冀北坝上地区3种人工灌木林地防风蚀效果的比较

Comparative Study on Wind Erosion Prevention Effect of Three Artificial Shrublands in Bashang Area of Northern Hebei

选取冀北坝上地区防风固沙林为研究对象,通过观测风速、地表粗糙度、临界起沙风速、输沙量、风沙流结构等指标,对比分析3种人工灌木林地(沙棘林地、柠条林地、沙柳林地)防风蚀效果。结果表明:人工植被能够增加地表粗糙度,改变近地表风场和风沙流结构,降低风速,减少输沙量,有效防治土壤风蚀。不同人工灌木林地防风蚀效果存在较大差异。从主要观测指标来看,粗糙度和临界起沙风速为柠条林地>沙棘林地>沙柳林地;输沙量为柠条林地<沙棘林地<沙柳林地;防风效应为沙棘林地>沙柳林地>柠条林地;固沙效应为柠条林地>沙棘林地>沙柳林地。冀北坝上地区应充分发挥林木防风固沙、保持水土的特性,采用生物治沙技术与措施,合理配置人工植被开展生态建设,防治土壤风蚀,改善生态环境。

Taking the wind-break and sand-fixing forests in the Bashang area of northern Hebei as the research object, the effects of three artificial shrublands(Hippophae rhamnoides Linn. Caragana korshinskii and Salix pasmmophia) on wind erosion prevention were compared and analyzed by observing wind speed, surface roughness, critical sand-blown wind speed, sand transporting quantity and wind-sand flow structure. The results showed that artificial shrubland could increase the surface roughness, change the near-surface wind field and wind-sand flow structure, reduce the wind speed, reduce the sand transporting quantity, and consequently effectively control soil wind erosion. The effects of different artificial shrublands on wind erosion prevention were quite different. From the main observation indicators, roughness and critical sand-blown wind speed: Caragana korshinskii > Hippophae rhamnoides Linn. > Salix pasmmophia;sand transporting quantity: Caragana korshinskii < Hippophae rhamnoides Linn. < Salix pasmmophia;windbreak effect: Hippophae rhamnoides Linn. > Salix pasmmophia > Caragana korshinskii;sand fixation effect: Caragana korshinskii > Hippophae rhamnoides Linn. > Salix pasmmophia. The characteristics of windbreak, sand fixation and soil and water conservation of trees should be fully utilized. The biological desertification control technology and measures should be used for ecological construction in Bashang area of northern Hebei, and ultimately for controlling soil wind erosion and improving the ecological environment.