LAUSR

Water dynamics in the unsaturated zone is one of the most important processes as it controls model precision. One of the limitations in using a catchment model based on a Richards’ equation is the huge amount of parameters required to run the model. In this study, we investigate the effect of unsaturated flow conceptualization models on the dynamic response of an integrated distributed hydrological model, which are (1) Richards equation (simple parameterization RI2) (2) Two layer water balance model (TLM). The physically based distributed modelling system, MIKESHE is applied to the Skjern catchment with the objective to test and analyze the effect of using different models for unsaturated flow on the dynamic response of an integrated distributed hydrological model. Results from this study show that regarding peak discharge at the catchment outlet follows the TLM, RI2 sequence. Similar results were found for the discharge characteristics of the sub basin. The close agreement between the simulated results of the two models also indicates that the simple TLM model is more suitable than the complex Richard equation model at least for the condition of the Skjern catchment, while its weaknesses is not describing the groundwater dynamics well.