Land Use Monitoring using Satellite Imagery and Its Relationship with Drought in the Doiraj Watershed of Eilam Province

Today, there are many factors affecting watersheds, consequently changing natural ecosystems succession. The aim of this study was to investigate the effect of drought events on land use changes at Doiraj Watershed of Ilam Province from 1996 to 2015. For this purpose, Landsat satellite images were used for land use change monitoring and Standardized Precipitation Index (SPI) was applied for drought characterization. The results showed that during the two last decades, the forest and rangeland have been continuously destroyed. However, in the first period (1996-2006), land use changes and land degradation have been more intensive than the second period (2006-2015). Generally, in the past twenty years, about a quarter of the forest land and more than half of the rangeland had been destroyed or changed to become other land uses. Drought monitoring results also showed an extremely wet condition in 1996 and normal and near normal conditions for 2006 and 2015. Therefore, we can conclude that in the first period, in addition to human activities, changes in drought condition as a climatic factor could affected  land use change and land degradation.