摘要
沙尘暴是指强风把地面大量沙尘卷入空中,使空气特别浑浊,水平能见度低于1km的灾害性天气现象。近年来,沙尘暴已成为国内外学者竟相研究的热点问题之一。在总结前人研究的基本理论基础上,通过风洞实验对不同结构类型防护林降解近地表沙降尘的基本规律及特征进行了分析研究。研究结果表明:(1)降尘量在林网内具有一定的水平分布特征,即从林缘至林网中心降尘量依次降低,同一网格内不同位置处的降尘量也随林带疏透度的变化而有所差异;(2)防护林结构对降尘量的影响较大,其中疏透度在0.24～0.34之间的防护林内降尘效果较好,在相同疏透度条件下网格状结构防护林对沙尘的降解作用大于带状结构防护林。因此,我们在设计防护林时,既要考虑疏透度,也要考虑林带结构,只有这样才能使防护林达到最佳防护效果。
Sanddust storm is a kind of calamitous weather phenomenon,which means that strong wind draws much sand and dust near the ground surface into the sky, making air very foul and with visibility lower than 1km.In recent years, sanddust storm has become one of popular problems which many researchers from all over the world try to study .In this paper,on the basic theories foundation study of summary people of the past, through wind tunnel experiment, we mainly study on the regulation and features of shelterbelt reducing sand and dust near the ground surface.In the end, the study results indicate:(1)horizontal distribution features of dustfall is that the amount of dustfall increases successively from the edge of shelterbelt to the middle part of shelterbelt, besides ,the amount of dustfall also change with the change of shelterbelt structure in different places in the same net; (2)shelterbelt structure influences the amount of dustfall greatly: the optimum degree of lighting of shelterbelt should between 0.24 and 0.34.Therefore in our future designing,we not only should consider its degree of lighting but also should consider its structure, only thus we can attain the best protection result.
出处
《水土保持学报》
CSCD
北大核心
2003年第1期162-165,共4页
Journal of Soil and Water Conservation
基金
国家自然科学基金资助项目(39960064))
关键词
乌兰布和沙漠
沙尘曝
防护林
降尘
疏透度
Ulan Buh desert
sand dust storm
shelterbelt
dustfall
degree of lighting
