Analysis of land use changes in the middle Taleghan watershed during a thirty year period

In this study, land use change in the middle Taleghan watershed has been studied and analyzed. First, the land use map of Taleghan Mian watershed was prepared during the last thirty years in four years 1987, 1998, 2008 and 2017. Landsat satellite imagery was used to prepare land use map in four years. In this research, the hybrid classification method (combination of supervized and unsupervized methods) was used and theiraccuracies were measured using Kappa and overall accuracy and acceptable results were obtained in percentages. T index was used to calculate the land use changes during the thirty years. The calculation of this index showed that, barelands had the most changes during last thirty years. In order to study more precisely, spatial patterns of land use chnges were also estimated using spatial statistics and the calculation of the share of changes in variousland use. For this purpose, location quotients was used to analyze the data. In this regard, it was calculated for the land uses which experieced the most changes in each subwatershed in 1987, 1998, 2008 and 2017.The results of the LQ showed that the rangelands area was almost constant during the period of 1987-2017. Also, the areas of irrigated and rainfed agriculture fluctuated due to emigration and imigration during this period.  Simultaneously, the area of residential land also increased significantly, due to the fact that villas and promenades were built by indigenous and non-indigenous people around the lake. Investigating the variations of the spatial pattern of different land uses also showed that the most changes occurred in the sub-watershed around the dam lake and the main river.