Predicting Urban Growth and Implication on Urban Thermal Characteristics in Harare, Zimbabwe

This study sought to determine the impact of urban growth on future micro-climate of Harare by predicting future distribution of land use and land cover (LULC), as well as land surface temperature. Landsat series data was used to map Land Use and Land Cover and land surface temperature distribution during the month of October for the year 1984, 1993, 2001 and 2015. The Cellular Automata Markov Chain analysis was used to determine long term landscape transformation at 10-year time steps from 2015 to 2045. The value of a range of vegetation and non-vegetation indices to predict land surface temperature were also tested. Results show that the Urban Index (UI), a non-vegetation index was the best predictor of surface temperature (R=0.9831). Based on 1984 and 2015 changes, results showed that high density built-up areas will increase monotonically from 470.02 in 2015 to 490.36km
²
in 2045, while green spaces would decrease from 57.42 to 27.85km2 during the same period. Using UI as predictor of land surface temperature, the 18-28°C class will decrease in coverage between 2015 and 2040, while the 36-45°C category will increase in proportion covered from 42.5 to 58% of city. We concluded that continued urban growth will increase warming and result in higher future temperatures.