Case Study: Congo Basin: Use of French Satellite to help forest management

The problem: Lack of current data and information to monitor adverse changes in the Congo Basin – the world’s second largest biodiverse and carbon rich forests

The solution: Use of high resolution satellite images of the Congo Basin from the SPOT satellite, made publicly available for use by Governments and others working in the area of sustainable forestry development in the Congo Basin

Context: The rainforests of Africa’s Congo Basin are vast – considered to be the world’s second largest – and one of the last remaining bastions of a once-widespread system of intact, biodiverse, and carbon-rich forests. These are increasingly becoming one of the most threatened areas due to agriculture, mining, logging, and climate change - which are already reducing the areas under forest. The biggest threat, however, in the Congo Basin forest is a lack of good information. The Congo Basin remains one of the most challenging environments in the world. Much of the region remains remote with poor infrastructure, which makes wide-scale, on-the-ground monitoring difficult. Looking down on forests from space can give a view of remote areas, but the Congo Basin presents challenges here as well. Dense rainforests generate water vapor through evapotranspiration, which can mask forests in clouds and obscure a satellite’s view.

The project: While there are several options for using freely available, global satellite data, such as MODIS (up to 250 meter resolution) and Landsat (30 meter resolution) systems, the nature of forest change in the Congo basin presents unique challenges. Within the Congo Basin, local and subsistence agriculture is the largest driver of deforestation, while charcoal production is the leading driver of forest degradation. These activities leave a smaller, more fragmented physical footprint than commercial agriculture or logging, the largest drivers in Asia and the Americas. As a result, change in the Congo Basin can be difficult to detect with medium or coarse-resolution satellite imagery, and only the sharpest images (less than a 30 meter-resolution) can give a clear picture of what is happening on the ground.

Starting in August 2014, 1,500 high-resolution (10 to 20 meters) satellite images of the Congo Basin from the  SPOT satellite constellation provided by Airbus Defence and Space was shared with the World Resources Institute, (WRI), through a joint agreement with French institutions participating in the Tropical Forest Spatial Observation program. The imagery was provided for viewing and analysis through Global Forest Watch and the Congo Basin Forest Atlases, along with other data on forest change and land management. Together, these WRI initiatives offer one of the largest publicly-available resources for high-resolution satellite images for the Congo Basin. They are being used by governments, businesses, and communities to provide insight into how forests in the region are changing.

Figure 1 shows a comparison of high resolution SPOT imagery and medium resolution LANDSAT imagery. The images provided so far were from the 2008 to 2012 time period, and new images, continuously being acquired, will also be made available for the coming years at a remarkable 1.5-meter resolution. The high-resolution SPOT images are being used to refine WRI’s analysis including quantifying forest cover change and identifying whether such change is due to expansion of agricultural crops around villages, or logging activities in or outside the forest concessions. They will also provide generally better understanding of the spatial dynamics of forest areas.