Assessment of urban green space fragmentation using landscape metrics (case study: district 2, Tehran city)

Land cover changes caused by human activities have severe environmental effects on natural ecosystems. The presence of green spaces in cities is necessary to maintain the environmental health of cities as well as the natural conditions of the urban ecological context. On the other hand, the presence of open and green patches is associated with their combination and distribution, and the measure of this relationship and connection is very important. In recent years, the destruction and changing the green and open spaces are one of the most important physical-spatial effects of urban development. Considering the negative effects of inappropriate usage of lands and land-use change, knowledge, and understanding of the process of changeability is necessary in assessing environmental impacts from development in order to sustainable planning and management. This study aimed to investigate the trend of landscape changes in district 2 of Tehran. Satellite images of TM and ETM+ and NP, AREA_MN, PARA-MN, CONTIG_MN, SPLIT, LPI, PLAND, MESH, SHAPE_MN and DIVISION metrics were used to prepare land cover maps and analysis of changes. In order to analyze the fragmentation, different landscape metrics at the class level were calculated using FRAGSTATS software. The analysis of landscape metrics indicates the extensive replacement of green lands by build lands. The results showed that increasing the number of patches and reducing the mean area is an important index of decomposition also, the process of decomposition and destruction of the landscape is incremental. The results show the necessity to pay attention to the land use and land cover in the region to suitable and sustainable utilization of natural resources.