Evaluation of evapotranspiration covers of landfills in Yangtze River delta region

Based on the mechanism of evapotranspiration(ET) covers,the plant interception,soil evaporation,ET,runoff and net infiltration are calculated considering the Penman’s potential ET.The calculated net infiltration is input into unsaturated flow models as boundary conditions to simulate the moisture transport and evaluate the performance of a monolithic cover and a capillary cover.The analytic results show that the ET is crucial to the moisture transport in ET covers.The moisture content of shallow soils is sensitive to the variation of rainfall and ET,whereas the moisture content of soils in the bottom remains almost unchanged.The storage and release of infiltrated water happen mainly within the root depth.The ET covers with a good stand of plants and a root depth of 50 cm are applicable to the Yangtze River delta region.The ET covers have advantages over conventional landfill covers in reducing rainfall percolation.