黄河花园口断面水沙变化特征及趋势分析

Analysis of changes and trend of water and sediment load at Huayuankou station on Yellow River

花园口站是黄河中下游重要的控制性水文监测断面,对于黄河流域上游下垫面的变化响应非常灵敏,因此,通过分析花园口断面水沙变化特征可以在一定程度上揭示长期以来在自然及人类活动影响下黄河流域所发生的深刻变化。利用花园口水文站1952-2008年径流和输沙数据,采用定量分析方法,分析了近60年以来花园口断面黄河水沙的变化特征、趋势以及在不同时期水沙关系的演变。结果表明:花园口断面径流和输沙均呈显著的下降趋势,且在可预报的未来几年内径流量和输沙量将进一步持续下降;径流量和输沙量均具有4个明显的阶段性变化特征,且具有大致相似的丰枯变化规律;径流—输沙关系的演变表现为4个阶段,转折年份分别为1960年、1980年和1999年,输沙对径流的响应程度在减弱,而人类活动引起的下垫面变化的影响日益增强。

The Huayuankou station is the most important hydrological monitoring station on the Lower Yellow River. Its response is very sensitive to the changes on the underlying surface of the upper and middle reaches of the Yellow River. Therefore, through analyzing the changing characteristics of water and sediment load at Huayuankou station the profound changes in the Yellow River Basin induced by long-term natural and human activities can be revealed to some extents. The runoff and sediment data at Huayuankou station during 1953 - 2002 are used to analyze the changing characteristics, future trend of water and sediment load, and evolution of water and sediment load relationship in different times in the past nearly 60 years by quantitative analysis methods. The results show that the runoff and sediment load at Huayuankou station showed significantly decreasing tendency, and will further decline in the predictable future. The runoff and sediment load appeared four change periods and had the similar rich-poor variation characteristics. The evolution of runoff and sediment load relationship could be divided into four periods in which the turning years were 1960, 1980 and 1999, respectively. The response level of sediment load to runoff became weaken gradually, and the humaninduced land surface changes had growing impacts.