Stream Asset Inventory GIS Model
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Johnson County AIMS http://aims.jocogov.org 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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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. Pilot Study. - PowerPoint PPT Presentation
Transcript of Stream Asset Inventory GIS Model
Johnson County AIMShttp://aims.jocogov.org
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
Johnson County AIMShttp://aims.jocogov.org
Pilot Study
• Test watershed is Blue River in southeast corner of Johnson County
• Approx. 100 mile2
Johnson County AIMShttp://aims.jocogov.org
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
Johnson County AIMShttp://aims.jocogov.org
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…
Johnson County AIMShttp://aims.jocogov.org
DEM Source
Johnson County AIMShttp://aims.jocogov.org
Filled DEM
Johnson County AIMShttp://aims.jocogov.org
Flow Direction
Johnson County AIMShttp://aims.jocogov.org
Flow Accumulation
Johnson County AIMShttp://aims.jocogov.org
Watershed Delineation
Johnson County AIMShttp://aims.jocogov.org
Stream Delineation
Johnson County AIMShttp://aims.jocogov.org
Slope
Johnson County AIMShttp://aims.jocogov.org
Stream Order
Johnson County AIMShttp://aims.jocogov.org
Additional Attributes
• Slope – Average
• Sinousity – Curve/Line
• Slope/Sinousity – Gives Condition Index
• Channel Stability (Erodiblility) – Slope/Soil
Johnson County AIMShttp://aims.jocogov.org
Modeled Hydrology
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Challenges of Watershed Delineation
• Not an exact science and there’s no standard
• Typically done with 30 meter DEM
• We’re 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
Johnson County AIMShttp://aims.jocogov.org
High Resolution Data
Johnson County AIMShttp://aims.jocogov.org
Anomalies
Johnson County AIMShttp://aims.jocogov.org
Next Steps
Subwatersheds &Streams
Env. ConditionsImpervious surfaceSoilVeg Coveretc…
Develop classification of streams and subwatersheds
Sensitive ImpactedNon-supporting Restorable
Johnson County AIMShttp://aims.jocogov.org
Layers for Analysis
• Essential– Impervious Surfaces – Current Land Use– Future Land Use
• Helpful– Vegetative Cover– Road Crossings– Sewer Lines– Developable Land– Wetlands– Soils– Pollution Sources
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Johnson County AIMShttp://aims.jocogov.org
Contours
DEM FlowDirection
FlowAccumulation
Masspoints
SlopeStreams Subwatersheds
StreamOrder
FilledDEM
Sinousity
StreamOrder
Obstructions
Veg Cover
Bridges
Landuse
Soils
etc…
Johnson County AIMShttp://aims.jocogov.org
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Johnson County AIMShttp://aims.jocogov.org
Data Collection
• Custom forms on pocket pc
• GPS wired to pocket pc for data capture
• Sync nightly through internet back to master database
