雨影区对海南岛西部土地沙漠化影响的风洞实验研究

 风洞系列实验证明，山体雨影区与垂直平板绕流后回流区的作用原理是一致的， 山体雨影区的宽度是山体高度的15 H。据实验结果分析，海南岛西部雨影区形成的原因是季风气流沿山脉迎风坡面爬升冷却，坡脚形成热低压，在背风面回流收敛形成暖高压，气流变性为焚风。海南岛中南部多道山脉的雨影区和中南半岛长山山脉雨影区叠加、交汇后，强化了海南岛西部的干热化并形成热带半干旱气候环境，始终影响着土地沙漠化发展演变。

Study of Influence of Rain Shadow Region on Sandy Desertification in West of Hainan Island based on Wind Tunnel Experiments

According to a serial of wind tunnel experiments,it can be proved that mountain rain shadow region has same effect principle as reflow region of airflow over a vertical plane plate,and it is reasonable to calculate the width of mountain rain shadow region according to 15 H of the height of the mountain in Hainan Island.The cause of the formation of rain shadow region in west of Hainan Island is that monsoon airflow cooled while climbing on windward slope and a hot low-pressure formed at the foot of the slope;and it reflows into warm high-pressure on leeward side,then the airflow turn into foehn.The rain shadow regions of four Mountains in mid-south of Hainan Island and Changshan Mountain in Indo-China Peninsula join together,and the effect of superposition intensifies xerothermic process in west of Hainan Island,results in tropical semi-arid climate and affects the development of sandy desertification whenever in geologic time,historic time or nowadays.