Watershed Tools For Massachusetts

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Watershed Tools For Massachusetts

• Pete Steeves
• USGS WRD MA-RI District

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A Cooperative Environment

• MassGIS
• development of centerline data (24k)
• creation of the ARCVIEW interface and initial set
  of tools
• AVENUE expertise
• USGS WRD -- MA/RI District
• initial watershed delineation programs in ARC
• compilation of DEM/GRID data and drainage
  enforcement programs
• working with MassGIS to enhance the watershed
  tools with new and improved features based on
  project applications

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Goals for the Development of GIS Watershed
Analysis Tools

• Quick and reliable method for delineating basins
  from any point on any river in the State
• Broad and flexible in its applicability to
  hydrologic investigations
• Demonstrate its use through pilot applications
  that address management concerns

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Datalayer Pre-requisites

• Networked centerline of USGS DLG hydrography with
  a system of reach codes attached
• Sub-basin boundaries within a watershed that
  will help to minimize the dependence on DEM based
  basin delineation and speed up subsequent
  analysis
• Drainage enforced DEM/Grid data

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Working Environment ARCVIEW

• Perform actions on the network such as upstream
  trace and find all downstream events
• Delineate a basin from a selected point on the
  network
• Batch delineate basins using an event table
• Make linear events from point events to establish
  a population of segments

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Watershed Tools View Menu
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Neponset Watershed Subbasins and Centerline Data
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Select a Point.
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...Delineate a Watershed
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Drainage EnforcementWhy and How?
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Drainage Enforcement Steps For 24K DEMs

• Merge DEM derived grids and clip to a 4000 foot
  buffer around selected watershed
• VIP 70 of the cells into a point coverage
• Run Topogrid
• resample cell size to 10 meters
• input would include vector centerline and VIP
  elev points
• watershed may have to be broken up and pieced
  back
• Run agree.aml from University of Texas
• exaggerate the depths of the streams by
  canyonizing them
• enhances the topogrid processing
• minimize smooth distance tolerance
• Run fill on the output, followed by
  flowdirection and flowaccumulation

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Application I

• Obtaining streamflow statistics for Massachusetts
  streams on the WEB
• User chooses any point on any stream
• The watershed is delineated
• The application calculates variables(area of
  stratified drift, total length of streams, mean
  elevation and slope values) from which stream
  flow statistics are calculated, including

• Peak-flow frequencies - mean annual, 10-, 25-,
  50-, 100-, and 500-year floods
• Low-flow frequencies - 7-day, 2- and 10-year low
  flows
• Flow durations - 99 through 1 exceedance
  probabilities
• August median flow

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THE STREAM STATISTICS WEB PAGEhttp//ma.water.usg
s.gov/streamstats/
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THE JAVA APPLICATION WINDOW
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ADD FEATURES SUCH AS ROADS TO FIND THE LOCATION
OF INTEREST
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USE MAPS AT SMALL SCALE TO FIND PRECISE LOCATIONS
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BASIN DELINEATION MAP
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BASIN FEATURES AND FLOW VALUES
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Application II

• Characterize water resources (streams,
  lakes/ponds) on a river network (Neponset River
  Basin) for water-quality monitoring
• Define a population of stream segments
• Determine physical characteristics of stream
  segments (length, stream order)
• Classify stream segments in terms of watershed
  characteristics that might affect water quality
  (i.e. - land use)

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Stream Segments are Defined Based on Locations
Where a Change in Water-Quality May Occur
Tributary confluences
Significant lakes (gt 5 acres)
Significant point-source discharges (NPDES sites)
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Resulting Segmentation in a Section of the Network
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Physical Characteristics of StreamsNeponset
River Basin
Total 312 stream segments152 stream miles
45 significant lakes(not shown)
Stream Order
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Determining Watershed Characteristics Requires
Delineating Watersheds
Batch Delineation
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Development of Watershed Tools in the NHD ArcView
Toolkit

• Currently working on adding watershed delineation
  functionality to the Toolkit
• Focusing on areas where 124,000 scale National
  datalayers are available
• Testing the validity of using 1100,000 scale NHD
• Plans to incorporate other tools into the Toolkit
  (event creation and search, a raindrop tool,
  batch delineation of watersheds)