Use Case Description
The imbalance between water supply and demand, along with its uneven distribution, presents a pressing problem. Stakeholders rely on contextual data to strategically target and scale water accessibility projects and infrastructure. Earth Observation (EO) provides crucial insights into both current and historical water supply trends by monitoring surface water extents in rivers and lakes, changes in reservoir storage, groundwater fluctuations, and irrigation water use.
Since groundwater is the largest accessible reservoir of freshwater globally, groundwater estimations are critical for assessing available water resources. In many regions, especially in arid, semi-arid, and rural areas, groundwater supplies a large share of water demand: it provides nearly half of all drinking water globally and supports around 43% of irrigation water use. However, direct groundwater-level observations are rarely available due to the associated costs of measurements, decentralised and/or non-digitalised measurements, or the non-disclosure of the data to the public for political reasons. In this sense, EO provides a major advantage by enabling the estimation of changes in total water storage and groundwater. Information on water resources aids stakeholders in monitoring resources, planning adaptation and investment operations, and assessing potential conflicts resulting from limited water availability.
Additionally, EO-derived information supports water-demand assessments by providing consistent inputs to demand models. Current EO applications focus on monitoring and analysing key historical hydrological variables that can inform model-based estimates of crop water consumption, water stress, water-use efficiency, and irrigation performance, thereby supporting investments to enhance agricultural productivity and water-resource efficiency.
