Change Detection of Green Space in Tehran City (Zone 2) Using Aerial Photographs and Satellite Data

Green space is a significant particle in large cities. Taking into account high-performance of urban green space ,management of this resources is required. In order to manage these resources properly, their change detection trends is the first priority. therefore, this article tries to survey the first data and the last data during 30 years, estimating changes rate influenced on green space in the study area. In this survey after geometric preprocessing on 1:10000 aerial photographs which is related to 1980, a mosaic was taken from images and visual interpretation was done on created Ortho-photo-mosaic and green space layer was extracted from the mentioned year. Satellite images (IRS-P6)which is related to 2007 was taken and were corrected with 1 pixels accuracy, as well. Then visual interpretation was done on corrected images and the area of green space were estimated in recent years. At the end of the study, changes rate were valued according to overlaying of layers. In order to determine urban extending rate during 1980 to 2007;Greenspace average rate and urban land use changes was evaluated from beginning the end of study period The results showed that area and Green space average of region has been increased. In order to assess of aerial photographs accuracy in quantitative characteristics of green spaces such as ;crown diameter, altitude and exploitable diameter, forest inventory was carried out and mentioned parameters on latest aerial photos was measured and correlations of measured matters were analyzed .The results of measuring quantitative characteristics of trees on photos and earth stated that there is close relation between these factors in transects trees and distributed trees (isolated tree) however, this accuracy is not acceptable in forest stand.