Simulation and evaluation of agricultural water distribution and delivery systems with a Hybrid Bayesian network model

Abstract

Regular appraisal performance of the irrigation water distribution systems from the adequacy, equity, and sustainable operation perspectives are essential due to the significant water losses that has been led by the improper adjustments of the hydraulic structures. Appropriate operational strategies could be adapted when the irrigation district authorities have a pragmatic approach to assess the hydraulic behavior of the system. This study develops an intelligent model for i) hydraulic simulation and ii) operational performance evaluation of the agricultural water distribution systems by employing a Hybrid Bayesian Networks (HBNs). The developed model was tested on a real test case located in Iran and under the different operational scenarios. In this regard, firstly, a hydrodynamic model of the test case was developed, calibrated, and validated to simulate the hydraulic condition of the irrigation canal based on a wide range of the canal inflow variations, called operational scenarios. Then, performance assessment was conducted for the scenarios based on adequacy, equity, and efficiency of water distribution perspectives. The results were employed for the training of the HBNs model. The HBNs model configuration was selected based on the irrigation district manages expectations, where the performance indicators of "adequacy," "efficiency" and "equity" of water delivery, needs to be calculated for the canal inflow variations in different operational scenarios. Validation of the developed HBNs model reveals that Mean Absolute Percentage Error (MAPE) and Coefficient of Determination (R2) of the superior model within the entire output nodes are 17.31% and 0.96, respectively. The results indicated the ability of the HBNs Model for the "Simulation/Performance Appraisal" of any operating systems in the irrigation districts. The developed model is a useful tool for i) periodic appraisal performance of the distribution system, ii) operational personals and ditch-riders, and iii) regionalization of the district to facilitate the recurrent inspections and field visiting.