Wetland ecosystems provide many benefits that contribute to human well-being. These include water supply, water purification, climate regulation, flood regulation, coastal protection, recreational opportunities, and ecotourism. In addition, wetlands support a rich diversity of plants and animals. The livelihoods of people living on the borders of wetlands often depend partially or entirely on wetland ecosystem services. Land use/land cover patterns of a watershed are important factors that can affect water quality of adjacent aquatic systems. Therefore, monitoring water quality is a critical issue in wetland ecosystems for assessment of ecological consequences of human interference. This study focuses on the effects of land use changes on the water quality of Anzali International Wetland in Gilan province, southern coast of the Caspian Sea, which is one of the most important wetland in Iran. Industrial and agricultural development around the wetland over the past decades, and introduction of Azolla ( Azolla filiculoides ) as an invasive species into the wetland have resulted in the degrading wetland ecosystem. The main goal of this study was to examine how land use change in Anzali wetland basin in a period of twenty nine years (1985–2014) influence on the water quality indices (including BOD, COD , EC, NO 3 , P and TDS). In addition, NSFWQI, as a common water quality index was calculated and compared between census years. Principal Component Analysis (PCA) was applied to assess the relationship between land use indices and water quality parameters. The increase of urban land and Agricultural land accounted for the most obvious transformation in the study area, which had negative effect on water quality. The result of this study on the impacts of land use on the Anzali wetland ecosystem could provide guidelines not only for resource managers in restoring the aquatic ecosystem but also for policy makers in evaluating alternate land management decisions. Keywords : Anzali International wetland, Azolla ( Azolla filiculoides ), Change detection, NSFWQI index, Land use, Water quality.
