达坂城地区1964—2008年蒸发量变化特征分析

Analysis of Evaporation Variatiom Features in Dabancheng Region during 1964-2008

利用达坂城气象站1964—2008年蒸发量实测资料,分析了达坂城蒸发量的变化特征及其影响因子。结果表明:达坂城年和各季的蒸发量均呈现不同程度的减少趋势,年蒸发量以179.7 mm/10 a的倾向率减少。减少趋势主要表现在夏季、春季,其中5月最明显。影响蒸发量变化的因子有日照日数、气温、风速、相对湿度等,其中蒸发量与风速呈显著正相关,与日照日数、气温、相对湿度均呈负相关。风速的逐年减小和相对湿度的逐年增加,是导致该地区蒸发量减少的重要因素。同时期气温的上升趋势和干旱指数分析表明,达坂城地区气候逐渐转向暖湿的信号已经出现。

By using the actually observed data on evaporating capacity at Dabancheng weather station of Urumqi from 1964 to 2008,the Variation features of evaporating capacity in Dabancheng and corresponding influential factors were analyzed.The results indicated that the annual,quarterly and monthly evaporating capacities at Dabancheng revealed a declining trend.The annual evaporating capacity was decreasing at a tendency rate of 179.7mm/10a.The declining tendency was mainly happened in summer and spring,and the evaporating capacity decreased the most in May.The influence factors of evaporating capacity were sunshine,temperature,relative humidity,among which evaporating capacity showed positive correlation with wind speed,and negative correlation with sunshine,temperature and relative humidity.The constant decreasing wind speed and increasing relative humidity year by year were the important reasons for the declining evaporating capacity in this region.The increasing tendency of temperature and drought index analysis alsohowed a warm-wet trend signal in Dabancheng region.