Using the historical surface water occurrence dataset by the European Commission's Joint Research Centre (JRC), we calculate seasonal water occurrence for every year from 1991 to 2020.

Using yearly seasonal water occurrence, we calculate the area of surface water for every year and season. We do this at a river basin scale and a river reach scale, to capture large/regional as well as local scale patterns.

To carry out the river reach scale analysis, we analytically create a geospatial dataset of transects across rivers. We use existing publicly available basin delineations for our river basin scale analysis.

Using yearly season-wise timeseries of surface water areas, we estimate the magnitude of annual rate of change in surface water area.