1 中国林业科学研究院华北林业实验中心，北京 102300；
2 国际竹藤中心，北京 100102；
3 北京林业大学水土保持学院，水土保持国家林业局重点实验室，北京 100083； 4 宁夏盐池毛乌素沙地生态系统国家定位观测研究站，宁夏 盐池 751500
收稿日期: 2019-08-23
修回日期: 2019-12-13
网络出版日期: 2020-05-25
基金资助
国家自然科学基金项目（31500586）；中央级公益性科研院所基本科研业务费专项（CAFYBB2016QB015）；国家自然科学基金项目（31270749）资助
Concave surface features and grainsize characteristics in polylactic acid sand barrier
1 Forestry experiment Center of North China,Chinese Academy of Forestry,Beijing 102300,China;
2 International Center for Bamboo and Rattan,Beijing 100102,China;
3 School of Soil and Water Conservation,Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University,Beijing 100083,China; 4 Yanchi Ecology Research Station of the Mu Us Desert,Yanchi 751500,Ningxia,China
Received date: 2019-08-23
Revised date: 2019-12-13
Online published: 2020-05-25
在乌兰布和沙漠平坦沙地布设1 m×1 m 、1.5 m×1.5 m和2 m×2 m规格的聚乳酸(PLA)沙袋格状沙障，在风季后利用插钎法和激光衍射法分别测量障格内部凹曲面形态、测定表面0~3 cm沉积物粒度组成，分析不同规格沙障内部凹曲面形态特征、蚀积效应，计算平均粒径、标准偏差等粒度参数。结果表明：3种规格PLA沙障内部均能发育成稳定凹曲面，凹曲面深度随着规格的增大而逐渐增加，蚀积系数则逐渐减小，保持在1/12~1/10之间；障格内不同方位蚀积剖面曲线基本符合二次函数，但蚀积强度差异较大；1 m×1 m和1.5 m×1.5 m规格沙障处于堆积状态，堆积强度分别是侵蚀强度的50.1倍和5.6倍，易发生沙埋；2 m×2 m 规格障内单位体积蚀积量为0.02 g·cm-3，接近蚀积平衡状态，有利于长期发挥沙障防护效益；各规格障内沉积物均以极细沙和细沙为主，除1 m×1 m规格外，PLA沙障的阻滞作用使得极细颗粒含量百分比迅速下降。综合考虑沙障铺设成本和防护效果，得出在平坦沙地或者弱风区域内适合布设2 m×2 m 规格PLA沙障，研究结果可为PLA沙障在防沙工程中的合理应用提供科学参考。
关键词： 聚乳酸（PLA）沙障; 不同规格; 凹曲面; 粒度特征; 乌兰布和沙漠
王艺钊, 原伟杰, 丁国栋, 虞毅, 高广磊, 章尧想, 王陇 . 聚乳酸（PLA）沙障凹曲面及沉积物粒度特征研究 [J]. 干旱区地理, 2020 , 43(3) : 671 -678 . DOI: 10.12118/j.issn.1000-6060.2020.03.13
The features of concave surfaces,the effect of erosion and deposition,grain size parameters of sediment (including average particle size,standard deviation,skewness,and kurtosis) were analyzed separately in three polylactic acid(PLA) sand barriers with different specifications,1 m × 1 m,1.5 m × 1.5 m,and 2 m × 2 m,which were laid on the flat sand in Ulan Buh Desert,Inner Mongolia,China.The concave surfaces and sediment grain size characteristics of the surface layer (0-3 cm) were measured using graduated sticks and laser diffraction methods after the wind season.The results showed the three kinds of PLA sand barriers could form stable concave surfaces.Along with the growth of sand barrier specification,the depth of surfaces increased while the erosiondeposition coefficient decreased in the range of 1/12-1/10.The profiles in different directions basically fitted the quadratic curve;nevertheless,the intensities of erosion-deposition varied widely.The 1 m × 1 m and 1.5 m × 1.5 m sand barriers stayed in the deposition,of which deposition intensities were respectively 50.08,5.6 times the erosion intensities.The deposition intensities were 1.1 times the erosion intensities and the erosiondeposition volume per unit was 0.02 g·cm-3 in the 2 m × 2 m sand barriers.In terms of particle size and composition,we found that the sediment was mainly composed of very fine sand,and with the exception of the 1 m × 1 m specification,the retardation effect of PLA sand barriers resulted in a rapid decrease in the content of very fine sand.The height of the PLA sand barriers was 6-8 cm.The 1 m × 1 m and 1.5 m × 1.5 m sand barriers with large deposition intensities were prone to sand burial and required additional labor costs for re-laying.The 2 m × 2 m sand barriers,blocked to erosion and deposition balance,were beneficial to perform the long-term protective effect of sand barriers.Considering the cost and protection effect of sand barriers,it was concluded that the 2 m × 2 m PLA sand barriers were suitable for flat sand or weak wind condition,and provided a scientific reference for reasonable application in sediment control engineering.
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