The AQUASTAT core database symbol scheme has changed to follow FAO corporate Statistical Working System standards for consistency within FAO and provide more information to users.
Here is an explanation to the new symbols:
*: Imputation in AQUASTAT is aiming at gap filling to enable aggregates and SDG indicators calculations using data referring to the same year. Imputations types includes:
**: Some of the data provided in the AQUASTAT Main Database were generated by other agencies. There are two reasons why the AQUASTAT Main Database includes these numbers:
The source of the value of a variable with the X symbol is given in the definition of the variable, which can be accessed by clicking on the (i) icon to the right of each variable in the database query page or in the list below.
FAOSTAT: Variables: Total area, Arable land, Permanent crops, Cultivated area, Undernourishment, Gross domestic product (GDP).
UN Population Division (through FAOSTAT): Variables: Population
UNDP: Variables: Human Development Index (HDI), Gender Inequality Index (GII)
CRU: Variables: Average precipitation in depth
FAO Climpag: Variables: National Rainfall Index (NRI)
WRI (World Resources Institute): Variables: Interannual variability, Seasonal variability
JMP of WHO/UNICEF: Variables: Access to improved drinking water source
Eurostat or UNSD: Variables: Some in: Water resources section and Water use section
OECD: Variables: Some in: Water use section
Data without a symbol comes from one national source that can be the FAO questionnaire on water and agriculture, a report, a publication or an official website.