The United Nations (UN) Sustainable Development Goal (SDG) 6, to secure access to fresh water and sanitation for all, is not just an aspiration but a manifestation of established human rights. Yet, achieving sustainable and equitable provisions of water and sanitation still poses considerable challenges and the world is not on track to achieve the SDG 6 targets by 2030. Disparities and gaps in water data, especially in developing countries, is part of the challenge. Nearly 60% of the 193 UN Member States that support the 2030 Agenda for Sustainable Development, encompassing the SDGs, don’t have adequate data to meet the reporting requirements of SDG 6. Satellite-based Earth Observations (EO) can help narrow these data gaps.
From the vantage point of space, geopolitical borders disappear. The same satellite fleet that informs us about wildfires in California can within the same day be used to map floods in Cambodia. These data have enabled us to achieve incredible leaps in environmental monitoring over the last several decades. EO sensors can take direct and indirect measurements of nearly all components of the hydrologic cycle. Today, we can measure changes in surface and ground water, measure the gain and loss of wetlands and even monitor some water quality parameters from space for almost any part of the world. Incredibly, most of these data are provided for free online. From this perspective, SDG 6 and EO share a common goal: to provide equal access to all.
Four of the eight targets in SDG 6 include indicators that can benefit from the integration of EO
Four of the eight targets in SDG 6 include indicators that can benefit from the integration of EO. In a recent study with colleagues from NASA and University of Maryland, we illustrated that nearly all of the components in the SDG indicator for water-related ecosystems (6.6) can be measured using readily and freely available EO-based data products. Others have shown that EO can support reporting on certain indicators under the SDG targets for water quality (6.3), water stress (6.4) and integrated water resources management (6.5). But while research can address the question of EO data availability to support these SDG 6 targets, data accessibility remains a challenge for many parts of the world.
Uptake of EO in support of the SDGs has been growing but it is uneven across nations. Technical and institutional capacity constraints have limited the use of this information even for countries that are eager to apply the data for their national SDG 6 reporting. And despite data accessibility advances, there is still a significant learning curve when it comes to using EO. Thus major capacity building efforts are needed. Technical challenges can also be barriers to adoption. For instance, lack of ground-based hydrologic information in many developing countries limits the ability to calibrate and validate EO data, a process critical to reducing errors associated with satellite data retrievals and classification uncertainties. Spatial and temporal resolution as well as the latency and legacy of EO data can also be constraining factors.
Even with the current challenges, EO can help level the playing field regarding disparities in water data access between countries
Innovations in cloud computing, plans for new user needs-focused EO satellites, capacity building and stronger policies and governance are all part of the solution. Platforms such as Google’s Earth Engine enable analyzing satellite data online with Google’s computers, significantly reducing the required level of data analysis literacy and computing power. At the same time, a vast number of government, commercial and private EO satellites planned for launch over the next decade promise to address some of the current technical challenges while keeping end-user needs more central in the planning and design phases. Coordinating bodies such as the Group on Earth Observations are also playing a significant part to help improve governance and institutional capacity issues by working with governments, UN agencies and the research and space communities to address barriers for adopting EO in support of the SDGs.
Even with the current challenges, EO can help level the playing field regarding disparities in water data access between countries. The fact that there is growing impetus for utilizing these data for SDG 6 is important. It’s an opportunity to build equity into water data availability and accessibility and to help all nations realize the ambitions set out in the 2030 Development Agenda. But it will take the technical, policy and governance worlds coming together in a big way to achieve this.