VARIATION CHARACTERISTICS AND CAUSES OF EVAPORATION CAPACITY IN AKTO COUNTY IN RECENT 46 YEARS

Based on the data in meteorological station of Akto County such as evaporation capacity of small evaporating dish,temperature,sunlight hours,wind speed,relative humidity,and other information during 1964-2009,the basic characteristics,trends and stages of evaporation in recent 46 years and the influence factors for evaporation variation were analyzed.The results showed that the average annual evaporation capacity and seasonal evaporation capacity had a trend of significant decreasing in the past 46 years in Akto County,the average decreasing rate was-263.17 mm/10a,the average decreasing rate of spring,summer,autumn and winter were-79.1 mm/10a,-130.2 mm/10a,-43.9 mm/10a,and-9.97 mm/10a.The main factors for evaporation capacity decreasing were temperature,wind speed,relative humidity and sunshine hours.