Evaluation of the Impact of Urban Forestry on Urban Heat Island

Abstract

The purpose of this study is to statistically evaluate the impact of urban forestry on urban heat Island in Umuahia city, located in Eastern Nigeria using Land Surface Temperature (LST) time series. The LST datasets were extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS, MYD11A2 V6) satellite using Python and JavaScript in Google Earth Engine (GEE) platform. Two microclimate environments were considered namely:  The Densely and sparsely populated areas in three different locations each. Each microclimate location had 976 observations starting from the 18th of February 2000 to the 1^st of May 2021. The Auto-regressive Moving Average (ARMA) was used to model and predict the time series future points of each location; accuracy was measured using Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE). The Land surface temperature of each selected microclimate location were monitored and the results showed an average observed temperatures difference of 2.9⁰C between the Densely Populated and Sparsely Populated areas. In conclusion, the study showed that inhabitants of densely populated areas experience higher temperature regime than the inhabitants living within the sparsely populated areas. This increase in temperature within the densely populated could be attributed to the gradual loss of vegetation cover, which is due to man-made activities such as land use, land cover changes, industrial activities, vehicular movements, and the heat generated from buildings within the city. Thus, a spatial development planning strategy, which controls the growth of the built area and add green spaces should be created for a friendly urban environment.