Experimental Study of Different Layers Infiltration of Soil Bunds on Purple-soil Sloping Farmlands
LI Juanjuan;WEI Jie;LI Jinlin;SHI Binglin;HONG Lan;College of Geography and Tourism Science,Chongqing Normal University;Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area;
An adjacent field was chose as a reference and soil infiltration rates of layered soil bunds(the upper,the central and the lower)were determined using double rings on the purple-soil sloping farmland.The results showed that:(1)The infiltration processes of all layered soil bunds and the field dropped steeply then decreased slowly till stable.However,there were differences on the duration to the stable infiltration.It cost a relatively longer time(110minutes)for the upper bund to the stable state.The time for the central,the lower bund and the field was 9%,82%,and 18%shorter than that of the upper bund.In perspective of infiltration performance,the soil permeability was sequenced as the initial infiltration rate,the mean infiltration rate,and then the steady infiltration rate.In view of layered soil bunds,the mean infiltration rate and the120 minutes cumulative infiltration was sorted as the upper bund,the central bund,the field,and the lower bund.The initial infiltration rate was sequenced as the central bund,the upper bund,the field,and the lower bund,while the steady infiltration rate was sorted as the field,the central bund,the upper bund,and the lower bund.(2)Four models had been used to simulate the soil bund infiltrations.Among them,the general experience model was considered as the optimum one,and it was followed by the Kostiakov model,the Horton model and the Philip model.(3)The permeability of soil bunds had close relation with soil physical properties.The initial infiltration rate was significantly negative related to the initial water content and soil bulk density(P0.05).The mean infiltration rate and the 120 minutes cumulative infiltration was significantly negative correlated with the silty particles volume and the initial water content(P0.05),and significantly positive correlated with the sandy particles volume and the total porosity(P0.05).The results of this study can provide a foundation for bunds construction as to control soil erosion on purple-soil farmlands.
【Fund】： 国家自然科学基金项目(41471234);; 重庆市基础与前沿研究计划项目(cstc2015jcyjBX0141);; 重庆市教委科技项目(KJ1500315)
【CateGory Index】： S157
【CateGory Index】： S157