沙袋沙障对流动沙丘地表风沙及植被恢复的影响

为了解沙袋沙障对风沙及植被生长的影响,通过野外观测和样方调查法对铺设沙袋沙障沙丘风速、植物种数、植株密度、高度和盖度进行了调查,测定了对0—30cm输沙量。对1m×1m,2m×2m,3m×3m方格沙袋沙障防风效能、地表粗糙度、输沙特征值及植被生长情况进行了研究。结果表明,沙袋沙障能够有效地提高防风效能和增加地表粗糙度,且随着规格的增大防风效能与地表粗糙度均减小;1m×1m,2m×2m和3m×3m规格沙袋沙障地表粗糙度为5.79,2.38和2.12cm,分别比对照高91.31%,78.88%和76.26%;沙袋沙障能够有效降低输沙量,使0—30cm各层输沙率均显著小于对照,3种规格沙袋沙障对输沙率的影响顺序为:1m×1m2m×2m3m×3m;沙袋沙障铺设1a后,植物种类比对照多出一种,平均高度、密度和盖度分别比对照高91.5%,71.1%和125.4%,并且随着沙袋沙障规格的增大,植被平均高度、密度和盖度均呈现逐渐增大的趋势。

Impacts of Sandbag Barrier on Sand Flow and Vegetation Restoration on Mobile Dunes

In order to understand the sandbag barrier's influence on sand flow and vegetation, wind speed, plant species, density, height and coverage were investigated through the ways of field testing and sampling. Transported sediment samples in 0-30 cm layer were collected and windbreak efficiency, surface roughness, transport rate and vegetation in 1 m×1 m, 2 m×2 m, 3 m×3 m sandbag barriers were studied. Results showed that sandbag barrier can improve wind efficiency and increase surface roughness effectively and meanwhile, wind efficiency and surface roughness were decreased with the sandbag barrier size increasing. Sandbag barrier sizes of 1 m×1 m, 2 m×2 m, 3 m×3 m had the different surface roughness values of 5.79, 2.38 and 2.12 cm that were 91.31%, 78.88% and 76.26% higher than CK, respectively. Sandbag barrier could effectively reduce sediment discharge which made sediment transport rate in every layer of 0-30 cm smaller than that of CK significantly. Compared with sediment transport rates for the three sandbag barrier sizes, the order was:1 m×1 m> 2 m×2 m> 3 m×3 m. After sandbag barriers were laid for 1 year, plant species of sandbag barrier was one more than that of CK, and the average height, density and coverage were 91.5%, 71.1% and 125.4% higher than that of CK. The average height, density and coverage of vegetation were increased with the sandbag barrier size increasing.