Remote Sensing ABSTRACT Quantification of Wetland Habitat ... · the efficacy of wetland policy...

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Remote Sensing Quantification of Wetland Habitat Change in South Carolina: Implications for Coastal Resource Policy

John AllDepartment of Geography and GeologyWestern Kentucky UniversityBowling Green, KY 42101E-mail: [email protected]

Jenna Nelson Thomas and Hutton Engineering CompanyMt. Pleasant, NC 29464

The Geographical Bulletin 50: 87-101©2008 by Gamma Theta Upsilon

ABSTRACT

Increased urbanization of coastal areas has resulted in the pollution and destruction of wetland ecosystems worldwide . The effect of development on local wetland habitat was examined for Mount Pleasant, South Carolina, USA . Changes in the areal extent of wetlands in Mount Pleasant were deter-mined through a quantification of changes in wetland margins from the 1970s to 1990s using Landsat data . The rate of wetland habi-tat loss accelerated from the 1980s to 1990s compared to the 1970s, even though coastal zone regulations had been strengthened and the rate of population increase was compa-rable for the decades selected for comparison . This paper analyzes shifting environmental policy administration in combination with stakeholder interviews to characterize the ef-ficacy of current policy decision-making and to offer recommendations for the restriction of further wetland loss .

Key words: coastal zone management, land use change, GIS, remote sensing, wetlands

INTRODUCTION

This study examines coastal wetland devel-opment over three decades from the 1970s to 1990s in South Carolina using satellite im-ages . It compares growth of residential devel-opments through time to changes in coastal zone management policies to examine the efficacy of such policies, and presents several different management scenarios based upon stakeholder interviews . This research focuses on one particular type of wetland, the tidally influenced marshes of the Atlantic coastal region of the southeastern United States .

Wetland habitat comprises approximately 21 percent of the total land area of the state of South Carolina (Dahl 1999) . In all, there are over 500,000 acres of wetlands found throughout the eight counties that comprise the coastal zone of South Carolina (SCDHEC 2003) (Fig . 1) . Charleston County is one of

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John All and Jenna Nelson

the eight counties in the coastal zone . It is the third-most-populated county in South Caro-lina and has historically been an economic focal area for the state, not only as a seaport and doorway for international trade, but also for the hugely profitable tourist indus-try (County of Charleston 2004) . Over the last two decades, metropolitan Charleston has sprawled rapidly . While the population grew by a moderate forty percent, residential development consumed 250 percent more land area per unit of local economic develop-ment than the two decades previous (SCCCL 2004) . Much of this development has been in fragile coastal wetland areas .

We evaluated the effect of persistent de-velopment from the 1970s to 1990s on local wetland habitat for Mount Pleasant, South Carolina (Fig . 1) . Mount Pleasant is located within Charleston County . The town has

experienced a significant increase in popula-tion over the last decade . Seventy-five percent of the residents of Charleston County live in towns (County of Charleston 2004) . Of these urban areas, Mount Pleasant experi-enced the greatest growth rate; between 1970 and 1980 the population of Mount Pleasant doubled, and it doubled again between 1980 and 1990 . From 1990 to 2000, it increased approximately fifty-eight percent (Fig . 2) . Prior to the 1970s, the Town of Mount Pleas-ant was a quiet, small southern village (Royall 2001) . Since that time, the town has evolved into an active, upscale suburb of the City of Charleston . The rise in population in Mount Pleasant has prompted an increasing demand for housing and urban amenities . As a result, there has been rapid and continued develop-ment of most available land area . The goal of this research is to determine the impact

Figure 1 . Map of South Carolina Coastal Zone . Map created from data layers obtained from ESRI .

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of this growth on coastal wetland areas in Mount Pleasant .

COASTAL AREAS AND DEvELOPMENT

Coastal areas are made up of sensitive ecosystems such as wetlands and wildlife habitats that are particularly vulnerable to the cumulative impacts of human encroach-ment (Hefner et al . 1994) . Wetlands are among the most important ecosystems on Earth and serve many purposes, including natural filtration of pollutants; support for ecosystem biodiversity; and stabilization of the water supply network by facilitating flood reduction, buffering against drought condi-tions, protecting against shoreline erosion, and recharging groundwater aquifers (Mitsch and Gosselink 2000) . They also reduce the effects of wind and wave action and serve as significant wildlife habitat areas (Godschalk et al . 2000) .

Many factors affect the rate and degree of wetland change within a coastal ecosystem,

including sea level rise, erosion, conversion to agriculture, and non-point-source pollu-tion (Clark 1974) . Wetland environments have particularly suffered from the effects of human encroachment and subsequent development (Mitsch and Gosselink 2000) . The overdevelopment of many coastal areas has resulted in the pollution of wetland eco-systems, the loss of habitat and, ultimately, the loss of abundance and biological diversity of native wildlife . Indeed, in an analysis of the spatial patterns of habitat destruction, Malanson referred to unprotected wetland habitat as “the greatest current threat to biodiversity and ecosystem integrity” (2002, 177) .

One of the largest threats to coastal wet-lands in the United States is the rapid de-velopment of land . Nineteen of the United States’ top twenty most densely populated counties are located along the coast (Beach 2002) . Current development patterns have resulted in damage to the coastal environ-ment that includes not only loss of wetland habitat but also leveling of forests, degrada-

Figure 2 . Mount Pleasant, South Carolina, population increase between 1960 and 2000 based on data obtained from the County of Charleston, South Carolina (2004) .

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tion of water quality, and increasing social vulnerability to coastal hazards such as hurricanes . Alongside this rapid develop-ment, demand for coastal land has increased even more rapidly, and so property values along coastlines have escalated . There has been an increase in the size of homes being constructed in coastal regions . These homes are, in turn, more consumptive of resources and are often being constructed within or adjacent to the more vulnerable ecosystems of the coastal zone, such as wetlands (Beatley et al . 2002) .

Coastal zone management has emerged as a body of research that deals with human-environment interaction and development along coastlines . This discipline has arisen from the recognition that humans are nega-tively impacting coastal zone environments . Coastal zone management occurs within a complex network of regulatory agencies, legislation, and stakeholder interests that overlap within a political framework (Beatley et al . 2002) .

A recurring theme in contemporary coastal zone management literature regards a search for balance between economic develop-ment and coastal environmental protection, which are generally in conflict . Pravdic has maintained that the most profound flaw in strategies created for the mitigation of coastal environmental degradation is the divergence between environmental requirements for sustainability and the economic realities of profit-maximizing business (1992) . Coastal zone management is a single, integrated approach that unifies the interests of both factions and reconciles conflicting goals to reverse negative trends in overall environ-mental quality . Beatley and others also point to the idea of a search for balance between economic development and environmental preservation, but the authors go further by stipulating that “[t]his [a search for balance] is all well and good, but we must go beyond balancing and operate under the principles of sustainability if we are to ensure that hu-mankind’s presence in the coastal region will not produce its demise” (Beatley et al . 2002,

11) . While recognizing that development will occur, this research relies on the coastal zone management integrated approach to evaluate the efficacy of wetland policy measures for limiting environmental impacts in a manner that is non-judgmental towards the various stakeholder groups and provides an objective evaluation .

Coastal managers have only recently be-gun to monitor and quantify wetland habitat change with GIS and remote sensing capa-bilities, and to increase strict monitoring regulations (Beatley et al . 2002) . Enhanced use of land use management tools can help reveal changes in habitat boundaries early on so managers can respond accordingly and stem damage and loss (NOAA 2002) . This study incorporates a comparison of physical habitat before and after strengthened wetland protection laws and regulations in order to determine the efficacy of the strengthened regulations . By examining the impact of these laws in the face of population growth and development using remote sensing, this research provides new tools for coastal zone management and evaluating regulatory ef-ficacy .

REGULATORy BACKGROUND

This study quantifies physical changes to the landscape as a way of evaluating regu-latory efficiency and effectiveness . Protec-tive regulations and management plans for wetlands have grown dramatically since the 1970s with increased public awareness of the many benefits of these ecosystems . Federal, state, regional, and local legislation pertain-ing to wetland regulation is extensive and complicated . The structure of the policy implementation framework for overall coastal management is fragmented among varying levels of government and regulatory agencies . The complex nature of coastal management guidelines is further exacerbated by the myriad codes and ordinances that are either specifically designed for the protection of wetland habitat, other environmental legisla-tion that impacts wetland habitat indirectly,


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or impacts wetland habitat as an unintended consequence (Beatley et al . 2002) . A back-ground of shifting environmental policy and administration as well as bureaucratic convolution generally frustrates developer compliance and results in enforcement chal-lenges for coastal managers .

Several key pieces of legislation affect the efficacy of coastal resource policy . The most pertinent federal legislation is the Coastal Zone Management Act (CZMA) enacted by Congress in 1972 . The legislation requires that coastal land-use planning be based on formal classification of land use and on identification and protection of critical ar-eas (Lennon et al . 1996) . State participation under the Act includes the opportunity for coastal states to benefit from federal-state col-laboration on management objectives and implementation (SCDHEC 2003) .

South Carolina enacted the South Carolina Coastal Zone Management Act (SCCZMA) in 1977 to comply with the federal act . This effort qualified the state for federal funds to aid in the establishment of a comprehensive coastal management program (Lennon et al . 1996) . The state was pulled into action by the increasing coastal development pressures and high-profile development proposals that oc-curred in the mid-1970s, as well as the con-cern over providing adequate protection for the state’s marshes and tidelands (SCDHEC 2003) . South Carolina passed the Coastal Tidelands and Wetlands Act in 1977, and the legislation is the primary mechanism for achieving the CZMA directives and for defining the state’s coastal management objectives . The legislative impetus behind the federal and state initiatives subsequently trickled down to the regional and local levels of government .

With the implementation of the SCC-ZMA, the state created the South Carolina Coastal Council, now known as the Office of Ocean and Coastal Resource Management (OCRM) (SCDHEC 2003) . The OCRM is responsible for implementing the state’s coastal management program . Regulatory enforcement strategies of the OCRM in-

corporate the use of a complex permitting process, which necessitates OCRM approval for defined activities in four designated critical areas in the coastal zone: tidelands, coastal waters, beaches, and primary ocean-front sand dunes . Regulated activities that require OCRM permits include dredge and fill, drainage, removal of material, and most construction projects (Lennon et al . 1996) . The U .S . Army Corps of Engineers has the ultimate responsibility for approval of proj-ects via a joint processing permit application and is also responsible for determining if an area is a wetland . However, the U .S . Environ-mental Protection Agency holds the final veto authority over all candidate project permit applications (SCDHEC 2003) .

Due to concerns over wetland habitat loss, cornerstone environmental legislation (both federal and state) that affects wetlands was strengthened in 1988 and 1990 . These changes have led to an overall decline in the rate at which wetland habitat was being lost throughout the nation . In 1988, President George H . W . Bush mandated a “no net loss” approach to wetland management and, at the state level, the South Carolina Beachfront Management Act strengthened the SCC-ZMA (SCDHEC 2003) . Changes enacted in 1993 further strengthened restrictions on dredge and fill practices, the establishment of mitigation guidelines for the impacts of de-velopment on wetlands, and the requirement for wetland master plans to be submitted for all new development projects . Under the Act, new county wetland master plans were required of all counties and had to include all platted and recorded wetlands, any associated vegetation buffer zones, and a description of any deed restrictions placed on the develop-ment’s wetland systems .

This legislation has led to an overall decline in the rate of wetland habitat loss, but it also includes inherent weaknesses and loopholes that allow wetland habitat destruction to continue in some areas through a variety of activities that entail heavy modification of the environment by humans such as conversion of land to agricultural use, filling for coastal


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home sites, canal dredging, road construction, and general urban and recreational develop-ment (Hefner et al . 1994) . Wetland destruc-tion continues to occur because legislative provisions allow for wetlands to be altered if no other feasible or practicable alternative locations exist (Beatley et al . 2002) .

Legislation often exacerbates the pres-sures on coastal wetlands and inadvertently promotes their destruction . Most of these unintended results stem from public poli-cies that encourage development in coastal communities . For example, the infrastruc-ture necessary for growth and development is usually subsidized by different levels of government, thus encouraging and allowing easier access for development in areas that were once isolated . In response to popula-tion pressures, Interstate 526 was built in Mount Pleasant . The opening of the road in 1989 opened large tracts of land for develop-ment in Mount Pleasant that were previously inaccessible (OCRM 2004) . Much of this newly vulnerable acreage is comprised of vast expanses of wetland habitat . Further, various types of hazard insurance, such as federal flood insurance provided through the National Flood Insurance Program, is easily attainable and serves as another incentive for coastal development to persist (Beatley et al . 2002) . Additionally, coastal development subsidies can be in the form of tax deduc-tions or rebates if permitted within federal and state tax codes .

MEASUREMENT OF WETLAND HABITAT OvER TIME

We used satellite images from the United States Geological Survey’s (USGS) Earth Resources Observation Systems (EROS) Data Center to measure wetland habitat change in Mount Pleasant for 1970s, 1980s and 1990s . The images are North American Landscape Characterization (NALC) data - component of the National Aeronautics and Space Administration’s (NASA) Landsat Pathfinder Program (Lunetta et al . 1998) . The NALC project was specifically designed

as a standardized series of remotely sensed data sets that support investigations of land use change detection (USGS 2004) . This Landsat data has a 60-meter nominal spatial resolution geographically referenced to a Universal Transverse Mercator (UTM) ground coordinate projection (Zone 17) based on the 1927 North American Datum (NAD27) (USGS 2004) . The images used in the analysis are from the years 1973, 1986, and 1991 .

Geographic Information System (GIS) data layers including topographic data and land cover/land use files were available online from the South Carolina Department of Natural Resources Data Clearinghouse (SCDNRDC 2004) . Digital Orthophoto Quarter Quad-rangles (DOQQs) with one-meter resolu-tion were obtained for 1994 and 1999 for the following 7 .5 minute, 1:24,000 USGS quadrangles: Charleston, North Charleston, Cainhoy, and Fort Moultrie . Wetlands/land use/land cover data layers from this site were also downloaded for the same quadrangles . These digital files were created by the U .S . Fish and Wildlife Service’s National Wetlands Inventory project in 1989 and donated to the Data Clearinghouse . All layers were pro-jected to a UTM ground coordinate system based on the 1927 North American Datum (NAD27) .

METHODOLOGy

After an initial examination, we selected several residential developments for analysis due to their proximity to large amounts of wetland habitat . Rivertowne, Park West, Hamlin Plantation, Brickyard Plantation, and Darrell Creek (Fig . 3) subdivisions are all located within Mount Pleasant and are relatively new developments within the community . Additionally, these subdivisions continue to grow in response to housing de-mand .

We measured geographic coordinate (lati-tude/longitude) ground control points and ground cover data using a handheld Global Positioning System (GPS) receiver in 112


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locations . The unit provides accuracy within 15 meters . The GPS control points corre-lated the NALC satellite raster cell values to on-the-ground land use classifications . We converted each ground control point to a UTM projection based on the 1927 North American Datum (NAD27) .

We selected the ground control points within each of the focal residential develop-ments as well as at locations of easily discern-ible landmarks such as the regional airport and some larger commercial and industrial sites on the margins of the study area . We emphasized ground control points (1) along the boundary between different land use clas-sifications and (2) in the center of a large area of a single land-cover classification . Ad-ditionally, we manually selected geographic coordinates from the land cover classes in the USGS land cover dataset noted above .

Finally, we measured historical wetland

positions and changes using the NALC data . Since each of the original images covers a larger expanse of the South Carolina coast than necessary to examine the study area, we identified the approximate location of the town using natural landmarks such as the Wando River . Upon determination of this estimated region, we cut an Area of Interest (AOI) from the original data set . The U .S . Army Corps of Engineers followed a similar methodology for preparing its images for analysis (Loechl et al . 2001) . This procedure not only allows the amount of data to be con-densed, but also decreases the time required to run complex analyses within the software system . Figure 4 displays the resulting AOI cut from the raw satellite data image files .

We performed an unsupervised classifica-tion for each image to aggregate land use raster cell values and to further simplify the data set . The data was automatically classified

Figure 3 . Residential subdivisions selected for examination within the study area . Map created from data layers obtained from the South Carolina Department of Natural Resources .


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into twelve separate land uses/land covers . We then manually assigned these twelve classes to categories (e .g . wetland, forest) using the ground control points .

Based on these results, we performed a su-pervised classification of each satellite image to generate a final clustering of similar raster cell values into four classes of interest: water, wetland, forest, and (human) disturbed . The “disturbed” land use classification was an ag-gregation of any land use that resulted from human disturbance such as transportation-related infrastructure, residential, commer-cial, and industrial land use classes .

We performed a change detection analy-sis to evaluate the changes in the four land use classifications for each year of data . This method is similar to that used by Curlis and others (2003) . Curtlis incorporates an im-age differencing (i .e ., subtraction) process

that resulted in a final set of derived images that highlighted only the extreme zones of change values and a mid-level zone of no-change values . Our first change detection analysis calculated the differences between the 1973 and the 1986 satellite images . The second change detection analysis was run on the 1986 and 1991 images . Finally, the last change detection analysis was run on the dif-ferences between the 1973 and 1991 images to derive change over time that encompassed the full span of years selected for the study . The resulting set of images highlighted ar-eas of increased disturbance, recovery from disturbance, and areas where no significant change took place .

RESULTS

The results of the change detection analyses

Figure 4 . Satellite image of the resultant area of interest (AOI) . The AOI was derived from the original, un-manipulated satellite image obtained from the EROS Data Center .


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were evaluated specifically for change in the quantity of wetland habitat for each pair of years . We then calculated the percentages of change in wetland habitat between the pairs (Fig . 5) . Between 1973 and 1986, a 2 percent decrease in overall wetland habitat occurred for the defined area of interest within Mount Pleasant (Fig . 6) . However, between 1986 and 1991, there was an approximate 28 percent decrease in the area of wetland habitat within the study area (Fig . 7) . This greater loss of wetland habitat between 1986 and 1991 oc-curred even though the rate of population increase was similar for both time periods . In total, there was a 30 percent decrease in the areal extent of wetland habitat within the area of interest in Mount Pleasant between 1973 and 1991 (Fig . 8) . Nearly all of this loss is adjacent to the subdivisions selected for study, and the concentrated nature of the degradation offers hope for management . By focusing on minimizing the impacts in the hardest hit areas, policy-makers can have the greatest effect on wetland loss .

Based on these results, there has been a failure to prevent the acceleration of wetland

Figure 5 . Graph of Results per Land Use Classification . Temporal changes in land use within the area of interest defined for Mount Pleasant, South Carolina, resulting from supervised classifications of NALC data for each year of interest .

habitat loss within the area of interest . A “no-net-loss” of wetland habitat has not been achieved in Mount Pleasant . The large in-crease in the rate of wetland habitat loss with-in the study area should not have occurred, given the timing and intent of strengthened regulations pertaining to wetland protec-tion . There are no special pressures driving development in the Mount Pleasant region, and given the failure of regulation to slow development, it is likely that similar habitat losses occurred in other communities within the coastal zone . Most likely, the failure to protect these particular wetlands is the result of ineffective policy implementation and enforcement in the Mount Pleasant region and necessitates an assessment of potential mitigation opportunities and alternatives .

RECOMMENDATIONS

We carried out a series of interviews with a broad series of stakeholders including govern-ment officials, business leaders, and commu-nity action groups to identify the key players in coastal management within the region


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Figure 6 . Image of change detection for 1973 to 1986 (white = areas of increased disturbance; black = areas of no change; gray = areas of decreased disturbance) .

and to determine how legislation becomes implemented at the local level as well as the level of cooperation between the various stakeholders in Mount Pleasant . Table 1 lists the affiliations of the seventeen individuals interviewed during the course of this study . We interviewed eight government officials and nine private stakeholders representing a wide spectrum of interests from developers to leaders of environmental organizations . The groups listed in the table represent a major part of the spectrum of interests, authorities, and jurisdictions responsible for creating and implementing coastal resource policy in the region and those that are affected by these policies .

Based on our stakeholder interviews, the improvement of regulatory enforcement strategies is necessary for improving the efficacy of coastal resource policy and man-agement . Beach has argued that prevailing

coastal management directives are ineffective because they lack incentives, enforcement, and measurable standards of performance (2002) . We recommend the implementa-tion and enforcement of policies that control incompatible development patterns through the use of zoning codes, infrastructure plan-ning, and land-protection programs . The current system for regulating wetland habitat was described as “broken” during interviews conducted with officials of both the OCRM (Mikell 2003) and the National Marine Fish-eries Service (Brownell 2003) . In fact, the majority of the officials interviewed for this research cited a pressing need to streamline the existing permitting process . The Assistant Director of the Planning Department at the Charleston County Planning Commission indicated that enforcement of county de-velopment regulations relies solely on code enforcement officers’ responses to formally


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issued complaints (Pennick 2003) . There is no “watchdog” process in place that monitors continued compliance by the developer and construction crew for permitted development projects . One official from the OCRM sug-gested a need for either a new federal or state law to create a more efficient streamlined approach to wetland habitat management and protection in order to ensure developer compliance (Mikell 2003) .

One of the objectives for conducting the stakeholder interviews was to investigate evidence of cooperation among the key players in coastal management in the study area . Based on the results of the interviews, there appears to be a distinct line of division between the entities that work cooperatively and those that work in opposition to sustain-able wetland habitat protection . The OCRM and the U .S . Army Corps of Engineers appear to work closely on permitting procedures;

however, the permitting mechanism often works against county and local planning objectives concerned with economic devel-opment and wetland habitat protection . This is a critical point because the greater part of responsibility for the kind of wetland habitat loss characterized in this study falls under the administrative purview of local-level officials and coastal managers .

Another recommendation of some of those interviewed was the use of compost filter berms to reduce erosion at construction sites in place of traditional silt fences . Erosion control adjacent to wetlands is critical since erosion is one of the leading causes of wetland degradation (Mitsch and Gosselink 2000) . Silt fences are ineffective as erosion control devices because once the fences are removed upon completion of a construction project, the next large storm event will inevitably wash the sediment and debris that accumulated


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behind the silt fence into adjacent wetlands and surface waters (TCWP 2004) . Compost filter berms are created out of compost, or mixed organic material such as manure or yard trimmings, that has been decomposed and recycled through a heat process that pro-duces a humus-rich soil booster . When used at development sites, compost filter berms act as filters and reduce the sediment load to nearby water bodies and wetlands . Working as a filter, compost berms can also reduce the that reaches wetlands (Risse and Fauc-ette 2001) . As a further benefit for habitat, compost filter berms can be left behind at the development site once construction is com-pleted to promote quicker establishment of permanent vegetation through planting and seeding and to increase water infiltration into the soil . Furthermore, a reduction in the use of silt fences would incur a corresponding de-crease in the number of silt fences deposited into community landfills once construction

projects are complete (Groundscapes Express 2004) .

Godschalk et al . (2000) contended that the acquisition of land for public use (e .g ., open space areas or parks) may help deter new construction and further protect vul-nerable environmental areas and wildlife habitat . If the acquisition of land for public use is not possible due to budget or resource constraints, there are other alternatives for protecting habitat in perpetuity . Conserva-tion-driven development and conservation easements have been recommended at all lev-els of authorities within coastal management to minimize the footprint of disturbance on the landscape so that there is a focus on the social aspect of development . One example of this type of conservation development is the nationally recognized I’On development (I’On 2004) . The I’On residential neighbor-hood is a pedestrian-friendly structure built upon a street-grid pattern where people can



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Table 1 . Major stakeholders that influence coastal resource policy in Mount Pleasant . Representatives of each were interviewed during the course of this study .

Major Stakeholders • Federal/NationalLevel - U.S Army Corps of Engineers - USDA Forest Service - U.S. Fish & Wildlife Service - National Marine Fisheries Services - National Oceanic and Atmospheric

Administration - The Nature Conservancy • StateLevel - Department of Health and

Environmental Control (DHEC) -OfficeofOceanandCostal

Resource Management (OCRM) • RegionalLevel - County and Town Planning

Commissions - South Carolina Coastal

Conservation League - Lowcountry Open Land Trust - Developers, Builders, Realtors,

Lawyers, Environmental Consultants, Conservationists, Land Owners

Unlimited (Sewee Preserve 2004) . The con-servation easement protects the acreage from further development and also allows for the protection of wildlife habitat, the preservation of the wetlands within and adjacent to the property, and contributes to the minimiza-tion of the impact of humans on the natural environment within Sewee Preserve . The re-maining development acreage is divided into thirty home sites on one contiguous block of property averaging over three acres per parcel in a low-density development . Other organi-zations such as the Lowcountry Open Land Trust in Charleston, South Carolina (LOLT 2004) have created similar easements . These organizations have protected millions of acres of land from development . Sewee Preserve serves as a strategic link in the preservation of a region within the coastal zone of South Carolina constituting over 300,000 acres of greenbelt from Sewee to Santee (Sewee Preserve 2004) . This stretch of coastline in-cludes the Francis Marion National Forest and the Cape Romain Wildlife Refuge . The economic feasibility of such projects relies on significant federal and state tax incentives as well as the market value for upscale homes (Avery 2003) .

CONCLUSIONS

Though coastal management regulations had been strengthened, the rate of wetland habitat loss accelerated within Mount Pleas-ant between 1973 and 1991; therefore, the efficacy of the imposed legislation is ques-tionable and needs to be altered . Based on the interpretation of the resulting change detection analyses, regulatory enforcement and land use monitoring practices need to be reinforced, and the current permitting process requires simplification to curtail persistent, incremental losses of wetland habitat over time .

The nature and scale of coastal develop-ment is largely defined at the local level; therefore, action to protect wetland habitat should begin at the local level to curtail per-sistent losses of wetlands . Efforts should also


live, work, shop, and recreate without the need for a vehicle (Quick 2003) . Throughout I’On, it is readily evident that an emphasis was placed on public rather than private areas . Parks and shared spaces, such as the outdoor amphitheater, have precedence over sprawl-ing lot sizes . By limiting the amount of land required to accommodate the residents living within I’On, coastal sprawl is reduced .

Another example of conservation-driven development in Mount Pleasant is Sewee Pre-serve; however, the premise by which Sewee Preserve functions as a conservation devel-opment is fundamentally different from the approach that produced I’On . Sewee Preserve set aside over 400 acres of a 500-acre area in a conservation easement maintained by Wetlands America Trust, a division of Ducks

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focus on eliminating the creation of isolated wetlands resulting from irregular patterns of development that consequently leads to diminished legal protection based on current legislation pertaining to isolated wetlands .

Safeguards should be implemented by coastal managers to ensure that wetland habitats are being sustained . The measure-ment of land use/land cover change over time through the use of tools such as GIS and re-mote sensing analyses provide support for the monitoring efforts necessary to achieve this objective . It is unrealistic to expect develop-ment to stop along the South Carolina coast and, given that this process will continue, the development that takes place should proceed in a judicious manner to avoid repeating the mistakes of past development activities that have resulted in environmental degradation . Endeavoring to achieve such a goal, a funda-mental research question remains: how can humans continue to inhabit fragile coastal areas without irreversibly damaging the natu-ral environment? Ultimately, research needs to guide the management and protection of those vulnerable coastal areas that are still intact . GIS and remote sensing data analy-ses quantify the impact of environmental policies and can assist in the establishment of coastal management strategies that direct development into the most appropriate loca-tions within a coastal watershed . Addition-ally, these tools support efforts to promote not only sustainable development patterns but, more importantly, sustainable wetlands protection by providing stakeholders with the tools and techniques to evaluate change at scales from the neighborhood to the county and region . The methods examined in this study are presented as one such attempt to analyze the probable exploitation of a valuable natural resource, to promote commitment to restrict exploitive development practices, and to help prevent further loss of habitat .

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