Space–time analysis of urban green spaces’ disappearance in Ilorin, Nigeria

Abstract

In recent years, urban green spaces (UGS) have fought for relevance and dominance with competing urban development agendas, which have often proclaimed moral victory, favoring competing interests over the need for UGS. This study examined the decline of UGS between 1986 and 2020 in Ilorin, Nigeria. The methodology employed survey (population estimates) and remotely sensed satellite data (Landsat imagery). The study estimated the UGS decline, land surface temperature (LST) and normalized difference vegetation index (NDVI) for Ilorin from images retrieved from Landsat 5, 7, and 8 thermal infrared sensors using the mono window algorithm and green spaces. Findings revealed the drastic depletion of green spaces, as the combined average reduction effect of riparian and densely vegetated green areas, woodlands, and agricultural sites took place at the rate of 3.37 percent. In comparison, built-up and gray spaces increased by an average of 4.90 percent over the study periods increasing the average LST from 38 °C to over 40 °C. With staunch assurances, Ilorin is on pace to lose 9.51 hectares before 2030. Conclusively, governments and city managers must do enough through environmental investments by revising policies that produce new results that can improve the roles of UGS in ecosystem services provision.