Assessing the relationship between the occurrence of drought and changes in the water area of Anzali Wetland using Landsat satellite images

Climate change is one of the greatest dangers facing human beings now and in future generations. The phenomenon of climate change has caused many changes in spatial patterns of rainfall and has led to an increase in marginal phenomena such as drought. It is also predicted that climate change will affect the frequency, severity and duration of drought. Drought occurs in all climates, even in humid and semi-humid climates, so wetlands, which are one of the most important habitats on Earth, are no exception. In this study, drought events in Anzali wetland and its relationship with changes in wetland area during the statistical period 1975-2016 have been investigated. Two SPI and RDI indices have been used to study drought. Landsat satellite imagery was used to determine the blue zone. The study of drought indices in Anzali wetland shows that the values ​​obtained by RDI index estimate drought with less intensity than the values ​​obtained by SPI index. The results also showed that the water area of ​​Anzali wetland has a decreasing trend during the years under study, which is completely consistent with the increasing trend of drought in terms of frequency and severity.