1. Department of Geography and Resource Development, University of Ghana, Legon GA-489-1680, Accra P.O. Box LG 59, Ghana
2. Institute for Scientific and Technology Information, Council for Scientific and Industrial Research (CSIR-INSTI), Accra P.O. Box CT 2211, Ghana
3. Section for Geography, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen, Denmark