南水北调对北方干旱化趋势可能影响的初步分析

使用地表土壤水量平衡模式和大气能量平衡模式，对南水北调中线工程对华北地区的可能局地气候效应进行了虚拟模拟试验，得出了在不同调水方案和气候情景假定下华北地区可能出现的局地土壤水分、蒸发、温度和降水的变化。结果表明，不同调水量在不同时间、不同气候条件下的气候效应是有差别的，并与降水的季节变化有关。总体而言，在给定气候背景下调入水可以改变土壤水含量和径流，并使局地夏半年温度降低、冬半年温度有所升高；夏半年局地降水量和蒸发量有所增加，而冬半年变化不大。因此，在目前情况下南水北调中线工程的实施不仅可以减缓华北地区水资源紧缺的矛盾，而且有可能在一定程度上改善当地的局地干旱气候环境，进而有利于生态环境的良性循环和有序人类活动的可持续发展。

POTENTIAL IMPACT OF SOUTH TO NORTH WATER TRANSFERRING ON THE DROUGHT IN NORTHERN CHINA

By using surface water balance model and energy balance model, the sensitive simulation experiments were made to explore the potential climatic influences of south to north water transferring project in northern China. The simulation results gave some possible local changes of soil moisture, evaporation, temperature and precipitation under different climatic scenarios. Results show that the different amount of water transferring will bring about different climatic effects when the climate backgrounds and seasons are different, and related to seasonal variation of precipitation. For the northern China, input water from the project could change the local soil moisture and runoff, and cause decrease in temperature in summer half year and increase in temperature in winter half year. At the same time, the local precipitation and evaporation in summer half year will increase, and those will change a little bit in winter half year. Therefore, the central line project of south to north water transferring will not only resolve the problem of water resources shortage in north China, but also improve the local drought climate environment to some extent. It is beneficial for the regional ecological environmental positive circulating and sustainable development.