A Survey of Changes to Forest Covering in the Northern Slopes of Alborz - A Case Study: the Distance between Harahz and Chalos River and Chalos, Noshar, Noor and Amol Cities

Population increase and the illogical use of the natural resources of special forest cover have led to natural hazards. The study area is located in the northern Alborz in Chalos, Noshar, Noor and Amol cities and in Mazandaran Provice. In this study, we used the digital numbers from the landsat satellite TM and ETM+ data for two different dates (summer of 1988 and 2000). First of all, remote sensing images and the processing techniques were used in this study. Then, the images were analyzed using the NDVI index and Tasseled Cap transformations and, finally, the change detection process was studied. This research was analyzed using the trend of total land cover changes, thematic changes in each one and the forest cover area. The findings revealed that the forest cover area that, at the two different dates, it comprised 2719 Km² (total 5121 Km²) and the greatest changes in area had taken place between the two periods in the semi-crowded forest region. Local changes occurred in about 32 percent of the distribution of forest area. Investigations also mentioned show that there are vast changes in the spatial distribution of quantity accumulation, estimated on average at about 3.2 percent.