水库对局地气候影响的数值模拟研究

The numeric-simuleted study on the local climate effect of reservoir in mountain area

大型水库建设改变了上游地区的地形高度和地表特征,必将对周边地区的局地气候产生影响.利用高分辨率边界层模式模拟研究了在高山峡谷地区由于水库建设可能导致的局地气候变化.结果表明:高山峡谷地区的水库将导致附近地区在冬季增温,增温幅度可达0.4～0.85℃,使春、夏、秋季降温,最大降温幅度可达2℃,但水库对附近地区气温的影响范围较小,影响温度0.1℃的水平范围约为2.5km,影响高度约500m;水库对气温影响的日变化规律冬季和其它季节不同,冬季使全天增温,白天增温幅度大,夜间增温幅度小,其余季节在夜间使气温增加,在白天使气温下降,夜间增温和白天降温的转换时刻大约在上午8时和晚间21时;在冬、春、夏和秋季,水库附近的相对湿度可分别增加约29.8%,37.2%,13.3%和20.3%,影响范围小于3km;水库将使附近的地面风速有明显增加,水库附近风速增加的幅度小于0.5m/s.

The reservoir has obviously effect on the local climate by modify the land use.In this paper,the local climate effects of reservoir in mountain area are studied by a high resolution boundary layer model.The results show that,the reservoir may increase the surface temperature in winter nearby the reservoir,with the amplitude rang from 0.4 to 0.85 ℃.The surface temperatures in spring,summer and autumn are decreased because of reservoir,the maximum value of decendent is about 2 ℃.The effect range of reservoir on the nearby temperature is small,the horizon range which the temperature variation is less than 0.1 ℃ is about 2.5 km and the vertical effect height is about 500 meter.The daily variation of temperature caused by reservoir in winter is different from other seasons.The increase of temperature in winter caused by reservoir in the daytime is greater than that in the night,but in other season,the reservoir make the surface temperature decrease in the daytime and increase in the night,the convert time is about 8 o＇clock and 21 o＇clock.The effect of reservoir on the relatively humidity is in the range of 3 km,with the maximum values of the increase of relatively humidity of 29.8%,37.2%,13.3% and 20.3% in winter,spring,summer and autumn respectively.The reservoir also make the nearby surface wind velocity increase,with amplitude below 0.5 m/s.