Evaluation of Land Cover Dynamics and Landscape Fragmentation in Ijebu Ode, Nigeria

Abstract

Landscape fragmentation has been found to be a major consequence of urbanization and land use/cover (LULC) changes. Thus, this study analyzed the spatiotemporal land use/land cover changes in Ijebu Ode, Nigeria, between 1986 and 2021. This is with a view to assessing the pattern of landscape fragmentation in the study area. The study used data obtained through a Global Positioning System (GPS) receiver and satellite imagery (Landsat 5 MSS/TM, 1986; Landsat 7 ETM+, 2000 and 2014; and Landsat 8 OLI/TIR, 2021). The data were analyzed using spatial landscape metrics. Results indicated that Ijebu Ode has witnessed a dramatic increase in built-up areas between 1986 and 2000 by 11.03%, 2000 to 2014 (65.24%), and 2014 to 2021 by 131.25%. Expansion of the built-up area was aided by reductions in bare land (1986 to 2000, 15.78%; 2014 to 2021, 98.27%), and the cultivated area by 47.74% between 1986 and 2014. Landscape metrics were estimated over the four epochs of the study. The results revealed that most of the metrics suggest similar trends over the entire period of study. However, the Largest Patch Index (LPI), Landscape Shape Index (LSI) and Normalized Landscape Shape Index (NLSI) were useful in capturing the spatio-temporal variations in landscape transformation. Also, Class Area (CA) was useful to show the degree of land cover change. The study concluded that the location of spatial structures influenced the landscape patterns and urbanization processes in the study area. Hence, the study recommended regular monitoring of the expansion of the built-up area to check for imminent urban sprawl in the study area.