Impact of seasonal urban greening variability on land surface temperature in Benin (West Africa).

Abstract Urban greening quantification and seasonal variation impact for surface temperature mitigation have been poorly understood and monitored in Benin. We have attempted to assess of season variability of normalized difference vegetation index (NDVI) using Landsat 7 and 8 data to get more accurate information about the vegetation tendency and effects on urban surface temperature mitigation. Monthly satellite derived NDVI series were collected using Google Earth Engine open-source while observed surface temperature were obtained at National Agency of Meteorology in Benin. We performed Mann-Kendall trend test to assess the significance of the trend chats. ANOVA followed by SNK test was applied to examine seasonal variation on NDVI significance. Likewise, a simple linear regression was applied to show the relationship between surface temperature and NDVI variables. No significant linear trends (p-values > 0.05) were observed for annual vegetation index (NDVI) and surface temperature. The NDVI tendency decreased from 2000 to around 2011 and started to increase up to 2020. However significant difference (P-Value < 0.001) between seasons was found for the mean NDVI and January-March period showed the lowest values of mean NDVI. Despite the negative relationship between annual mean land surface temperature (LST) and NDVI, the dry seasons showed a positive correlation in each city. Thereby, judicious urban management of water availability such as greenery irrigation would be more helpful for ensuring the sustainable urban surface temperature mitigation.