Effect of Unsaturated Flow Model Conceptualization on the Dynamic Response of an Integrated Distributed Hydrological Model

Abstract

Abstract. 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.

Estimating the Change of Vegetation Coverage of the Upstream of Minjiang River by Using Remote-Sensing Images

“…The vegetation coverage is generally defined as the fraction or percentage of the vertical projection of the crown area of vegetation on the ground surface in the reference area (Ts et al 1998, Gitelson et al 2002, Guo et al 2007, Fu and Liu 2017, Fang et al 2017, Khan et al 2018. However, considering the supplementary requirements of remote sensing techniques, vegetation coverage can be defined as the green vegetation area which can be directly detected by the sensor from any view direction (Singh et al 2018, Lu et al 2017. In this study, the above definition of vegetation coverage was adopted.…”