Analysis on Interactions Among Atmosphere, Surface and Ground Water using EARTH Model in the Unsaturated Zone

Water flow in the unsaturated zone is predominantly vertical, and can generally be simulated as one-dimensional flow. Five sites (boreholes) under different landuse were selected to conduct the soil water flow modelling. The selection of the sites was based on the presence and representativeness of the dominant natural vegetation covers and the availability of long record groundwater level measurements. The main objective of this paper is to take into account the spatial variation of vegetation and by doing so to assess the influence of each vegetation type on the groundwater recharge of the area. EARTH model were applied at the five sites and the calculations with EARTH model were carried out on a daily basis.The annual vertical groundwater recharges of 105.374(forest), 95.2230(heather), 95.1919(homestead), 104.1995(grain), and 96.1977(grass) are 299 mm/a, 287 mm/a, 367 mm/a, 284 mm/a, and 312 mm/a, which accounts for 21.2%, 19.9%, 15.7%, 18.1%, and 16.4% of the total of the precipitation respectively. EARTH model simulation of the five representative zones shows that the infiltration recharge coefficient of homestead is higher (37.07% on average) than that of grass (32.06% on average), heather(29.4% on average), forest(30.7% on average),grain(29.1% on average).