This layer represents the average volume of surface water that left the country to other countries in 2014. It refers to water leaving through transboundary flow (rivers, canals, pipes) in km3/year, but not to water flowing to the sea through The table also provide information on the volume of surface water leaving a country and that is not submitted to formal agreements or treaties, the volume which is submitted to treaties, and through formal agreements or treaties, all in km3/yr.For more information, please see this example of the calculation rules: http://www.fao.org/nr/water/aquastat/data/wrs/readPdf.html?f=AFG-WRS_eng.pdfVisit the FAO Aquastat website at: http://www.fao.org/nr/water/aquastat/data/query/index.html?lang=en