Hedging rule-based optimized reservoir operation using metaheuristic algorithms

In this study, optimal operation of a reservoir by incorporation of the hedging policy and the Bat Algorithm (BA) is investigated. The deficit in water supply by the dam is minimized as the objective function and the optimal monthly releases from the reservoir are determined and compared in three hedging-based operation rules. In the first rule, which has a single decision variable, a constant monthly release is considered for all 240 months of the operation period. In the second scenario, one fixed release is determined for each month of the year and is repeated in successive operating years which results 12 decision variables for the problem. In the third rule, all monthly releases are varied as the decision variables resulting 240 unknowns for the problem. The developed models are utilized for the Zhaveh reservoir in west of Iran. Results show that while BA is a suitable algorithm to be applied for optimal reservoir operation planning, the amount of water deficit is lower when a higher degree of freedom is defined for the operating rules

Pumping Drainage Well Layout and Optimum Capacity Design to Lower Groundwater Table in Urban Areas

High groundwater levels in urban areas pose major problems in construction and mining projects. A typical and effective solution in these situations is to dig drainage wells to lower the water table to the desired level through an appropriate pumping strategy. Although the method is efficient, the operating costs are relatively high and it is, therefore, of great importance to optimize the groundwater pumping system to save costs. In this paper, a simulation-based optimization approach is exploited to minimize the total costs through optimizing the layout and capacity of pumping wells. For this purpose, MODFLOW, the groundwater simulation software, is used to investigate aquifer behavior under pumping wells and the well-known Firefly Optimization Algorithm is exploited to find the optimal well layout and capacity. The proposed FOA-MODFLOW model is tested on the small urban ancient Grand Mosque region in Kerman City, southeast of Iran, to minimize the cost of the draining project. Experimental results indicate that the proposed cost-effective design noticeably outperforms the one proposed by the consulting engineers in terms of both the number of drilled wells and the associated pumping costs. The optimal strategy observes the constraints and demands by constructing only two wells with a total pumping rate of 5503 m3/day and a water table drawdown of more than 1.5 m provided the ground subsidence is within the allowable limit of less than 80 mm. Additionally, examination of the values obtained for the various design parameters shows that the proposed strategy is the best and its sensitivity to maximum permissible water level and pumping rates is highest as compared with other similar designs

Adaptive operation of a reservoir in climate change condition: a case study of Maroon Dam in Iran

The purpose of this research is to investigate the climate change impacts in Maroon Basin, Iran. To investigate the impacts of climate change on rainfall, temperature, and inflow in Maroon Dam, a simulation of four general circulation models (GCMs) was done in three future periods 2021–2040, 2041–2060, and 2061–2080. The results showed that the projected increased temperature would significantly reduce the runoff in the basin, despite the projected increase in rainfall. The most significant decrease of the average inflow to the Maroon Dam Reservoir in the near future of the RCP4.5 and RCP8.5 scenarios in March 24 and 26.4%, the middle future in March 25.4 and 29%, and the far future in March 27 and 30.6%, respectively, is predicted. Also, the MODSIM model simulation results showed that the Maroon Dam Reservoir would face a water resources shortage in the future to provide maximum demands. The average water supply reliability in climate change scenarios showed that the maximum water supply of 85% in the period 2021–2040 and the minimum of 80.4% in 2061–2080 would occur in the RCP4.5 and RCP8.5 scenarios, respectively. HIGHLIGHTS To plan for water resources allocation to demands in the Maroon Basin affected by climate change, a combination of SWAT and MODSIM models was used.; It was found that the RCP8.5 scenario will have the most severe water stress and the worst allocation conditions.; Add-on of a water management model to a hydrological model results in a powerful simulation tool that can serve for sustainable river basin management.