Assessment of factors influencing water harvesting based on input to dam reservoirs

Reservoir dams are important structures for surface water harvesting and flood control. Before construction, various studies are carried out in multiple phases to calculate the input to their reservoirs and the volume of stored water. The non-optimal operation of a reservoir dam occurs when the volume of the inflow during operation does not match the volume of the calculated inflow. The water intake systems of dams and their volumes can be measured with different criteria and options. Using the opinions of expert experts and the realism of different technical, economic, and social conditions with different multi-criteria decision-making models in identifying factors affecting the correct inflow forecasting of water harvesting by dams is a common method in water resources management research. In this study, using different multi-criteria decision-making methods including ElectreIII, Entropy, Topsis, SAW, VIKOR, PROMETEE and Fuzzy TOPSIS, the inflow to the reservoirs of 17 dams in Kermanshah province has been investigated. This research is the first research work in the field of evaluating the inflow forecasting to the reservoirs of the dams of Kermanshah province, which, with a comprehensive approach, expresses and examines the most important factors influencing the failure to estimate the optimal inflows to the dam. According to the findings of the research, the option that has more frequency than other options is the proportionality of water allocation in each dam reservoir, in fact, the inadequacy of the amount of water allocation with the objectives of the dam reservoir studies, the time-consuming studies and implementation of the dam cause deviation from the right path. Water harvesting is done in reservoir dams, and the trustees inevitably change the goals of the plan by making interim decisions and even during implementation. Such a process without economic analysis leads to a loss of opportunities and a waste of investments.