| Author | Nguyen Thi Phuong Mai |
| Call Number | AIT Thesis no.WM-05-7 |
| Subject(s) | Water transfer Vietnam Mathematical models
|
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The application of regionalization method in transferring parameters from gauged basin to ungauged basin combined with two rainfall-runoff models are studied with the main task of prediction continuous stream flow in ungauged basin. The models are NAM-MIKE 11 model and IHACRES model in rainfall-runoff modeling. NAM is abbreviated from Nedbor - Afstromning model while IHACRES stands for identification of unit hydrograph and component flows from rainfall, evaporation and stream flow data. The NAM model, which is a lumped, conceptual rainfall-runoff model, simulates overland flow, interflow and base flow as a function of the moisture content in each of four mutually interrelated storage such as snow storage, surface storage, root zone storage and groundwater storage. The other model is IHACRES that considers seven parameters through two modules. The nonlinear rainfall loss module converts rainfall to effective rainfall, which is defined to be the share of rainfall that eventually becomes stream-flow. The linear module represents the transformation of rainfall excess to stream-flow. The estimate of the IHACRES model parameters were found out by developing relationships between model parameters and watershed characteristics, while automatic calibration was used for finding first NAM model parameters. The final parameter estimation was performed by calibrating through comparison of the computed time series hydrographs with the observed data. The calibration and verification procedure included criteria with multiple objectives that measured different aspects of the hydrograph namely: (1) overall water balance, (2) overall shape of the hydrograph, (3) peak flows, and (4) low flows. The two models were applied to the upper LaNga River Basin in central Highland in Southern Vietnam. The methodology was presented to find the optimal parameters. The two models fitted well with all five years observed data from 1997-2001 with correlation coefficients ranging from 0.85 to 0.94 in NAM and El from 0.89 to 0.96 in IHACRES and the peak values were always approximately the peak observation. However, in some cases, both NAM and IHACRES gave the time to peak lagged by 1 day and the maximum discharge error of bout 20% appeared at the peak time. The near elevation method, one of four methods in Regionalization was applied to transfer optimal parameter in Upper LaNga basin to Dariam basin (ungauged basin). After that, these parameters were checked in the whole LaNga Basin and it gave the El > 0.83. The continuous stream flow in Dariam basin was predicted after adjustment parameter with the real condition. The stream flow results in two models were quite similar and hence were accepted. The performance of the two models were analyzed and discussed. In general, the two models work equally well |
| Year | 2006 |
| 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) | Tawatchai Tingsanchali |
| Examination Committee(s) | Babel, Mukand Singh ;Clemente, Roberto S.;Vilas Nitivattananon |
| Scholarship Donor(s) | AIT Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |