Industrialization and development of technology havecaused rapid changes to land and contributed towards urbanization. Villages andsmall cities are being converted to urban areas and into towns frequently thesedays. Similarly, over the last few decades developed areas and urban sites incities and towns have been expanding in Bangladesh at a significant rate.
Establishmentof industries and other landmarks have contributed significantly towards thismassive outburst and expansion of developed areas. To add to that there is alsobetter living standard and easier lifestyle in the cities. Thereforeurbanization is happening continuously.
At the heart of this expansion in Bangladesh,lies the city of Dhaka. Most of the outward expansion in terms of developmenthave happened centering Dhaka. The urban growth rate has risen up massivelysince the last 15-20 years.Bangladesh has seen a massive population outburst in thelast few decades.
Dhaka is at the core of this rapid rise in population. Currentlyabout 2 billion people live in the city of Dhaka. To cope up with thisincreasing number of population various other changes has been happening.
To accommodatea population this big the infrastructure and land use has also seen rapiddevelopment. Social development, better financial chances and better lifestylehave been the most intensive and leading factor towards change in land use. Thefast development has also caused changes in all the domains for this particulartown. Number of markets, industries, airports and different other establishmentshave increased in Dhaka which has attracted even more people in this town andas a result changes in land use is happening everyday by leaps and bounds. Allthese influential factors have made rapid changes to Dhaka in geo level.In this context remote sensing imagery and concepts cancome in handy.
Terabytes of satellite image data are generated everyday withall the satellites that have been launched to monitor the earth from differentcriterion. All these images illustrate the condition of built up areas,vegetation, water bodies and of various other natural and man-made entities.Using satellite based images for land cover analysis and classification providepromising results and enables to perform detailed study on areas that otherwise,would not have been possible.
To perform the analysis based on the satellite image a reliablework flow and model had to be designed. This workflow consisted of multiplemeasures and decisions based on which the information had to be obtained fromthe image. This extraction of information from the data can sometimes bedifficult and time consuming. Therefore, the goal was to design a general patternfor analysis of the images which can later on provide important details interms of the changes and development of the land use.
Thus. The objective of this study is to study andinterpret the satellite images of the study area. By performing this analysisthe various measures for different types of lands and can be generated. Thisapproach uses various remote sensing techniques and algorithms. The interpretationwas performed for various years spanning over 3 decades. This allows to have aclear picture of the changes that are occurring and also provides a moreaccurate representation.
Finally, it generates a model representing the growthpatterns and the most densely urbanized areas for Dhaka.The study area chosen for this study is the Dhaka district.Dhaka city is the capital of Bangladesh. It is the largest city of Bangladeshand accommodate the lion’s share of this huge population the country. After the1990s the urbanization and industrialization has begun enormously in this city.The rapid development of infrastructures and multinational companies led to theoverall development of the town.
All these factors played the role of catalysts forattracting people from all over the country to migrate to Dhaka. All the socioand economic factors played a key role too. As people started migrating toDhaka the land use change has been significant. The reduction of trees andplantation is pretty much visible with naked eye. High raised buildings and skyscrapersare a common scene now on every block of the city whereas there had been ascarce number of high raised buildings only 20 years ago.
Besides construction of houses for this large number ofpeople the city needed to provide more land to the countless industries and millsthat have been established lately. They are more often located at the outskirtsof the city, near the rivers where it’s easier to commute. As a result, therivers have been overused and in some cases they are filled up. Not only therivers, many water bodies, such as small lakes and ponds are frequently filledup to build houses and markets. Many trees have been cut down to build roadsfor the rising number of cars in this town.
All these factors are influential for conducting a studyfor analyzing the patterns of land use for the district of Dhaka. Anotherobjective is to monitor and figure out the changes across multiple decades andwhere the changes have been maximum.Remote sensing is commonly known to be the field thatdeals with obtaining information about the surface of the Earth from a distantplace. The process is accomplished by sensing and recording reflected andemitted energy.
After that, that information can be processed analyzed andapplied for further use. Mostly in remote sensing, the process involves interactionbetween incident radiation and targets of interest. Remote sensing also usesnon imaging sensors and involves sensing emitted energy through differenttechniques. The steps involving remote sensing can be broken down into differentphases.The first requirement for remote sensing is to have aconstant energy emitting source.
In our case, it’s the sun. Sunlight emittedfrom the sun directly falls on the lands and water bodies. The latter phaseswork after based on the reactance of the objects to this energy coming from thesun.As the energy from the sun travels to reach earth it hasto travel through the atmosphere and the different levels of it. As it goesthrough it it, it interacts and radiates energy through it. The same process isrepeated while it returns after being reflected from the target object fromearth before reaching the satellite.After reaching the area of interest the energy interactswith the target object.
After that the target object reacts to it, or emitsenergy as