无定河流域1956—2009年径流量变化及其影响因素

黄河是中国的第二大河,近几十年,黄河的径流量发生明显变化,分析径流量变化及驱动力,对流域治理及水资源的开发利用、解决水资源的供需矛盾,促进社会、经济、生态可持续发展等具有重要作用,因此分析径流量的变化趋势及驱动力已成为国内学术界的热点话题。无定河是黄河中游重要的一级支流,也是中游区水土保持措施实施最早的流域,因此以无定河流域为例分析黄河中游径流量的变化趋势及原因。论文首先分析白家川站1956—2009年径流量的变化趋势,并采用7种时间序列突变检验方法分析序列的突变点;其次,通过估算不同时期气候变化对径流量的影响,从而分析人类活动对径流量的影响。结果显示:1956—2009年无定河流域径流量显著减少,气候干旱化加剧;径流量时间序列突变发生在1971年和1997年,这与20世纪70年代大规模实施的水保措施及1997年以来的退耕还林等生态修复措施有关;70年代以来人类活动影响是径流量减少的主要原因。

Annual Runoff Change and Influencing Factors in the Wuding River Basin in 1956-2009

The Wuding River is one of the major tributaries of the Middle Yellow River.This basin is the earliest one to implement soil conservation measures.The result obtained through analyzing the changing trend of runoff and influencing factors of the Wuding River Basin,will promote the social,economic and ecological sustainable development;and also help solve the contradiction between supply and demand of water resources,reasonable exploitation and utilization of water resources in the middle reaches.In this paper,firstly,the variation trend of annual runoff and the abrupt change point are analyzed at Baijiachuan station from 1956 to 2009.To estimate the influence of climate change three meteorological factors including precipitation,temperature and humidity are analyzed,at the meantime,the drought trend as an important feature of climate change is also analyzed.Then,the influencing of climate change and human activity are calculated through multiple regression analysis.Result shows that annual runoff is continually decreasing;the drought trend is aggravating;the abrupt change points of runoff series appear in 1971 and 1997;human activity is the main influencing factor to reducing runoff from 1972 to 2009;water and soil conservation measures have significant effects on runoff,ecological restoration measures of converting cropland to forest has a certain effect on runoff since 1997.