晋陕蒙接壤区蒸散发时空变化及对气象因子的响应

Spatio-temporal Variations of Evapotranspiration and Its Response to Meteorological Factors in the Border Region of Shanxi, Shaanxi, and Inner Mongolia

摘要:

晋陕蒙接壤区作为我国西北典型生态脆弱地区，探讨该区蒸散发（evapotranspiration, ET）时空变化特征及其对气象因子的响应机制，对该区水土保持和生态恢复具有重要意义。研究以2001—2018年ET数据为基础，利用趋势分析、相关性分析、地理探测器等方法研究晋陕蒙接壤区ET时空变化特征及其与气象因子的关系。结果表明：晋陕蒙接壤区ET的空间分布具有显著差异，受地形影响较大，表现为南部吕梁山脉和北部阴山山脉ET显著高于中部地区。时间上，受雨热同期影响，月尺度ET表现出夏、秋高，冬、春低的特点，其最大值出现在7—8月。气象因子对ET的解释力依次为降水量、水汽压、气温、风速、日照、相对湿度，以协同影响为主。降水和气温的协同影响最强，风速、日照直接作用ET较弱，主要通过影响降水和气温，间接影响ET。

Abstract:

As a typical ecologically fragile area in northwest China, the border region of Shanxi, Shaanxi, and Inner Mongolia is of great significance for soil and water conservation and ecological restoration to study the spatio-temporal variation characteristics of evapotranspiration (ET) and its response mechanism to meteorological factors in this area. In this study, we used MODIS ET data as data sources, and analyzed the spatio-temporal variation characteristics of ET and its relationship with meteorological factors by using trend analysis, correlation analysis, and the geographic detector method. The results showed that the spatial distribution of ET in the border region had significant differences, and was greatly affected by the terrain. ET in the southern Luliang Mountains and the northern Yinshan Mountains was significantly higher than that in the central region. In terms of time, affected by the coincidence of rainfall and heat, the monthly ET in the border region was high in summer and autumn, and low in winter and spring, and its maximum value occured in July-August. The explanatory power of meteorological factors on ET in the border region was in the order of precipitation, vapor pressure, temperature, wind speed, sunshine, and relative humidity, and they mainly had a synergistic effect. The synergistic effect of precipitation and temperature was the strongest, while the direct effect of wind speed and sunshine on ET was weak, mainly through affecting precipitation and temperature, and indirectly affecting ET.