TITLE: LEON COUNTY KARST FEATURES
Geodataset Name: C37_KARST Geodataset Type: SHAPEFILE Geodataset Feature: POLYGONGENERAL DESCRIPTION:
| This dataset contains karst features derived from 1996 DEM. Karst is a type of topography that results from dissolution and collapse of carbonate rocks such as limestone and dolomite and characterized by closed depressions or sinkholes, caves, and underground drainage. |
DATA SOURCE(S): Leon County Dept. of Growth and Environmental Management SCALE OF ORIGINAL SOURCE MAPS: 1:2400 DATE OF AUTOMATION OF SOURCE: 1999 GEODATASET EXTENT: Leon County
FEATURE ATTRIBUTE TABLES:
Datafile Name: C37_KARST.DBF
| ITEM NAME | WIDTH | TYPE | N. DECIMAL DEGREES |
|
FID
|
4 | OID | --- |
|
Shape
|
0 | Geometry | --- |
|
AREA
|
19 | Number | 5 |
|
PERIMETER
|
19 | Number | 5 |
|
NAME
|
25 | String | --- |
|
ACTIVE
|
1 | String | --- |
|
ACREAGE
|
19 | Number | 5 |
|
SOURCE
|
75 | String | --- |
|
COMMENTS
|
240 | String | --- |
|
Descript
|
25 | String | --- |
FEATURE ATTRIBUTE TABLES CODES AND VALUES:
| Item | Item Description | |
| FID |
Internal feature number. |
|
| Shape |
Feature geometry. |
|
| AREA |
Area of the polygon (sq meters). |
|
| PERIMETER |
Perimeter of the polygon (meters). |
|
| NAME |
Name of the feature if available. |
|
| ACTIVE |
Sites that have been examined and been determined to be active karst sites.
|
|
| ACREAGE |
Acreage of the site. |
|
| SOURCE |
Source of data. |
|
| COMMENTS |
Comments on the site. |
|
| Descript |
Based on ACTIVE field. |
| GeoPlan relied on the integrity of the attribute information within the original data. |
|
Most features in this layer were not field verified. With the exception of Features identified as Known and/or active, feartures were identified as potentially being karstic due to the closed depressional topography represented in the DEM. The Karst layer has been derived from the most accurate DEM data available, but in all cases where this data is used a Licensed Geologis should be acquired for verification. |
A note concerning data scale: Scale is an important factor in data usage. Certain scale datasetsare not suitable for some project, analysis, or modelling purposes. Please be sure you are using the best available data. 1:24000 scale datasets are recommended for projects that are at the county level. 1:24000 data should NOT be used for high accuracy base mapping such as property parcel boundaries. 1:100000 scale datasets are recommended for projects that are at the multi-county or regional level. 1:250000 scale datasets are recommended for projects that are at the regional or state level or larger. Vector datasets with no defined scale or accuracy should be considered suspect. Make sure you are familiar with your data before using it for projects or analyses. Every effort has been made to supply the user with data documentation. For additional information, see the References sectionand the Data Source Contact section of this documentation. For more information regarding scale and accuracy, see our web pages at: http://www.geoplan.ufl.edu/education.html |
Tallahassee /Leon County GIS - http://www.tlcgis.org/ Also available from TLCGIS is a pdf entitled metadata.pdf for all there available layers. |
Create TIN for study area from 1996 Land base data. TIN should include mass polygon data, contour data, spot elevation data and breakline data. Create DEM lattice from TIN. Start with a resolution of 5 feet and interactively increase the resolution until the DEM resolution fits the terrain variance well. From DEM generate Flow direction, Sink,Sink Watershed and Sink Depth grids. Identify sink depth threshold which correctly eliminates DEM errors whilepreserving actual closed depressions in the landscape. Fill original DEM using this threshold. Some sink errors willremain but these will be eliminated in the remaining steps. Delete original DEM, flow direction, sink, sink watershed and sink depth models. Generate new flow direction and sink models from filled DEM. Convert new Sink grid to Polygon coverage. Establish linear relate linking Sink grid and Polygon coverage. Use point coverage of topographic sinks as a background coverage, open the contour coverage for edit. Construct a select set consisting of the highest closed contour for each depression making sure to include depressions within depressions. Create coverage from select set. Build polygon topology. Create regions to represent depressions within depressions. Create and populate attribute table. Known and active features are identified based on recommendations from licenced geologists who represent the Northwest Florida Water Management District, City of Tallahassee, and the Florida office of the United States Geological Survey. Features attributed as active are found to be consistent with the requirements and definitions put forth in the land development regulations of Leon County and the City of Tallahassee. Sources used as reference for the delineation process are 1988/1991Landbase, 1996 Land base 1996 Digital Elevation Model, and 1996 Digital Ortho Photography. Process Date: 19990000 |
Projection ALBERS Datum HPGN Units METERS Spheroid GRS1980 1st Standard Parallel 24 0 0.000 2nd Standard Parallel 31 30 0.000 Central Meridian -84 00 0.000 Latitude of Projection's Origin 24 0 0.000 False Easting (meters) 400000.00000 False Northing (meters) 0.00000
DATA SOURCE CONTACT (S):
Name:
Abbr. Name:
Address:
Phone:
Web site:
E-mail:
Contact Person:
Phone:
E-mail:
|
Tallahassee - Leon County GIS TLCGIS 301 South Monroe Street Tallahassee, FL 32301 805 - 4882818 |
Name: FLORIDA GEOGRAPHIC DATA LIBRARY
Abbr. Name: FGDL
Address: Florida Geographic Data Library
431 Architecture Building
PO Box 115706
Gainesville, FL 32611-5706
Web site: http://www.fgdl.org
Contact FGDL:
Technical Support: http://www.fgdl.org/fgdlfeed.html
FGDL Frequently Asked Questions: http://www.fgdl.org/fgdlfaq.html
FGDL Mailing Lists: http://www.fgdl.org/fgdl-l.html
For FGDL Software: http://www.fgdl.org/software.html