We are delighted to announce that DHI GRAS has been contracted by the European Space Agency (ESA), to lead a consortium consisting of GeoVille GmbH (Austria), GISAT (Czech Republic), GRID-Arendal (Norway) and the technical university of Denmark (DTU), in a large new application project: “WorldWater - Surface Water Dynamics”.

Water is essential for life on Earth and a critical natural resource that underpins all social and economic activity. During the last century, water consumption has increased twice as fast as the world’s population, and today water scarcity affects more than 40 percent of people globally – a disturbing figure which is expected to rise if we do not change our habits and respond to climate change and future global warming.

The dedicated goal on water in the 2030 agenda for sustainable development has brought a spotlight on water policy at global level, and in national planning, to avoid an accelerating ‘water crisis’ towards 2030. However, a ‘water crisis’ is ultimately a management crisis, that can be solved through the application of sound water management policies and initiatives. The need for proper and timely information on water (non-) availability is a critical requirement for water management activities. In large, remote and inaccessible regions, in-situ monitoring of inland waters is sparse, and hydrologic monitoring can significantly benefit from information extracted from satellite earth observation (EO).

Through the lens of Sustainable Development Goal (SDG) 6 and specific use case studies, the WorldWater project will demonstrate how global coverage EO data, can be used to systematically and accurately measure inland surface water resources. WorldWater will complement existing EO initiatives and projects (e.g. Global Surface Water Explore and the Copernicus global land services) by further developing EO tools and products to effectively use the most up to date, open and free satellite data, primarily from the Sentinel missions, for improved monitoring of the world’s inland water resources in both extent and volume.

WorldWater is, therefore, a crucial project aiming to address the critical needs of authorities, at all levels, to adapt and formulate water policies, and report on water resources, in a timely manner and based on valid scientific information. More specifically, WorldWater will provide essential tools and information to strengthen evidence-based planning and management to support authorities in addressing the global ‘water crisis’.

Building on the Sen-ET project led by DHI-GRAS, the European Space Agency (ESA) just published this news story featuring our state-of-the-art technology for deriving accurate measurements of evapotranspiration at parcel level. Our technology enables detection of water stress and irrigation support, at individual field scale, anywhere in the world. Currently, we are supporting irrigation management and precision agriculture activities in five continents.

Background
The Sentinel-2 and Sentinel-3 satellite constellations have highly suitable spatial, temporal and spectral characteristics for many agricultural applications. This includes estimating water evaporation from the soil and transpiration from the leaves (together called evapotranspiration – ET), the knowledge of which is critical for agricultural water resources management and water use optimization.

In order to robustly model ET, both optical and thermal satellite data are needed. The former data is acquired daily by Sentinel-3 at 300 m resolution and by Sentinel-2 every 3 to 5 days at 10 – 20 m resolution. Thermal data is acquired only by Sentinel-3 at around 1 km resolution. ET estimates derived directly from this thermal data would also have a resolution of “just” 1 km, which would obscure many agricultural landscape features.

This is why DHI GRAS together with IRTA and SANDHOLT worked on developing a method to fuse Sentinel-2 and Sentinel-3 data, with the aim of obtaining ET maps with a resolution of 20 m. This was the primary objective of the Sen-ET project.

Denmark and France have been severely impacted by record rainfall during March and February 2020, triggering severe flooding’s in many regions. Authorities have struggled to gain control over the large volumes of water which have saturated the soils and overloaded rivers and streams, causing them to run over their banks.

The scale of such events illustrates the potential of satellite-based information to underpin emergency response and preparedness, by offering timely and synoptic insight on the largescale extent of the flooding’s, and its change over time, at local, regional and even at national level.

To demonstrate the potential of largescale satellite-based flood mapping, we decided to map the national level extent of the flooding’s in Denmark, as well as the dynamic change over time, in five of the most affected municipalities in Denmark and in two French regions.

With our novel operational flood mapping tool, we apply state-of-art machine learning and image analytics to assess the extent of flooding’s in near real time. The flood extent map can be acquired a few hours after a flooding has occurred and delivered in less than 24-48 hours globally (different solutions apply). The results of the two mappings can be seen from the links below.

Just three weeks ago, we mapped the impacts of the devastating bushfires in Australia, triggered by the driest and hottest year on record. Heavy rainfall over the weekend has been a welcome relief for millions of animals and has helped to subdue some of the fires in New South Wales, however in return, the torrential rain has caused major flooding’s in the coastal regions.

Using our automated satellite-based operational flood mapping tool, we have mapped the extent of the flooding’s in one of the worst affected areas, around the city of Nowra in the Shoalhaven region, just south of Sydney. While the flood map quantifies the severity of the flooding’s, satellite images are also ideally positioned to visualize its effects on the overall water environment, as illustrated in the video.

So while the seesaw of events in Australia is a testimony to the unsustainable trajectory of our planet, we believe we are part of the solution – by bridging critical earth observation data and relevant stakeholders, we enable decision makers to take confirmative actions to respond to the severity of climate change and act upon climate impacts.

Our satellite-based product portfolio are ideally positioned to provide rapid and cost-efficient information about the impact of climate change and climate induced extreme events.

This year’s fire season in Australia is widely regarded as one of the most severe on record, causing detrimental damage to natural landscapes, wildlife, cities and critical infrastructure across the nation. Using data from NASA's MODIS satellites, we have detected an accumulated quarter of a million km2 affected by active bushfires, during the last two months, more than the total land mass of the United Kingdom.

We are saddened by the ferocious bushfires sweeping across Australia and devoted to continuing to deliver our impactful tools and services to assist authorities in responding and scaling efficiently and effectively during such disaster scenarios. Our satellite-based product portfolio is ideally positioned to provide rapid and cost-efficient information about fire risk, impact and movement, thus offering critical tools for fire response. As an example, our high-resolution soil moisture product can be applied nationwide to conduct largescale assessments of fire risk.

Driven by our passion for change and curiosity about innovative and integrated satellite-based solutions, we continue to explore avenues to support decision makers in making critical evidence-based decisions.