Computational Ecology and Software, 2021, 11(1): 46-53 IAEES www.iaees.org Article Agricultural activities impacts on water resources of Masouleh river basin with WEAP model Rahil Rahimi, Leila Ooshaksaraie, Hasan Karimzadegan Department of Environmental Engineering, Lahijan Branch, Islamic Azad University, Lahijan, Iran E-mail: l.ooshaksaraie@liau.ac.ir Received 29 September 2020; Accepted 5 November 2020; Published 1 March 2021 Abstract The Masouleh river basin is in south of Iran. Different water user such as urban, rural, agriculture and industry are presented in the catchment. Municipal, rural, agricultural, industry and environmental need are going exacerbate future water resources management. The agricultural activities are related to a range of environmental factors such as conservation of the natural resources, water and biodiversity. WEAP capabilities are extensive related to water resources for municipal and agricultural sector including water conservation, ware allocation priorities, water demand and ecosystem requirements. In this study, three scenarios (Reference, Change of priority and Agriculture reuse Scenario) were selected in order to assess the impact of water demands on the water resources of the Masouleh River catchment in 2035. Scenario made in the current situation and the model enabled analyses of unmet water demand for each scenario for 25 years (from 2011 to 2035). The results of the study showed that Change of priority scenarios water supply is not insufficient to completely meet the demands of all sectors therefore, reuse scenario is the next priority. Application of Water Conservation and Demand Management practices and improvement water distribution can reduce the unmet demand. Keywords Water Evaluation and Planning System WEAP; water resources management; Masouleh river basin; agricultural activity. 1 Introduction Regarding to unsuitable local rain distribution and not its suitable time according irrigation season, water crisis is a serious problem in almost country. Certainly in a near future, many countries would encounter to lack of renewable water resources for continuation of agricultural activities and providing its necessities. Consequently, in order to counter with this crisis, water resources must be managed through the most executable and economized methods (Shamsaei, 2013). WEAP has been developed to integrate information about water supply, water demand and the costs and benefits of water management in the Upper Tana Computational Ecology and Software ISSN 2220721X URL: http://www.iaees.org/publications/journals/ces/onlineversion.asp RSS: http://www.iaees.org/publications/journals/ces/rss.xml Email: ces@iaees.org EditorinChief: WenJun Zhang Publisher: International Academy of Ecology and Environmental Sciences