Literature Review On Researches About Urban Sprawl

Though there is controversy about the precise description of urban sprawl, the common consensus is that urban expansion is categorized by unplanned and irregular growth patterns, which are determined by various practices, resulting in disorganized use of resources. The straight effect of this extent is the change in land use and land cover in the area, as the extent has led to an increase in buildings and paved areas (Sudhira and Ramachandra 2007). It remains substance stating that researchers, policymakers, activists, and the public have very different views on the sprawl, and the deficiency of consent on how to define the sprawl certainly complicates the determinations to characterize and limit this land development. The municipal expansion was first revealed through a variety of techniques to measure urban growth. 

One tactic is to use remote sensing and GIS to extent urbanization proportions (Masek et al. 2000). Other researches have measured the spread of the data layer in GIS to identify patterns of urban expansion (Clarke et al. 1998). Wilson and others. (2003) not only measures variations in distinct pixels, but also within the framework of pixel neighborhoods. This method, known as neighborhood statistics, is very worthwhile in visualizing the compactness of new growth ranges. In simulating the multifaceted nature of urbanization development, it is frequently essential to apply various techniques to comprehend how to ration the growth of urban development or urban expansion. Whereas quantification of metropolitan growth often contains a direct measurement of newly built or urban land, it is moreover important to comprise qualitative information. 

Zhang (2001) a study conducted in the Chicago metropolitan area and found that socio-economic dynamics are most important in attracting residents to new developments, which may lead to urban expansion. Obviously, there are several ways to measure city dynamics, indicating that there are many ways to reach parallel terminuses. The rapid growth rate of a population may be the motivating force behind urban expansion. A non-profit organization that studies urbanization, shows that the US Census Bureau says there is a correspondence between population growth and land consumption in urbanized regions (Sprawl City, 2005). The urban area consists of continuously developed land in the central business district (CBD) and its suburbs (Sprawl City, 2005). To understand the spread of the city, 10 It is important to consider several different urban growth subtleties, containing population growth, land transformation practices, and market services. Urban expansion is categorized by arbitrary land use patterns; cross-land use patterns, profitable development along highways, and extraordinary-compactness mixed-use expansion, totally of which happen in comparatively small periods of time (Ewing 1997). It is also defined as a relevant reason: urban expansion is generally considered to be due to improper planning of areas that have not previously been used for urban purposes, large-scale new housing, commercial and industrial development (Zhang 2001). 

Though, there is one of the most important themes in recognizing the spread of cities: the unique temporal and spatial characteristics of this phenomenon. The outcome of this enlargement process is often stated as 'urban sprawl.' In this practice, development spreads out in an arbitrary manner, consuming extra land than needed and generating unnecessary communal costs for public accommodations and services (Lee et al., 1998, 865). Sprawl is development in the urban area that occurs radially around a mature city or linearly alongside a highway for a period of time (Sudhira et al. 2004). Noticeably, radial and linear are two kinds of map outlines that can be used for urban expansion (Sudhira et al. (2004) pointed out that to understand the complication of urban expansion, it is necessary to determine land use change analysis and urban growth pattern identification. Urban Sprawl Trends 2.1.1 Global Trends in Urban Sprawl As the growth rate of population upsurges, urban expansion on a universal scale becomes more and more obvious. The increase rate of the population frequently leads to a growth in development, which straight affects the transformation of agricultural land. Moeser (2000) pointed out that urban growth is unavoidable in the next two decades, and most of the growth will occur in less developed countries. In China, land use has changed rapidly (Gar-On Yeh et al. 1998). 

A study there measured the urban expansion of land suitability and the feasibility of land conversion to urban use (Gar-On Yeh et al. 1998). Authors were intent in developing a mechanism for sustainable development the purposes of that attempts to control urban expansion under hasty rural urbanization (Gar-On Yeh et al. 1998). In southern China and in coastal areas this is the utmost serious issue where economic development is very fast, and the conflict among environment and economic development is the most severe (Gar-On Yeh et al., 1998, pp. 169-170). Such as India, with more than one billion population, accounting for one-sixth of the world's population, urban expansion is directly affecting natural resources (Sudhira et al., 2004). “This shows the amazing speed of urbanization and the extent of possible spread. In order to apprehend the urbanization development speed, an effort trying to understand the dynamics of development and develop appropriate management strategies to comfort the region achieve sustainable development ( Sudhira et al., 2004, 29). Use landscape-level changes in GIS to calculate shattering and area density in new growth regions and classify these areas as sprawl the method studied by Sudhira (2004). While several models endeavor to achieve this objective, they do not tie urban expansion to urban growth. “Some of the shortcomings are that the model cannot interrelate with pivotal features that drive the sprawl, such as population growth, land accessibility, and vicinity to urban centers and roads (Sudhira et al., 2004, 30). 

Sudhira et al. (2004) used geographical information system, remote sensing and landscape measurement techniques to compute urban expansion by measuring the compactness and spatial distribution of impervious surface. Using landscape gauges that illustration urban land density and connectivity to the land, the authors can reasonably classify different types of urban sprawl: clustering, spanning, and linearity (Sudhira et al. 2004). The dense and compact areas of the building land are classified as clusters, while the medium density areas with low connectivity areas represent the spanning mode. The spread linear model is classified as a high-density and medium-density building development zone along the highway (Sudhira et al. 2004). This technique of quantifying urban sprawl is very adequate. National development of urban sprawl With the continuous development of urban areas, urban expansion is a problem faced by many cities in developing countries. A typical example is Pakistan, where several satellite towns around Islamabad have emerged. These towns and societies mostly developed in zone 2, zone 4, and zone 5 which are dormitory towns in the county of Islamabad. 

In summary, various descriptions of sprawl specify that the term is most frequently used as a noun (Galster et al. 2001). The sprawl defines the circumstances and outlines of a part of the developing appearances of a city or urban area over time (Galster et al. 2001). The certain description proposes that there may be different points and categories of sprawl, and because of the presence time, sprawl can be seen as a process (Galster et al. 2001). The advantage that GIS provides for extended research is the ability to visually assess and quantify defined spread patterns. The studies discussed so far use techniques such as landscape indicators and neighborhood statistics, which are extremely effective in measuring the density and connectivity of new urban growth over a given period of time. I have shown that while these methods are great for the understanding spread, they are usually more complex than they are needed. In this approach, it will be shown how to use neighborhood statistics in GIS is a very effective way to visually assess and quantify sprawl. Kenya’s urban expansion model is not much different from that of other major cities in the world. Several municipalities are undergoing this phenomenon due to market failure. For example, the town of Kitengela has seen many people working in the city prefer the towns around the city. This is because of the enhancement of the transportation system with the construction of the Athi River-Namanga International Expressway. In addition, increased demand for better housing and space has enabled many families to acquire their own homes in this area that was originally rural agricultural land. The result is a decentralized development from the town center to nearby towns such as Isinya. The same phenomenon has been witnessed in some places in the towns of Ruiru and Kiambu, and many are taking advantage of recent infrastructure development. The construction of the north and east through the passage and the Thika highway has prompted many office workers to live in Nairobi, even so far. 13 It is 40 km away. 

On the other hand, urban expansion in other towns is spread by land demand and holding land for speculation. This is common in towns where cities and shopping centers are expected to be in the future. While many developers will own land and develop land in the short term, many developers will hold land for a long time until speculation begins. Because of institutional failures and lack of strong policies, there is no strong legal framework to force development, so the development of these lands will occur in an uncontrolled and unpleasant manner (Skilla, 2013). Factors affecting urban expansion The spatial structure and dynamics of urban development are important analytical topics in contemporary urban research. Some studies have addressed these issues involving various topics (eg, Acioly and Davidson 1996; Wang et al. 2003; Páez and Scott 2004; Zhu et al. 2006; Geymen and Baz 2008). As a concept, urban expansion has difficulties in the definition (Johnson 2001; Barnes et al. 2001; Wilson et al. 2003; Roca et al. 2004; Sudhira and Ramachandra 2007; Angel et al. 2007; Bhatta 2010). Galster et al. (2001) criticized the conceptual ambiguity of contagion and observed that many existing kinds of literature are “lost in the semantic wilderness.” Their review of the literature found that propagation can replace or simultaneously mean: (1) certain land use patterns, ( 2) the land development process, (3) the causes of specific land use practices, and (4) the consequences of land use behavior. A widely accepted concept of urban expansion is related to its negative and unpleasant consequences on land. As its name implies, urban expansion is an inherent spatial phenomenon characterized by low density, dispersion and automatic dependence that affect the environment and the social environment. The link between urban expansion and urban growth is relevant, as urban expansion is driven by this growth force as towns develop. Hasse and Lathrop (2003) emphasize that 12 million hectares of land in the United States have been converted into development land, one-third of which comes from agriculture and forests. In their research, they concluded that the increase in urban development has the potential to attract urban expansion in the context of weak policies and the implementation of development rules (Hasse & Lathrop, 2003). 

However, in another study, Bruckner pointed out that criticism of urban sprawl may not be applicable to all environments. He proposed the shortcomings of urban expansion and its differences 14 The advantages of a free market. While many studies have fallen victim to the overall concept of urban sprawl, it is important to note that the opposite is true in a free market environment. Market forces determine the value and value of the land. This does not guarantee the dominance of primary agriculture over and secondary mechanization (Brueckner, 2000). The allocation of land depends on the demand for land for specific uses. In 1993, Mieszkowski and Mills summarized the key forces of current generations of land demand, such as contemporary population pressures, improved transportation, and increased household income. His conclusion is that as these forces continue to influence how people use their land, urban expansion is inevitable, especially in cities and surrounding areas. The increase in population has led to an increase in demand for housing, and as household incomes have increased, many households have one-time funding to direct the space and area they want. Proper transportation networks mean location convenience, mobility, and connectivity. 

Many people in urban areas find themselves moving from the CBD to the town. Urban sprawl has led to these scenarios due to the desire for convenience and satisfaction (Brueckner, 2000). Economists have different approaches to criticizing urban expansion and growth. Economists use the term market failure to reveal the concept of urban expansion. Market failures are events in which the authorities fail to allocate resources as expected to achieve maximum economic aggregates. Market failures are associated with unbalanced economic incentives due to institutional dysfunction, leading to harmful economic impacts on society in terms of sustainability. This happens not only in spatial planning but also in the allocation and utilization of all natural resources. Economists have identified three market failures that have led to urban expansion during urban growth. The first failure was due to the failure to plan the social value of open space when land was converted to urban use. The second reason is that individual passengers fail to understand the social costs of using road networks to cause congestion,