Evapotranspiration covers offer a number of potential advantages over conventional covers. But they are mainly used in arid and semiarid areas. Analyses of water movement and performance of evapotranspiration covers of landfills in humid regions become interesting. Influences of design parameters such as cover thicknesses

soil types

LAI and climate factors on performance of evapotranspiration covers were investigated by using a two-dimensional saturated-unsaturated flow model. Water movement

performance and applicability of evapotranspiration covers were evaluated. The results show that final percolation decreases with an increasing cover thickness and an increasing LAI. But their influence becomes inapparent when they are relatively large. Cover soils with a large storage capability and a moderate hydraulic conductivity are most effective to minimize percolation. Seasonal distribution of precipitation has a great influence on performance of evapotranspiration covers. The performance of evapotranspiration covers can meet design requirements when most of rainfalls companying with high temperature in a humid region. Capillary covers are more efficient than monolithic covers to minimize percolation under unsaturated condition because of a capillary break caused by the differences in the unsaturated hydraulic conductivity between finer-grained layer and coarser-grained layer. However

the performance of capillary covers will dramatically reduce under bad climatic combination when capillary break fails.