ZOOGEOMORPHIC IMPACT OF AFRICAN ELEPHANTS IN HWANGE NATIONAL PARK, ZIMBABWE: INSIGHTS FROM SATELLITE-BASED ANALYSIS

Large mobile terrestrial animals produce massive impact on landforms, sediments, and vegetation, often initiating and maintaining smaller-scale geomorphic cascades. This study focused on satellite image-aided (GoogleEarth Pro^TM) analysis of locomotion traces and geomorphic impact of African bush elephant (Loxodonta africana) in Hwange National Park, Zimbabwe. Morphometric assessment included temporally persistent trails, tramplegrounds, and waterholes produced by super-herds, where the number of individuals can exceed 300. Major trails radiated from larger waterholes and ranged in length from 2.03-9.69 km. For the waterholes (n=26), the average area was 308 m², with surrounding trampled zones typically 6-7 times greater in extent. Calculations based on a published set of metrics show that a herd of 250 elephants can affect (compact/remove) >0.18 km³ of sediment per year, which is consistent with 0.3-1.7 km³ values estimated from long-term zoogeomorphic features. A normalized difference vegetation index (NDVI) was used to assess the overall impact on local vegetation over a 30-year period. Our study demonstrates the utility of spatial analysis for identification, mapping, and quantification of the impact of large mammals on vegetation and landforms.