紫色土坡耕地埂坎裂隙发育对土壤入渗的影响  

Water seepage in soil bunds under different crack development degrees on the purple-soil sloping farmlands

作　　者：罗莹丽 韦杰[1,2] 刘春红 Luo Yingli;Wei Jie;Liu Chunhong(College of Geography and Tourism Science,Chongqing Normal University,Chongqing 401331,China;Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area,Chongqing 401331,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]三峡库区地表过程与环境遥感重庆市重点实验室,重庆401331

出　　处：《农业工程学报》2021年第21期116-123,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：重庆市杰出青年基金(cstc2019jycjjqX0025);重庆英才青年拔尖人才项目(CQYC201905009);国家自然科学基金(41471234);重庆市基础研究与前沿探索项目(cstc2018jcyjAX0489)。

摘　　要：为揭示埂坎裂隙发育程度对土壤入渗性能的影响,该研究选取了3种裂隙发育程度(重度发育、中度发育、轻度发育)的埂坎为研究对象,利用双环入渗试验揭示裂隙发育的埂坎土壤入渗规律并采用入渗模型进行模拟。结果表明:1)不同裂隙发育程度下,埂坎土壤入渗率变化趋势均为先迅速下降后逐渐趋于稳定。有裂隙埂坎各时段的入渗率均大于对照组无裂隙埂坎,但其差值均随入渗时间的增加而减小;2)随着埂坎裂隙发育程度的增加,土壤初始入渗率、平均入渗率、稳定入渗率和累积入渗量均增大,其中初始入渗率的增幅最高(98.72%);3)控制初始含水率条件下,裂隙深度和面积-周长比仍与初始入渗率、平均入渗率及120 min累积入渗量呈显著正相关(P<0.05),裂隙面密度仅与平均入渗率呈显著正相关(P<0.05);4)Kostiakov模型和Mezencev模型对不同裂隙发育程度下埂坎入渗过程拟合效果较好(R^(2)为0.84~0.99),但Kostiakov模型只有在一定时间范围条件下才能有效描述裂隙埂坎入渗过程。研究结果可为紫色土区坡耕地埂坎的建设、维护管理和合理利用及水土保持提供参考。A sloping farmland has been widely considered a major contributor to the sediment yield in Southwestern China.Numerous measures have also been launched to control soil erosion and land degradation in recent years.Among them,the soil bund has been widely adopted for the water flow regulation of soil conservation or land reconstruction in the sloping farmlands.However,the stability of the bund depends mainly on the crack seepage under the soil conservation.The objective of the present study is to reveal the features of water seepage in the soil bunds under different degrees of crack development on the purple-soil sloping farmlands.Photography and laboratory digital image processing were also carried out to determine the degrees of crack development for the bunds in the Beibei District,Chongqing of China.Three typical purple soil bunds were selected as the cases for infiltration experiments,including the heavy,medium,and slight crack developments.The double-ring and four infiltration models were applied to simulate the infiltration process,such as the Kostiakov,Mezencev,Horton,and Phillip model.The results showed that:1)The Crack Area Ratio(CAR)was applied to establish the four types of crack development degrees,including the slight(CAR≤3.5%),medium(3.5%<CAR≤6%),heavy(6%<CAR≤10%),and extremely heavy development crack(CAR>10%).2)The infiltration processes of all soil bunds dropped steeply,then decreased slowly till stable.The infiltration rate of crack development bunds was also much higher than that without cracks,where the difference also decreased with time.Correspondingly,the soil permeability was significantly improved with the enhancement of crack development degrees.However,there was an outstanding difference in the increment of initial infiltration rate,the mean infiltration rate,the stable infiltration rate,and 120 min cumulative infiltration,among the testing crack development degrees from no crack development to heavy development crack.The maximum increment occurred in the initial infiltration rate(9

关 键 词：土壤 入渗 裂隙 紫色土 土坎 

分 类 号：S152.7[农业科学—土壤学]