内容简介
Geoheritage sites can provide an excellent resource for sustainable development that represents a growing movement in Africa. Kobokwe Cave is formed within the Middle Proterozoic–aged sandstone of Kobokwe Gorge and is nationally important; the cave is the site where British missionary David Livingstone spent a night in 1847 and subsequently converted Kgosi (Chief) Kgari Sechele I, the first and only Christian “conversion” at that time by Livingstone. However, the site currently appears undervalued as there are little stewardship and minimal organized tourism and is affected by litter, graffiti, fires, illegal dumping and sand mining, and noise pollution from a nearby road; the building of the road itself destroyed a boulder of cultural significance. To test the level of environmental disturbance, the Karst Disturbance Index (KDI) was employed and this is the first known application to a non-carbonate karst environment and the first such application in Africa. Field observations were coupled with laboratory analyses of physico-chemical, nitrate, and heavy metal parameters in soil and water from the site. The final KDI score for Kobokwe of 0.29 is classed as showing “minor disturbance” and likely due to low visitor numbers although the sub-category of cultural disturbance scored 12 and is relatively high, as also found in previously published KDI studies from the USA, Italy, and Mexico. The analytical results are mostly at natural background levels, except for Pb in the cave floor soil (5.13 mg/L) and Pb in all water samples (0.3–0.63 mg/L) likely due to nearby vehicular traffic; also, Fe in all water samples (0.79–1.13 mg/L) that has possibly leached from the gorge sandstone and the spring water was slightly above standard background levels and possibly leached from nearby soil/rock. Future recommendations to avoid further disturbance and to promote environmental management of the site include community involvement, litter bin installation, graffiti removal, tour guides, information panels, entrance gate, tarred road, footpath installation, and enforcing of stronger site stewardship.