1926-2009年额尔齐斯河流域中游地区气候变化及其对水资源的影响分析

Analyses of the Climate Change and Its Impact on Water Resources in the Middle Reaches of Irtysh River during 1926-2009

额尔齐斯河流域中游地区是哈萨克斯坦共和国重要的水资源富矿与战略经济区,资料表明这一地区过去几十年来气候与水资源均发生了显著变化,分析研究其气候变化及其对水资源的影响,对水资源合理利用具有重要的指导意义.利用研究区7个气象站1926-2009年84a逐月降水和气温资料,应用高桥浩一郎公式计算研究区月平均蒸发量及可利用降水量,分析了1926-2009年研究区气候变化及其对水资源的影响.结果表明:1)与全球气候变暖一致,过去84a来研究区平均气温呈较快的升高趋势,且自20世纪80年代末以来进入快速升温变暖期;2)84a来,研究区降水总体呈增加趋势,随着温度的升高,蒸发量同步增加.因此,研究区可利用降水量尽管有波动但总体变化不大;3)降水是影响研究区可利用降水量的最重要的影响因素,二者呈现显著的正相关关系,1%的降水变化可导致1.68%的可利用降水量变化.研究区是全球气候变化的敏感区域,水资源开发利用需切实做好应对气候变化的适应性对策.

The middle reaches of Irtysh River Basin are abundant in water resources and are a strategic economic zone in the Republic of Kazakhstan.Instrumental records indicate that the climate in the middle reaches has undergone significant change and the state of water resources has experienced a remarkable fluctuation over the past 84 years.Therefore,to analyze the climate change and its impact on water resources has a guiding significance on rational utilization of water resources in the study area.Based on the monthly mean temperatures and precipitations from seven meteorological stations in the middle reaches of the river from 1926 to 2009,the mean monthly evaporation and the utilizable precipitation（precipitation minus evaporation） of the river were computed by using Takahashi’s equation.The climate change and the trend of water resources change,as well as the impact of climate change on the water resources,in the middle reach of the river from 1926 to 1999 were analyzed.The results show that： 1） Temperature in the river basin keeps at an average level equal to that in the 1930s,and was lower than the level from the early 1940s to the late 1970s,showing a negative anomaly.And it was continuously increasing from the late 1970s,showing a positive anomaly.Precipitation in the river basin non-linearly increased from the 1930s to the 1980s,reaching a top in the 1980s,and then decreased in the 1990s;finally it has rapidly increased after the 2000s.2） The utilizable precipitation decreased from the early 1930s to the early 1950s and broke the mean value in the 1990s,and from the early 1950s to the early 1970s and the 1980s there were high precipitation periods,finally the precipitation has rapidly increased after the 2000s.3） There is a positive correlation between the precipitation and the utilizable precipitation,based on which,a statistical assessment model for the impact of precipitation on the utilizable precipitation is established for the Irtysh River.