2.1. Country-led national data-collection and AQUASTAT database aggregation

2. Method and process: how to monitor and interpret indicator 6.4.1

2.1. Country-led national datacollection and AQUASTAT database aggregation

Data collection for the estimation of both SDG target 6.4 indicators is carried out through AQUASTAT, FAO’S global information system on water and agriculture. AQUASTAT’s datacollection method has evolved since 2018 to align with the principles of data gathering that are promoted through the SDGs, i.e. following country-led and country-owned processes.

In this regard, AQUASTAT has established a network of national correspondents across 156 countries (at this moment) to improve country participation and data ownership. Every year, AQUASTAT sends a questionnaire to these national correspondents, which includes the variables needed to calculate indicators 6.4.1 and 6.4.2. Throughout the data-collection process, national correspondents have the key role of ensuring data quality and coordination at the country level. Having national coordination in place will ensure that data are collected in a timely and consistent manner on a regular basis. National ministries and institutions with water-related thematic areas included in their mandate (such as ministries of water resources, agriculture, industry or the environment) usually collect indicator 6.4.1 data. Countries compile their different variables in the questionnaire (see the reporting template in annex 1), which is returned to FAO for regional and global aggregates to be produced. Sectoral water-use data prior to 2015 were easily obtained from the AQUASTAT database, though such data included long-term estimations that were not entirely suitable for the computation of the water-use efficiency trend.

Once countries submit their data, AQUASTAT carries out a validation process to ensure the quality and consistency of the data, which includes an ongoing dialogue with national correspondents. FAO thoroughly reviews the information reported, using the following tools:

• a manual cross-variable check, which includes a cross-comparison with similar countries and historic data for the countries

• time series coherency, by running an

R-script to compare reported data with those corresponding to previous years.

After the validation process, the AQUASTAT database is used to provide data on water use for agriculture, industry (MIMEC) and services. Economic data on GVA in each of these three major economic sectors is acquired from national statistics departments or other relevant national government agencies and international