Stochastic simulation approach for analyzing the performance of irrigation water delivery systems | |
| Author | Mainuddin, Md. |
| Call Number | AIT Diss. no. WM-99-03 |
| Subject(s) | Irrigation--Management Irrigation--Simulation methods |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WM-99-03 |
| Abstract | A stochastic simulation model was developed for predicting the performance of irrigation water delivery systems and the model treats selected hydraulic and hydrologic input parameters as random variables. The methodology combines an open-channel water delivery model to simulate unsteady spatially varied flow and a Monte-Carlo simulation routine for predicting the response of the water delivery system performance to successive realizations of the stochastic hydraulic and hydrologic parameters. Three hydrologic parameters, upstream water level at the intake of the main canal, rainfall and evapotranspiration and two hydraulic parameters, canal cross-section geometry and roughness coefficient were considered in the simulation model under the condition of uncertainty. The developed stochastic simulation model was applied to the upstream 72.5 km of the main canal of the Phitsanulok Irrigation System, a large-scale irrigation system in Thailand. Both deterministic and stochastic simulations were carried out. Stochastic simulation was conducted considering many different scenarios by combining the parameters and operating conditions of the main canal. In the stochastic simulation both manual (as practiced) and . automatic control of the check structures to keep the water level at the target level at the upstream side of the structures were used. The result of the stochastic simulation was compared with that of the deterministic simulation. The sensitivity of the performance measures to each of the parameters was analyzed to determine the most sensitive parameters. Weekly rainfall and evapotranspiration were generated by Thomas-Fiering model considering three-parameter lognormal distribution. The upstream water level at the headworks was considered to be temporally variable hydrologic parameters and modeled as a periodic autoregressive (lag one) normally distributed time series. Irregular cross-section geometry was modeled by representing the cross-sectional area, hydraulic radius and top width as power functions of the flow depth. A multivariate normal lag-0 cross-correlation model was used for generating the geometric parameters along each reach of the canal. An independent normally distributed random field model was used for generation of hydraulic resistance or Manning roughness coefficient. Fifty realizations of each of the parameters were generated to use in the si~nulation model. The simulation results were evaluated based on the performance measures, which are easily understandable to the managers and farmers of the irrigation system. Water delivery performance was evaluated by adequacy, efficiency, dependability, equity, delivery performance ratio (DPR) and operation efficiency. By analyzing the performance measures of different scenarios recommendations were made to achieve the best perfoqnance of the irrigation system. The developed methodology will allow decision-makers to statistically describe the variation of the performance measures (adequacy, efficiency, dependability, equity, etc.) under alternative scenarios as affected by stochastic input parameters. The proposed methodology enables the decision-maker or manager of the irrigation system to take decisions under different adverse natural conditions. |
| Year | 2000 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WM-99-03 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Gupta, Ashim Das;Loof, Rainer; |
| Examination Committee(s) | Huynh Ngoc Phien;Trankler, Josef;Clemente, Roberto S.;Wolff, Peter; |
| Scholarship Donor(s) | Asian Institute of Technology; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2000 |