Study On The Influence Of Xiaolangdi Reservoir On The Climate Of Mengjin County

Because of the heat capacity of water is bigger than that of land, and theincrease of water area after impoundment of Xiaolangdi Reservoir, the local climateecological environment will be affected. The change of the underlying will impact onthe formation, evolution and characteristics of the weather system, then lead to thechange of the local climate characteristics. This paper based on the basicmeteorological data on1971to2010of Region meteorological observatory. At first,analyse the trend of the40a climate change in Region, then compared the climatefactors’ change before and after impoundment. Furthermore, discusses theimpoundment’s influence to Region’s climate factors. The results show that:From1971to2010, Region’s mean temperature, maximum temperature,minimum temperature and earth temperature are ascending; the duration period andaccumulated temperature of daily mean temperature≥0℃,≥5℃and≥10℃increased significantly; the frostless period was prolong, the first frost dates have beengotten earlier, and late frost dates have been gotten later; The trends of precipitationappear reduced, the trends of continuous rainfall increased slightly, thenon-continuous days decreased; relative air humidity decreased, evaporation issignificantly reduced; the fog days increased. Average sunshine duration and sunshinepercentage increased significantly.The comparison result of before and after impoundment shows that: The meantemperature rise significantly, the maximum temperature increased slightly, theminimum temperature and soil surface temperature raised; the duration period andaccumulated temperature of daily mean temperature≥0℃,≥5℃and≥10℃increased significantly; the first frost date and the final date is later, the frostlessperiod increased; precipitation decreased, continuous rainfall days increase; thenon-continuous days increased, air relative humidity increased; evaporation reducedgreatly; fog days increased. Sunshine duration and sunshine percentage reduced.After impoundment of the Xiaolangdi reservoir, the actual annual mean temperature of Region was lower than the mean temperature simulation; the actualannual precipitation was more than the annual precipitation simulation; the differenceof the actual and simulation relative air humidity is weak; The actual evaporation isless than the actual simulation; actual sunshine hours are more than the simulation.