Watershed Delineation

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Watershed Delineation

• 9-12-07

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Caney Fork Watershed

• 05130108 HUC8 Cat Number
• Copy folder from classfiles\GEOG4650-Li\Data\caney
  -dem to your own folder. You will start working
  on the layer from your own folder. Be careful
  when you copy folder from one place to another.
  DO NOT MOVE, use COPY.
• Start a new ArcMap project or use the existing
  project and add a new Dataframe to the TOC.
• While adding 05130108 to your project, you will
  be asked to perform Create pyramid for
  05130108, simply click Yes then, sit and
  wait..Z Z Z Z Z Z Z Z Z

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05130108

• Is the layer projected?
• If not, what is the datum used for the layer?
  (from Properties / Sources)
• How to project DEM from DD to ?
• Lets look at the elevation data we found that
  the elevation ranges from 13522 to 67699.
• It seems to be a ????? Unit
• From Properties / Sources.. We found that the
  Pixel Type is unsigned integer
• So, you need to change it back to ?????
• Lets use Spatial Analyst Raster Calculator
• And you may get a Calculation, right-click on
  the Calculation Data Make Permanent

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Project DEM

• ArcToolBox
• Data Management Tools
• Projections and Transformations
• Raster
• Project Raster (Remember to create a new folder
  to hold the projected DEM)

Create a new dataframe and move the projected DEM
to the new dataframe
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Nonprojected vs Projected

• Nonprojected vs projected

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Watershed Delineation

• Use ArcToolBox
• Spatial Analyst Tools
• Hydrology
• Fill (Why?) and this process will take forever
  to complete (at least on my computer), then
• Flow Direction and Flow Accumulation

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Flow Accumulation
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Caney-HUC-12

• Add Caney-HUC-12.shp to the current dataframe.
  (make sure the fill pattern is set at transparent
  so your flow accumulation layer can be seen under
  HUC layer).
• We will dissolve features (HUC-12) into HUC-10
  based on criteria from the table.
• Lets open up the attribute table and decide what
  attributes to be remained on the new attribute
  table.

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Dissolve Features

• ArcToolBox
• Data Management Tools
• Generalization
• Dissolve
• Keep these
• Area
• Name 10
• Grassacre
• HUC_10
• HUC_8
• HUC_6
• HUC_4
• HUC_2
• Statistics Fields
• AREA SUM
• GRASSACRE SUM
• Name of new shape
• Caney_huc_10.shp
• (underline, instead of hyphen)

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HUC-10

• There are 9 HUC-10 watersheds in the Caney.

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Create Pour Points

• PourPoint.shp (UTM1983)
• Find 9 points at the outlets of each HUC-10
  watersheds and create them.
• Use spatial join to join attributes from
  Caney_huc_10.shp to PourPoint.shp

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Spatial Join Table formed

• Tables attribute joined from other layer based
  on spatial relationship.

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Spatial Analysis Tool

• Hydrology Watershed

Problem ????? DEM or Fill Sink process is not
detailed enough..
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Create 3D Model

• Start ArcScene from ArcGIS
• Add Caney-dem-de to the project
• Set Base Height from the layers properties.
• You may have to exaggerate 20 times for your Z
  scale.

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