Vegetation Change Detection of Neka River in Iran by Using RS and GIS

Land use change has transformed a vast part of the natural landscapes of the developing world for the last 50 years. Land is a fundamental factor of production, and through much of the course of human history, it has been tightly coupled with economic growth. On the other hand, bare soil has recently increased and has become one of the most important land degradation processes in the Mediterranean basins. The land use has changed rapidly within and near Neka River which is a fast growing agricultural river Basin. The land use changes in this region were analyzed based on Landsat data from 1977 to 2001. Supervised/unsupervised classication approach, coupled with RS and GIS analyses, was employed to generate the change over land use/cover maps. In order to analyze landscape fragmentation, land-use change was calculated using normalized different vegetation index( NDVI). Based on the results of the analysis, the range of NDVI has changed from the reflection of 0.9597 to 0.2876 in 1977 to the reflectin of 0.6420 to 0.187 in 2001, which indicates that an increase in bare lands led to a decrease in forest lands. The political and economic condition in Iran after 1970s, favored a sudden increase in the application of scientific methods in agriculture and forestry. The exports of timber to Romania had taken a leap forward and there was a need for the application of quick and speedy production and exploitation of natural resources. It was at this time that the introduction of tractors and the use of machines in cutting trees were introduced in Iran. Due to the mechanization there was a rapid increase in the cutting of trees and disappearance of forest and reduction of the area under forest. The change in the temperature and rainfall began to be noticed from 2000 onwards, which the temperature and rains between 1977 and 2001 has remained constant. The vegetation has taken a noticeable decline, and the bare soil has suddenly increased. Due to these changes, the incidence of floods has also increased. The flood which occurred in 1998 was one of the most destructive causing a great damage to life and property. The impact of deforestation has led to an increase of barren land and soil erosion. These impacts have affected the water permeability of the soil. The rate of percolation has diminished, leading to the gushing of water into the Neka valley causing floods. It is in this context that the present study will aim to analyze the change in the forest area for a period of 25 years. In this study, some change detection techniques, radiance/reflectance band differencing, NDVI differencing, tasseled cap (KT), change vector differencing and NDVI Rationing changes the north of Iran environment used image differencing, image rationing and normalized difference vegetation index (NDVI) differencing to detect land-use changes in a coral mining area of India and found that no significant difference existed among these methods in detecting land use change. Dhaka et al. (2002) Maximum value compositing (MVC) is the most common form of NDVI compositing used to produce NDVI time-series data sets with minimal effects from