Landsat informing better wetland management in Australia and Africa

Learning from the past to plan for a better future: Supporting nature-based climate change solutions through Earth observation

When facing a challenge like climate change, looking to nature can provide us with some uniquely robust and effective mitigation and adaptation techniques, known as ‘nature-based’ climate solutions. It is estimated that nature-based climate solutions could provide 37% of the mitigation required to achieve the targets of the Paris Agreement in 2030. They also play a key role in climate change adaptation and building resilience in landscapes and communities.

Nature-based climate solutions have many positive effects on human well-being and biodiversity, as well as helping to address food and water security, and reducing the impact of natural disasters.

Mangroves and freshwater wetlands are two examples of precious ecosystems that provide nature-based solutions to climate change and a range of benefits for the environment and human populations.

Planting mangroves in coastal areas buffers the coastline against erosion and storm surges, protecting local communities from flooding. Mangroves also store carbon (carbon sequestration) and provide an ecosystem for local wildlife and other plants.

Wetlands hold excess water which can help to reduce the impact and overall risk of flooding, particularly in urban areas. Providing natural filtration, wetlands absorb pollution and maintain water quality and sanitation for local communities. In addition to storing carbon, the plants and soils in these diverse ecosystems provide natural stabilisation of the external temperature through heating and cooling.

But how do we know how to manage our freshwater wetlands and mangroves to make these strategies the most effective? One of the ways we can do this is by using satellite imagery. Since the 1970s, NASA and the United States Geological Survey have used Landsat satellites to capture imagery about our environment, but using this collective information was a challenge. In 2018, Geoscience Australia launched Digital Earth Australia (DEA), harnessing over 35 years of this archive, enabling us to view changes and trends over time. Digital Earth Africa, built on DEA technology, has been operating since 2019 to provide these benefits to the African continent.

The Wetlands Insight Tool and Mangrove Canopy Cover data use Landsat data and Digital Earth technologies to help understand the current condition of wetlands, the extent of the vegetation and how these have changed over time. These tools can also be layered with other data such as rainfall, climate, water observations and satellite imagery to help identify what might affect the changing condition and extent of freshwater wetlands and mangroves. This is powerful information to help decision makers protect and restore these ecosystems, enabling more nature-based climate solutions.

Protecting the world’s wetlands

Digital Earth Australia’s Wetlands Insight Tool (QLD) (DEA WIT) and Digital Earth Africa’s Wetlands Insight Tool (DE Africa WIT) visualise wetlands by showing how the amounts of water, green vegetation, dry vegetation and bare soil have changed since 1987. They can help decision makers, researchers and private industry to conduct climate impact assessments. This includes agriculture drought monitoring, ecological drought monitoring, sustainable water use, and land degradation assessments.