Transcript USGSFY16_SS_Jenny_PP..

Implementation of the U.S. Geological
Survey’s StreamStats Program in
Kansas—
A Web Application for Streamflow
Statistics and Basin Characteristics
Kansas Water Science Center
Jenny Lanning-Rush, Geographer
U.S. Department of the Interior
U.S. Geological Survey
Flood Frequency Analysis
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USGS routinely publishes reports that provide predictor
equations that correlate discharge to other independent
geomorphologic and climatic basin parameters for much
of the United States.
The multivariable linear regression equations for
estimating the magnitude and frequency of peak
discharges in rural ungaged streams are periodically
updated to account for additional years of record
These regional flood-frequency regression equations are
used by engineers, ecologists, public works directors,
and many others in their day-to-day work
Regional Regression Analysis Input
Variables require extensive time and
computational resources to compute
Equation for estimating the 100-year peak flow (the peak flow that has a 1 percent
probability of being exceeded in any given year) from Rasmussen and Perry takes
the form:
Q100 = 0.810(CDA)0.532(P)2.070(S)-0.309(Sl)0.272
where:
CDA
P
S
Sl
is the contributing drainage area for the site, in square miles
is the average annual precipitation for the entire drainage area, in inches
is the average soil permeability for the entire basin, in inches per hour
is the slope of the main channel, in feet per mile, as measured by dividing
the difference in elevation at points in the channel at 10 and 85 percent of
the main channel length by the intervening main channel length.
USGS StreamStats is a Map-based
Web Application
 StreamStats uses geographic information system (GIS) software
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and programming techniques to extract watershed parameters
with minimal time and resources.
Extracted watershed characteristics (area, CN, …) are “Sent” to
NFF and results are “Published” to the web browser
Arc Hydro tools implement
specialized data structures and tools
 Use Arc Hydro tools for terrain
preprocessing. They build an interconnected
set of spatial data that facilitate quick
execution for analytical tools, a “analytical
data cache”
 Raster data:
 DEM, flow direction, flow accumulation, drainage lines,
sinks, …
 Vector data:
 Drainage lines, catchments, adjoint catchments, sinks,
lakes, …
Watershed Delineation from a Point
SS website uses Arc Hydro tools for watershed delineation,
characterization, and analysis that leverage the preprocessed data
structures.
Sample from Basin Characteristics Report
Parameter
These
attributes are
also stored in
shapefile of
the delineation
& can be
downloaded
Value
Contributing drainage area, in square miles
51.18
Contributing drainage area minus the area
upstream of NRCS floodwater-retarding
structures, in square miles
51.18
Percent of contributing drainage area regulated
by NRCS floodwater-retarding structures
0.0
Mean basin elevation, in feet
1250
Elevation at outlet in feet
1070
Mean basin slope in percent, computed from 10meter DEM
4.50
Longest-flow-path 10-85 slope in feet per mile
11.5
Soil permeability from STATSGO, in inches per
hour
0.420
2) Delineate watershed
1) Select area
3) Get results
Development for new skin (SSv4)
targeted for FY16