漫灌淋洗暗管排水协同改良滨海盐土水盐时空变化特征  

Spatial-temporal variation characteristics of water-salt movement in coastal saline soil improved by flooding and subsurface drainage

作　　者：张金龙[1,2] 刘明 钱红 张清 王振宇[1,2] Zhang Jinlong;Liu Ming;Qian Hong;Zhang Qing;Wang Zhenyu(Tianjin Engineering Center of Saline-alkali Soil Eco-landscaping,Tianjin 300457,China;Tianjin TEDA Greening Group Limited Company,Tianjin 300457,China)

机构地区：[1]天津市盐碱地生态绿化工程中心,天津300457 [2]天津泰达绿化集团有限公司,天津300457

出　　处：《农业工程学报》2018年第6期98-103,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：天津市应用基础与前沿技术研究计划(15JCYBJC23400);天津市科技支撑重点项目(17YFZCSF01200)

摘　　要：为揭示暗管排水下漫灌淋洗土壤水盐运移规律,改进灌排工程技术,提高灌排改良效果,该文应用Vedernikov入渗方程和Van der Molen淋洗脱盐方程,对滨海盐土灌排改良过程土壤水分入渗、淋洗水量分配、盐分时空变化特征等进行了模拟研究。结果表明,间距分别为3、6、9 m的暗管排水控制区域(0~1.5、0~3、0~4.5 m)田面漫灌稳定入渗强度分别在3.14~4.26、1.19~3.68和0.58~3.55 cm/d之间,排水暗管间距越大的田面土壤入渗强度空间变化也越大。暗管排水下田面漫灌入渗强度的空间变化导致淋洗水量空间分配不均,距暗管越近的区域分配的淋洗水量越多,也导致了土壤淋洗脱盐空间差异明显。漫灌淋洗20 d,间距9 m的暗管排水控制区域(0~4.5 m)仅靠近暗管0~0.6 m宽的区段0~60 cm土层土壤含盐量下降到3.00 g/kg以下,该区段(达到改良目标)仅占暗管排水控制区域面积的13.3%;漫灌淋洗40 d,仅靠近暗管0~1.6 m宽的区段0~60 cm土层土壤含盐量下降到3.00 g/kg以下,该区段(达到改良目标)仅占暗管排水控制区域面积的35.5%;为了使暗管排水控制区域0~60 cm土层土壤含盐量都下降到3.00 g/kg以下,需要漫灌淋洗100 d。完全一致地漫灌淋洗整个区域将导致暗管附近区域土壤过度淋洗,浪费水资源;而距暗管较远区域土壤淋洗不充分,降低淋洗效率。Flooding the field and leaching salts from the soil through a subsurface drainage is a typical method for reclaiming saline soil.However,water-salt movement is non-uniform in the drained region under flooding,which affects leaching efficiency.In the paper,the spatial-temporal variations of water-salt movement in coastal saline soil under flooding with subsurface drainage were simulated with Vedernikov infiltration equation and van der Molen leaching equation.The subsurface drainage systems for a drainpipe depth(1.2 m)and various spacing(3,6 and 9 m)were laid in 3 simulated field trial plots respectively,and leaching water volumes were the same in the trial plots.Furthermore,it was assumed that the soil was homogeneous and isotropic,and the flooding head was negligible in the simulation study.The results showed that,the stable infiltration rate in the regions with 3,6 and 9 m spacing varied between 3.14-4.26,1.19-3.68 and 0.58-3.55 cm/d respectively,and soil water moved more quickly in areas near the drainpipes than in the midway between drainpipes,and the greater the drainpipe spacing,the more obvious the spatial variation of the infiltration rate in the drained region.In several zones between drainpipes,the spatial variation of infiltration rate was obviously different too,and was apparently greater in the zone near the drainpipe.The spatial distribution of leaching water volume was extremely uneven in the drained region,and the more water was allocated for the area closer to the drainpipes.Comparison between 3 subsurface drainage systems showed that,the greater the spacing of the drainpipes,the more the flooding water that was allocated above the lines of the drainpipes,and the amount of water allocated above the lines of the drainpipes with 9 m spacing was 1.39 and 2.00 times that above the lines of the drainpipes with 6 and 3 m spacing respectively.The apparent spatial difference of infiltration rate resulted in spatial uneven distribution of flooding water in the drained region,and accordingly the changes of

关 键 词：暗管排水 盐分 土壤 滨海盐土 漫灌 淋洗 水盐运移 模拟 

分 类 号：S276[农业科学—农业水土工程]