新疆北疆气候对地表水资源变化的影响与评估

EFFECT AND ASSESSMENT OF THE CLIMATE ON THE CHANGE OF SURFACE WATER RESOURCES IN NORTH XINJIANG

通过气候因子与北疆地表水资源的相关分析 ,主要得到以下结论 :9月～次年 8月的水文年降水量是影响北疆地表水资源的主导气候因子 ,它起着增加地表水资源的作用 ,而 5～ 7月月平均气温累积值是辅助气候因子 ,它通过增加蒸发对地表水资源起减少作用。位于北疆西部地区的几个代表站 ,其气候因子对北疆地表水资源的影响最为显著。气候变化对北疆地表水资源影响的定量评估大致为 :5～ 7月月平均气温累积值为多年平均值时 ,水文年降水增加或减少 1 0 % ,北疆地表水资源增加 6 .0 %或减少 8.1 %。水文年降水量为多年平均值时 ,5～ 7月月平均气温累积值偏高或偏低 2℃ ,则北疆地表水资源减少 3.5 %或增加 1 .4%。

Xinjiang is divided by the Tianshan Mountains into two parts, i.e., north Xinjiang and south Xinjiang. Surface water resources in north Xinjiang occupies 49.4% of the total in whole Xinjiang. It contributes to the rational utilization of surface water resources, timely guiding the operation of the reservoirs and cannal system, and providing the reliable scientific basis for the rapid economic development to correctly assess the volume of surface water resources and the quantitative effect of the main climatic factors on surface water resources under the different climatic conditions in north Xinjiang. Through the correlation analysis between the climatic factors and the surface water resources in north Xinjiang, the following main conclusions can be obtained in the paper: (1) The annual precipitation in a hydrologic year from September to August next year is the dominant climatic factor affecting the surface water resources in north Xinjiang, and increases the surface water resources; the cumulative value of the mean monthly air temperatures from May to July is the subsidiary climatic factor, and reduces the surface water resources owing to the increase of evaporation during this period. (2) The climatic factors at the representative meterological stations in the western part of north Xinjiang have the most significant influence on the surface water resources in north Xinjiang. (3) The quantitative assessment about the influence of climatic fluctuation on the surface water resources in north Xinjiang are roughly as following: when the cumulative value of the mean monthly air temperatures from May to July is equal to the multi year average value and the annual precipitation in a hydrologic year increases or decreases for 10%, the surface water resources in north Xinjiang increases for 6.0% or decreases for 8.1% respectively; when the annual precipitation in a hydrologic year is equal to the multi year average value and the cumulative value of the mean monthly air temperatures from May to July is 2.0℃ higher or lower than that of average, the surface water resources here decreases for 3.5% or increases for 1.4% respectively.