Aerial photography of traces of human activities around the UNESCO World Heritage site in the Nimba Mountains Biosphere Reserve, Republic of Guinea

The objective of this study is to identify traces of human activities on the central area (UNESCO Heritage Site) of the Biosphere Reserve of the Nimba Mountains through drone photographs and the cartographic analysis of images from 1990 and 2020. The methodology was: aerial photography of peripheral areas using a MAVIC-4 drone, and cartographic analysis of satellite imagery from 1990 and 2020. The analysis of satellite imagery from 1990 and 2020 show that the land uses of the Biosphere Reserve have increased considerably. The total area under construction fell from 81.66 ha to 303.76 ha, the bare soil from 1226, 28 ha to 3344.11 ha and the agricultural areas from 19.89 ha to 58.98 ha. However, the primary forest decreased from 11,326.05 ha to 4,345.09 ha, recording a loss of 6,980.96 ha or -15.19% of its area. The images taken with the drone at low altitude show traces of anthropogenic activities getting closer and closer to the central area, traces of clearing, and fallow. The degradation is strongly observed in the buffer zone and gradually weakens towards the center. Keywords: Aerial photography, anthropogenic activities, World Heritage site, Biosphere reserve, Republic of Guinea