Optimal Irrigation Water Allocation Using a Genetic Algorithm under Various Weather Conditions

Somayeh Sadati,Bijan Ghahraman,Mahmood Sabouhi,Mohsen Gitizadeh,Stijn Speelman

doi:10.3390/w6103068

Abstract

Growing water scarcity, due to growing populations and varying natural conditions, puts pressure on irrigation systems, which often are the main consumptive water users. Therefore, water resources management to improve the allocation of limited water supplies is essential. In this study, a non-linear programming optimization model with an integrated soil/water balance is developed to determine the optimal reservoir release policies and the optimal cropping pattern around Doroudzan Dam in the South-West of Iran. The proposed model was solved using a genetic algorithm (GA). Four weather conditions were identified by combining the probability levels of rainfall, evapotranspiration and inflow. Moreover, two irrigation strategies, full irrigation and deficit irrigation were modeled under each weather condition. The results indicate that for all weather conditions the total farm income and the total cropped area under deficit irrigation were larger than those under full irrigation. In addition, our results show that when the weather conditions and the availability of water changes the optimal area under corn and sugar beet decreases sharply. In contrast, the change in area cropped with wheat is small. It is concluded that the optimization approach has been successfully applied to Doroudzan Dam region. Thus, decision makers and water authorities can use it as an effective tool for such large and complex irrigation planning problems.

Highlights

Water scarcity is a global problem, but it is most severe in arid and semi-arid regions.Often, increasing water demands due to population growth further aggravate the problem [1].At the global level, the agricultural sector is the largest consumer of water resources
The change in area cropped with wheat is small because wheat requires less irrigation water
A non-linear programming optimization model with an integrated soil/water balance has been developed for determining an optimal reservoir release policy and the optimal cropping pattern for the Doroudzan Dam region in the Fars province (Southwest Iran)

Summary

Introduction

Water scarcity is a global problem, but it is most severe in arid and semi-arid regions.Often, increasing water demands due to population growth further aggravate the problem [1].At the global level, the agricultural sector is the largest consumer of water resources. Water scarcity is a global problem, but it is most severe in arid and semi-arid regions. Often, increasing water demands due to population growth further aggravate the problem [1]. The agricultural sector is the largest consumer of water resources. This sector is heavily impacted by water scarcity and yield reduction may result in a decline of food security worldwide [2]. Improvements in agricultural water management are needed. Optimization of irrigation systems and improvement of water resource allocations through appropriate multi-cropping patterns and irrigation scheduling are considered as crucial responses to address water scarcity [3]

Methods

Results

Conclusion