辽宁省蒸发量变化特征及其成因分析

ANALYSIS OF VARIATION CHARACTERISTICS AND CAUSE OF EVAPORATION IN LIAONING PROVINCE

关键词:  蒸发量时空分布变化特征影响因子辽宁省

Key words:  evaporation  spatial and temporal distribution  variation characteristics  influencing factors  Liaoning province

摘要:

［目的］为农田土壤水分监测农业水平衡研究提供依据。［方法］采用1951—2017年辽宁省各气象监测站气象资料，运用数理统计方法，研究辽宁省蒸发量气候变化特征以及蒸发量的影响因子。［结果］辽宁省蒸发量以及气候倾向率地域分布特点是自西北向东南递减； 3—8月蒸发量明显减少，是年蒸发总量减少的主要贡献时段； 9月至翌年2月呈弱增加趋势。春夏季明显减少，秋冬季变化趋势不明显。年蒸发量倾向率为-2298mm/10年，并在2002年气候突变，突变之后平均减少159mm。辽宁西北部丘陵区减少趋势最显著，气候倾向率为-3090mm/10年； 中南部平原沿海区气候倾向率为-1933mm/10年； 辽宁东部山区减少趋势不明显。平均最低气温、气温日较差、日照时数、风速等主要影响因子对蒸发量的贡献率达到858%。［结论］辽宁省蒸发量时空分布差异性明显，东部、中部、西北部3个不同气候区，各区蒸发量变化特征不同； 蒸发总量的减少，其各月变化不同； 因此，在研究农田水分平衡、水循环、水资源评价时蒸发量的时空分布尤为重要。

Abstract:

This research aims to analyze the characteristics of climate change of evaporation and its influencing factors by adopting mathematical statistics method based on the meteorological data of 14 national stations from 1951 to 2017 in Liaoning province, so as to provide basis for local water balance and cycle of agricultural. The results showed that the regional distribution of evaporation and climatic tendency in Liaoning province was decreasing from northwest to southeast. The evaporation from March to August decreased significantly, which was the main contribution period for the decrease of annual total evaporation. From September to February of the following year, the trend was weakly increasing. The evaporation decrease in spring and summer and the change of autumn and winter was not obvious. The annual evaporation trend was -22.98mm/10 years, which had an abrupt climate change in 2002 and reduced by an average of 159mm since then. From 1951 to 2017, the reducing trend of annual evaporation of northwest hilly region and the central plans and southern costal areas were 30.9mm/10 years ,19.33/10 years respectively ,while the reducing trend in eastern mountain region was not obvious. The mean minimum air temperature, sunshine duration and wind velocity contributed 85.5% to the evaporation. The spatial and temporal distribution of evaporation differs significantly in Liaoning province which can be divided into three climate zones, the east, the central and the northwest part. The decrease of total evaporation varies from region to region from month to month. Therefore, the result in this research is particularly important for regional study in farmland water balance, water circulation and water resource evaluation.