布袋沙障对流动沙丘地表风沙和土壤湿度的影响

 为了解布袋沙障对风沙流和土壤湿度的影响，通过测定风速和采集地表0~30 cm 输沙，同时对地下0~40 cm 土壤含水率进行测试，分别研究1 m×1 m、2 m×2 m、3 m×3 m 规格布袋沙障防风效能、粗糙度、输沙量和土壤湿度差异。结果表明，布袋沙障能够有效提高0~30 cm 高度范围的防风效能，增加地表粗糙度，显著降低0~30 cm 地表输沙量和改变风沙流结构。3 种布袋沙障的防风效能顺序为1 m×1 m>2 m×2 m>3 m×3 m，1 m×1 m 与其他两种规格布袋沙障的防风效能差异显著（P<0.05），2 m×2 m 和3 m×3 m 规格布袋沙障的防风效能间无显著差异；粗糙度顺序为1 m×1 m>2 m×2 m>3 m×3 m>对照，1 m×1 m、2 m×2 m 和3 m×3 m 规格沙障粗糙度分别比对照高91.31%、78.88%和76.26%，差异极显著（p<0.001）；0~30 cm 输沙量顺序为对照>3 m×3 m>2 m×2 m>1 m×1 m，对照的0~30 cm 输沙量达到了71.43 g/（min·cm²），是布袋沙障的32.98 倍，3 种规格布袋沙障与对照沙丘2~10 cm 和0~1 cm 两层沙量的比值λ均大于1，说明在监测期内地表均处于风蚀状态。土壤含水率顺序为对照>3 m×3 m>2 m×2 m>1 m×1 m，在0~20 cm 土层此变化趋势明显，对照的土壤含水率分别比3 m×3 m、2 m×2 m、1 m×1 m 规格沙障样地的土壤含水率高55.15%、58.63%和67.45%。

Effect of Hop-pocket Sand Barrier on the Wind and Sand Flow and Soil Moisture of Mobile Dune

To understand the influence of hop-pocket sand barrier on wind and sand flow and soil moisture, the wind-break potency, surface roughness, parameters of sediment transport rates and soil moisture of 1 m×1 m, 2 m×2 m, 3 m×3 m square hop-pocket sand barrier were studied through anemometry, sand collection of ground 30 cm and soil moisture of underground 0-40 cm on sand dune. The results showed that hop-pocket sand barrier can improve the wind-break potency of 0-30 cm height range effectively, increasing the sand dune surface roughness, reducing the sediment discharge of 0-30 cm height range significantly. The order of wind-break potency of hop-pocket sand barrier was 1 m×1 m>2 m×2 m>3 m×3 m. The difference of 1 m×1 m was significant compared to 2 m× 2 m and 3 m×3 m, and there was no significant difference between 2 m×2 m and 3 m×3 m. The order of surface roughness was 1 m× 1 m>2 m×2 m>3 m×3 m>CK; the roughness of 1 m×1 m, 2 m×2 m and 3 m×3 m were increased by 91.31%, 78.88% and 76.26% higher than the control and the differences were significant (P<0.001). 0-30 cm sediment discharge of the control reached 71.43 g/(min·cm²), and it was 32.98 times more than hop-pocket sand barrier.λ eigenvalues was the sediment discharge ratio of 2-10 cm and 0-1 cm of hop-pocket sand barrier and the control, and λ >1, deducing that their surfaces were wind eroded during the monitoring period. The order of soil moisture was CK>3 m×3 m>2 m×2 m>1 m×1 m, the trend of 0-20 cm layer was obvious, and soil moisture of the control was increased by 55.10%, 58.63% and 67.45% higher than 3 m×3 m、2 m×2 m and 1 m×1 m hop-pocket sand barrier.