干旱风沙区农田防护林网空间风速与地表风蚀特征  

Spatial wind speed and surface wind erosion characteristics of farm-shelter forest network in arid sandy area

作　　者：左忠[1] 潘占兵[1] 张安东 余殿 周景玉 

机构地区：[1]宁夏农林科学院荒漠化治理研究所,银川750002 [2]四川大学生命科学学院,成都610065 [3]宁夏哈巴湖国家级自然保护区管理局,盐池县751500

出　　处：《农业工程学报》2018年第2期135-141,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：宁夏回族自治区十三五重大项目"宁夏多功能林业分区域研究与示范";2015年中央财政林业科技推广示范项目"宁夏半干旱黄土丘陵区退化生态系统恢复技术示范推广"(项目编号2015[09]);"全国退耕还林工程生态效益监测(宁夏)"项目联合资助

摘　　要：为准确了解和评价干旱风沙区在典型大风环境下农田防护林空间风速分布,以及林网内风蚀状况,分别利用三杯风速仪和诱捕法,对干旱风沙区盐池县农田防护林网空间风速与地表风蚀特征开展了林网内不同水平距离内的距地表50、200 cm高度风速分布与地表风蚀状况监测。研究表明:1)随着防护距离的逐渐增大,风蚀量呈先增加后减少的变化趋势,而风速变化规律正好相反;50和200 cm高度的风速变化规律均一致,均呈先逐渐降低后逐渐升高的变化,以12H处对风力减小作用最明显,50和200 cm高度的风速降幅分别达到了51%和46%;林带防风效益与距离呈先增加后减小趋势,以12H(12倍的防护林带树高,下同)处200 cm高度最佳,为53.65%;侵蚀模数由林带内的轻度、1H处的强度到3H、7H处的剧烈,12H处为极强度,以3H处最大,为21 944.62 t/km^2。2)沙粒粒径以73.99、87.99、104.6μm区间为主,其中82.53%~99.93%沙粒均集中在248.9μm以下,为细沙粒,而旷野对照组沙粒粒径主要集中在104.6~148μm,沙粒明显较粗。因此,干旱风沙区沙质农田防护林网在典型大风日内对风速的减缓非常有效。但由于林网内沙物质源丰富,风蚀现象依然严重,对当地沙尘暴发生影响较大。该研究对准确掌握当地林网风蚀,科学评价林网防护功能等有一定的借鉴作用。To accurately understand and evaluate the spatial distribution of wind speed and the erosion characteristics of farm-shelter forest network in a typical strong wind environment,the research on space wind speed and surface wind erosion characteristics of farmland shelterbelts in Yanchi County,Ningxia Hui Autonomous Region in arid sandy area is carried out.The spatial distribution of wind speed within 50 and 200 cm vertical space above the ground and the erosion characteristics have been studied at the different distances from the farm-shelter forest network with portable anemometer and trapping method respectively.The result shows that：With the increase of monitoring distance,the amount of wind erosion increased first and then decreased,while the wind speed changed in the opposite direction.The wind speed changes at 50 and 200 cm height are the same,which show a very regular inverted parabolic linear change of first gradually decreasing and then gradually rising.The effect of wind reduction at 12 H height（12 times shelter forest height,the same below） is the most obvious.Wind speeds decreased by 51% and 46% at 50 and 200 cm height respectively.With the increase of the distance,the wind-break potency presented the tendency of increasing at first and then decreasing.The wind-break potency was the best at the 200 cm height from 12 H,and the value was 53.65%.The amount of wind erosion was positively correlated with the distance from the farm-shelter forest network.The erosion modulus in the farm-shelter forest network was the least,and the order was 1 H 12 H 3 H and 7 H.The value at 3 H height was the biggest,21 944.62 t/km2.The sand diameters were about 73.99,87.99 and 104.6 μm,82.53%-99.93% was under 248.9 μm,and the sand was the fine sand.However,the sand diameters of the bare land were about 104.6-148 μm.These reflected that the sandy irrigated farmland was the main dust source.So configurating the farm-shelter forest network scientifically and reducing the bare soil could prevent sand disaster effectivel

关 键 词：土壤 风 侵蚀 干旱风沙区 农田防护林网 风蚀 

分 类 号：S424[农业科学—植物保护]