Urban Sprawl has become one of the most important issues facing New Jersey at the onset of the new millennium. Housing developments and shopping malls encroach on lands that were formerly farm fields and forests. Changes to the landscape are occurring every day with significant implications for taxation, quality of life, water quality, agricultural viability, wildlife habitat and social equity. Measuring these landscape changes, however, is a significant challenge. This report summary highlights an excerpt of research on measuring urban sprawl in New Jersey being conducted at Rutgers University. The primary data source employed in this analysis is the New Jersey DEP land use/land cover digital database, which contains detailed landscape change information for the period of 1986 to 1995. This data set provides a unique window into the landscape changes occurring in the Garden State at the end of the 20th century.
The changes revealed in the data set are remarkable. Every year New Jersey adds nearly 16,600 acres of new development while losing more than 9,600 acres of farmland, 4,200 acres of forest, and 2,600 acres of wetlands. Impervious surface is being created at the rate of 4,200 acres per year. The net new land developed during the nine year 1986 to 1995 period of this analysis was 135,764 acres, an area equal to the total land area of Union and Essex counties combined. Put on a more comprehensible scale, the daily urban growth rate in New Jersey was equivalent to adding 41 football fields worth of new urban land every day while losing 20 football fields of farmland, 9 football fields of forest and 6 football fields of wetlands. Impervious surface was created at the rate or 9 football fields worth of coverage per day. If development continues at this rate and if New Jersey is successful at preserving a million acres of open space, the remaining available land will be developed within 40 years making New Jersey the first state in the nation to reach build-out. It is our hope that a better understanding of these land development patterns will contribute to wiser land management policies and practices in New Jersey in the coming years.
The authors would like to acknowledge the New Jersey Department of Environmental Protection (NJDEP) for both the Land Use Land Cover (LULC) data, as well as collaborative analyses of the data and peer review. NJDEPs LULC data are the primary GIS data for this report. The data set production and quality assurance was managed by the NJDEP, Office of Information Resources Management, Bureau of Geographic Information and Analysis, Lawrence L. Thornton, Chief, and co-production manager with John M. Tyrawski. Analyses of the NJDEP data have included NJDEP scientists Marjorie Kaplan, Division of Science, Research & Technology, Ernie Hahn, Office of Natural Resource Restoration, and Jeff Tash, Division of Fish and Wildlife, Endangered and Nongame Species Program. Funding for the most recent update of the dataset was provided by the NJDEP Watershed Management Program and the NJDEP Division of Science, Research and Technology. The Production of the dataset was provided by Aerial Information Systems of Redlands, Ca, Lisa Cotterman, Manager. CRSSA and NJDEP continue to partner in development and analyses of additional data sets related to New Jerseys environment. Through these cooperative efforts, independent verification of the data are further assured.
Urban Growth Analysis of NJ's DEP's Land Use/Land Cover Data Set
The landscape changes due to urban and suburban development reported in this analysis were derived from 1986 and 1995 aerial photography. The above images provide an example of urban growth in the town of Mullica Hill, Gloucester County. The panchromatic photograph on the left was taken in 1977. The color infrared photograph on the right was taken in 1995. Areas of new urban growth that occurred from 1986 to 1995 are delineated in yellow.
The NJ DEP produced detailed land use/land cover data from multi-date imagery. This data contains land use/land cover data from 1986 and 1995 as well as estimates of impervious surface coverage for each land use polygon. This report utilizes this and additional geodata sets for the entire state.
Annual Change in Acres
|Urban Growth: 16,600 acres/yr|
|Farmland Loss: 9,654 acres/yr|
|Forest Loss: 4,200 acres/yr|
|Wetlands Loss: 2,642 acres/yr|
Impervious Surface is created with new urban growth. Impervious surface has important implications for water quality and flooding as non-point source pollution and runoff are greatly increased. New Jersey added an estimated 4,200 acres of impervious surface coverage per year between 1986 and 1995.
Impervious surface coverage can be used as an indicator of water quality. Watersheds with less than 5% impervious coverage are green, 5-10% yellow. Watersheds with between 10 and 30% impervious surface (orange) are considered impacted. Greater than 30% impervious coverage (red) is considered degraded.
Many watersheds experienced a significant increase in total impervious surface coverage from 1986 to 1995. Watersheds with significant total impervious surface increase are colored yellow. Watersheds with accelerated increase in impervious surface are colored red.
Urban Growth in New Jersey's Watershed Management Areas
New Jersey is beginning to manage environmental issues by watershed management areas (WMAs). The proportion of developed land within each WMA should determine the priorities of land management. The map on the left delineates the percentage of each WMA that has been urbanized as of 1995. The map classifies these into three groups: heavily urbanized, mixed landscape and mostly rural. The map on the right depicts the percentage growth in each WMA from 1986 to 1995. The fastest growing WMAs are colored red. Both the proportion of developed lands and the rate of growth should be considered in determining the land management strategies of each WMA.
Types of Urban Growth in Acres
The NJDEP data set contains detailed land use classifications for each mapped land unit. Summarizing the changes for each urban category reveals the type of growth that has been occuring. Residential land use accounted for 67% of all newly developed land in New Jersey from 1986 to 1995. Residential, Rural, Single Unit was the most consumptive category of land development using 45,448 acres or 30% of the total new growth in acres. This type of development is typically on large lots supported by private wells and septic systems.
Urban Growth and the State Development and Redevelopment Plan
Analyzing urban growth for the State Development and Redevelopment Plan reveals patterns of development in environmentally sensitive and rural lands. Of the 135,000 acres of new development that occurred from 1986 to 1995, 13.6% occurred in the environmentally sensitive planning PA5, 14.5 % of growth occurred in rural planning area PA4 and 10.2% occurred in the environmentally sensitive rural planning area PA4B. Although the goals and objectives envisioned in the state plan of channeling growth toward centers and away from sensitive lands have been hailed by both researchers and planners, this analysis demonstrates that the non-regulatory status of the SDRP has had limited success in meeting those goals.
Urban Growth and the Pinelands Management Area
While this urban growth research suggests that the NJ state plan has had limited success in protecting sensitive lands on a statewide level, analysis of development within the NJ Pinelands Comprehensive Management Planning area (PCMP) suggests one of NJs land management successes. Analyzing rates of development within the various Pinelands Management Planning Areas provides evidence that PCMP has been effective in controlling misplaced urban growth. The planning areas which are designated as growth areas received the majority of new development whereas the Preservation Area, Agricultural Production Area and Special Ag Production Area combined received less than 5% of the total growth. Within the Pinelands Management Area sensitive lands remain reasonably intact while planned growth areas and existing towns and villages received the majority of new development growth.
Open Space and Remaining Available Lands
The geospatial technologies utilized in this research provide a powerful method for analyzing how landscapes have changed in the recent past. However, predicting future landscape change is a more tenuous endeavor. Urban growth is affected by multiple factors not withstanding economic conditions, political trends, cultural values and changes in technology. Nonetheless, a projection of current rates of growth help to put the land management circumstances facing New Jersey into perspective. It is estimated that there are 1.7 million acres of available land in New Jersey. If the state is successful at preserving 1 million acres of additional open space then the remaining available land will be lagely developed within 40 years at current rates of growth. New Jersey is likely to be the first state in the nation to reach build-out.
Conclusions and Continued Research
This report summarizes one segment of ongoing research on landscape changes in New Jersey being conducted at the Grant F. Walton Center for Remote Sensing & Spatial Analysis, Rutgers University. The objective of this research program is to monitor trends in land use/land cover change, analyze the implications of these changes and make this information available to a wide audience of interested stakeholders. Our analysis of the NJDEP land use/land cover data shows that New Jersey underwent rapid and extensive land use changes during the latter part of the 20th century. Land planning is at a critical juncture. The land development and open space decisions that we make now will determine the shape of our future landscape, affecting the quality of life for generations of citizens to come.
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While efforts have been made to ensure that the landscape analysis performed at the Center for Remote Sensing and Spatial Analysis (CRSSA)- Rutgers University is accurate and reliable within the state of the art, CRSSA cannot assume liability for any damages, or misrepresentations, caused by any inaccuracies in the information. These data are not for use in litigation. Any maps, graphics, publications, reports or any other type of document produced as a result of using Center for Remote Sensing and Spatial Analysis (CRSSA) - Rutgers University data should credit the original author(s) as listed in the 'Introduction' as well as the Center for Remote Sensing and Spatial Analysis (CRSSA), Rutgers University.