荆门和桂林灌溉试验站蒸发皿蒸发变化规律及其影响因素的初步分析

以湖北荆门灌溉试验站和广西桂林灌溉试验站的蒸发皿蒸发和气象要素实测资料为例，采用线性趋势线法分析蒸发皿蒸发量的变化趋势以及气温、降雨量、风速、日照时数、日较差和相对湿度等6个气象因子的变化趋势，采用单因素相关分析和多元线性回归分析，研究了气象因子对蒸发皿蒸发的影响。分析结果表明，荆门灌溉试验站1973~2003年蒸发皿蒸发呈下降趋势，其主要影响因素是相对湿度的增大、风速的减小和日较差的减小，桂林农田灌溉试验站1980~2003年蒸发皿蒸发呈上升趋势，其主要影响因素是日较差的增大。

Recent Changes in Pan Evaporation and the Possible Climate Factors in Jingmen Irrigation and Drainage Experiment Station and Guilin Irrigation and Drainage Experiment Station

Based on the measured data during 1973~2003 in Jingmen irrigation and drainage experiment station and 1980~2003 in Guilin irrigation and drainage experiment station, the trend of pan evaporation change and influencing climate factors in recent 30 years is analyzed; and the relationship between pan evaporation and average air temperature, precipitation, average wind speed, Based on the measured data during 1973~2003 in Jingmen irrigation and drainage experiment station and 1980~2003 in Guilin irrigation and drainage experiment station, the trend of pan evaporation change and influencing climate factors in recent 30 years is analyzed using the linear tendency linear method; and the relationship between pan evaporation and average air temperature, precipitation, average wind speed, the sunlight time, average relative humidity, and diurnal temperature range are also analyzed using single factor correlation analysis and multiple regression analysis. It is obvious that the decreasing trend of pan evaporation existed in Jingmen irrigation and drainage experiment station in recent 31 years, and the influence of average relative humidity, wind speed and diurnal temperature range change were dominant. And it is found that the increase of pan evaporation in Guilin irrigation and drainage experiment station in recent 24 years was mainly caused by the diurnal temperature range change.