A water balance study of water supply from a small agricultural watershed for lowland rice production at Iloilo Philippines | |
| Author | Climente, Roberto S. |
| Call Number | AIT Thesis no.AE-79-01 |
| Subject(s) | Water-supply, Agricultural Water balance (Hydrology)--Philippine Islands--Iloilo |
| Note | A thesis submitted in partial fulfillment of the requirement of the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A research project was carried out on a small rainfed watershed to quantify the water supply of the upland portion over time, and find how it affects multiple cropping potential of the lowland area served. Data were collected under farm level conditions to establish a water balance of the inflow and outflow parameters. A model was then developed to calculate the water balance components such as rainfall, evapotranspiration, surface and subsurface flows and change in storage. All the components were monitored daily except for the moisture content which was taken every six days. To account for this, water balance accounting was done on a six day basis. Since deep percolation and paddy overflow were not measured in the field, they were considered as the residual or unknown variables in the water balance equation. The area was entirely dependent on rainfall for water accumulation so it became the limiting factor to water availability in the watershed. As high as 470 mm of rainfall was observed during the month of August and this compensated the relatively low rainfall input during the months of May, July and November. The computed water balance components seems to point out that on the average, about 20 percent of rainfall is measured as surface runoff. This is bit lesser than the average subsurface outflow which was found to be 23 percent of rainfall. The balance of 57 percent is shared by change in storage, evapotranspiration, paddy overflow and deep percolation. Since the experiment was done in only one season not much conclusion can be derived from it. But with reference to the findings and information available, it is quite evident that during the wet season enough water supply is available for crop production. This available water plus the inputs introduced to the crop have led to a relatively optimum average yield of 3.5 tons/ha. |
| Year | 1979 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Apichart Anukularmphai |
| Examination Committee(s) | Olesen, Svend Elsnab ;Eggers, Helmut |
| Scholarship Donor(s) | RED |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1979 |