To make a proper evaluation and better understanding of gas component movement inside a landfill site, investigation of the different parameters related to gas flow is important. In this study, air permeability (ka) and gas diffusivity (DP/Do; where Do is the gas diffusion coefficient in free air) were measured as a function of soil air content (D} in final cover soil at Maharagama landfill in Sri Lanka. The ka and D, were measured at different gravimetric water content in some samples and another set of samples
were treated under different pF conditions (pF= log (-'¥) where '¥ is the soil water matric potential in H2O a) and water blockage parameter (.i..) were calculated accordingly
