JIBRAN KHAN1*&TAHREEM OMAR2

JIBRAN KHAN&TAHREEM OMAR

IMPACTS OF URBANIZATION ON LAND SURFACE TEMPERATURE OF

KARACHI

INTRODUCTION

• Urbanization is a global multidimensional process that is manifest through rapidly changing human population densities and changing land cover

• The growth of cities is due to a combination of four forces; natural growth ,rural to urban migration ,massive migration due to extreme events and redefinitions of administrative boundaries

INTRODUCTION

• Since the emergence of Pakistan in 1947, the population of Karachi has seen 35-fold increases in its population and almost 16-fold increases in the spatial expansion

• It has been observed that there is a close relation between surface air temperature and urban growth. There are distinct seasonal differences in effects of urbanization on surface air temperature change trend and the different effects are observed temporally

• Karachi is the rapidly growing city not only in Pakistan but also in South Asian region in respect of population, area and economic activities. It is the shelter to 11% population of Pakistan. About 55% growth in urban population and urban area is observed after 1990s

ENVIRONMENTAL PROBLEMS OF KARACHI:

• There are many problems in Karachi, one of them is related to climate, which is dependent on several issues. Like increasing temperature of the city has been noted which is related to increase in urban development in terms of buildings ,population and vehicles ,also decrease in plants of city .As well as cause of pollution.

STUDY AREA

• Karachi is the largest and most populous city in Pakistan. Karachi is the biggest city of Pakistan and is the provincial capital of Sindh which is covering an area of 3,527 km. It is located at 24 º 45” to 25 º 15” north and 66 º 37” to 67 º 37” east.

DEMOGRAPHIC DISTRIBUTION

The demographic and population distribution in the Karachi has undergone numerous changes over the past 150 years. Non-governmental and international sources report that Karachi's current population is estimated to be 20 million a huge increase over its population in 1947 (400,000).

People are continuously migrating from different parts of Pakistan and have contributed to a rich and diverse mix of people that live in Karachi. This has given the city a very metropolitan character, and it has earned it the title as “the Melting Pot of Pakistan”.

Population in 1998 Population in 2010

•In our study we used data of Landsat (ETM+) of the year 2000,2006, 2010,2011,Landsat of the year 2000, 2010 (TM), Quick bird 2011.These images were downloaded from the USGS Earth Resource Observation Systems Data Center and from the other sources. For processing of images ERDAS IMAGINE 9.3, ArcGIS 10.1 has been used

• Due to the increased in urban growth during the last decade, we compared the satellite imageries of Karachi using unsupervised classification to perform change detection analysis. Unsupervised classification is showing the difference in terms of buildup area and growth of population. Our comparison shows that there has been increased urban extent observed during the past ten years

Image showing the comparison of unsupervised classification of Karachi of year 2000 (left) and 2011 (right)

DIGITAL IMAGE PROCESSING

• Due to the increased in urban growth during the last decade, we compared the satellite imageries of Karachi using unsupervised classification to perform change detection analysis. Unsupervised classification is showing the difference in terms of buildup area and growth of population. Our comparison shows that there has been increased urban extent observed during the past ten years..

• Normalized Difference Built up Index (NDBI) of Karachi has been find out. It is also an important tool to analyze the overall buildup of any city. It has been observed that Karachi has been through extreme urbanization in the past few years

Image showing the comparison of NDBI of Karachi of year 2000 (left), 2011 (center) and 2013 (right)

• The NDVI (Normalized Difference Vegetation Index) tool in the Image Analysis Window calculates how vigorous the vegetation is in an area. But it’s not the only index available, although it may be the most widely used. shows the comparison of NDVI of Karachi.

Image showing the comparison of NDVI of Karachi of Landsat 2000 (left), Landsat 2013 (center) and Quick bird 2011 (right)

• Land surface temperature is the direct consequential parameter of urban growth. Results have shown the there is a direct effect of increased urbanization in Karachi on its land surface temperature

Image showing the extracted classified land surface temperature (LST) of Landsat ETM+ imagery

CONCLUSION

• It has been observed that there is a direct influence on the land surface temperature of Karachi due to its increased urban growth for the recent past years

• The results also show the practicability of such powerful tools of GIS for the urban development studies.

Questions/Suggestions?

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