Evaluation of global precipitation products for hydro-meteorological applicants in data-sparse region : a case study of Narayani River Basin, Nepal | |
| Author | Kumar, Sonu |
| Call Number | AIT Thesis no.WM-21-12 |
| Subject(s) | Precipitation (Meteorology) Hydrometeorological services--Case studies Hydrology--Mathematics Water-supply--Nepal--Narayani River Basin |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Hydro-meteorological and natural disaster studies such as hydropower generation, irrigation, domestic water supply, droughts, and floods in the Narayani River Basin (NRB), Nepal are still challenged mainly due to lack of accurate precipitation, sparse and irregular distribution of rain gauges. Furthermore, the performance of global precipitation products (GPPs), which could be alternative sources of gauge-based observed rainfall, is also uncertain across the Himalayan terrain. Therefore, this study was conducted to assess and identify the suitability of GPPs for Hydro-meteorological applications in the NRB. Firstly, twelve advanced and latest version GPPs were evaluated against observed rainfall based on the categorical and continuous variable performance matrixes. Secondly, the performance of GPPs was analyzed at various elevations, and all GPPs were also ranked for each sub-basin of the NRB using the compromise programming. In the last part of the study, four best-ranked GPPs were chosen to evaluate based on the ability to simulate streamflow using the GR4J hydrological model. As a result, CHIRPS outperformed in capturing the spatial pattern of annual rainfall across the river basin. A considerable amount of consequence of topography on the performance of GPPs was found and reported better performance in lower elevation zone (<1000m) than higher elevations zone (>1000m) on the daily time scale. Moreover, no single GPPs outperformed among all selected GPPs based on all selected performance indicators. However, IMERG_Final surpassed all GPPs in the majority evaluating matrixes and received the first rank in the five sub-basins and the second rank in the reaming one sub-basin. Furthermore, IMERG_Late, IMERG_Final, MERRA_2, and ERA5 were chosen for evaluation against streamflow using the GR4J model. The NSE values of the calibrated model at two locations Narayan Ghat and Angsing were 0.88, & 0.84 on daily and 0.94 & 0.92 on monthly time scales, respectively. The simulated discharge using GR4J forced with IMERG_Final captured the pattern of observed streamflow at each location at both time scales. To sum up, IMERG_Final can be used as an alternative to gauge rainfall in the NRB, Nepal. |
| Year | 2021 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Babel, Mukand S. |
| Examination Committee(s) | Shrestha, Sangam;Shanmugam, Mohana Sundaram;Agarwal, Anshul |
| Scholarship Donor(s) | Thai Pipe Scholarship;Asian Institute of Technology Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2021 |