摘要
为探究残膜对紫色土土壤水分特征曲线的影响规律,设置了5组残膜量(0,90,180,360,720 kg/hm2),通过压力膜仪测定含残膜紫色土土壤水分特征曲线,并利用RETC软件结合统计分析方法确定最优模型.结果表明:残膜会降低紫色土持水性,减小容水度,降低土壤供水能力,含残膜土与纯土的含水率、容水度差异显著,在土壤水吸力400 kPa时,残膜量720 kg/hm^(2)处理(LS5)的土壤含水率为无残膜处理(LS1)的86.36%;随着残膜量增多,低吸力段(主要排大孔隙土壤水)的当量孔径体积占比增大,而高吸力段(主要排中小孔隙土壤水)的当量孔径体积占比则减小,处理LS5的大孔隙占比较处理LS1增大了近16%;模型适应度分析表明,含残膜紫色土的最优拟合模型为VGM(m,1/n),最优模型的非饱和导水率模式为Mualem模式.研究结果可为研究西南片区残膜对紫色土水、盐运移的影响提供一定的参考.
In order to explore the influence of residual plastic film on the soil-water characteristic curve of purple soil,5 sets of residual plastic film amount(0,90,180,360,720 kg/hm2)were set.The soil-water characteristic curve of purple soil with residual plastic film during dehumidification was measured by pressure film apparatus.RETC software and statistical analysis were used to determine the optimal fitting model.The results show that the residue plastic film reduces the water holding capacity,water capacity and soil water supply capacity of purple soil.There are significant differences in water content and water capacity between the treatment with residual plastic film and pure soil.When the soil water suction is 400 kPa,the soil moisture of the 720 kg/hm^(2) residual plastic film treatment(LS5)is 86.36%of the non-residual plastic film treatment(LS1).As the amount of residual plastic film increases,the proportion of equivalent pore volume in the low suction section(mainly draining soil water from large pores)increases,while the proportion of equivalent pore volume in the high suction section(mainly draining soil water from medium and small pores)decreases.Compared with LS1 treatment,the macropores of LS5 treatment increase by nearly 16%.Model fitness analysis shows that the best fitting model of the purple soil with residual plastic film is VGM(m,1/n),and the unsaturated hydraulic conductivity mode of the best model is Mualem mode.The results can provide a reference for the influe-nce of residual plastic film on the migration of purple soil,water and salt in the southwestern area.
作者
蒋文君
汪时机
李贤
李达
JIANG Wenjun;WANG Shiji;LI Xian;LI Da(College of Engineering and Technology, Southwest University, Chongqing 400715, China)
出处
《排灌机械工程学报》
CSCD
北大核心
2021年第8期844-850,共7页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(11972311)
中央高校基本科研业务费专项资金资助项目(XDJK2018AB003)。
关键词
残膜
紫色土
孔隙
土壤水分特征曲线
模型分析
residual plastic film
purple soil
porosity
soil-water characteristic curve
model analysis
