Modelling irrigation schedules for low-land rice irrigation with stochastic rainfall & evapotranspiration | |
| Author | Azhar, Aftab Hussain |
| Call Number | AIT Thesis no.AE-90-51 |
| Subject(s) | Rice--Irrigati Irrigation scheduling |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, and Development |
| Publisher | Asian Institute of Technology |
| Abstract | In planning the operation of major irrigatior1 systems, a reliable estimate of the expected rainfall and evapotranspiration in any week du ring t he growing season of crops i s an important design parameter. A procedure has been presented to estimate probabilistic irrigation requirements for low land rice cultivation . The procedure uses a water balance equation with random components to maintain minimum desired water levels in paddy fields at the end of each irrigation period. The procedure makes the use of Leaky-Law and /or Total Probability Theorem for estimation of weekly rainfall and Normal distribution for estimating weekly evapotranspiration , at various system operation probability levels, which are in t urn used to estimate weekly irrigation requirements through the water balance relationship . This model when applied t o Ma e Klong Irrigation Project - Thailand, gave quiets at is factory results and showed that a significant amount of water can be saved even when the system is operated at higher probability levels. Distribution s like Leaky - Law and To t al Probability Theorem an d transformations such as SMEMAX and Power were tested on weekly data series of rainy month for Tha Makka and Tha Muag rainfall stations (Kanchanaburi-Thailand). Although Power transformation in combination with Total Probability Theorem and Leaky-Law gave almost similar estimates of rainfall of higher system operation probability levels , Leaky Law w<1 s found to be most reliable for estimating the expected rainfall even at lower system operation probability levels. A study was also conducted to investigate the effect of various ponding depths on the paddy yield arid 5 cm ponding depth with ± 1 cm fluctuation was found to be t he best ponding depth from maximum yield point of view . |
| Year | 1990 |
| 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) | Murty, V.V.N ;Goto, Akira; |
| Examination Committee(s) | Nielsen, Jens Moller ;Huynh, Ngoc Phien ; |
| Scholarship Donor(s) | DAAD, (Fedra] Republic of Germany); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |