气候变化和人类活动对黄河中游输沙量影响的甄别

IMPACTS OF CLIMATE CHANGE AND HUMAN ACTIVITY ON SEDIMENT DISCHARGE IN THE MIDDLE REACH OF THE YELLOW RIVER

根据黄河流域1951—2011年间的主要水文站实测降雨量、径流量和输沙量的月际和年际序列资料,采用水文法和对比分析法,发现在4个阶段(1951—1968、1969—1986、1987—1999、2000—2011年)内汛期5—9月份的产沙率变化为80.97%、78.04%、89.31%、97.42%。建立了基准期的汛期"降雨量—输沙量"关系统计模型,据此估算人类活动对其输沙量的减少贡献快速上升,2000—2011年期间基本上完全受人类活动(小浪底水库调蓄)控制,气候变化(主要为降雨)的影响已不足3%。研究结果表明,过去的61年来黄河河流系统发生重大调整,河流输沙量的变化由过去的气候因素控制快速转变为人类活动控制,导致黄河入海泥沙通量在快速减少,对黄河三角洲的冲淤演变产生了根本性的影响。

Based on the hydrological study and correlation analysis,yearly/monthly datasets of precipitation,water discharge and sediment load from the main gauging stations of the Yellow River during the period of 1951-2011 are collected.Data suggests that the sediment load during the flood seasons（May to October）of the four phases of 1951-1968,1969-1986,1987-1999 and 2000-2011 is 88.46%,88.79%,90.41%,95.94%respectively.And a statistical model denoting the relationship between precipitation and sediment load is built for the base phase and the first phase.According to the estimation of the model,the contribution of anthropogenic activities to the sediment load increases with time.During the latest period（2000-2011）,the sediment load was basically contributed by human activities（e.g.,the Xiaolangdi Reservoir）,and the contribution of climate change（especially the rainfall）was less than 1%.It designates that the Yellow River drainage system has been severely reversed in the past 61 years.Now the sediment budget of the Yellow River is mainly controlled by human activities instead of the nature and it will bring great impact onto the development of the Yellow River delta.