Application of remote sensing and GIS to agricultural land encroachment analysis: A case study of Sokoto-Rima Valley

Abstract

The Sokoto-Rima valley is agriculturally important and has witnessed encroachment from Sokoto metropolis. This study therefore used Remote Sensing (RS) and Geographic Information System (GIS) tool to map this encroachment. A Quick-bird image of 0.5m resolution of 2003 and readings from a Global Positioning System (GPS) hand-held receiver of 2009 were combined as data in the Idrisi 15 (Andes Edition) GIS software and changes were mapped and extrapolated. Results show that between 2003 and 2009, the city expanded by about 15.82% (26.48 hectares) and that the agricultural land lost the same land mass to the city. Agricultural job loss, poor yield, loss of farmland, flooding, pollution and possibility of land filling were fingered as the consequences of continued expansion of the city into this valley. It was therefore recommended that further expansion be stopped, the dwellers resettled for agricultural land reclamation and better agricultural land management through the help of government was also established.