Impacts of Urbanization on Precipitation and Temperature Trends: A Case Study of Peninsular Malaysia

Malaysia is a fast developing country where urbanization takes place rapidly to accommodate for the growing population in the country. Continuing urbanization associated with land development and deforestation are completely altering the water surface profiles and flood risks by increasing impermeable urban areas. High intensity of rainfall and severe weather condition due to climate change effects have also caused a gradual deterioration in the efficiency of stormwater pathway, which has resulted in an increase in the frequency and magnitude of flooding. This study aims to investigate the impact of urbanization on climate change for a case study in Peninsular Malaysia. Specifically, the relationship between urbanization, precipitation (P) and temperature (T) will be explored to provide evidence that urbanization increases the correlation between precipitation and temperature. In this study, urbanization is defined using an Urban Ratio, λ_U where the urban ratio is a fraction of total urban area within a specified grid to total grid area. Square grids of 100 km² will be assigned uniformly across Peninsular Malaysia and urban areas will be determined based on the European Space Agency (ESA) Climate Change Initiative (CCI) Land Cover. Satellite rainfall data Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) and satellite surface temperature dataset MODIS/Terra LST/E Daily L3 Global 1 km SIN Grid (MOD11C2) will be used to generate a correlation contour map between the annual mean daily precipitation and annual mean daily temperature. The correlation contour map will then be compared against the Urban Ratio grid to prove that grids of higher urban ratio has more significant correlation between Precipitation and Temperature. The results will then be divided into 5 separate regions based on the Urban Stormwater Management Manual for Malaysia (MSMA 2), where the regions include the West Coast, East Coast, Northern, Highland and Southern regions. The regional analysis will provide insight to where the correlation between the three factors are stronger. In addition, an analysis to the correlation between monthly mean precipitation and monthly mean temperature will also be conducted to determine seasonal correlation between Urban Ratio, Precipitation, and Temperature.

Keywords: Urbanization, Precipitation, Temperature, Climate Change, Correlation