To bring this work to a successful conclusion, the scientists sampled 12 drainage basins (the area that includes an entire river and all its tributaries, from its source to its mouth), spread over the entire African territory and all the different variations of these basins according to the corresponding climate and vegetation: from the humid climate dominated by the tropical forest of the river Congo (DRC) to the semi-arid climate dominated by the savannah of the river Tana (Kenya) and the very steep basin of the river Rianila (Madagascar).

"This large spectrum revealed the mechanisms controlling greenhouse gas emissions in inland waters, from basin to basin across the entire African continent. This also opens the way for a comparison study between the Amazon and Congo rivers or any other tropical river", continues Alberto Borges, who intends to release the database as all the authors are Open Access and Open Data adherents. According to him, the study undertaken establishes a "baseline", a photograph of Africa in the 2010s, at the dawn of great changes.  "We know that the population of the Democratic Republic of the Congo is set to double, increasing from 65 to 130 million inhabitants in 25 years", he points out. "This huge increase will inevitably have an impact on the functioning of the river Congo, probably in response to increased deforestation and a shift towards intensive farming, since current farming practices are traditional. It is conceiveable that the number of hydro-electric dams will increase as the hydroelectric energy potential of Africa is currently under-exploited. Similarly, water diversion for purposes of irrigation will increase. All these factors will have consequences for greenhouse gas emissions from rivers".
 
Among the factors learned from this study, the researcher draws particular attention to the important role of wetlands (these include inundated forests, flood plains and large "meadows" of floating plants). These wetlands are characterized by intense "aerial" photosynthesis (by submerged vegetation) but the organic matter produced is transferred into the water sooner or later. This organic matter in the water increses the production and emission of CO₂ and CH₄.  The carbon emissions (CO₂ and CH₄) associated with the humid zones are enormous because the surfaces they occupy are also extremely vast. In the Congo basin, wetlands (mainly inundated forests) cover an area of 360 000 km², equivalent to the entire area of Germany.