Alternative Text Description for DRASTIC Coverage for the Intermediate Aquifer System

TABLE OF CONTENTS

MAP OVERVIEW

This map displays DRASTIC vulnerability ratings for the Intermediate Aquifer System across portions of Florida. DRASTIC is a standardized system developed by the U.S. Environmental Protection Agency and the National Water Well Association to assess aquifer vulnerability to contamination from pollutants introduced at the ground surface. The map uses a graduated color scheme to show numeric vulnerability index values, with darker purples representing lower vulnerability and brighter colors (magenta, blue, green) indicating progressively higher vulnerability levels.

GEOGRAPHIC CONTEXT

The map covers portions of central and northern Florida. Two distinct geographic areas are shown: a northern region near Jacksonville in the upper portion of the map, and a much larger southern region encompassing Tampa, St. Petersburg, Clearwater, Orlando, and surrounding areas. Major cities labeled on the map include Jacksonville, Gainesville, Ocala, Orlando, Tampa, St. Petersburg, Clearwater, Daytona Beach, Palm Coast, Port Orange, Deltona, Titusville, Melbourne, Palm Bay, and Homosassa Springs. The mapped areas represent where the Intermediate Aquifer System is present and has been evaluated for vulnerability.

KEY INSIGHTS

The most significant pattern visible in this map is the concentration of higher DRASTIC vulnerability values in and around the Tampa metropolitan area. This region shows substantial areas of brighter magenta, blue, and multi-colored patches indicating moderate to high vulnerability scores. The majority of the southern mapped region displays the darkest purple coloration, representing the lowest vulnerability range (1-79). The northern region near Jacksonville shows predominantly low to moderate vulnerability values with limited areas of higher vulnerability. This spatial pattern suggests that aquifer contamination risk varies considerably across the region, with the Tampa area presenting notably elevated vulnerability compared to surrounding areas.

VISUAL ELEMENTS

DRASTIC Vulnerability Index Values

This layer represents aquifer vulnerability scores for the Intermediate Aquifer System using the DRASTIC methodology.

Low Vulnerability Areas (darkest purple)

Appearance:

Deep purple to dark magenta coloration, representing values 1-79

Distribution:

Dominant throughout most of the southern Florida region shown, particularly in areas south and east of Tampa, extending toward Orlando and southward

Notable locations:

Extensive coverage in central Florida, areas around and south of Lake Okeechobee region, and portions of the northern mapped area

Spatial patterns:

Forms the background vulnerability classification across the majority of the mapped extent, creating a continuous base layer punctuated by areas of higher vulnerability

Moderate-Low Vulnerability Areas (bright magenta)

Appearance:

Bright magenta coloration, representing values 80-99

Distribution:

Scattered throughout both the northern and southern regions, with notable presence in the Tampa metropolitan area

Notable locations:

Concentrated patches in and around Tampa, eastern portions of the Tampa region, and scattered locations in the northern mapped area

Spatial patterns:

Appears as discrete patches and zones intermixed with both lower and higher vulnerability areas, particularly prominent in urban and suburban zones

Moderate Vulnerability Areas (bright blue)

Appearance:

Bright blue coloration, representing values 100-119

Distribution:

Concentrated primarily in the Tampa metropolitan region with some presence in the northern area

Notable locations:

Most prominent in central Tampa and immediate surrounding areas, with scattered occurrences elsewhere in the southern region

Spatial patterns:

Forms distinct zones often adjacent to or intermixed with the bright magenta areas, creating a mosaic pattern of moderate vulnerability

Moderate-High Vulnerability Areas (green)

Appearance:

Green coloration, representing values 120-139

Distribution:

Limited distribution, appearing primarily in the Tampa area

Notable locations:

Small patches within the Tampa metropolitan region

Spatial patterns:

Appears as isolated zones rather than continuous coverage, indicating localized areas of elevated vulnerability

Higher Vulnerability Areas (yellow, orange, red)

Appearance:

Yellow (160-179), orange (180-199), and red (200-226) coloration representing the highest vulnerability values

Distribution:

Very limited spatial extent with minimal to no clearly visible presence in the map at this scale

Notable locations:

If present, extremely localized and not forming significant concentrations

Spatial patterns:

The highest vulnerability categories do not form discernible patterns at the map scale shown

Overlapping Patterns

The Tampa metropolitan area shows the most complex vulnerability pattern, with multiple vulnerability categories intermixed in a mosaic arrangement. This creates a heterogeneous landscape of aquifer vulnerability, likely reflecting variations in soil type, aquifer depth, recharge characteristics, and land use that influence contamination potential. The contrast between this complex pattern and the predominantly low-vulnerability areas elsewhere highlights Tampa as a region requiring particular attention for aquifer protection.

SYMBOL GUIDE

ADDITIONAL INFORMATION

The DRASTIC methodology combines seven environmental factors to calculate vulnerability: Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone media, and hydraulic Conductivity of the aquifer. Higher DRASTIC scores indicate greater vulnerability to groundwater contamination from surface sources. This map focuses specifically on the Intermediate Aquifer System, which is one of several aquifer systems in Florida. Areas shown in white or gray on the map may represent regions where the Intermediate Aquifer System is not present, is not mapped, or where data is unavailable. The vulnerability assessment helps inform land use planning, groundwater protection strategies, and environmental management decisions.

DATA CONTEXT

Data Source:

The data was developed using the DRASTIC methodology, a standardized system created jointly by the U.S. Environmental Protection Agency and the National Water Well Association for mapping aquifer vulnerability to surface contamination. The methodology integrates multiple hydrogeologic factors to generate vulnerability index scores. Data source layer name: AQDRINNAD

Definition Query:

No definition query or filter criteria was specified for this map view. The map displays all available DRASTIC vulnerability data for the Intermediate Aquifer System statewide.

Scale Information:

The map displays regional-scale vulnerability patterns appropriate for statewide assessment and planning purposes. The level of detail is suitable for identifying broad vulnerability zones and regional patterns rather than site-specific evaluations.

Coordinate System:

The map uses the 1983_HARN_Florida_GDL_Albers projection (WKID 3087), an Albers Equal Area Conic projection optimized for Florida statewide mapping applications.

Time Period of Content:

The time period of data collection or validity is not specified in the provided information.

Limitations:

The DRASTIC system provides a relative ranking of aquifer vulnerability based on hydrogeologic factors and does not account for specific contaminant properties or actual contamination occurrence. Vulnerability scores represent potential risk rather than confirmed water quality impacts. Areas outside the colored regions may indicate absence of the Intermediate Aquifer System, lack of data coverage, or areas where vulnerability assessment was not conducted. Site-specific assessments may be necessary for detailed evaluation of contamination risk.

Map Coverage:

The map covers portions of northern and central Florida where the Intermediate Aquifer System has been mapped and assessed. The primary concentration is in the central Florida region extending from approximately Tampa-St. Petersburg on the west coast through the Orlando area and southward, with a secondary mapped area in the northern portion of the state near Jacksonville. Base map context showing the full state outline and neighboring areas provides geographic orientation.

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