人工绿洲近缘植被对风沙活动降减作用的研究

通过野外定位监测试验,对干旱荒漠区灌草植被防风固沙、阻沙效应、风蚀和风沙沉降影响进行了研究,结果表明:灌草植被能显著增加地表粗糙度,是其具有防蚀、阻沙功能的内在机理;随着植被盖度的增加,输沙量、风(积)蚀量、沙尘沉降量均大大下降,固定沙丘、半固定沙丘随植被盖度的增加其输沙量较新垦沙地输沙量分别下降93.6%和59.8%,绝对风蚀量最大月份,固定沙地、半固定沙地绝对风蚀量仅为新垦沙地的32.6%和73.4%;沙尘沉降量的分布表现出共同的规律性,降尘均集中在4—6三个月,4月份最大,为总降尘量的1/4~1/2强,在水平和垂直梯度上各月降尘量差异显著。

Study on Vegetation Reducing Wind-sand Disaster around the Artificial Oasis

Research on the functions of vegetation for reducing wind-sand disaster through field test was conducted.The results indicate that plants can obviously increase the surface roughness of different dunes,which provides mechanism of wind-preventing and sand-controlling.With the vegetation coverage increasing,the sand transporting amount and sand erosion(accumulation) and dust drops amount significantly reduced.Based on the analysis on sand transport rate of the different dunes,we can see that the rate separately drops 93.6% in fixed dune and 59.8% in semi-fixed dune.Comparing with the newly cultivated sandy land the wind-erosion status only has 32.6% in fixed dune and 73.4% in semi-fixed dune in the month of highest wind-erosion status.There is a common regularity.The dust amount concentrates in April,May and June,and biggest in April,accounting for 1/4~1/2 of the total;the dust amount changes significantly on horizontal or vertical gradient in each month.