大渡河流域水电开发对区域气候的可能影响

The impact of the land-use change associated with the development of a hydropower station on regional climate

利用WRF中尺度天气预报模式,从拓宽大渡河整个干流的水体分布与改变单一水库(瀑布沟水电站水库)的水体覆盖两个角度,对比分析下垫面水体变化对区域气候的可能影响。结果表明:整个干流水体变化和瀑布沟水库水体加宽后所产生的气候效应类似,均表现为对水体附近区域的局地影响。年平均气温在水体附近区域下降0.2~0.4℃,冬季平均气温小幅升高,春季、夏季和秋季的平均气温降低;冬季、春季和秋季的降水量变化不明显,在河流两岸的年平均降水量、夏季降水量有所减少;相对湿度在水体区域微弱增加,平均风速变化不大。

Studying the impact of land-use and hydrological change on regional climate can provide theoretical guidance for socioeconomic development.The impact of land-use change associated with the development of a hydropower station on the Daduhe River,located in Sichuan Province,on the regional climate of the region,was examined through comparison of two simulations-a control experiment and a land-use change（sensitivity） experiment-using the WRF（Weather Research and Forecasting） model.Two study areas-Daduhe River and Pubugou Hydropower Station-were selected.According to precipitation characteristics,representative years（dry/wet/normal） were chosen,and the normal year of 2011 was selected as the simulation year.In addition,the months of January,April,July and October were taken as spring,summer,autumn and winter,respectively.First,the temporal variability and accumulated frequency of precipitation were studied by applying statistical analysis methods to daily precipitation data for the period 1970-2012 at 12 observation stations along the Daduhe River.Then,the control experiment and sensitivity experiment were separately conducted for the Daduhe River and Pubugou Hydropower Station study areas.The results indicated that the climatic effects of the land-use change associated with the hydropower station in the above two areas were weak on the local scale.The annual mean surface temperature decreased,ranging from 0.2℃ to 0.4℃.In addition,the temperature increased weakly in winter and decreased in the other seasons.No significant influence on precipitation in winter,spring and autumn was found,but a weak decrease in summer was detected.The relative humidity increased weakly surrounding the water body,and the wind speed showed almost no change.These meteorological variables only changed in the vicinity of the water body.The farther from the reservoir,the weaker the influence.