Effect of tree canopy on urban heat island in Makurdi, Benue State, North-Central Nigeria

Abstract

This study determines the effect of tree canopy on urban heat island in Makurdi, Benue State of North-Central Nigeria. Applying a multi-stage sampling technique, 150 residential houses with tree canopies, and 150 without tree canopies in urban and rural locations in and around Makurdi were sampled for the study. Data were collected by measuring wall temperatures in selected residential houses with tree canopies and those without tree canopies for both dry and rainy seasons. A total of 29 species of trees with 284 individuals representing 15 families were encountered in residential houses within and around Makurdi. There was a significant difference in temperatures of residential houses with tree canopy and those without tree canopy in rural areas (Mean Difference = 0.88 ± 1.55, p = 0.01) and in urban locations (Mean Difference = 3.64 ± 2.86, p = 0.01). There was significant difference in mean temperature variation between urban (27.75 ±3.57a) and rural (24.64 ±2.16b) locations within the study area. Significant difference exists between mean temperature values for rainy and dry seasons within the study area (Mean Difference = 1.42 ± 1.69). Individuals living (50%) in residential houses without tree canopy felt discomfort while those with tree canopy showed no discomfort. There was no discomfort to residents in rural areas of Makurdi. This study has established the existence of urban heat islands within Makurdi and therefore proved the positive effect of trees in contributing to reducing the occurrence of urban heat islands