investigation of coastline change of the urmia lake using remote sensing and gis (1990 - 2012)

the study on water level fluctuation in the urmia lake has become of a great importance in recent years. this is due to the importance of the position of this lake as a natural heritage at an international level. the water level decrease at the urmia lake during the recent years has made it necessary to address the matter more than before. investigation and assessment of changes in the lake is necessary because it is the largest international wetland and one of the iranian national parks. the main purpose of the current study was to investigate changes in the lake water levels using satellite imagery and gis technique, preparing and processing multispectral landsat images in 1990, 1998, 2006 and 2011, classifying the images and extract the land use map for these four time periods. results of this study indicated that the urmia lake has faced significant decrease in water level during the past twenty years, especially in the past decade. also, the surface area of the lake decreased by 3052 km 2 and the salt area increased from 1990 to 2011. the present study indicate the incidence and development of environmental crisis in the region. hence, it is essential to take into account the entire social, economic, and environmental considerations as well as all the macro-environmental issues at a regional scale to save the urmia lake.