Hydrologic network metrics based on functional distance and stream discharge

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Hydrologic network metrics based on functional
distance and stream discharge

• David Theobald Mary Kneeland
• Natural Resource Ecology Lab
• Dept of Recreation Tourism
• Colorado State University
• Fort Collins, CO 80523 USA
• May 16, 2003

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• Goal develop approaches for spatio-temporal
  design and modeling in order to further our
  understanding of aquatic resources
• Objectives, to develop
• 1. spatio-temporal models for a continuous
  response,
• 2. spatio-temporal models for count and/or
  categorical data,
• 3. design and analysis methods for data collected
  at different scales.

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STARMAP Projects

1. Combining environmental datasets (Hoeting)
2. Local inferences (Briedt)
3. Development and evaluation of landscape
   indicators (Theobald)
4. Extension and outreach (Urquhart)
5. Integration and coordination (Urquhart)

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Big questions

• Broad-scale processes (e.g., acid deposition in
  Mid-Atlantic region) to watershed processes
• Probability-based sampling for state compliance
  to CWA
• Sampling perennial/intermittent streams (I.e.
  flow all year for most years)
• What is perennial and shouldnt be? (24)
• What is not included and should be? (18)
• Fragmentation of hydrologic regime on biodiversity

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Goals of indicator development

• Develop and evaluate landscape-level indicators
  suitable for spatial and temporal analyses of
  EMAP data
• Investigate limitations of currently-available
  data and offer new, robust methodologies

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Overview of presentation

• Link watershed and hydrologic network in every
  respect, the valley rules the stream. Hynes
  1975
• From surrogates to direct measures
• Towards network-based metrics

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Indicators that measure watershed characteristics
and aquatic ecology Reviews

• 1. Land use in entire watershed vs. riparian
  buffer (IBI)
• watershed better Richards et al. 1996
• buffer better Arya (1999) Lammert and Allan
  (1999)
• 2. Other indicators
• - road density (Bolstad and Swank)
• - dam density (Moyle and Randall 1998)
• - amount of roads near streams (Moyle Randall)
  and Arya (1999)

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Key measuring watershed-stream linkage?

• 1. Lumped measures
• - , , density
• 2. Spatially-explicit
• - Euclidean distance
• 3. Network-based (directional, cumulative)
• - Strahler stream order
• - Length of stream line
• - Watershed area
• 4. Direct network-based
• - Discharge?!

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1. Lumped

• agricultural, urban
• Ave road density
• Dam density (Moyle and Randall 1998)
• mines
• Road length w/in riparian zone

Southern Rockies Ecosystem Project. 2000.
EPA. 1997. An ecological assessment of the US
Mid-Atlantic Region A landscape atlas.
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1. Lumped (cont.)

• ArcINFO, Basinsoft (Harvey and Eash 1996)
• Drainage area, shape, relief
• O1 streams, main channel length, stream density

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2. Spatially-explicit, Distance

• As the crow flies (Euclidean)

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3. Network-basedDistance

• As the seed floats (downstream)

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Distance

• As the fish swims (down up stream)

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Distance

• Upstream length
• mainstem (2)
• arbolate (1234)

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Upstream 66 km
Mainstem Upstream 37 km
Network 16 km (down) 6 km (up)
Downstream 298 km
RWTools ArcView v3 extension
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Direct measures

• Surrogate, e.g. Strahler order
• The usefulness of stream order assumes, with a
  sufficiently large sample, that order is
  proportional to stream discharge
• Strahler 1957
• Ordinal data
• Not robust to data artifacts

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Link watershed and network

• 1 to 1 relationship between stream reach and
  catchment
• Need robust method of delineation for
• large extents

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Pilot area Colorado, Yampa
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Smart bump delineation

• 1. Reach catchment
• - flowdirection 30 m DEM
• - watershed from buffered hydrology (USGS NHD
  1100K)
• 2. Differentiate local ridges (artifacts) from
  true catchment boundary
• - smart bump using ZONALMIN
• 3. Remove conversion slivers at shared boundaries
• - regiongroup
• - if lt10 cells, NIBBLE
• Currently, 1-2 days processing time per basin

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Comparison of automated vs. hand-delineated

1. Randomly selected 111 (out of 2151 watersheds)
2. Computed area of automated vs. hand-delineated
   (truth)
3. RMSE 204.39 (in ha)
4. Mean error 2.4
5. Challenges in defining commensurate watersheds

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Hand-delineated truth watersheds

• 11 error

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Reaches are linked to catchments

• 1 to 1 relationship
• Properties of the watershed can be linked to
  network for accumulation and networking
  operations
• Ordinal value (order) to real value (length,
  area, etc.)

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Networking

• Import into ArcGIS Geometric Network
• Use networking tools, e.g.
• 1. Set flag
• 2. Trace upstream
• 3. Trace downstream

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4. Direct metric stream discharge

• Physical-based model
• Q Precipitation Evapotranspiration
• Q is VMAD (Virgin Mean Annual Discharge)

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USGS Stream Gauges
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R20.7282 P-value3.407e-006
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Surrogate ? Direct metric

• Order
• Area
• Discharge

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Fragmentation and flow regulation

• Deynesius and Nilsson, Science (1994) 77 of
  upper 1/3 of northern hemisphere rivers are
  strongly or moderately affected
• - F regulated/total channel length
• - R of VMAD (cumulative reservoir live,
  gross capacity)

RCL
TCL
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Alteration of natural flow regime

• Accumulation of dam storage

Tributaries below dams mediating flow
modification?
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Flow modification

• How to measure relative modification of
  hydrologic regime?
• 1. Degree of modification to flow cumulative
  annual flow cum. dam max. storage
• Q Q-S
• 2. Proportion of modified to VMAD (natural)
  flow
• F Q/Q

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Reservoirs
Dam shadow
High
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Or/CO

• Table of output data
• Expand this to other factors e.g., geology,
  vegetation, etc.
• Linked to rest of data

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EMAP sites
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Oregon
dam accumulation overlap of catchment area
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Within catchment hydrologic distance

• Moved from basins, HUCs and watersheds to stream
  reach catchments
• Within catchment
• Distance along hydro network distance (distance
  along the network upstream of pour point)
• Allocation (using flat weight surface)

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Challenges

• Data
• NHD 1100K
• Dams NID
• Processes
• natural flow
• diversions
• ET

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Data attribute errors
Irrigation canals and pipelines incorrectly
attributed as river/stream
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Data positional error
Spatial location of dam locations is imprecise
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Data duplicates
Stagecoach reservoir is duplicated Challenges
of understanding diverse datasets
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Data missing data?
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Scale
Dam on tributary that is not in 1100K network
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NID dams (red) gt 50 high, many other dams (in
yellow) and other structures!
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Dam data
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Western Water Assessment, Figure 7
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Network metrics

• Have foundation direct measure
• Build on/refine existing metrics
• first order streams
• Main-channel length
• Total stream length
• Drainage density stream length / catchment area
• Examine location within network and make
  available to statistical models

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EMAP sites
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Euclidean distance
2

• Use x,y to create distance matrix
• Reasonable for broad-scale processes

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Hydrologic distance
2

• Follows stream
• network

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3
1
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Spatial weights
W
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 1
0 1 0 0 0 1 0
1 0
1
1
2
3
5
4
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Functional distance

• Reflect distance
• weighted by
• Stream gradient
• Geology
• Land use
• Etc.

1.7
A
1.2
B
1.0
1.9
C
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Functional weighting
W
0 0 0 0 0 0 0 0.7 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0.7 0 0 0 0.2
0.8 0 0.2 0.8 0 0 0.1 0.2 1.0 0.1
0.2 1.0 0
1
1
3
2
4
5
7
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E.g., downstream hydrology
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Connectivity matrix
To/ from 1 2 3 4 5 6 7
1
2
3 1 1
4 1 1 1
5
6
7 1 1 1 1 1 1
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Functional spatial weights
Station Order Area overlap (, km2) Length (m) Discharge
1 ? 3 5 ? 5 982900/2952 4532 99.00
1 ? 4 5 ? 5 112900/25316 42568 15.00
1 ? 7 5 ? 5 112900/26001 58389 15.00
2 ? 3 1 ? 5 0.414/2952 23121 0.20
2 ? 4 1 ? 5 0.0514/25316 59715 0.04
2 ? 7 1 ? 5 1114/26001 75536 0.04
3 ? 4 5 ? 5 112952/25316 38105 15.00
3 ? 7 5 ? 5 112952/26001 53925 15.00
4 ? 7 5 ? 5 9725316/26001 15820 96.00
5 ? 7 2 ? 5 0.5145/26001 54964 0.80
6 ? 7 4 ? 5 0.5140/26001 30933 0.80
5
6
2
4
1
3
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Station Discharge (kacft)
1 1501
2 4
3 1515
4 9651
5 84
6 82
7 9972
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Incorporate watershed conditions?
W
0 1 0 0 0 0 0 1 0 0
0 1 1 0 0 0 0 0 0
0 0 0 0 0 0 1 0 0 0
1 0 1 0 1 0 0 1 0
0 1 0 1 0 0 0 0 0
1 0
1
1
3
2
4
5
7
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E.g., macroinvertebrates
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Challenges

• Generating spatial weights matrix
• O(n2) ? O(n)?
• Functional (cost-weighted) spatial weights table

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Products

• Watershed-reach network database
• GIS-based tool to develop functional spatial
  weights matrix
• ArcGIS extension for hydrologic network metrics

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• Thanks!
• Comments? Questions?
• Work funded by US-EPA STAR Cooperative agreement
  CR829095 awarded to CSU
• STARMAP www.stat.colostate.edu/nsu/starmap
• RWTools email davet_at_nrel.colostate.edu