The Effects of Urban Sprawl on Greenspace

Sarah Lim

Summer Research 2022

ENVS

July 22, 2022

The term “sprawl” was coined in 1937 by Earle Draper- one of the first city planners in the southeastern United States (Nechyba et al. 2004). Since 1937, urban sprawl has been generated outside major cities in the United States. Urban sprawl provides citizens with homes outside of the city with large land space away from the city noise, traffic, and crime. However, the growth of urban sprawl has encroached on greenspace, habitats, and rural land, causing CO2 emissions to rise. Our current environment is deteriorating as humans are focused on economic growth rather than conservation. Discovering a balance between positive economic growth while restoring and conserving our natural resources should be the priority of politicians, business owners, and everyday citizens.

In a study by Nechyba about urban sprawl, he noticed there can be different varieties of sprawl. They can be formed in “edge cities'' which are clusters of populations located on the edge of the urban fringe and contain office buildings, retail, and manufacturing. Secondly, they can occur as planned communities that have a centrally located downtown and contain lakes and parks. Lastly, it can occur as individual housing across rural landscapes. Since the 1950s, central cities with urbanized areas have remained stagnant while suburbs have experienced and are continuing to experience enormous growth (Nechyba et al. 2004). The urban growth from the different types of urban sprawl can be contributed by the “monocentric city model”. This economic model explains urban spatial structure as the trade-off between commuting costs and land rents. Through this model, citizens are paying for cheaper housing farther away from urban cities, which increases commute costs. According to Nechyba, the percentage of workers that drove to work stood at 64 percent in 1960 and rose to 78 percent by 1970 and 84 percent in 1980. The monocentric city model also suggests that rising incomes have led to decreasing city densities to the extent that the income elasticity of demand for housing and land is sufficiently large relative to the income elasticity of commuting costs. Moreover, this suggests there is a direct linkage between urban sprawl and air pollution because of the increased emissions per mile traveled and the linkage between low-density housing (Nechyba et al. 2004). In 2001, road vehicles accounted for 37 percent of total nitrogen oxides in the United States, which have a significant role in the formation of ground-level ozone and smog.

Within urban sprawl, open space is a top priority to foster housing prices and household happiness. Open space among the urban sprawl provides high amenity flow at high levels of development. The term open space can be broad, however, Nechyba discovered two different types of open space. Open space in the urban fringe is considered rural land which holds less value to households, while open space located in the suburbs is significantly more important to households. Land in the suburbs can be classified as public parks, lakes, and fields that foster community. Open spaces are not only valuable to homeowners, but to private developers. The “tiebout-type” model suggests that developers have incentives to create public goods (such as parks, small lakes, and recreation areas) to drive up prices for the land they are developing near such spaces (Nechyba et al. 2004). Within urban sprawl, there must be more open space which can lead to the preservation of species diversity and habitats.

Concerns about the negative effects of the fast-paced urban sprawls lead to the formation of “smart-growth”. Smart Growth is development initiatives that protect open space and farmland, revitalize communities, keep housing affordable, and provide more transportation choices (Cho et al. 2010). The objective is to target open space preservation and other environmental areas. In a study by Cho, he studied moderating urban sprawl and discovering if there can be a balance of urban sprawl and open space. He recognized that smart growth can be implemented when policies are designed to concentrate growth in targeted areas to control urban sprawl. He focused on urban sprawl in Knoxville Tennessee and uncovered that targeting areas for compact development could be the solution to sharing open space and urban sprawl. Cho explains that market-driven residential development patterns of sprawls cause negative externalities, requiring government intervention to correct the market failure. Enacting policy intervention will allow policymakers to prioritize the wildlife habitats and preservation of species diversity.

Through using landscape ecology methods, there is an opportunity for balancing green space and urban sprawl. Landscape ecology provides a basis for planning landscape in general and green networks in particular (Uy et al. 2008). Through creating sustainable planning and strategic architecture, green space will be prioritized in urban sprawls without disrupting the functionality of the sprawl. According to Uy, in Nanjing China, green space planning and landscape ecology produce fundamental strategies for green space system designs. Moreover, In the study by Uy, he found that adding more green space into residential and industrial businesses provides more area for species to the habitat. Although this tactic may seem to have little impact, if large businesses and households were to implement more green space on their property, environmental change can occur. Furthermore, restoring green spaces that already exist is important because they contain higher biodiversity and are considered “green cores”. Green cores are considered green spaces that provide a foundation within the sprawl. In Hanoi Vietnam, the tree-planting program gives priority to native species which are adapted to urbanization. Hanoi has a growing awareness of the roles and benefits of greening in urbanized areas, which has resulted in planners involving the Hanoi government and the Department of Planning and Architecture. Hanoi is a perfect example of preserving green space while considering urban sprawl.

As the United States and Columbus Ohio continue to grow, the effects of sprawl need to be considered. To mitigate and prevent the effects, there need to be public policies to add more green space into urban sprawls. Policymakers should lead by example and consider using other cities with good economic urban sprawl and green space. Rules and regulations should prevent the effects of urban sprawl and use landscape ecology to boost decision-making. “Smart-growth” model should be implemented in cities to protect open space and provide smart living options to citizens.