Optical and SAR data for application of Interim Ecological Monitoring (IEM) on Studena Dam, Bulgaria

The general idea of the study is to emphasize the necessity of Interim Ecological Monitoring application based on remote sensing tools for effective monitoring on water bodies used to supply drinking water to urban areas. The aim of the study is to identify the changes in the water surface of the “Studena dam” for a period of three years (2018-2020) and in different seasons. The investigation is made based on Sentinel 1 and Sentinel 2 (MSI optical) data for different time intervals. Orthogonalization of Sentinel 2 data has been applied. Correlation between the obtained data from Sentinel 1 and Sentinel 2 has been defined. The results have been verified by additional data generated by analyzing the inflow and outflow in watershed and alluvial outflow based on officially published information by the Ministry of Environment and Water in Bulgaria (e.g. monthly schedules for water usage from dams with great importance for Republic of Bulgaria, calculations, etc.) and the influence of climate factors (precipitation and temperature). The final results from IEM application based on remote sensing data could be applied to generate tendency for changes in dam water volume in different time periods and gives opportunity for decision-makers to undertake preventive actions or effective actions in case of a water crisis.