Table 15 shows the urban area size for each city by year, as estimated from the classification results, and the rate of urban area growth along with the estimated population size and rate of population increase. Figure 28 is a visual representation of the results shown in table 15.
Table 15: The urban area size (km2), rate of urban area growth (%), UN population estimates (1000 and rate of population growth (%) for each of the cities by year
Cairo Delhi Dhaka
Year Urban Size (km2) Growth Rate (%) Pop. est. (1000) Pop. growth rate (%) Urban Size (km2) Growth Rate (%) Pop. est. (1000) Pop. growth rate (%) Urban Size (km2) Growth Rate (%) Pop. est. (1000) Pop. growth rate (%) 1990 491.3 9892.0 474.5 9726.0 97.6 6621.0 1995 818.0 66.5 11962.0 20.9 564.6 19.0 12407.0 27.6 99.0 1.4 8332.0 25.8 2000 1013.7 23.9 13626.0 13.9 663.9 17.6 15732.0 26.8 106.7 7.8 10285.0 23.4 2005 1208.4 19.2 15174.0 11.4 938.6 41.4 18670.0 18.7 122.8 15.1 12331.0 19.9 2010 1397.7 15.7 16899.0 11.4 1062.8 13.2 21935.0 17.5 190.2 54.9 14731.0 19.5 2015 1631.2 16.7 18772.0 11.1 1647.6 55.0 25703.0 17.2 355.2 86.7 17598.0 19.5
Lagos (area of analysis) Shanghai (area of analysis)
Year Urban Size (km2) Growth Rate (%) Populati on est. (1000) Populati on growth rate (%) Urban Size (km2) Growth Rate (%) Populatio n est. (1000) Population growth rate (%) 1990 254.61 (1984) 4764.0 488.9 7823.0 1995 5983.0 25.6 737.6 33.7 10450.0 33.6 2000 448.02 47.6 7281.0 21.7 1033.8 28.7 13959.0 33.6 2005 586.58 23.6 8859.0 21.7 1227.9 15.8 16763.0 20.1 2010 745.88 21.4 10781.0 21.7 1782.0 31.1 19980.0 19.2 2015 987.24 24.4 13123.0 21.7 2513.0 29.1 23741.0 18.8
Figure 29
1990 to 2015. ( to 2015. ( cities by year. ( cities by
the five cities by year. ( the five cities by year.
The population estimates inc 2015, to a point where
largest increase in population times).
times, Shanghai
Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city to be surpassed by the other cities.
The rate of population
population growth decreases noticeable from 1995 to 2000
29: (Top right
1990 to 2015. (Top left to 2015. (Middle left cities by year. (Middle right cities by year. (Bottom left the five cities by year. ( the five cities by year.
population estimates inc 2015, to a point where
largest increase in population times). This was
Shanghai
Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city to be surpassed by the other cities.
The rate of population
population growth decreases noticeable from 1995 to 2000
Top right) A box plot indecating the population growth experianced by each city from Top left) A box plot indecating the urban gro
Middle left) A line plot indicating the growth in population estimates for each of the five Middle right) A line plot indicating the growth in urban area size for each of the five Bottom left) A line plot indicating the rate of growth in population estimates for each of
the five cities by year. (Bottom right the five cities by year.
population estimates inc
2015, to a point where estimates more largest increase in population
This was followed by
Shanghai increased 2.64 times and Cairo 1.89 times. Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city to be surpassed by the other cities.
The rate of population, in %
population growth decreases noticeable from 1995 to 2000
) A box plot indecating the population growth experianced by each city from ) A box plot indecating the urban gro
A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of
Bottom right) A line plot indicating the rate of urban area growth for each of
population estimates increased at estimates more largest increase in population, from 7
followed by Dhaka with
increased 2.64 times and Cairo 1.89 times. Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city to be surpassed by the other cities.
in %, slowed down for all five cities population growth decreases noticeable from 1995 to 2000
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) A box plot indecating the population growth experianced by each city from ) A box plot indecating the urban gro
A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of ) A line plot indicating the rate of urban area growth for each of
reased at a steady estimates more than double
from 7.8 million with a 2.75 times increased 2.64 times and Cairo 1.89 times. Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city
slowed down for all five cities population growth decreases noticeable from 1995 to 2000
) A box plot indecating the population growth experianced by each city from ) A box plot indecating the urban growth experianced by each city from 1990 A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of ) A line plot indicating the rate of urban area growth for each of
steady rate for all five cities from 1990 to than doubled for all 5.
to 23.7 million 2.75 times increase increased 2.64 times and Cairo 1.89 times. Delhi’s population surpasses Cairo's in the early 1990’s was surpassed by Shanghai. This makes Cairo the only city
slowed down for all five cities population growth decreases noticeable from 1995 to 2000
) A box plot indecating the population growth experianced by each city from wth experianced by each city from 1990 A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of ) A line plot indicating the rate of urban area growth for each of
for all five cities from 1990 to d for all 5. Lagos experienced the .7 million and increase of 3.034
increase, Delhi increased 2.64 times and Cairo 1.89 times.
Delhi’s population surpasses Cairo's in the early 1990’s, and by
was surpassed by Shanghai. This makes Cairo the only city’s population estimates
slowed down for all five cities from 1990
population growth decreases noticeable from 1995 to 2000, especially from 2000 up
) A box plot indecating the population growth experianced by each city from wth experianced by each city from 1990 A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of ) A line plot indicating the rate of urban area growth for each of
for all five cities from 1990 to Lagos experienced the and increase of 3.034 Delhi increased 2.67
the late 1990’s it ’s population estimates
from 1990. The rate of especially from 2000 up
) A box plot indecating the population growth experianced by each city from wth experianced by each city from 1990 A line plot indicating the growth in population estimates for each of the five ) A line plot indicating the growth in urban area size for each of the five ) A line plot indicating the rate of growth in population estimates for each of ) A line plot indicating the rate of urban area growth for each of
for all five cities from 1990 to Lagos experienced the and increase of 3.034 ncreased 2.67 the late 1990’s it ’s population estimates . The rate of especially from 2000 up
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until 2005. Shanghai experienced the sharpest drop in growth rate from 2000 to 2005.
When comparing the estimated population numbers with the growing urban footprint, by analysing these results, a number of points are highlighted. For one the population estimates for Delhi is higher than any of the other cities, yet the physical urban size does not reflect this and is only the third largest city. This might reflect a densely populated urban area.
The same is true for Dhaka; the physical urban size is much smaller than the other cities at 355.2km2 in 2015. Yet it has a large estimated population close to 17 million. Again this might point to a highly dense urban area, however it might also be that a lot of people live in sparsely built up areas around the Dhaka urban area. Due to the scattered nature of these settlements and dense vegetation, it is possible that they could not be properly detected on the Landsat images with a resolution of 30m. A parametric (Pearson’s correlation with an R > 0.9) and a non-parametric (Spearman’s rank correlation with rho = 1 ) test for correlation was performed, both of which indicated a significantly positive relationship. A linear model was created for each city to analyse the strength and direction of relationship between the population estimates and physical urban growth. The results indicated that there is a linear relationship between these two variables for all 5 cities, though the strength of the relationship differs significantly between the five cities. All the regression tests resulted in a significant p-values, for Cairo the p-value was 0.000005, for Dhaka it was 0.02, for Delhi it was 0.0288, for Lagos it was 0.00203 and for Shanghai it was 0.000761, see table 16 for detailed test results.
The model indicated that if the estimated population increases by one unit (1000) the physical urban area for Cairo will increase by 0.1259 km2, 0.02176 km2 for Dhaka and 0.06936km2 for Delhi. The analysis for Lagos and Shanghai only took into consideration the urban growth within the administrative boundaries in which the population estimates are estimated. For Lagos (Lagos State) the urban area will increase by 0.0234 km2 for each unit of increase in population and 0.12213 km2 for Shanghai. Table 16 shows the model results for each of the cities.
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From these results, we can observe that the strongest relationships between the two variables are seen for Cairo, Lagos and Shanghai. Compared to the other three cities, a weaker relationship is observed.
Table 16: Results from the regression models to test the relationship between population growth and
urbanisation for each of the five cities
Cairo Dhaka Delhi Lagos Shanghai
Pearson's correlation 0.9981 0.868 0.955 0.9936 0.965144 Spearman’s correlation 1 1 1 1 1 0.00277 0.00278 0.00277 0.01667 0.00277 p-vlaue Intercept Estimation -717.4 91.7073 -312.25008 -955.39 -589.965 Intercept Pr (>t) 0.000213 *** 0.2662 0.18276 0.0021* 0.0526. Pop Estimate 0.1259 0.02176 0.06936 0.0234 0.12213 Pr (>t) 0.000005 *** 0.0200* 0.00288** 0.00203** 0.000761*** R-squared 0.9964 0.77 0.9137 0.9718 0.9553 Adjusted R-squared 0.9954 0.072 0.8921 0.962 0.9441 DF 4 4 4 3 4 P-value 0.00000499 *** 0.01996* 0.00288** 0.002028*** 0.0007613*** Slope in degrees 7.1734° 0.396° 3.967° 13.1704° 6.96295°
Durbin Watson Autocorrelation
Test P-value 0.284 0.074 0.342 0.204 0.034
Testing for heteroskedasticity
0.1897 0.30127 0.33825 0.5365 0.4456
P-value
Bonferroni Outlier test 0.00424 0.01477 0.01876 0.0853 0.327
As explained in the research methodology section, due to the small sample size these models are subject to noise. The small sample size also makes it impossible to perform a time series analysis and as a result, a Durbin Watson test was performed to test if the models were influenced by autocorrelation.
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