| Author | Phetcharinthon Sriviha |
| Call Number | AIT Thesis no.WM-98-6 |
| Subject(s) | Evapotranspiration--Thailand--Remote sensing
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Water balance method is used for the quantification of available water resources
potential for planning and decision making. In computing the water balance, whether for a
large or small area, the major factor in the equation is evapotranspiration, the problems,
encountered in the estimation of evapotranspiration are many, but are often simplified by point
estimates. The advent of Geographic Information System (GIS) and Remote Sensing have
made it possible to estimate the actual evapotranspiration on single parameter only. The
present study deals with the use of GIS and RS in five river basins, in the tropical region with
the monsoon.
The spatial variation of topography and vegetation coverage are estimated using GIS
and A VHRR (Advanced Very High Resolution Radiometer) sensor of NOAA (Nation
Oceanographic Atmospheric Administrator) satellite data respectively. NDVI (Normalized
Differential Vegetative Index) of each basin for both wet and dry season was calculated from
the reflectance of electromagnetic spectrum registered from the A VHRR satellite. The
monthly variation of rainfall, runoff and ground water storage change is investigated. The
wellknown rainfall-runoff Tank model is used to calibrate the hydrograph and to compute the
change in water storage. Putting these values in the water balance equation, monthly actual
evapotranspiration is computed. The least square method is carried out with the data set of
average NDVI in wet and dry season and actual evapotranspiration estimated from water
balance for all five basins to find out a relationship with a best fitted regression line. For
those, the logarithmic function is found more suitable for the estimation. This function is
applied to all basin to investigate the actual evapotranspiration distribution and produced
satisfactory result. |
| Year | 1999 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Kazama, So ; |
| Examination Committee(s) | Loof, Rainer ;Morishita, Hideharu; |
| Scholarship Donor(s) | The Government of Australia ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |