چكيده به لاتين
Helleh river basin is one of the southern basins of Iran, which has an arid and semi-arid climate. In recent years, due to water shortage and low water quality (salinity) in Helleh, some challenges have arisen in the management of water resources and there have been major dam construction and development projects. In this study, using the combination of soil moisture module in WEAP software for water moisture balance simulation and water allocation with salt balance module (Python External Environment), a hydrological simulation model is presented and by linking this model with the PSO optimization algorithm a quantitative-qualitative calibration model is developed and used to estimate the simulation model parameters; Then by combining this hydrologic model with an agronomic and economic modulus, and finally by a PSO optimization algorithm, two hydro-economic simulation-optimization models for the evaluation of non-structural and operation plans in short-term and a long-term horizons for exploring and optimizing the structural and development projects are developed due to the plurality of considered infrastructure and development measures for Helleh river basin. Firstly, using the developed long-term hydro-economic optimization model, these measures are optimized, in which the dam construction projects including Chorom dam, Dalaki dam and Nargesi dam, with optimum reservoir volume, respectively, equal to 43.5, 305.5 and 76.8 million cubic meters, and land development of about 1511 hectares for the Nargesi left bank with 48 percent Surface irrigation technology and 52 percent Sprinkler technology, 3604 hectares for Nargesi right bank with 50 percent Surface technology and 50 percent Sprinkler technology, 195 hectares for development in downstream of Chorom dam, 1168 hectares of Dashtgoor with Tape irrigation technology, 179 hectares of Siahmansour’s Palm dates with 48 percent Surface irrigation technology and 52 percent Tape techonlogy, 2699 hectares of Siahmansour’s agricultural lands with 25 percent of surface irrigation technology and 75 percent of Tape technology and 589 hectares of Shabankareh with Surface irrigation technology for downstream of Raeisali dam as an optimum combination of development measures are selected in this model. Subsequently, the net agricultural profits of the basin and the net profits of the whole basin, with taking into account construction and operation costs, respectively, increase by about 36 percent and 18 percent compared to the current status. Finally, considering the obtained results and the optimal combination of long-term infrastructure and structural designs, the implementation of this combination is divided into four stages, including zero stage, without the implementation of structural projects, first stage, the construction of the Dalaki dam and the completion of the irrigation districts on Raeisali dam’s downstream, Second stage, the construction of the Nargesi dam and its downstream irrigation districts following the first stage and the third stage, the implementation of the entire projects, including the construction of the Chorom dam and its downstream districts. In each of these stages, using a hydro-economic simulation-optimization model in short term horizon at two different 5 years hydrological periods (normal and severe drought), operational measures including optimal crop patterns, irrigation strategies and optimal leaching strategies and operation priority of dams (optimal operation) are optimized. The results of the short-term model indicate that the cultivated area of cereals (wheat) and vegetables (tomato) under drought periods in each stage increased due to their economic efficiencies and the irrigation strategies in this period as well as the normal has led to deficit irrigation strategy, especially for products with lower economic efficiency. Also, by applying an optimal leaching strategy interacting with optimal irrigation strategy in both periods, increasing salinity in the root zone of the plants is also controlled.
Key words: Helleh river basin, Hydro-economic model, Development measures optimization, Crop pattern, Irrigation strategy, WEAP, Leaching, Soil Moisture Module, Simulation-Optimization, PSO.
