Cartographie de la dynamique de terroirs villageois à l'aide d'un drone dans les aires protégées de la République Démocratique du Congo

Protected areas of the Democratic Repu-blic of Congo (DRC) are under threat from various human pressures that need to be monitored accurately and on a regu-lar basis. A small Falcon drone mounted with a Sony NEX-7 camera was used for mapping missions to track the dynamics of village lands in the Mondo Missa Game Reserve, which lies along the eastern border of Garamba National Park in nor-th-eastern DRC. The mapping missions collected a total of 3,143 photos taken in April and July 2015, covering an area of 114 ha with a ground resolution of 8 cm/pixel. The images were then ortho-rec-tified, and the resulting ortho-images segmented. The segments were then classified manually by photo-interpreta-tion. Significant changes had occurred between the two periods: 6.5 ha of natu-ral forest and savannah had been lost (declining from 86.6 to 80.1 ha), fallow areas had increased from 16.9 to 8.2 ha and cleared land from 4.1 to 10.0 ha. The variations in seasonal crop areas ranged from 3.2 to 11.8 ha. The average size of cultivated plots was 0.2 ha (s = 0.14 ha, n=50). Finally, the area covered by iso-lated trees had increased very slightly (from 1.3 to 1.9 ha) while the area occu-pied by human settlements remained constant (1.7 ha). These results show that the expansion of itinerant slash-and-burn cultivation results in the conversion of natural habitats and modifies plant com-munities. Unmanned aerial systems can thus help to produce accurate maps and undertake rapid monitoring of small-scale land use changes in protected areas in tro-pical forests and savannah. They offer an efficient solution for assessments of defo-restation and degradation in areas used by local communities. Such assessments are an issue of considerable importance in the REDD+ process, which is aiming to quantify these changes accurately.