Evaluation of the Decreasing Process of Green Space Expanse and Woodsy Cover of the Central part of Rasht County, Using TM - ETM+ Imagery

In the present research, the decreasing process of green space expanse and woodsy cover in central part of Rasht county during a period of 13 years (1368- 1381) using Landsat satellite TM5 - ETM imagery was considered. For this purpose, with applying remote sensing technology and using softwars ENVI and Geography Information System "Arc GIS", Vegetation Index "NDVI" was Provided. After applying NDVI, the produced layers of above process were converted to vector and were transferred to Arc GIS software for calculation and production of final maps. In addition to checking the changes in vegetation cover of the region during the study period, produced NDVI imageries of processing were compared with each other in ENVI environment with using change detection. The result of calculations on satellite imageries indicate quantitative and qualitative changes, so the area of dense woodsy cover of central part of Rasht county, from 123 km2 in 1368 has decreased to 33 km2 in 1381, there fore it has had considerable effects on ecosystem in this region. Furthermore, considerable decrease in central part of Rasht County can be observed.