Evaluation of degradation dynamics of Zeribar wetland using multi-temporal satellite images

Information about the degradative dynamicsof Wetlands is important because these natural ecosystems provide numerous vital services for both terrestrial and aquatic systems. In addition to supplying of water, food and other materials, the supporting benefits of wetlands for people livelihoods directly and indirectly via regulation (e. g. flood mitigation, water quality regulation) and or recreational/culturalcan be substantial. Because of water use, contaminants input and land use change, the Zeribar wetland, northwest of Iran, have undergone remarkable losses and changes in its water area and structure in recent decades, with undesirable consequences for this ecosystem and the communities that depend upon it. The aim of this study was to evaluate the nature and magnitude of these changes from 1977 to 2014 using TM, MSS and ETM+ landsat images. The images were preprocessed and corrected atmospherically and geomaticaly prior to classification upon on water layers, wetland margin, agriculture lands, sparse forest, and dense forest using maximum likelihood classification, parallel piped classification, and minimum distance to means algorithms. The results of temporal processing of the data maps showed a 15% loss in water area and 21% increase in wetland margin area from 1977 to 2014, while, 44.99% loss in dense forest and versus 38% and 43% increase in sparse forest and agriculture usage, respectively, was also detected. Our findings revealed high level degradation in Zeribar wetland resulted in intensive change in its components such as plant cover and water area into eutrophication and shaping an environmental crisis during this short-term 37-year period. Therefore, it is necessary the wetland managers and decision-makers to revise their view, and to more focus on social, environmental and economical issues of the Zeribar Wetland stakeholders in their managemental framework than before.