风沙土开垦中的风蚀研究

STUDY ON WIND EROSION OF AEOLIAN SAND SOIL UNDER RECLAMATION

针对以往对土壤风蚀与土地开垦的关系缺乏定量研究，本文以野外实地采集的风沙土样为实验材料，对土地开垦过程中影响风蚀的两个主要因素──地表破坏与植被破坏分别进行风洞实验，结果表明，土壤风蚀率随地表破坏率的增大呈二次幂函数增加；随植被盖度的减少呈指数增加。综合地表破坏及植被盖度对土壤风蚀的影响，最后得出，土壤风蚀率随土地开垦率的增大呈指数增加。在此基础上提出了风沙土开垦中，有效地防止土壤风蚀需要掌握的临界开垦指数以及风沙土开垦所必备的条件。

By a wind tunnel experiment with an aeolian sand soil sample collected from a field, a study was carried out to ascertain the wind erosion characteristics of the soil under reclamation. Two factors influencing soil wind erosion, surfaee destruction and vegetation coverage were studied. After a seies of laboratory work, the quantitative relationships between wind erosion rate and surfaee destruction rate and between wind erosion rate and vegetation coverage percentage were established. It was found that the former relationship complied approkimately with a second power funtion, while the latter could be expressed by an exponential funtion. By means of computerized simulation the correlation between wind erosion rate and land reclamation rate was found to follow an exponential fimtion. Furthurmore, some surface destruction, vegetation coverage and land reclamation thresholds are suggsted to prevent aeolian sand soils from wnd erosion, and some required soil conditions and measures of aeolian sand soils to be reclaimed for wind erosion control are pointed out in the present article.