An Examination of the Impacts of Urbanization on the Environment
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19, 2016 19, ‐ 17 An Examination of the impacts of Urbanization , October October , on the Environment: Experiences from current and former capitals of Myanmar Vietnam Soe W. Myint Ho Chi Minh City, Ho Chi Minh City, Professor, School of Geographical Sciences and Urban Planning Senior Sustainability Scientist, Global Institute of Sustainability International Meeting on Land Use and Emissions in South/Southeast Asia Arizona State University Background Yangon is a former capital of Myanmar between 1948 and 2005. It remains the largest city, and the most important commercial center of Myanmar. Population: 7.36 million In November 2005, the military government designated Naypyidaw as the new administrative capital. Constructions started in 2002, and it is still in progress. Population: 0.92 million Study Area Objective (1) To compare the spaio-temporal patterns of urbanization between Naypyidaw and Yangon from 2000 to 2013. (2) To examine the effects of urbanization on the regional environment and atmosphere. Data The urbanization study uses classified Landsat images: Landsat 7 ETM+ for 2000-2003 Landsat 5 TM for 2004-2011 Landsat 8 OLI for 2013 The analysis of regional environment uses MODIS land products that include: Land Surface Temperature (LST) (MOD11A2) Annual Net Primary Productivity (ANPP) (MOD17A3) Evapotranspiration (ET) (MOD16) Percent Tree Cover (PTC) (MOD44B) Aerosol Optical Depth (AOD) (MOD04_3K) Method Classification of Landsat images: ISODATA unsupervised classification: 200 clusters Two classes: built-up vs. non-built-up Overall accuracy > 85% Method (continued) Time-series trend analysis Mean annual daytime LST, nighttime LST, ET, ANPP, and PTC Pixel values are analyzed against the year sequence for all the image pixels using OLS regression to identify areas that have statistically significant changes 14 data points x = [2000, 2001, 2002, …, 2013] y = [ET2000, ET2001, …, ET2013] y = β0 + β1× x Only pixels with statistically significant changes are retained (p<=0.05) Method (continued) Time-series analysis for aerosol optical depth (AOD) Monthly mean AOD values were calculated and plotted against each month Yearly mean AOD values were regressed against the year sequence for all the image pixels using OLS regression to identify areas that have statistically significant changes Results (Yangon Built-up area) Results (Built-up) Yangon (2000-2013) Results (Built-up) Naypyidaw (2000-2013) Carbon Stock Trend Yangon (2000-2013) Daytime Temperature Trend Yangon (2000-2013) Nighttime Temperature Trend Yangon (2000-2013) Evapotranspiration Trend Yangon (2000-2013) Percent Tree Cover Trend Yangon (2000-2013) Carbon Stock Trend Naypyidaw (2000-2013) Daytime Temperature Trend Naypyidaw (2000-2013) Nighttime Temperature Trend Naypyidaw (2000-2013) Evapotranspiration Trend Naypyidaw (2000-2013) Percent Tree Cover Trend Naypyidaw (2000-2013) Yangon Naypyidaw Yangon vs. Naypyidaw Urban Growth Built-up area % difference vs. ANPP SLOPE (Yangon) 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 -2.0 -4.0 ANPP slope coefficient -6.0 -8.0 -10.0 -12.0 y = -34.278x + 6.7225 -14.0 R² = 0.7196 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. Daytime LST SLOPE (Yangon) 0.6 y = 1.2281x - 0.0339 0.5 R² = 0.5734 0.4 0.3 0.2 0.1 0.0 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 -0.1 Daytime LST slope Daytime coefficient -0.2 -0.3 -0.4 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. Nighttime LST SLOPE (Yangon) 0.12 0.10 y = -0.232x + 0.0875 R² = 0.3509 0.08 0.06 0.04 Nighttime slope coefficient 0.02 0.00 -0.08 -0.06 -0.04 -0.02 0.00 0.02 0.04 0.06 0.08 0.10 0.12 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. ET SLOPE (Yangon) 20.0 15.0 10.0 5.0 0.0 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 ET slope coefficient y = -42.214x + 7.1405 -5.0 R² = 0.7938 -10.0 -15.0 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. Percent Tree Cover SLOPE (Yangon) 0.015 0.010 0.005 0.000 -0.40 -0.35 -0.30 -0.25 -0.20 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 -0.005 PTC slope coefficient -0.010 y = -0.0226x + 0.0021 R² = 0.7124 -0.015 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. ANPP SLOPE (Naypyidaw) 15 10 5 0 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -5 -10 ANPP slope coefficient -15 -20 y = -15.074x - 2.5598 R² = 0.4851 -25 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. daytime LST SLOPE (Naypyidaw) 0.3 0.2 0.1 0.0 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -0.1 -0.2 y = 0.2715x - 0.0033 Daytime LST slope Daytime coefficient R² = 0.3658 -0.3 -0.4 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. nighttime LST SLOPE (Naypyidaw) 0.25 0.20 0.15 0.10 y = 0.0607x + 0.0895 R² = 0.3558 Nighttime LST slope coefficient 0.05 0.00 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. ET SLOPE (Naypyidaw) 20.0 15.0 10.0 5.0 0.0 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 -5.0 -10.0 ET slope coefficient -15.0 -20.0 y = -19.213x - 4.8423 R² = 0.4131 -25.0 -30.0 Built-up area percent difference between 2000 and 2013 Built-up area % difference vs. PTC SLOPE (Naypyidaw) 0.02 0.01 0.00 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 -0.01 y = -0.0253x - 0.0067 -0.02 R² = 0.34 PTC slope coefficient -0.03 -0.04 Built-up area percent difference between 2000 and 2013 Monthly Aerosol Optical Depth (Yangon) 1.8 1.6 1.4 1.2 1.0 0.8 0.6 AOD (km) 0.4 0.2 0.0 0 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 Month Monthly Aerosol Optical Depth (Naypyidaw) 1.2 1.0 0.8 0.6 0.4 AOD(km) 0.2 0.0 0 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 192 Month AOD Yearly Trend (Yangon vs. Naypyidaw) Conclusion The growth of urban built-up area exhibits a polynomial relationship for Yangon and an exponential relationship for Naypyidaw. Urbanization has caused significant carbon release, increased LST for both daytime and nighttime, decreased Evapotranspiration (ET) rate, and decreased percent tree carver (PTC) within and around the cities. The observation of aerosol optical depth (AOD) presents no significant change for both cities over the study period. .