PLA沙障对沙丘土壤粒径的影响分析

Analysis on Impact of PLA Barrier on Soil Particle sizes of Sand Dunes

PLA可降解纤维是一种新型的固沙材料,用它灌沙形成的筒状沙袋铺设于沙丘上,可有效改变近地表风沙流结构及地表粗糙度等。PLA沙袋沙障通过对地表风速影响,进而影响沙丘表层土壤粒径的重新分布。本次试验通过对不同铺设规格沙障沙丘0—11cm深土壤粒径的测定,分析不同铺设规格和坡位等对土壤粒径的影响。结果表明:2m×2m铺设规格沙障对土壤粒径影响较大,土壤平均粒径比未铺设沙障沙丘的大16%,1m×1m规格影响最小;同种规格沙障在坡顶处土壤粒径变化最大,比未铺设沙障沙丘的大21%,迎风坡、背风坡分别比对照大3.9%,2.4%;土壤深度不同,粒径变化也不同,地表0—1cm土壤粒径变化最大,比未铺设沙障沙丘的大16%。因此可知,沙障铺设后,使得沙丘表层的土壤粒径增大。

Biodegradable PLA fiber is a new type of fixing material.The tubular shapes of sandbags made of PLA are filling with sands,and are piled up on the sand dunes,which can effectively change the near-surface wind flow structure and roughness.Based on the impact to surface wind speed,PLA sandbag barriers can also impact the redistribution of soil particle sizes on the surface dunes.Through the measure of soil particle sizes in 0—11cm in different specification sand barriers,this article discussed the impact of different specifications and different slope positions to soil particle sizes.The results showed that:specifications(2m×2m)of laid sand barrier has the greater impact on soil particle size,and soil particle sizes on average are 16%bigger than that of sand dunes without laid sand barriers.Instead,specification(1m×1m)showed minimum impact.Soil particle size in the same specification showed the most obvious change on the top position.They are 21%bigger than those of sand dunes without laid sand barriers.The soil particle sizes on windward slope of the leeward slope were 3.9%and 2.4%larger compared to the control;soil particle size changes with the different soil depth.Soil particle size of 0—1cm depth changes most obviously,which is 16% bigger than that of sand dunes without sand barriers.Therefore,It can be seen that the sand particle size of dunes surface increases after the laying of sand barrier.