Monitoring changes in agricultural water use efficiency related to SDG indicator 6.4.1 using WaPOR data

Satellites nowadays provide a large amount of data useful for monitoring biophysical environmental changes. The FAO Water Productivity Open-access portal (WaPOR) compiles such satellite data into a database comprising of various components required to estimate water productivity at various spatial resolutions for the Africa and MENA regions. In addition to maps and statistics generated at national or sub-national administrative levels to monitor the status and progress of sustainable development goal (SDG) indicators, remote sensing derived products such as WaPOR provide opportunity to develop value added applications. In this study, we developed a dashboard using the Google Earth Engine (GEE) platform to compute and visualize the agricultural component of the water use efficiency, SDG 6.4.1, using the WaPOR dataset. Using land cover classification, evapotranspiration, and precipitation data from WaPOR, irrigation water use (IWU) was computed. This was then applied to the computation of Gross Value Added (GVA) by the agricultural components in the overall formulation of SDG6.4.1 to estimate water use efficiency. The dashboard allows the comparison of water use efficiency computed using these remote sensing derived WaPOR datasets with the national and sub-national level statistics as is conventionally computed from the AQUASTAT database of FAO. With the development of this application, we demonstrate that satellite derived datasets are an important, easily accessible, and economical alternative and/or complementary to conventional procedures to compute water use efficiency particularly of the agricultural components. With an added value of sub-national level details, the dashboard is a promising tool for a quick computation and visualization of changes in agricultural water use efficiency over a period of time and continuously both for practitioners as well as for policy makers.