Implementing agricultural water pricing policy in irrigation districts without a market mechanism: Comparing the conventional and automatic water distribution systems

摘要

Considering the essence of economic orientation in agricultural water management, this study proposes a practical framework for i) determining agricultural water price scenarios, ii) addressing the economic, social, and environmental effects resulting from imposing the scenarios, and iii) operating systems performance appraisal for implementing the scenarios. Accordingly, the framework constitutes interrelated components of economic, hydraulic/operational, and multicriteria decision-making models. The first component of the framework is the Positive Mathematical Programming, which intends to determine water price scenarios and assess the scenarios' inter-sectoral economic, social, and environmental impacts. The hydraulic/Operational Model, the second component, is coupled with the economic model to investigate how successful the water distribution systems' economic policy in the status quo. The third component is an operational model that provides a real-time and automatic water distribution configuration, using a centralized Model Predictive Controller. The automatic system deals with the adoption of dynamic water prices as a free-market-oriented economic policy. The last component, the multicriteria decision-making model, provides the possibility of water price scenarios ranking based on sustainability. The proposed framework was implemented in a real test case, Rudasht Irrigation district, located in Iran's arid region. The results indicate that the "economic value of water" got the first rank based on the sustainable water management criteria between the possible price scenarios. The results indicate that the status quo's water distribution system showed unreliable water distribution performance under the entire water price scenarios, based on the water distribution adequacy and equity indicators. However, reliable and fairly water distribution between the stakeholders, located upstream to the district's downstream regions, is provided by the automatic control system in the water price scenarios. The results indicate that employing the robust operating system led to -59% of water overused and -15% of the energy consumption, as the environmental benefits, in the best pricing scenario.