中国干旱半干旱地区土壤凝结水研究综述

An Overview on Soil Condensate in Arid and Semiarid Regions in China

中国北方干旱半干旱地区的气象条件有利于土壤凝结水的形成。从20世纪60年代以来,相继开展了一系列土壤凝结水的实验与研究。土壤凝结水特指地面温度和表层地温达到露点时,大气水汽和土壤孔隙水汽由汽态水凝结而成的液态水。近地气温、地温、相对湿度、下垫面性质、地下水埋深等因素都会影响凝结水形成的速度、深度和数量。土壤凝结水的水汽来源主要是近地表大气和包气带孔隙中的水汽。土壤凝结水是土壤水和地下水水分平衡不可忽缺的因素。土壤凝结水也是干旱半干旱地区的主要水源之一,具有重要的生态与环境意义。

The micro-meteorological conditions are advantageous for forming soil condensate in arid and semiarid regions in north China. Since the 1960＇s, some scientists have successively carried out many experiments and studies on soil condensate. Soil condensate means the liquid water condensed from air vapor and soil pore vapor on ground surface and in topsoil when surface temperature and topsoil temperature are decreased to dewpoint, and it is a component of soil water. The formation speed, depth and volume of soil condensate are closely related to many factors, such as the air temperature near ground, ground temperature, relative humidity, features of underlaying surface, and groundwater depth. Soil condensate is an important component in water equilibrium of soil water and groundwater, one of the main water sources, and of significance in conserving ecology and environment in arid and semiarid regions. Many achievements in the experiments and studies on soil condensate, including the aspects of formation mechanism, affecting factors, condensation volume, measurement methods of soil condensate, have been achieved in China. However, there are still some problems needing to be considered and resolved. In this paper, the experiments and studies on soil condensate in China are reviewed from the aspects of the factors affecting the formation of soil condensate, vapor sources, vertical distribution and volume, ecological environmental effects and measurement methods of soil condensate, etc.