趋势。

Based on the data of the main hydrological stations in the Songhua River basin, the variations of the sediment loads at these stations were analyzed. The sediment load in the Nen River changed little from 1955 to 2005 except the year 1998. The sediment load in the Second Songhua River showed an evident decreasing trend and the sediment load in the main stem also showed a decreasing trend, but the sediment load in the whole basin showed a decreasing trend before 1979 and conversely after 1979. The main stem of Songhua River and the Second Songhua River are the main sources of sediment, accounting for 72.1% and 16.2% respectively. Through decoupling indicator analysis, there is a significant relationship between the variation of sediment loads and human activities related to important historical events, national policies, and the human activities play an important role in the variation of sediment load. The sediment load in the Nen River basin showed an evident increasing trend during ＂Great Leap Forward＂. The sediment load of four sections in the Songhua River basin showed peak values during ＂Three Years of Natural Disaster＂ and obvious fluctuation during ＂The Cultural Revolution＂. After ＂Reform and Opening＂, especially the household responsibility system, the sediment load of the four sections showed an increasing trend and continually appeared peak values during the 1990s since the frequent natural disasters. Until 1999 the sediment load showed a decreasing trend because of the policy of returning farmland to forest. But the sediment load had an increasing trend more or less after 2000.