Geospatial Analysis of Osun Osogbo Unesco Cultural Site Based on Landuse and Landcover Dynamics Using Remote Sensing and Gis

ABSTRACT Understanding spatiotemporal patterns of land use and land cover (LULC) change is fundamental to sustainable landscape management and environmental conservation, especially in ecologically and culturally significant sites. In this context, this study analyzed the LULC dynamics of the Osun Sacred Grove, a UNESCO World Heritage Site in Osogbo, Osun State, Nigeria, using Remote Sensing (RS) and Geographic Information System (GIS) technologies. Multi-temporal satellite imageries from 1984, 1991, 2002, 2014, and 2022 were processed and classified into five major LULC categories—built-up area, bare soil/open space, farmland, forest, and water body—to assess the magnitude, trend, and rate of land transformation over a 38-year period. To improve accuracy, field surveys and ancillary data were also employed for classification enhancement and result validation. The findings revealed profound spatiotemporal changes in land use and cover driven primarily by human activities. Notably, the built-up area increased dramatically from 0.26 hectares (0.14%) in 1984 to 11.70 hectares (6.29%) in 2022, indicating rapid urban expansion, infrastructural development, and population growth around the Grove. In contrast, forest cover declined consistently from 129.88 hectares (69.89%) to 68.31 hectares (36.76%) over the same period, representing a significant loss of vegetation due to deforestation, agricultural encroachment, and expansion of settlements. At the same time, farmland increased from 39.07 hectares (21.02%) in 1984 to 76.59 hectares (41.21%) in 2022, reflecting intensified cultivation and conversion of forested land for agricultural purposes. Similarly, the area under bare soil/open space rose from 4.75 hectares (2.56%) to 23.22 hectares (12.49%), signifying active land clearance, construction, and exposure of soil surfaces. Regarding water bodies, the area displayed an irregular pattern, decreasing from 11.88 hectares (6.39%) in 1984 to 5.46 hectares (2.94%) in 2002, increasing to 7.22 hectares (3.88%) in 2014, and then slightly declining to 6.03 hectares (3.24%) in 2022, possibly due to seasonal variation, sedimentation, and land reclamation activities. Trend and rate analyses further support these observations: built-up areas recorded the highest annual rate of ix increase between 2014 and 2022 (-0.432), while forest cover experienced the highest annual rate of decline during 1984–1991 (1.542) and 2014–2022 (1.531). Together, these results underscore the growing anthropogenic pressure on the Grove’s ecosystem. Consequently, the observed spatial dynamics suggest a gradual but persistent transformation of the Grove from a densely forested ecosystem to a human-dominated landscape, posing threats to biodiversity conservation, ecosystem integrity, and cultural heritage preservation. The study further demonstrates the effectiveness of RS and GIS tools in monitoring landscape transformations and generating data for evidence-based environmental decision-making. Taken together, these findings suggest that unless proactive measures are taken, the continued expansion of settlements and farmland around the Grove will further endanger its ecological stability and cultural value. Therefore, the study recommends stronger land-use regulations, community participation in conservation, reforestation of degraded zones, periodic GIS-based monitoring, and the integration of sustainable urban planning with heritage protection. Ultimately, the results provide a vital framework for policymakers, environmental managers, and cultural heritage custodians to promote the sustainable management of the Osun Sacred Grove and similar ecocultural landscapes across Nigeria and sub-Saharan Africa. x