Spatial analysis of agricultural landuse change in Asaba, Southern Nigeria

Abstract

This paper examines agricultural land use change because of urban encroachment into the agricultural landscape. It analyses the pattern and rate of land use change in Asaba between 1987 and 2013, and determines the impact of the observed changes on agricultural land use. Three time point multi-temporal remote sensing images are analysed using hybrid unsupervised/supervised image classification techniques to identify four dominant land cover classes in the study area. The average rate of change is also determined by computing the difference in areal extent of a land cover in the initial and final time points. The results show that cultivation and settlement increased by 1.4% and 1.5% respectively while forest and water decreased by 0.7% and 1.2% respectively in the first interval, 1987-2002. In the second interval, however, cultivation increased by 0.5% while settlement, forest and water decreased by 0.2%, 0.1% and 1% respectively. In spite of an average overall increase observed for cultivation and settlement, the results show a reduction in total area cultivated in the second interval while forest and water also declined by 0.4% and 1.1% respectively. The study concludes that urban encroachment into rural landscape should be controlled and sustainable rural development strategies to minimise rural-urban migration be implemented so as to curb the loss of interest in agriculture. Agro-business ventures should also be promoted among the youths.

Keywords: Agriculture; Food Security; Urban Expansion; Remote Sensing; GIS; Nigeria