Abstract
WEP MODEL, the physically based distributed model developed at PWRI, was applied to a watershed with mixed agriculture and urban land uses. The watershed is 166km2 in total area having a population of more than 0.12 million, and feeds two main streams flowing into a downstream lake. Paddy field is a dominant type of land use along the rivers, whereas urbanized area scatters over the watershed. Some recent modifications to WEP MODEL and parameter settings were briefly described, and the application results were verified using records of river discharge and groundwater level of the unconfined aquifer. It was found that the groundwater level in the unconfined aquifer is much more sensitive to its hydraulic conductivity than the conductivity of the river bed. The irrigation of the paddy fields plays significant role in maintaing groundwater level and river flow not only during irrigation period, but also in non-irrigated seasons.
