Water Transitions (1984-2018)

Freshwater, in sufficient quantity and quality, is essential for all aspects of life and fundamental to sustainable development. Yet water-related ecosystems are threatened by human activities (flow alteration; loss of connectivity; pollution; habitat degradation and loss; overexploitation of species). Tracking changes in water-related ecosystems enables decision makers to determine the extent of change over time, understand the threats and implement appropriate mitigation measures. The water transition map shows the total change in the annual extent of permanent and seasonal surface water area for lakes and rivers between 1984 and 2018. It includes surfaces of: permanent water (i.e. area where water is present 12 months per year), new permanent water (i.e. conversion of land into permanent water), lost permanent water (i.e. conversion of permanent water into land), seasonal water (i.e. area where water is present less than 12 months per year), new seasonal water (i.e. conversion of land to seasonal water), lost seasonal water (i.e. conversion of seasonal water to land), seasonal to permanent (i.e. conversion of seasonal water into permanent water) and permanent to seasonal (i.e. conversion of permanent water into seasonal water).