摘要
为进一步揭示地下水浅埋下的层状土波涌畦灌间歇入渗机制,通过试验资料分析与理论研究,建立了波涌灌间歇入渗条件下的层状土Brook-Corey和Green-Ampt(BC-GA)改进入渗模型,推导出层状土间歇入渗湿润锋面水吸力与湿润锋运移深度的函数关系,确定了含砂层内部土壤饱和导水率、进气吸力是层状土间歇入渗运移距离变化的主要影响参数。周期数增大,上层土壤饱和导水率减小,饱和含水率减小,进气吸力增大,夹砂层内部仅进气吸力随周期数增加而增大。根据BC-GA模型计算不同埋深的含砂层土壤间歇入渗特性及湿润锋运移特性,对比分析指出,周期数增加,相同含砂层埋深下的累积入渗量减小,湿润锋运移距离增大;含砂层埋深增加,相同供水周期的累积入渗量增大,湿润锋增大;供水周期达到最大时,含砂层埋深对累积入渗量和湿润锋运移距离影响减小。
In order to further reveal infiltration mechanism of intermittent infiltration of layered soil under surge irrigation, through the analysis of experimental data and theoretical research, Brook Corey and Green Ampt (BC GA) improved infiltration model of layered soil under intermittent infiltration of surge irrigation was built. Relationship between water suction and wetting depth of intermittent wetting front of layered soil was built, which showed that the suction value S f was decreased with the increase of wetting depth z f . Soil saturated hydraulic conductivity, retained moisture content, intake suction value, water conductivity coefficient, shape coefficient and depth change in the sand layer were proved to be the main influence parameters of migration distance of layered soil under intermittent infiltration. When the number of cycles was increased, the saturated hydraulic conductivity of the upper soil was decreased, saturated water moisture content was reduced and the suction was increased. Only the intake suction value in the sand layer was increased with the increase of cycle number. Calculation of intermittent infiltration characteristics and wetting front migration characteristics of sandy soil with different burial depths based on BC-GA model pointed out that the cumulative infiltration amount under the same sand layer depth was decreased and the wetting front migration distance under the same sand layer depth was increased. The cumulative infiltration volume and the wetting front was increased under the same water supply period. When the water supply period reached the maximum, the buried depth of the sand layer would reduce the cumulative infiltration amount and the wetting front migration distance. The research result could lay a scientific foundation for further development of surge irrigation technology.
作者
陈琳
费良军
傅渝亮
钟韵
CHEN Lin;FEI Liangjun;FU Yuliang;ZHONG Yun(Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi an 710048, China;State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi an 710048, China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2018年第12期314-324,共11页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51479161
51779205)
陕西省水利科技项目(2014slkj-02)
