1. A Quantitative Assessment of
2 and 4 feet Sea Level Rise
on the Broward County, FL Landuse
Using GIS
Ugur Dagkilic
Student Competition-Undergraduate Category
URISA, 2010
2. About the author;
Ugur Dagkilic holds a bachelor’s degree in Urban Planning and
certificates in Environmental Planning and GIS. For more than a decade,
he worked in South Florida as a truss designer. This experience
provided him the opportunity to experience some aspects of the civil
engineering and construction industry.
After realizing his interest in analysis using various tools, he got
enrolled in the Advanced GIS Certificate Program at Florida Atlantic
University in 2008 and will complete the program in May 2010. Besides
the academic education, he has been self-studying and improving his
knowledge in the field using various sources.
He can be reached;
By email at ugurdagkilic@yahoo.com or
By phone at 954-643-6053
3. About the project;
The project is the author’s first project after completing his core
GIS classes. After observing assorted sea level rise
demonstrations on the media, he personally wanted to experience
it. A quantitative effect of the sea level rise on urban environment
in terms of numbers and landuse categories would be a good
exercise.
Broward County, FL was a good project location due to its low
elevation, dataset availability and familiarity due to the authors
place of residence.
4. (Source: www.noaa.gov)
• Global warming and melting glaciers
• Sea level has been rising 1-10 mm/year around the continental
U.S., probably faster
5. • Low-lying coastal towns
are in danger in the long
term
• Federal & Local Govt’s
should make long term
plans
6. How can I assess
the impact of sea level rise
for the Broward County
using GIS ?
Florida State
Broward County
7. Relevant Datasets
LIDAR for the Broward County NED for the Broward County
Bare earth or unfiltered, 5 ft res. 1/9 arc-second (approx 3m res)
(http://gis.ihrc.fiu.edu) 1/3 arc-second (approx 10m res)
1 arc-second (approx 30m res)
1 m vertical resolution
(http://seamless.usgs.gov)
8. Relevant Datasets
Broward County vector DOQQ tiles for the
(polygon) type landuse Broward County
(http://www.broward.org/ (www.labins.org)
planningcouncil/gisdata.htm)
10. Sea Level Rise & Elevation
11.75
Elevation Data Brightness Scale
(1 ft vertical resolution)
2 2 ft
1 1 ft
0 0 Level
-0.72
A math query on the elevation dataset using the raster calculator
would provide the desired sea level rise effect
11. Methodology
Project Workspace
Project Goal
Setup
Elevation Data Land-use Data
Data Collection
In raster format In polygon format
Conversion Dissolve and
into feet Merge
Determination of
2 and 4 feet Symbolization
sea level
Conversion into Conversion into
Remain as raster Remain as polygon
polygon raster
Determine the
Multiply the files Intersect the
lands above 2 and 4
in raster calculator feet sea level polygons
Option 1 (Vector op)
Option 2 (Raster operation) is Quantify and
used for this project
Visualize the results
Option 2 (Raster op)
12. Preparation
• Create the job folder, geodatabase
• Project the datasets into same spatial
reference
• Clip the datasets with the Broward County
border
14. Elevation Conversion
• Need the elevation data in feet
• LIDAR vertical resolution is already in feet
• DEM vertical resolution is 1 m
• 1m = 3.28 ft
Raster Calculator Query : Elev * 3.28
11.75 38.56
-0.72 -2.37
Elevation in meter Elevation in feet
15. 2 and 4 feet sea level determination
Raster Calculator Query : Elev ≥ 2
Land above 2 feet water = 1
Land below 2 feet water = 0
Raster Calculator Query : Elev ≥ 4
Both LIDAR and NED datasets are
calculated for comparison purposes Land above 4 feet water = 1
Land below 4 feet water = 0
16. NED provides meaningful regions
Ex: A
Ex: B
NED provides meaningful regions. In South NED
Florida, if a house on a block is under water
means the whole block is under water LIDAR
(Bare earth)
17. LIDAR provides better accuracy
Ex: A Ex: B
There are areas that are covered by NED but
not covered by LIDAR
Similarly;
NED
There are areas that are covered by LIDAR
but not covered by NED LIDAR
(Bare earth)
18. Which one to use; NED or LIDAR ?
NED LIDAR
Accuracy Good Better
Easy to use Better Good
Computer crashes
Better Good
due to the file size
Meaningful Regions Better Good
1/3 arc. sec. NED is used since it is easier to work with and it has
meaningful uniform regions. The idea and calculations of the project is
based on these regions.
However, LIDAR would be better if there was a custom script that
produces water based regions similar to NED.
21. Dissolve & Merge on Landuse Data
• Used merge tool to
combine the block-
level attribute data
• Used dissolve tool to
generalize landuse
classes under new
landuse classification
22. Conversion of land-use into raster
Dissolved & Merged Symbolized raster land-use
Non-symbolized
Polygon Land-use
Set the cell size same as of the elevation data
24. Matching land-use with sea level
Landuse Sea level Outcome
• A simple map algebra operation
• Value 1 (land) keeps the values, 0 (water) replaces
them
25. Matching land-use with sea level
Land-use * 2 ft water file
2 ft
water
L
R
A Land above 2 ft water
A
N
S
D
T
U
E
S
R
E
4 ft
water Land-use * 4 ft water file
Land above 4 ft water
26. New land-use raster quantities
Original land-use Attribute table Attribute table
Attribute table after 2 ft water rise after 4 ft water rise
Export to MS Excel
29. Conclusion..
• Mainly high residential (especially high rise buildings)
and conservation areas by the beach submerse with 2 feet
sea rise.
•Almost half of the county submerses with 4 feet sea rise
pointing out the degree of vulnerability of the county to 4
feet elevation difference.
•The precision of the results depends on a comprehensive
environmental analysis that uses the most up-to-date data
and employs various hydrologic analysis techniques.