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Disputation: Bikas Chandra Bhattarai

Doctoral candidate Bikas Chandra Bhattarai at the Department of Geosciences, Faculty of Mathematics and Natural Sciences, is defending the thesis Hydrologic model forcing over the Himalaya for the degree of Philosophiae Doctor.

Bikas Chandra Bhattarai. Photo: Private

Bikas Chandra Bhattarai. Photo: Private

The PhD defence and trial lecture are fully digital and streamed using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'. 

Trial lecture

Projected climate change impacts on the hydrology of High Mountain Asia

Conferral summary

There are critical gaps in our knowledge of the hydrology in the Himalayas. The aim of this PhD study contribute to fill this gap.
The study has been focused on estimation, analysis, and evaluation of hydrologic model response over the Himalayan region. The findings from this research can be applied locally to achieve better hydrologic prediction in the Himalayan region.

Main research findings

Popular scientific article about Bhattarai’s dissertation:

Hydrologic model forcing over the Himalaya

In the Himalayas – the mountain range in Asia, there is a high demand for hydro-meteorological datasets for the water resource management. Hydro-meteorological observations is minimal because of the adverse geographical conditions and this represent a problem. Remote sensing and climate models offer a global perspective on many atmospheric climatic variables. However, low spatial resolution and inability to measure some atmospheric properties, such as Aerosol Optical Depth (AOD) over the brighter surface limits their ability to reflect the effects on hydrologic systems. 

This map show the study area for this PhD work (marked in green colour). Credit/MAP: Bikas Chandra Bhattarai 
This map figure and illustration over the Himalayas – the mountain range in Asia, display the study area for the PhD work (marked in green colour). Credit/MAP: Bikas Chandra Bhattarai 

During this PhD study, the candidate and team developed an empirical based model to estimate the AOD for the region. The model helps to understand aerosol and its impacts on the Himalayan hydrology. Similarly, we evaluated a regional climate model and reanalysed datasets for hydrological simulations. We fond the highest-fidelity of discharge simulation when using observation combined Watch Forcing Dataset ERA Interim (WFDEI) datasets.

Our results show the successful application of global forcing datasets over the Himalayas. Finally, we demonstrated that catchment discretization has a significant impact on hydrologic simulation results. Triangular Irregular Network (TIN) based catchment discretization gives the highest model performance. Hence the selection of models with an appropriate complexity and accurate forcing data are the most required to achieve reliable hydrologic simulation over the entire Himalayan region.

Photo and other information:

Press photo: Bikas Chandra Bhattarai, portrait; 500px. Photo: Private

Other material: Figure and map over study area, credits and text as specified in the article above, size 1000px.

Published June 11, 2020 9:35 AM - Last modified Sep. 22, 2020 1:55 PM