Farhad Nouri Najafi; Hadi Veisi; Reza Mirzaee
Volume 16, Issue 1 , April 2018, , Pages 207-224
Abstract
Introduction: Recently, land use change is one of the main possible causes in losing biodiversity and ecosystem services. Dams as main human-made structures in order to save surface water play an important role in this regards. Due to the rapid increasing of dam construction over last 40 years in Iran, ...
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Introduction: Recently, land use change is one of the main possible causes in losing biodiversity and ecosystem services. Dams as main human-made structures in order to save surface water play an important role in this regards. Due to the rapid increasing of dam construction over last 40 years in Iran, the contradiction between dam productivity and the loss of ecosystem services has become an issue of increasing concern. The aim of this study was to investigate the effect of Sahand Dam construction on land use, land use changes and ecosystem services. Materials and methods: In this study three Landsat satellite images were used to track land use changes over a period of 28 years (1989, 2006 and 2017). First, these images were used for geometric, atmospheric and topographic correction. The maximum possibility of different land uses and cover were determined using supervised classification method and their accuracy checked again by field inspection. The user authenticity and Kappa coefficient calculated and resulted in value of 63 and 79 percent respectively. The value of ecosystem services and changes in land uses carried out using aerial photographs and satellite imagery between 1989 and 2017 throughout 49400 ha of areas around Sahand dam in East Azarbaijan province. Results and discussion: Results showed that the total area for rangeland decreased significantly between years 1989 and 2017 while there has been a noticeable increasing in cropping land. In general, the share of area under rangeland decreased by 56% over period 1989-2017. The total area for rainfed and irrigated cropping areas increased by 38 and 32 percent respectively indicating significant changes in this area. In regards to ecosystem services value, land uses changes from rangeland to crop land led to a 35900000 dollars annually loss in ecosystem services value (10.6 $ per hectare per year). Conclusions: To conclude, although dam construction and shifting from natural land toward crop land may be profitable but due to depletion of the ecosystem capacities to deliver ecosystem services, long-term losses may exceed short-term gains. Land use and policy making should aim at balancing society needs and preferences, while considering long-term negative effects of dams and ecosystem service losses. Therefore, providing a land management roadmap for future economic development programs is receiving a great priority. It will be beneficial if natural ecosystems are preserved and used adequately.
