Stream Asset Inventory GIS Model

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Stream Asset Inventory GIS Model

• Goals
• Use a variety of spatial datasets to test
  feasibility and accuracy of modeling stream types
  and orders
• Support the field data collection efforts by
  providing accurate reference data prior to
  sampling

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Pilot Study

• Test watershed is Blue River in southeast corner
  of Johnson County
• Approx. 100 mile2

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Process

• Use spatial analysis and hydrological modeling
  tools to model stream network and environmental
  conditions
• Solid DEM is basis of accurate results
• Majority of hydrologic products derived from DEM
  including the streams, subwatersheds, slope, etc

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Tools

• Free extensions packaged with Arc8 and AV3.x
• Hydrology Modelling, HydroAnalyst
• Free 3rd party extensions for use with ESRI
  products
• ArcHydro, Strahler Stream Order

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DEM Source
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Filled DEM
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Flow Direction
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Flow Accumulation
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Watershed Delineation
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Stream Delineation
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Slope
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Stream Order
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Additional Attributes

• Slope Average
• Sinousity Curve/Line
• Slope/Sinousity Gives Condition Index
• Channel Stability (Erodiblility) Slope/Soil

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Modeled Hydrology
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Challenges of Watershed Delineation

• Not an exact science and theres no standard
• Typically done with 30 meter DEM
• Were not hydrologists
• Testing the various inputs to generating
• watershed data
• Contour vs. Masspoint
• Burning In Streams
• Establishing Input Parameter Thresholds
• Handling high resolution data
• Handling Anomalies

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High Resolution Data
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Anomalies
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Next Steps
Subwatersheds Streams
Env. Conditions Impervious surface Soil Veg
Cover etc
Develop classification of streams and
subwatersheds Sensitive Impacted Non-supportin
g Restorable
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Layers for Analysis

• Helpful
• Vegetative Cover
• Road Crossings
• Sewer Lines
• Developable Land
• Wetlands
• Soils
• Pollution Sources

• Essential
• Impervious Surfaces
• Current Land Use
• Future Land Use

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Contours
DEM
Flow Direction
Flow Accumulation
Filled DEM
Masspoints
Slope
Streams
Subwatersheds
StreamOrder
Sinousity
StreamOrder
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• Delineate subwatershed units for analysis
• Compile and verify current and future landuse
• Rapid development leads to underestimation of
  impervious area
• Estimate impervious cover
• Establish stream classification

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• ???

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Data Collection

• Custom forms on pocket pc
• GPS wired to pocket pc for data capture
• Sync nightly through internet back to master
  database