1964-2017年山西省潜在蒸发量时空变化及其影响因素分析

Spatial and Temporal Variation Characteristics of Potential Evapotranspiration and Its Impact Factors of Shanxi Province During the Period 1964-2017

采用Penman-Monteith模型计算出山西省潜在蒸发量,运用小波分析、Mann-Kendall非参数检验和地统计等方法分析了山西省潜在蒸发量的时空分布特征,并且利用主成分分析法分析了其影响因素。结果表明:(1)山西省多年平均潜在蒸发量为1 148.6 mm,存在以27 a为主周期和9 a,45 a左右为次周期的周期变化;(2)山西省多年平均潜在蒸发量空间分布特征表现为由中部向南北两边递减,北部地区潜在蒸发量低于南部地区,地势低的地方潜在蒸发量较高;(3)山西省潜在蒸发量西北部和东南部呈现下降趋势,东北部及西南部呈增加趋势,东北部增加趋势尤为显著;(4)平均水气压和相对湿度是影响山西省潜在蒸发量的主导因素,潜在蒸发量与平均水气压、相对湿度和海拔高度呈负相关,与温度、风速、日照时数及纬度呈正相关。

The potential evapotranspiration capacity represents the maximum evaporation capacity of a region and is an important component of the heat balance of the Earth′s surface,providing a reference for regional water resources management.We analyzed spatial and temporal variation characteristics of potential evapotranspiration in Shanxi Province with daily observed data of 17 meteorological stations from 1964 to 2017 based on Penman-Monteith model,Wavelet Analysis,Mann-Kendall and ArcGIS interpolation method.And its influencing factors were analyzed by using the principal component analysis.The results showed that the average potential evapotranspiration in Shanxi Province was 1 148.6 mm and presented the fluctuation growth trend;the main period was 27-year while the minor periods was 9-year and 45-year.The spatial variation of the multi-year average potential evapotranspiration in the Shanxi Province showed that the central region was decreasing to the north and south,the northern region had lower potential evapotranspiration than the southern region,and the low-lying region had higher potential evapotranspiration.The potential evapotranspiration of Shanxi Province showed a downward trend in northwest and southeast,while it showed an increasing trend in the northeast and southwest,especially significant in the northeast.The average water vapor pressure and relative humidity are the main factors affecting the potential evapotranspiration of Shanxi Province.Mean annual potential evapotranspiration is positively correlated to the mean temperature,wind speed,sunshine hours and latitude,and negatively correlated with relative humidity,water vapor pressure and altitude.