Transcript The ATLSS High Resolution Topography/Hydrology Model

The ATLSS High Resolution
Topography/Hydrology Model
Scott M. Duke-Sylvester
ATLSS Project : University of Tennessee
Project web-site : www.atlss.org
E-mail : [email protected]
Overview of Presentation
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Purpose of the High Resolution
Topography (HRT)/High Resolution
Hydrology (HRH) models
HRT/HRH creation
Verification, calibration and validation
Versions and availability
Purpose of the HRT/HRH
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To provide an estimate of finer scale
spatial variation in hydrology for the
ATLSS models
Resolution : 500x500 meters
 Used by all ATLSS models including:
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SESI models
 Fish model (ALFISH)
 Deer/panther model
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Why 500x500 meters?
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Plants and animals respond to local
variations in hydrology at a spatial
resolution finer than the 2x2 mile SFWMM
blocks:
Tree islands
 Transition from slough to prairie
 Permanent ponds vs. marsh with transient
water depths
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Tree Island : Skinner’s Camp
Slough to prairie transition
Variation in water depths
Wet
0
Dry
SFWMM
HRH
HRT Features
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Common resolution : 500x500 meters
Available : 30x30 meters
Coverage : Most of the natural areas of SF
HRH features
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Common resolution : 500x500 meters
Common time step : 5 days
Time span : Jan 1 1965 - Dec 31 1995
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Adaptable to longer SFWMM runs
Spatial coverage : SFWMM region
Adaptable to use with other data sets
HRT Creation
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Basic premise : Plants are present in
locations where local topography and
hydrology combine to create favorable
hydroperiods
Topography + Hydrology => Vegetation
 Vegetation + Hydrology => Topography
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Inputs
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Hydrology : SFWMM Calibration/verification run
Vegetation : FGAP
Hydroperiod ranges : Literature, expert opinion
Adaptable to other data sets
Hydrology Data
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Transform the Stage
Height data into
hydroperiod histograms.
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Describes the number of days at
or above each elevation.
We use an average of
values from 1986 to
1995.
Currently based on the
Calibration/Validation
(Cal/Val) run of the
SFWMM.
Hydroperiod values for
vegetation types.
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Hmin
0
365
10
60
0
0
10
0
….
Hydroperiod values are
drawn from the literature.
Hmax
0
365
45
180
30
15
40
45
….
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Class
0
1
2
3
4
5
6
7
….
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For each vegetation type in
the FGAP map we estimate
a range of hydroperiods.
The hydroperiod used for
any particular cell in the
FGAP map is interpolated as
follows:
Vegetation Map
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Raster Map
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high spatial resolution
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high spatial heterogeneity
Each cell contains an index
value which represents one
vegetation type.
Currently based on the
Florida GAP Map.
Processes
Ep
Class
0
1
2
3
4
5
6
7
Max HP
0
365
45
180
30
15
40
45
MinHp
0
365
10
60
0
0
10
0
….
….
….
HRH Creation
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2x2 mile SFWMM hydrology data is
distributed over a 500x500 meter HRT
Redistribution takes place on a 2x2 mile
cell basis
Total daily water volume is preserved in
each cell
Resulting hydrology has a 500x500 meter
resolution
Verification
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Simple visual inspection
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e.g. tree islands are higher than surrounding
slough
Comparison to independently computed
values
Function testing
Calibration
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The main features of the HRT that can be
calibrated are the hydroperiod ranges for
each vegetation type.
Hydroperiod ranges estimated from
published literature
 Expert opinion
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HRH Validation
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Comparison of HRH water depths to measured
water depths
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Time series : Feb, Apr, Jul, Oct, Dec 1995
Region : WCA-3 and Shark River Slough
16 sites, 3 plots at each site
r2 for HRH to field data : 0.289
r2 for SFWMM to field data : 0.236
Gaff, H. 1999. Spatial heterogeneity in
ecological models : two case studies. PhD.
Dissertation, University of Tennessee.
HRT Validation
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Comparison to USGS HAED
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Compared the mean elevation and variance between
the HRT, USGS High Accuracy Elevation Data (HAED)
and SFWMM data.
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HRT variance is more
similar to HAED
variance
HRT mean is lower
than either SFWMM
or HAED mean
Conclusion
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HRT is not an exact fit to measured
elevations.
HRT is generating a level of topographic
variation consistent with the HAED data in
many instances.
Further calibration of model will improve
the fit between the HRT output and HAED.
Application to Restoration
Planning
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Provides an estimate of topography and
hydrology to other models at a spatial
resolution relevant to ecological modeling
Versions
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Version 1.0
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Available for use today
Has been used in the past
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Based on:
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1997-1998 hydrology scenario evaluation
FGAP 2.1
Hydroperiod values from Michael Huston
SFWMM 3.4, Calibration/verification run
Version 2.0
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Available by June 30 2002
Based on:
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FGAP 6.6
Hydroperiod values from Paul Wetzel
SFWMM 3.5, Calibration/verification run
Calibrated with latest USGS HAED
Availability
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HRT maps
Created at UT
 Maps are available to collaborating agencies
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ENP, SFWMD …
High Resolution Hydrology
Created as part of the ATLSS SESI package
 Sun/Solaris Workstations
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ENP
Collaborators/Contributors
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FGAP : Leonard Pearlstine
SFWMM : Ken C. Tarboton, SFWMD
ATLSS :
Paul Wetzel, ATLSS
 Charley Comiskey, ATLSS
 Michael Huston, ORNL
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E-mail : [email protected]
Web site : www.atlss.org/~sylv
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