近50ａ来南疆气候变化对可利用降水量的影响

选择1951~2006年逐月降水和温度资料,计算出南疆年平均蒸发量及可利用降水量.在详细分析了50 a来南疆地区降水、气温、蒸发及可利用降水量变化特征的基础上,采用逐步回归周期分析法对降水、气温和可利用降水量进行了模拟,并对未来5 a上述要素进行了预测.结果表明,20世纪70年代以后南疆地区的温度、降水和蒸发变化基本呈上升态势,可利用降水量却呈现出偏多和偏少交替的波状变化特征.这说明气候变暖,可利用降水量不一定增多,未来5 a南疆地区可利用降水量将可能减少.

Influence of climate change in Southern Xinjiang over last 50 years on available precipitation

Based on the monthly precipitation and temperature data from 1951 to 2006, the annual mean evaporation and the available precipitation in Southern Xinjiang were calculated. By analyzing the characteristics of changes in precipitation, temperature, evaporation and available precipitation over the last 50 years, the precipitation, temperature and available precipitation were simulated using the periodic analysis of stepwise regression. Then, they were predicted for the coming five years. The results show that the changes in temperature, precipitation and evaporation have basically had an increasing tendency since the 1970s. However, the available precipitation has exhibited fluctuating characteristics, that is, relatively larger and smaller amounts than the average ones at different time. With climate change, the available precipitation does not necessarily increase, and it may decrease in Southern Xinjiang in the coming five years.