摘要
从腾发封顶系统工作机制出发,依据Penman公式从能量角度计算潜在腾发量,然后依次分析和求解植被截留量、土面蒸发量、植被蒸腾量和地表径流量,从而求得净入渗量;并将净入渗量作为条件边界,选取典型参数建立腾发封顶的非饱和渗流模型,分析得到封顶内的水分运移规律,并对其性能进行评价。分析结果表明,蒸发蒸腾对该类型封顶中的水分运移起着决定性作用,封顶中浅部土体含水量受降雨和腾发作用影响显著,底部含水量基本不发生变化,起蓄水–释水作用的主要是植被根系发育区。在所考虑的气候条件下,植被良好、根系深度50cm、总厚度为120cm的腾发封顶系统的累积透水量很小,完全能满足设计要求,其减小降雨入渗的性能优于传统压实黏土封顶。
Based on the general principles included in the performance of an evapotranspiration cover, the plant interception, the soil evaporation, the evapotranspiration, runoff, and the net infiltration are calculated considering Penman＇s potential evapotranspiration. The calculated net infiltration is input into an unsaturated flow model as a boundary condition to simulate the moisture transport and evaluate the performance of an evapotranspiration（ET） cover. The analytical results show that evapotranspiration is crucial to the moisture transport. Water contents of soils in the upper portion are sensitive to the variation of rainfall and evapotranspiration, whereas water contents of soils in the bottom remain almost remain unchanged. The storage and release of infiltrated water happen mainly within the root depth. A 120cm thick ET cover with a good stand of plants and a root depth of 50cm can satisfy the design requirement. The ET cover has an advantage over conventional landfill covers in reducing rainfall percolation.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第A02期3367-3373,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
上海大学创新基金资助项目
上海市优秀青年教师科研专项基金资助项目
关键词
土力学
腾发封顶
水分运移
净入渗量
非饱和渗流
soil mechanics
evapotranspiration（ET） cover
moisture transport, net infiltration
unsaturated flow
