Assessing the Relationship of LST, NDVI and EVI with Land Cover Changes in the Lagos Lagoon Environment

Abstract

The Lagos Lagoon is under increased pressure from growth in human population, growing demands for natural resources, human activities, and socioeconomic factors. The degree of these activities and the impacts are directly proportional to urban expansion and growth. In the light of this situation, the objectives of this study were: (i) to estimate through satellite imagery analysis the extent of changes in the Lagos Lagoon environment for the periods 1984, 2002, 2013 and 2019 using Landsat-derived data on land cover, Land Surface Temperature (LST), Normalised Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI); and (ii) to evaluate the relationship between the derived data and determine their relative influence on the lagoon environment. The derived data were subjected to descriptive statistics, and relationships were explored using Pearson's correlation and regression analysis. The effect of land cover on LST was measured using the Contribution Index and a trend analysis was carried out. From the results, the mean LSTs for the four years were 22.68°C (1984), 24.34°C (2002), 26.46°C (2013) and 28.40°C (2019). Generally, the mean LSTs is in opposite trend with the mean NDVIs and EVIs as associated with their dominant land cover type. The strongest positive correlations were observed between NDVI and EVI while NDVI had the closest fit with LST in the regression. Built-up areas have the highest contributions to LST while vegetation had a cooling influence. The depletion in vegetative cover has compromised the biodiversity of this environment and efforts are required to reverse this trend.

Potential Influence of Urban Sprawl and Changing Land Surface Temperature on Outdoor Thermal Comfort in Lagos State, Nigeria

“…All over the world, the intensity of human activities, coupled with fast-paced urbanisation, is leading to alterations of the land cover and, in effect, the LST. Land cover change, including variations in surface reflectance and topography, are important indicators that influence LST (Hou et al 2010, Obiefuna et al 2018, Alademomi et al 2020. Due to the physical properties of the land surface, surface temperatures are typically higher in urban areas than in vegetated areas and in the countryside; this difference is attributable to their physical properties (Nse et al 2020).…”

Urban Heat Island Footprint Effects on Bio-Productive Rural Land Covers Surrounding a Low Density Urban Center

“…With EVI, the forested and wetlands surfaces obtained a marginally higher correlation, with April and May results deviating the most in Table 3. Considering that LST generally trends in contrast to NDVI and EVI (Alademomi et al 2020), the stronger correlation with EVI is due to the denser vegetation and reduced soil reflectance while agriculture is distributed more dominantly and performs better with NDVI.…”

“…The multispectral Landsat 7 bands required from each date are blue, red, near infrared (NIR), and shortwave infrared (SWIR). Amongst the vegetation indices, NDVI is more commonly used due to its cancellation of topographic, cloud cover, atmospheric, and changing sun angle effects with vegetation monitoring (Alademomi et al 2020).…”

“…Enhanced Vegetation Index (EVI) acts as an enhancement to it with its atmospheric correction, saturation in areas with high biomass, and soil reflectance reduction abilities (Alademomi et al 2020).…”

“…It is well established that vegetated land covers behave as cooling zones within a UHI (Oke 1979;Sun, Wu, and Tan 2012;Li, Zhang, and Kainz 2012;Skelhorn, Levermore, and Lindley 2016;Q. Huang et al 2019;Alademomi et al 2020).…”