CO2 EMISSIONS FROM LAND USE/COVER CHANGE IN OUAGADOUGOU MUNICIPALITY, BURKINA FASO

Abstract

This study was conducted to quantify carbon dioxide (CO₂) emission from land use/cover (LULC) change in the municipality of Ouagadougou in Burkina Faso. Historical LULC maps were obtained from Random Forest classification of cloud free Landsat TM image of 1990 and OLI image of 2022 in Google Earth Engine platform. Field measurements were carried out to estimate the aboveground carbon stock of different LULC types using an allometric equation. The LULC change and the carbon stock data were integrated to quantify CO₂ emission using the IPCC method. The results showed that, between 1990 and 2022, the municipality of Ouagadougou was characterized by built-up and cropland expansions at the detriment of the savanna vegetation. Built-up area increased from 5.75% to 52% of the study area and cropland from 14.47% to 24.74%. At the same time, tree savanna and shrub savanna reduced from 58.64% to 11.66% and from 20.44% to 10.96% respectively. The highest mean carbon stock was recorded in tree savanna (36 ± 4.5 tC/ha), followed by shrub savanna (21.9 ± 6.1 tC/ha) and cropland (18 ±3.3). The change in LULC caused more emission of CO₂ (2630490.96 ±0.74% tCO2e) than absorption (207867.93 ± 0.67% tCO2e). The expansion of built-up appeared as the main source of CO₂ emission (83.65% of total emission) from LULC change. CO₂ absorption is mainly driven by the conversions to tree savanna (85.13% of total absorption), particularly the conversion of shrub savanna to tree savanna (63.07%) that released 131111.20 ± 0.28 tCO2e into the atmosphere. The findings of this study can be used to address sustainable land use planning in Ouagadougou, since they highlight the issue of land use planning and call for mainstreaming climate change adaptation into the city’s master plan or land use policies.