Application of multi-objective particle swarm optimization algorithm in quantitative-qualitative exploitation of water resources (Case study: Dez Dam and River)

Document Type : Research Paper

Authors

• saeid farokhi ¹
• Mohsen Najarchi ²
• hossein mazaheri ³
• saeid shabanlou ⁴

¹ Ph.D. Candidate, Department of Civil Engineering, Arak Branch, Islamic Azad University, Arak, Iran, Iran

² Department of Civil Engineering, Arak Branch, Islamic Azad University, Arak, Iran

³ Department of Chemical Engineering, Arak Branch, Islamic Azad University, Arak, Iran

⁴ Department of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran.

Abstract

Keywords

• Multi-objective optimization
• MOPSO
• Quantitative-qualitative model
• Dez River

Main Subjects

• منابع آب

Application of multi-objective particle swarm optimization algorithm in quantitative-qualitative exploitation of water resources (Case study: Dez Dam and River)

EXTENDED ABSTRACT

Introduction

As the most significant and essential sources of water supply for lakes and oceans, rivers also serve as the primary conduits for the movement and distribution of water in most situations for use in urban, agricultural, and industrial settings. The environmental status of the rivers is negatively and unfavorably affected by the cumulative consequences of urban, agricultural, and industrial growth. Rivers operating at their best on both a qualitative and quantitative level are thought to be ideal for managing water supplies. The Dez River's surface water resources system between the Dez regulatory dam and Bandar-e-Ghir is the focus of the current study in order to create a qualitative-quantitative model that can be used to determine the best operating strategies. In order to ensure the river's qualitative desirability at the level of international standards, the goal of this research is to develop a multi-objective particle swarm optimization algorithm that can be connected to the body of a quantitative-qualitative operation model to provide optimal solutions for the system's operation while meeting the needs of various uses, including drinking, industry, agriculture, and environmental.

Materials and Methods

In the research region, water resources are managed and planned using the WEAP model. Next, the pattern of pollution and quality in several Dez River sections is predicted using the QUAL2KW model. In order to replicate the existing operational state, a dynamic link between quantitative and qualitative models is built under the "reference scenario" such that hydraulic linkages are generated between all of the system's components in the coupled system. To replicate the quantitative and qualitative consequences of the surface water operation, this structure exchanges information and data between these two models. Then, a novel structure to extract the optimal rules for the operation of the dam and river system is built by connecting the body of the quantitative-qualitative coupled model with the multi-objective particle swarm optimization method. The monthly environmental demands of the river are one of the choice factors in the optimization scenario. The goals are to maximize the percentage of needs met and minimize quality standard violations.  

Results and discussion

The river is in a critical condition with regard to BOD pollution from the discharge of urban and industrial sewage, EC pollution from the discharge of agricultural land drains (primarily the Neyshekar project), and NH4 pollution from the discharge of urban and industrial sewage and drainage of agricultural lands, according to the recorded values of quality parameters and pollution in the quality monitoring stations and the results of the QUAL2K model implementation for the Dez River. Additionally, studies show that no particular plans have been made to regulate the amount of water withdrawal from the Dez River along its whole course in order to regulate the concentration of these and other crucial factors like temperature, PH, DO, and N-NO3. The optimization approach is used to compute the environmental discharge in various months of the year in the reference scenario, which is the optimal scenario pertaining to the inefficiency of the current water resource operation in the region. The findings demonstrate that, in the ideal situation, all of the plain's demands, regardless of priority, were met with a high degree of dependability. Additionally, the reservoir volume of the dam is higher than the minimal level of operation and has only dropped to the minimum level in five months of the whole operation history, with the exception of a drought spell (2020). This problem illustrates how the reservoir should operate in an ideal state. In many places along the river, particularly the agricultural water withdrawal sites, the minimum violation of water quality standards has happened, according to a comparison of the pollution and quality parameters in the optimization scenario and the reference scenario. The amount of pollution and quality parameters has also improved.

Conclusion

The findings show that it is possible to plan more effectively for the appropriate use of currently available water resources by taking into account all stakeholders and utilizing the qualitative-quantitative dynamic connection method of water resources to develop a coupled model using the MOPSO algorithm. This will ensure that, in addition to meeting needs, the quality and pollution of the river remain close to the standard limits during the operation period. The operators will be able to understand the repercussions of their acts, the invasion of the river's privacy, and the bad effects of their actions by employing this strategy. Water resource planners can use this model as a guide, particularly in locations with a range of contaminants and consumptions.