Investigating the trend of water level changes in Allahabad wetland by using temporal images

Wetlands are some of the most important ecosystems on Earth. They play a key role in alleviating floods and filtering polluted water and also provide habitats for many plants and animals. Wetlands also interact with climate change. Over the past 50 years, wetlands have been polluted and declined dramatically as land cover has changed in some regions. Remote sensing has been the most useful tool to acquire spatial and temporal information about wetlands. In this paper, digital processing of satellite images was used to investigate the trend of water level changes in this wetland Therefore, for this purpose, ETM + and OLI sensor images related to 2017 and 2000 were obtained from USGS database and processed by image classification (ML) method. Image processing accuracy of both periods based on kappa coefficient was more than 70%. The results of comparing the water body of the wetland in the two periods show a significant increase in water level in the cold season in the wetland and has a significant relationship with rainfall in the region. Due to the lack of ground information related to the condition of the wetland in the first period of the field study, the method used in the present study was able to monitor the changes in the wetland with relatively appropriate accuracy.