【作者】 袁立敏；

【导师】 高永；

【作者基本信息】 内蒙古农业大学 ， 水土保持与荒漠化防治， 2010， 硕士

【摘要】 本研究以PLA纤维灌沙形成的半隐蔽式PLA沙障为研究对象,通过测定1m×1m、2m×2m、3m×3m规格PLA沙障的风速、输沙量、障格内凹曲面形态,土壤物理性质及植被指标,并以裸露沙丘和相同规格的麦草沙障作为对比进行研究,综合分析PLA沙障的防风固沙效益,对土壤物理性质及植被恢复的影响,得到的结论如下:(1)研究风速效能降低程度及地表粗糙度得到:PLA沙障>麦草沙障>对照。PLA沙障与麦草沙障的风速廓线曲线呈现出“S”型,而对照的风速廓线曲线服从指数函数分布。3种规格相比,随着规格的增大,风速效能降低程度越小、地表粗糙度越小,并且风速廓线呈现“S”型特征变的不明显,逐渐与指数函数曲线形状接近。(2)PLA沙障在0~30cm的输沙量曲线波动较大,麦草沙障次之,并且麦草沙障输沙量总体趋势与对照的相似,随着高度的增加,输沙量呈现减小的趋势。1m×1m的PLA沙障对输沙量变化影响最大,2m×2m的次之,3m×3m的最小,而3规格麦草沙障输沙量的变化趋势基本与对照的一致。(3)PLA沙障形成的凹曲面形状比较规则,表面比较光滑,而麦草沙障凹曲面的4边均低于4个角,表面高低不平,没有PLA曲面光滑。拟合N-S和W-S曲线都符合一元二次函数,但是1m×1m规格凹曲面相关系数R2最高,2m×2m规格次之,3m×3m规格最差,并且N-S曲线的均开口较小,曲线凹曲程度较W-S大;随着规格的增大,PLA沙障与麦草沙障的障间蚀积系数均减小,但是,所有规格的障间蚀积系数值均小于1/10。更多还原

【Abstract】 The study focus on PLA sand barrier,it was fibre irrigatting sand, through testing speed of wind, sand-transporting quantity, concave surface characteristic of square grid and soil physical properties, vegetation restoration of 1m×1m,2m×2m,3m×3m specifications PLA sand barrier. Analysing effect of sand-fixed benefit, soil physical properties and vegetation by PLA sand barrier, and comparing the bare sand and the straw barrier which are the same specification as PLA sand barrier and got the following conclusions:(1)From the contrast the declare level of wind speed and the roughness of the surface performanced: PLA sand barrier>straw barrier>the control; the wind profile of the PLA sand barrier and straw barriers was "S", and the wind profile was fit for exponential distribution. Comparing to the three specifications of sand barrier, with the specification larger, the effects of wind speed reducing was worse and roughness of the surface was smaller, furthermore, shape "S" becomed not as clear as before and gradually it was more close to the shape of the wind profile of the control.(2) 0~30cm sand-transporting quantity of PLA sand barrier had great fluctuations, followed by wheat straw sand barrier and straw sand barrier overall trends were similar to the control. With the height increasing, sand-transporting quantity tends to declare. PLA sand barrier of 1m×1m had the greatest effect on sand-transporting quantity, the second was 2m×2m, 3m×3m was the minimum, however, the trends of sand-transporting quantity of 3 specifications straw barriers were nearly the same as comparison.(3)Form of square grid concave surface of PLA sand barrier was regular, and surface was smooth. The hight of the concave surface 4 sides of the straw barrier were lower than 4 corners, there were different hight on surface and was not as smooth as PLA sand barrier. Suspect that N-S and W-S curves fit quadratic function, but the coefficient R2 of the 1m×1m concave surface was the highest, followed by 2m×2m, 3m×3m was the worst, the opening of the N-S curve was small and the level of the curve concave was larger than W-S, with the size increasing, the erosion coefficient of PLA sand barrier and straw sand barrier both decrease, and all the coefficient of specifications were less than 1/10.更多还原