Integration of GIS, remote sensing and hydrological model for runoff simulation | |
| Author | Chen, Ginn-yein |
| Call Number | AIT Thesis no.WM-95-01 |
| Subject(s) | Runoff--Simulation methods Geographic information systems |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-95-01 |
| Abstract | The main objective of this study is to evaluate the feasibility of combining a GIS based management system, remote sensing and HEC-1 hydrologic model. Traditional hydrologic analysis uses maps and ground survey as tools to acquire the basic parameter of the watershed. However, for large and/or remote watersheds, the above analysis is both costly and time-consuming. Thus, using GIS (Geographic Information System) which contains (1) computer data base concept (2) pattern recognition of remotely sensed data method and (3) computer cartography technology to establish the watershed geographic data base is able to provide both fast and accurate results on watershed hydrologic parameters. This will be much helpful in basic hydrologic studies. A selected watershed in Taiwan was used to test the efficiency of applying GIS and remote sensing to provide spatially related input for HEC-1 model. The GIS performed the tedious and time-consuming tasks of spatial averaging (such as basin area, SCS curve number, etc.) quite well. Several storms were simulated in Ruey-Fa subcatchment of Chi-Lung River basin, some of them were used for calibration and the others were used for validation. A good result which compare the computed hydrograph with observed hydrograph was obtained during the simulation. Sensitivity analysis was also done during model simulation. The effects on simulation include : (1). Discretization Effect and (2). Physical Parameter Effect. Some conclusions were drawn after sensitivity analysis : 1. Variation of time step .1t will effect the magnitude of peak. But the rising limb and falling limb are unchanged. 2. Variation of spatial size .1x has effect of shifting hydrograph curve forward, when .1x is increased. But this condition is for main channel only, but overland flow component without any effect. 3. Variation of physical parameter CN value will effect the rising limb and peak together. But the falling limb always unchanged. As CN value decreases, the rising limb will be shifted forward and the peak will decrease gradually. 4. Similar to the effect of varying .1x, the variation of physical parameter n (Manning's roughness coefficient of main channel) will shift the hydrograph curve, but it will change the magnitude of peak flow. When n value of main channel is increased the peak decreases and hydrograph curve shifts forward. The result of sensitivity analysis will be useful to improve the estimated parameter and reach a "best fit" during calibration. The method which used GIS concept in the analysis of rainfall runoff relationship shows very excellent approach to acquire watershed flood hydrograph. This will be helpful in hydrology routing, especially for large watershed. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-01 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Tawatchai Tingsanchali; |
| Examination Committee(s) | Apisit Eiumnoh;Ammentorp, H. C.; |
| Scholarship Donor(s) | Asian Institute of Technology; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1996 |