Lisa-Maria Rebelo
Communities across the world are feeling the impact of climate change through increased flood events, longer dry spells and extended droughts, and hotter temperatures.
According to the UN Environment Programme, Africa is disproportionately the most vulnerable region to climate change in the world because of the continent’s low levels of socio-economic growth.
Earth-observing satellites have been collecting images of the Earth’s surface since the 1980s. The images show us the status of land and water resources, forests and wetlands, coastlines and deserts; and they also show us our cities, buildings and infrastructure.
Through them, we can identify and better understand change. However, accessing and interpreting the images can be challenging due to a lack of digital infrastructure or technical capacity, which has resulted in the data not being fully exploited across Africa in comparison to other parts of the world.
By providing satellite images for the continent in an “analysis-ready” format and using these to provide decision-ready information on our cities, land, water, vegetation and coastlines, Digital Earth Africa is a programme that aims to address this gap. Hosted at the SA National Space Agency as of August 2022, the programme provides free access to all services to all African countries to inform climate action.
Solutions for water security form a critical part of the Digital Earth Africa Climate Action toolkit. Earth observation data are an important tool for water resources monitoring in general and for preparing for extreme events such as floods, but are particularly suited for monitoring large, remote or inaccessible locations.
Through Digital Earth Africa, users can identify the presence of water, monitor how it changes through time, and understand short and long-term patterns of water availability due to seasonal variations, extreme climate events such as droughts and floods and longer-term changes in climate.
The data can show where water features may be retracting or expanding due to a disturbance or increased human use, and can assist in planning for water resources extraction for human consumption, irrigation or livestock/wildlife watering.
Digital Earth Africa’s Coastline Monitoring Service uses satellite data to map the typical location of the African coastline through time. It helps to understand the past changes in the coastline and identify areas of concern for the future. Using an interactive map, users can easily visualise and translate years of satellite imagery into information about the growth and erosion of coastlines across Africa.
Users can leverage the coastline monitoring service to:
◆ Monitor and map rates of coastal erosion along African coastlines.
◆ Evaluate the impact of local and regional coastal management based on historical coastline change.
◆ Model how coastlines respond to drivers of change such as extreme weather events, sea level rise or human development.
◆ Support studies of how and why coastlines change over time.
The Digital Earth Africa team is developing a coastline monitoring dashboard that provides further tools for users to analyse changes in the coastline. An early version of the dashboard is shown below with information for South Africa’s coastlines and there are plans to make it available in early 2024.
The Digital Earth Africa Climate Action toolkit provides a comprehensive set of resources for African countries to address the challenges of climate change. By providing satellite images for the entire continent, the programme supports all African countries to have more information allowing them to address climate action. The water management and coastline monitoring applications are just two examples of the many ways that Digital Earth Africa is helping African countries adapt to and mitigate the impacts of climate change.
Dr Rebelo is a lead scientist at Digital Earth Africa.
Cape Times