Numerical Analysis of Moisture Transport in Evapo-transpiration Landfill Cover with Capillary Barrier   Qing-lei Yang School of Civil and Hydraulic Engineering and the State Key Lab. of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, China e-mail: qingleiyang@yahoo.com.cn Qing Yang School of Civil and Hydraulic Engineering and the State Key Lab. of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, China Jin-li Zhang School of Civil and Hydraulic Engineering and the State Key Lab. of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, China Mao-tian Luan School of Civil and Hydraulic Engineering and the State Key Lab. of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, China
			ABSTRACT

Based on the mechanism of unsaturated seepage flow, a one-dimensional numerical model is developed to simulate moisture transport in capillary evapo-transpiration (ET) landfill covers in response to precipitation and ET. The calculated net infiltration is input into the model as boundary conditions to simulate moisture transport of a capillary ET cover on the base of precipitation and ET data of Dalian in 1976. Results of simulation are analyzed. It is readily apparent that water content near the surface is highly sensitive to climate loading, but the effect is significantly attenuated and time lagged along with increasing depth. Water content of barrier soil layer is partially saturated. It is shown that capillary ET cover (thickness:120cm) is absolutely sufficient to resist strongest precipitation of Dalian in 48 years. Parametric analysis was conducted to simulate variations in soil types, plants and precipitation intensity. This research work provides scientific evidence for building ET landfill covers. The comparison of model simulations and experimental data shows that they are reasonably agree with each other, which provides a quantitative verification of the model.

Keywords: evapo-transpiration cover system; capillary barrier; net infiltration; water content; parametric analysis

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