Predicting Urban Growth on the Atlantic Coast Using an Integrative Spatial Modeling Approach Jeffery S. Allen and Kang Shou Lu Clemson University Strom Thurmond Institute Coastal Community Workshop, February 7, 2006, Charleston, SC

Population Change in South Carolina Coastal Counties from CountyPopulation 1970Population 1990Population 2000 Beaufort 51,136 86, ,937 Berkeley 56, , ,651 Charleston 247, , ,969 Colleton 27,622 34,377 38,264 Dorchester 32,276 83,060 96,413 Georgetown 33,500 46,302 55,797 Horry 69, , ,629 Jasper 11,885 15,487 20,678 South Carolina 2,590,713 3,486,703 4,012,012

Population density map for North Carolina, South Carolina, and Georgia # of People Per Square Mile* > * 1999 population estimates by CACI International, Inc. based on 1990 US Census

Source: (London and Hill, 2000) -- USDA, US Census Bureau and Jim Self Center on the Future, Clemson University.

The total number of parcels is 4107 of which 618 parcels have no transaction date and were thus excluded from the above chart. Calculated using only the data for years with at least one parcel transaction. 30 of 73 years during have no transaction at all. Number of Parcel Transactions Year Land (Parcel) Transaction in Murrells Inlet,

Charleston Area Urban Extent 1973

Charleston Area Urban Extent 1994

1.Components or structures of the land use systems:simple vs. complex 2.Relationships between components, agents, factors, and processes: deterministic vs. indeterministic. 3.Changes over space (and time): ordered vs. random vs. chaotic 4.Spatial distribution or patterns: regularity vs. irregularity (fractal) Challenges Faced in Urban Land Use Modeling Land Land Use Systems Uses Economic Social Cultural Natural resources Activity settings Aesthetic sanities Natural functions Functions Structures Activities Ownership Use status Geology Geomorphology Hydrology Climate Soil Vegetation Human Systems Physical Systems Availability Suitability Capacity Sustainability Model vs. Reality

Urban Area Growth by 256% Urban Area Growth vs. Population Growth in the Charleston Area, Per Capita Urban Area Consumption (128%) Growth Ratio (Sprawl Index) = = 6.22 : 1 256% 41% Population Growth by 41%

Parcel --smallest legal unit Zone --area demarcated by the major roads Grid or Cell --square-shaped area Murrells Inlet Mount Pleasant Part of Mount Pleasant Analysis Units x200 m 2 grids (cells) for calibrating models ---30x30 m 2 grids (cells) for prediction

Examples of Predictor Variables Population Density Protected Land Wetland Slope Cost Distance Previous Urban Roads Water Lines

0 1 Urban Transition Probability Water Urban-Land Transition Probabilities

Logistic Regression Prediction Integrated GIS Prediction Focus Group PredictionRule-Based Prediction Comparison of Predicted Results of Four Models Urban 1973 Urban 1994 Urban 2030 Non-Urban 2030 Water Interstate Hwy Secondary Hwy

Region-Level (COG) Growth Simulation BCD Region: Ratio 5:1

Growth Scenarios: Ratios 1:1 – 6:1

Resources at Risk by 2030 Cultivated Agriculture - 57% Freshwater Wetlands - 35% Tidal Creeks - 41% Cultural/Historic Sites - 57% Archaeological Sites - 36%

Urban Growth Problems Uncontrolled growth - urban sprawl results in many problems such as: è Increased cost of living è Rising taxes and pressure on infrastructure and urban services è Traffic congestion and increased (travel) time è Environmental pollution/degradation è Loss of farm/forest land, habitats and rural (natural) landscape è Downtown declines and community segregation è Increased dependence on the automobile è Loss of sense of place - undifferentiated landscape

Benefits of Urban Growth è Increased standard of living è Generation of wealth è Increase in amenities è Production of affordable housing è Increase in tax base è New business opportunities è New job opportunities è Increased “freedom” with the automobile è It is what we desire - “Freedom of Choice”

What do we do now? è Growth is coming whether we want it or not è Determine where we do not want to grow è Increase communication among SPD’s, etc. è Be inclusive in planning è Provide incentives for growth in “growth areas” è Provide “dis-incentives” for areas to protect è Make users pay the freight for new growth è It is always easier said than done!!!