Seminar by Bikas Bhattarai, Doctoral Research Fellow, Dept of Geosciences.
"Impact of catchment discretization and imputed radiation on model response: a case study from central Himalayan catchment"
Abstract:
Here we examine how different catchment discretization approaches and radiation forcings influence hydrological simulation results. Three catchment discretization methods, i.e. elevation zones (Hypsograph) (HYP), regular square grid (sqGrid), and triangulated irregular networks (TIN) were evaluated in a highly steep and glacierized Marsyangdi-2 river catchment, central Himalaya, Nepal. To evaluate the impact of radiation on model response, shortwave radiation was translated using two approaches, one with the measured solar radiation assuming a horizontal surface and another with a translation to slopes. The results indicate that the catchment discretization has a great impact on simulation results. Evaluation of the simulated streamflow value using Nash-Sutcliffe efficiency (NSE) and log-transformed Nash-Sutcliffe efficiency (LnNSE) shows that highest model performance was obtained when using TIN followed by HYP (during the high flow condition) and sqGrid (during the low flow condition). Similar order of precedence in relative model performance were obtained both during the calibration and validation periods. Snow simulated from the TIN based discretized models were validated with Moderate Resolution Imaging Spectroradiometer (MODIS) snow products. Critical Success Index (CSI) between TIN based discretized model snow simulation and MODIS snow were found satisfactory. Biased in catchment average snow cover area from the models with and without using translated radiation is less than two percent, but implementation of translated radiation into Shyft gives better CSI with MODIS snow.
About the seminar:
This seminar is offered by the Section for Geography and Hydrology at the Department of Geosciences, University of Oslo. The seminar is announced as a lunch seminar so bring your lunch if you want to.
Everyone is welcome, and especially students.
The lunch seminar team.