Alternative Text Description for FL DEM Inches (Negative values)

TABLE OF CONTENTS

MAP OVERVIEW

This map displays negative elevation values in inches for Florida, representing areas that are below a reference datum level. The map uses a graduated color scheme from light blue to dark blue to show varying depths of negative elevation across the state. The visualization focuses on coastal and low-lying areas where land elevation falls below the established baseline measurement.

GEOGRAPHIC CONTEXT

The map covers the entire state of Florida and portions of neighboring states including southern Georgia (with cities Dothan, Albany, and Valdosta visible) and southeastern Alabama (Pensacola area). Major Florida cities labeled include Jacksonville, Palm Coast, Orlando, Tampa, St. Petersburg, Lakeland, Gainesville, Cape Coral, Miami, Coral Springs, West Palm Beach, Port St. Lucie, and Palm Bay. The map shows Florida's distinctive peninsula shape bordered by extensive coastline on the Atlantic Ocean to the east and the Gulf of America to the west and south. The Straits of Florida appear at the southern tip of the state.

KEY INSIGHTS

Negative elevation values are concentrated almost entirely along Florida's coastal perimeter, forming a continuous band around the state's edges. The Atlantic coast from Jacksonville south through Miami shows particularly strong patterns of below-datum elevations. The Gulf of America coastline displays similar coastal concentration of negative values, especially around the Tampa Bay area and southwestern coastal regions. The interior of Florida shows no negative elevation values, appearing as uniform gray, indicating that below-datum elevations are restricted to coastal and nearshore environments. The gradient intensifies (darker blue) in offshore areas and at the extreme edges of the coastal zone, suggesting deeper negative values in marine and immediate coastal areas.

VISUAL ELEMENTS

FL DEM Inches (Negative values)

This layer represents elevation measurements below a reference datum, expressed in inches as negative values.

Coastal Negative Elevation Areas (graduated blue shading)

Appearance:

Blue-to-purple graduated color scheme where lighter blues represent higher negative values (closer to zero/datum) and darker blues represent lower negative values (further below datum).

Distribution:

Distributed continuously along the entire Florida coastline, including both the Atlantic Ocean side and Gulf of America side. The band of blue shading extends into nearshore waters and follows the complex geometry of Florida's bays, inlets, and coastal features.

Notable locations:

Spatial patterns:

The negative elevation values form a relatively narrow but continuous coastal band that widens in some bay and inlet areas. The intensity of color (indicating depth below datum) generally increases from the inland edge of the coastal zone toward the open water. Interior Florida remains completely free of negative values, showing a sharp transition between coastal low-lying areas and the higher-elevation interior.

Overlapping Patterns

The negative elevation areas align precisely with Florida's coastal geography, showing clear correspondence between shoreline configuration and the distribution of below-datum measurements. Areas with complex coastal geometry, such as the Tampa Bay region and the southeastern coast near Miami, show more intricate patterns of negative elevation values.

SYMBOL GUIDE

The graduated color scheme shows a continuous range of negative elevation values rather than discrete categories, with color intensity corresponding to depth below the reference datum.

ADDITIONAL INFORMATION

This map specifically isolates and displays only negative elevation values, meaning areas below the established vertical datum. Positive elevation areas (above datum) are not symbolized and appear as gray background. The focus on negative values makes this map particularly relevant for understanding coastal topography, sea level relationships, and areas potentially at or below mean sea level. The visualization emphasizes the extent and depth of below-datum areas around Florida's extensive coastline while clearly showing that the state's interior maintains elevations above the reference datum.

DATA CONTEXT

Data Source:

The data comes from Digital Elevation Model (DEM) measurements representing terrain elevation in inches, filtered to show only negative values relative to a vertical datum. Data source layer name: NAFLIDAR_INCHES_NEG.

Definition Query:

This map displays only negative elevation values from the DEM dataset. All positive elevation values (areas above the datum) are excluded from the visualization, allowing focus on below-datum coastal and nearshore areas.

Scale Information:

The map shows a regional scale covering the entire state of Florida and portions of neighboring states, appropriate for understanding statewide patterns of negative elevation distribution along coastal areas.

Coordinate System:

Albers Conical Equal Area projection, as referenced from the Florida Geographic Data Library.

Time Period of Content:

The specific collection date for this elevation data is not provided in the available information.

Limitations:

The legend indicates a value range from -1 inches (high) to -16,381 inches (low), though the specific class breaks within this range are not clearly legible in the legend. The focus on negative values only means this map does not provide information about positive elevations in Florida's interior. The transition zone between negative and non-negative values may vary depending on the specific vertical datum used as reference.

Map Coverage:

The map extends from southern Georgia and southeastern Alabama in the north to the Florida Keys and Straits of Florida in the south, encompassing Florida's full coastline along both the Atlantic Ocean and Gulf of America.

The alternative text description of this map was AI-generated and may contain inaccuracies.