Exploring Land Cover Changes in Arak Using GIS and Remote Sensing

Land cover changes are among the most important alterations of the Earth’s land surface which affect the environment and environmental processes.
Material and

In this study, aerial photos from 1956 and 1972, Landsat TM and IRS-P6 LISS-III images obtained in 1980 and 2006 as well as the post-classification method were used to detect land cover changes and to evaluate Arak and its periphery during 1956-2006. At first, geometric correction was done to prepare aerial photos and satellite images. For this purpose, topographic maps at scales of 1:50000 and 1:25000 and nearest neighbor method and resampling method were applied. Root mean square error for all aerial photos and satellite images was less than one pixel. Afterwards, all georefrenced photos were mosaicked and land cover maps with 4 classes (urban areas, vegetated areas, barren lands, and rocks) were generated using visual interpretation of aerial photos. Following satellite images geometric correction, topographic correction was applied to images using DEM and Lambert model. In the next step, thye artificial neural networks classification method was implemented after producing false color composite images and image fusion.

Land cover maps in four classes were generated with overall accuracy of over 90%. To detect the land cover changes during 4 periods between 1956 and 2006, land cover maps of 1956, 1972, 1990 and 2006 were compared, and change maps and Tables were made. The results showed significant urban expansion, vegetated and barren lands losses and stability in rocks and mountainous areas during 1956-2006.