Assessment of the Environmental Risks of the Urmia Lake Peripheral Parts Due to the Lake's Border Fluctuations During 1985 to 2010

 
 Evaluating the effects and environmental capacities is one of the most fundamental issues for economical and social planning, urban and rural projects these days. Lake Urmia is situated between 45°10′ and 45°45′ east longitude and lies between 37° to 38°16′north latitude. Its maximum area is in the months of May and June and minimum spread occurs in September and October. The total area of the Lake Urmia's drainage basin is over than 51,876 square kilometers; its length, width and environment are estimated respectively almost 140, 20 to 50 and 500 square kilometers. At the West side of this lake there is an internal flow that rills from north to south, on its east part it rills from south to north, while in the northern coast it has east-west direction ,in the southern coast it has west-east direction and it would increase the problems of the east coast that also has maximum rollback. The research according to the type of the purpose is an applied manner and point of view `pictures of the years 1985 and 2010 were utilized. In software's environment different sections were cut and in ARC GIS software environment on the Lake Urmia four levels were determined considering the state of land's staff productivity and population area. Then by using different layers of population, residential areas, height ,usage etc… and by laying layers on each other ,five appropriate maps were provided that each map was analyzed , and on the basis of it most of the cities that located in the east part of study area such as Tabriz, Azar shahr ,  Sufian , Miandoab , Marand etc… are most exposed to ones to danger and therefore the cities like Bonab where wind blows from the west they are at the highest risk because the  most peripheral parts of the lake are 30 meters lower than sea level  and  it causes  this area to be more risky. Transferring salt by wind and irrigation of the lands by farmers cause the salination of 10 million hectares of the water and dryland farms and being at the risk of more problems and therefore immigration of hundred thousand s of our compatriots during the time. So this problem added to the other environmental problems that should be taken seriously. There are two ways to decrease the danger; first, it is suggested to abandon water withdrawals from the illegal digging wells immediately and abusers should be met by justice, Secondly the share of Lake's water should be increased, otherwise according to diffusion of Mediterranean winds to west of our country not only it can cause damage to the peripheral provinces but also it can destroy Tehran