FAO AQUASTAT Information: Difference between revisions

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We have included some key FAO AQUASTAT groundwater and other water statistics in the country pages of this Atlas, as they provide a very useful overview of the extent of groundwater resources and use in each country, compared to surface water resources, and allow comparison between countries.  
We have included some key FAO AQUASTAT groundwater and other water statistics in the country pages of this Atlas, as they provide a very useful overview of the extent of groundwater resources and use in each country, compared to surface water resources, and allow comparison between countries.  


Explanations of the AQUASTAT variables presented in the Atlas country pages are given in the tables below. These are taken from the FAO AQUASTAT [https://www.fao.org/nr/water/aquastat/data/glossary/search.html?lang=en glossary].
Explanations of AQUASTAT variables presented in the Atlas country pages are given in the tables below. These are taken from the FAO AQUASTAT [https://www.fao.org/nr/water/aquastat/data/glossary/search.html?lang=en glossary].





Revision as of 08:09, 26 September 2018

Africa Groundwater Atlas >> Resource pages >> FAO AQUASTAT Information page


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FAO AQUASTAT is the FAO’s global water information system, providing data for countries in Africa, Asia, Latin America, and the Caribbean, with a special emphasis on agricultural and irrigation water use. AQUASTAT is widely used as a source of information on groundwater use.

AQUASTAT provides country profiles with general information on the geographical and economic situation of each country, and more detailed information on surface water and groundwater resources, water use, and water management. The aim is to describe the particularities of the country and problems relating to the development of the water resources and, in particular, irrigation. There is information on irrigation trends; existing policies and legislation relating to water use in agriculture; possible treaties and agreements between countries; and prospects for water management in agriculture are presented.

The AQUASTAT database holds water statistics at a country level. The statistics are based on the best available data and analysis techniques, but even so, there are data gaps for many countries. These gaps are often worse for groundwater, because groundwater use is more difficult to measure directly than surface water use. This is especially the case for agriculture, as large scale irrigation schemes, which are easier to measure, are usually based on surface water. By contrast, groundwater-based irrigation and other agricultural use in Africa is dominantly small-scale and managed by individual farmers or communities, and so is very difficult to measure and record. AQUASTAT uses modelling to fill in some of these data gaps. It should be recognised that these modelled data may not be accurate.

We have included some key FAO AQUASTAT groundwater and other water statistics in the country pages of this Atlas, as they provide a very useful overview of the extent of groundwater resources and use in each country, compared to surface water resources, and allow comparison between countries.

Explanations of AQUASTAT variables presented in the Atlas country pages are given in the tables below. These are taken from the FAO AQUASTAT glossary.


Key groundwater resource statistics

AQUASTAT Variable Explanation
Estimated groundwater produced internally (Groundwater recharge) Defined as long term annual average groundwater recharge, derived from precipitation within the country boundary. Estimated by calculating an annual infiltration rate (in arid countries) or calculating river base flow (in humid countries).
Estimated total renewable groundwater Calculated as the sum of the estimates of internal renewable groundwater resources (groundwater recharge, called by AQUASTAT 'Groundwater produced internally') and total external renewable groundwater resources (Groundwater entering/flowing into the country).
Estimated exploitable regular renewable groundwater resources Generally defined as the groundwater resources available for development, taking into account environmental, economic and engineering factors. Specifically defined as the average groundwater flow available 90% of the time and economically/environmentally viable to extract. It is unclear how this is estimated by AQUASTAT, but AQUASTAT states that estimation methods vary from country to country.
Estimated fresh groundwater withdrawal (abstraction) Includes primary and secondary groundwater withdrawals (abstractions). Primary groundwater withdrawal is groundwater that has not been abstracted before; secondary is groundwater that was previously abstracted and returned to an aquifer (e.g., including irrigation returns or recharge of waste water). In practise, distinguishing between primary and secondary withdrawals is rarely possible. Additionally, groundwater abstractions in most African countries are difficult to measure, as they are largely widely distributed and unrecorded. Estimates of groundwater withdrawal are likely to be calculated differently in different countries.
Estimated groundwater: entering the country Defined as the long term average annual quantity of groundwater leaving the country not submitted to treaties or secured through treaties. Another AQUASTAT variable, Groundwater: accounted inflow, has not been included in the Atlas: this is defined as the long term average annual quantity of groundwater annually entering the country, taking into consideration eventual treaties. There are no countries in Africa with agreed treaties on the quantity of groundwater entering the country, and so there is no practical difference between these two variables. Additionally, very few countries in Africa hold any data on any groundwater inflows from outside the country.
Estimated groundwater: leaving the country to other countries Defined as the average annual quantity of groundwater leaving the country, without treaties. It refers to groundwater flowing to other countries, NOT any groundwater that flows to the sea for countries located next to the sea. Another AQUASTAT variable, Groundwater: accounted outflow to other countries, has not been included in the Atlas. This is defined as the long term average annual quantity of groundwater leaving the country that is not submitted to treaties or secured through treaties. There are no countries in Africa with agreed treaties on the quantity of groundwater leaving the country, and so there is no practical difference between these two variables. Additionally, very few countries in Africa hold any data on any groundwater outflows to other countries, or to the sea.


Key general water resource statistics

AQUASTAT Variable Explanation
Estimated exploitable total water resources Calculated as the sum of exploitable total renewable surface water + exploitable regular renewable groundwater. Note that methods of estimating exploitable water resources vary from country to country.
Estimated total internal renewable water resources Calculated as long term average river flow + long term average recharge (groundwater produced internally) - overlap from the sum of surface water and groundwater resources, divided by population.


Key general water supply and use statistics, including for agriculture

AQUASTAT Variable Explanation
Rural population with access to safe drinking water (%)
Urban population with access to safe drinking water (%) Population affected by water related disease Estimated freshwater withdrawal as % of estimated total internal renewable water resources Industrial water withdrawal (all water sources) Agricultural water withdrawal (all water sources) Irrigation water withdrawal (all water sources) Irrigation water requirement (all water sources) Total area of country cultivated (%) Area of permanent crops (ha) Cultivated land (arable and permanent crops) (ha) Area equipped for irrigation by groundwater (ha) Area equipped for irrigation by mixed surface water and groundwater (ha)

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