Water accounting
Transparent and comprehensive information of water resources is needed for sustainable integrated water resources management. Water accounting is the systematic analysis of the current status and trends in water supply, demand, distribution, accessibility and use in time and space within specified domains, producing a basis for evidence-based water policy decision-making (FAO, 2017). Water accounting outputs reveals how water is used across different sectors and help shape an understanding of the benefits and existing trade-offs of the water allocations and use patterns. The integrated and cross sectoral presentation of the information in water accounting helps the users to see the bigger picture and cross linkages in water management.
Understanding the current status of water resources systems globally requires detailed information on the source of water in space and time as well as detailed information on the utilisation of those water resources. Unavailability of sufficient observed data is a big issue in most parts of the world to be able to fully assess available water resources and its utilisation. Fortunately, more and more remote sensing based products are becoming available, providing information on various components of the water cycle, such as precipitation, actual evapotranspiration and storage variations.