Termite mound identification through aerial photographic interpretation in Lubumbashi, Democratic Republic of the Congo : methodology evaluation

Tropical termites are of critical importance for ecosystem functioning and ecosystem services in woodland and savannah areas. Termite mounds can also be used as fertilizer and biological indicators of anthropogenic disturbance linked to agriculture or charcoal production. Remote sensing may help to identify and characterize termite mound density and distribution at low cost. To test its effectiveness, termite mounds were identified in the field and compared with the results of image interpretation of free Google Earth aerial photographs. This comparison was carried out for 17 sites in the hinterland of the mining city of Lubumbashi, Katanga, Democratic Republic of the Congo, which faces high population growth, food insecurity, and intense fragmentation and degradation of the original Miombo woodland cover. The influences of mound height and diameter as well as the timing of the image capture (year and dry or wet season) were statistically tested. The actual number of termite mounds observed in the field was generally overestimated on the corresponding image. Height and wet season favoured correct identification, while spatial distribution was not significantly influenced by misidentifications. A corrective model was defined and its relevance statistically verified. Mound identification using Google Earth appears efficient so long as the precise individual mound position is not concerned. This approach represents considerable cost reduction for field surveys of termite mounds.