papier (7) Afrique (7) South Africa (7) Paper (7) puits (6) mine (6) karst (6) activité minière (6) Groundwater (6) Mining engineering (6) Mines and mineral resources (6) Mineral industries (6) Karst (6) karst (6) eaux souterraines (5) Area (5) Area (5) Water (5) Gold mines and mining (5) Gold (5) Aquifers (5) or (5) uranium (4) besoin (4) ordre (4) Dewatering (4) Water-supply (4) Uranium (4) Series (4) Order (4)