Prioritization of forest degradation factors in West Gilan during 24-years, using remote sensing techniques

The purpose of this study was to estimate the level of deforestation in Astara county over a 24 year period and to prioritize the effective factors on deforestation in the area. For this purpose, the forest cover map of the study area for the years 1987 and 2011 was prepared and compared using Landsat 8 satellite TM images. In this study, 100 training samples for two classes of forest and non-forest were used and the images were classified according to the maximum probability method. The physiographic factors map of slope, direction, elevation and human factors of distance from road and distance from residential areas were also obtained using digital elevation model (DEM) and related objects map. Existing maps were matched and zoning map of destruction risk of the area prepared in GIS environment and finally correlation between levels of destruction and factors affecting the destruction were taken. The results showed that the forest area of the study area decreased over the 5744 hectares during 24 years. Distance from residential areas and distance from the roads were had the most correlation with the level of destruction. The direction and altitude factors had no significant relationship with degradation but slope had a moderate effect on degradation. As a result, human factors were identified as the main causes of deforestation in the region. Therefore, the restoration and protection of forests in the region should be prioritized through the control of human-made areas.