watershed tools for massachusetts
DESCRIPTION
Watershed Tools For Massachusetts. Pete Steeves USGS WRD MA-RI District. 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 - PowerPoint PPT PresentationTRANSCRIPT
Watershed Tools For MassachusettsWatershed Tools For Massachusetts
Pete Steeves
USGS WRD MA-RI District
A Cooperative EnvironmentA 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
Goals for the Development of GIS Goals for the Development of GIS Watershed Analysis ToolsWatershed 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
Datalayer Pre-requisitesDatalayer 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
Working Environment: ARCVIEWWorking 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
Drainage Enforcement Steps For 24K DEMsDrainage 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’
Application IApplication 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
THE STREAM STATISTICS WEB PAGETHE STREAM STATISTICS WEB PAGEhttp://ma.water.usgs.gov/streamstats/http://ma.water.usgs.gov/streamstats/
ADD FEATURES SUCH AS ROADS ADD FEATURES SUCH AS ROADS TO FIND THE LOCATION OF TO FIND THE LOCATION OF
INTERESTINTEREST
Application IIApplication 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)
Tributary confluences
Significant lakes (> 5 acres)
Stream Segments are Defined Based on Locations Where a Change in Water-Quality May Occur:
Significant point-source discharges (NPDES sites)
Physical Characteristics of StreamsPhysical Characteristics of StreamsNeponset River BasinNeponset River Basin
0
20
40
60
80
100
120
140
160
1 2 3 4 5
SegmentsMiles
Total:
312 stream segments152 stream miles
45 significant lakes(not shown)
Stream Order
Determining Watershed Characteristics Requires Determining Watershed Characteristics Requires Delineating WatershedsDelineating Watersheds
Batch Delineation
Development of Watershed Tools Development of Watershed Tools in the NHD ArcView Toolkitin the NHD ArcView Toolkit
Currently working on adding watershed delineation functionality to the Toolkit
Focusing on areas where 1:24,000 scale National datalayers are available
Testing the validity of using 1:100,000 scale NHD
Plans to incorporate other tools into the Toolkit (event creation and search, a raindrop tool, batch delineation of watersheds…)