JWSS - Journal of Water and Soil Science

At the river catchments, different strategies at the whole or different parts of the basin can be applied for water resources management. One of these strategies is optimal water allocation and crop pattern. In this study, an optimization model for water allocation and cropping pattern is presented based on the cooperative game theory. To measure the performance of the developed model, the cultivated area of Ordibehesht Canal in the Doroodzan irrigation network has been studied. First, using a fuzzy model and considering the fuzzy coefficients values in the objective function and constraints, the optimal crop pattern and allocated water has been determined for each crop. Second, benefits of stakeholder’s coalitions have been determined by developing a cooperative game model and based on the structure and properties of the irrigation water distribution network and water rights of each part. Then, the total net benefit has been reallocated to the different stakeholder in a rational and equitable way using Least Core games. The results show that by allocating more water to the sectors with more potential production, more profits are generated and water productivity increases. For example when players cooperate together and form the grand coalition, the net benefit increases from 8.906 billion Tomans to 9.724 billion Tomans that show an increase in the economic productivity of water.

Prioritization of sub-watersheds is very important and necessary in order to implement soil and water conservation practices. This study has prioritized 13 sub-watersheds based on morphometric and land use characteristics using RS and GIS techniques in Haraz watershed to identify erosion-prone sub-watersheds. Morphometric characteristics including bifurcation ratio, drainage density, stream frequency, drainage texture, form factor, basin circularity, compactness coefficient, elongation ratio, length of overland flow, shape index, and basin relief were considered in morphometric analysis. Land use map was classified into seven classes of forest, water-body, irrigated farming, bare land, rangeland, orchard and residential area. Finally, sub-watersheds were classified into four categories as very high, high, medium and low in terms of priority for soil conservation. On the basis of morphometric analysis sub-watershed WS-4 was considered as high priority, whereas according to land use analysis, sub-watersheds WS-6, WS-8, WS-12 were in class of high priority. Sub-watershed WS-4 was categorized as a very high priority class based on the integration of morphometric and land use analysis. This region was identified as critical region therefore should be considered as priority class for implementation of soil and water conservation practices.