OVERVIEW

The layers listed on this page were developed for use with the Watershed Analyst extension that may be used in the ArcView GIS 3.x version of the MassGIS Data Viewer. The WATRSHED library contains 32 tiles based on the SARIS (Streams and Rivers Information System) IDs of the major basins. Each tile name is a four-letter abbreviation of the basin name. The tiles are named as follows:
 

SARIS ID		Major Basin Name		Tile Name
11		Hoosic		HOOS
12		Kinderhook		KIND
13		Bashbish		BASH
21		Housatonic		HOUS
31		Farmington		FARM
32		Westfield		WEST
33		Deerfield		DEER
34		Connecticut		CONN
35		Millers		MILL
36		Chicopee		CHIC
41		Quinebaug		QUIN
42		French		FREN
51		Blackstone		BLAC
52		Ten Mile		TENM
53		Narragansett Bay		NARR
61		Mount Hope Bay		HOPE
62		Taunton		TAUN
71		Mystic		MYST
72		Charles		CHAR
73		Neponset		NEPO
74		Weymouth & Weir		WEYW
81		Nashua		NASH
82		Concord		CONC
83		Shawsheen		SHAW
84		Merrimack		MERR
91		Parker		PARK
92		Ipswich		IPSW
93		North Shore (N.Coastal)		NCOA
94		South Shore (S. Coastal)		SCOA
95		Buzzards Bay		BUZZ
96		Cape Cod		CAPE
97		Islands		ISLA

The WATRSHED library stores vector and raster data used in the MassGIS Watershed Analyst, an add-on suite of tools and menu choices in the MassGIS Data Viewer that allows for hydrological and watershed-based analysis within ArcView GIS. This page describes the data stored in the WATRSHED library for use with the Analyst. Please see the Watershed Analyst page for details on using these data in the Data Viewer.

Each tile contains:

cl_ : The centerline coverage. It contains arcs, routes, and SARIS routes. The centerline was created and routed using a set of ARC/INFO AMLs from the 1:25,000 Hydrography as featured on the USGS topographic quads.

Each CL_.AAT (arc attribute table) contains the following attributes:

TILE-NAME		name of SARIS major basin tile
MINOR_TOT		Type of water feature;Concatenated Digital Line Graph (DLG) codes
SOURCE		Data source for coverage (100K enhanced or 25K DLG)
PWSID		DEP PWS ID number of downstream Public Surface Drinking Water Supply
CLASS		Designated Use Classification (not yet implemented; Mass. Surface Water Quality Standards)
ARC_CODE		Generalized arc code derived from MINOR_TOT
HYA		Generalized arc code derived from MINOR_TOT
RMIN		Minor_num of polygon to right of arc
LMIN		Minor_num of polygon to left of arc
RHYP		Generalized arc code to right of arc
LHYP		Generalized arc code to left of arc
CONNECTED		Arcs that are in the route system
SARISNAME		Name of stream or river based on SARIS system
ARCLINK#		Links arc to its route in the section table
T-MEAS		Meters from mouth of routed major basin based on All route
SARISCODE		Stream code based on the SARIS (Stream and River Id System)
**  REDEFINED ITEMS  **
MINOR_NUM		numeric version of MINOR_TOT

Each CL_.RATRIVER (river route attribute table) contains the following attributes:
 

LENGTH		Length of the route in meters
ORDER		Stream order (values 0-9 [no 1]) higher number = smaller tribuary
URA		Id number of directly downstream rout
UMA		Measure in meters that route branches off downstream route
URB		Id number of directly downstream route
UMB		Measure in meters that route branches off downstream route
URC		Id number of directly downstream route
UMC		Measure in meters that route branches off downstream route
DRA		Id number of directly upstream route
DMA		Measure in meters that route comes off of upstream route
DRB		Id number of directly upstream route
DMB		Measure in meters that route comes off of upstream route
DRC		Id number of directly upstream route
DMC		Measure in meters that route comes off of upstream route
RIVER_NUM		Statewide unique id number for route
URAPX		Copy of URA in character format
URBPX		Copy of URB in character format
URCPX		Copy of URC in character format
DRAPX		Copy of DRA in character format
DRBPX		Copy of DRB in character format
DRCPX		Copy of DRC in character format

dbf directory: Under the dbf directory are 3 types of files:

• mth.dbf - this file is a point event table of the mouth points of the subbasins
• mXX00?us.dbf, mXX00?ds.dbf - for each mouth point of the major basin, there is a file for upstream and downstream. The XX is the SARIS id of the major basin. The ? is filled starting with 1 for the various mouth points of the major basins. For example, the Housatonic has 2 mouth points, so the files in this directory include m21001us.dbf, m21001ds.dbf, m21002us.dbf, m21002ds.dbf. These files are linear event tables and could be viewed by the user, but are for upstream/downstream trace processing purposes.
• sg.dbf - for each subbasin (subid), the square miles of each type of surficial geology is listed (sg1 = code 1, etc, as listed in the Surficial Geology datalayer description). This table allows for quickly accumulating the upstream surficial geology values without having to clip a large area, making for a faster delineation. These sg.dbf tables are used only when the user wants to get lowflow statistics (not when just doing a simple delineation).

odb directory: XX00?us.odb, XX00?ds.odb - for each mouth point of the major basin, there is a file for upstream and downstream. The XX is the SARIS id of the major basin. The ? is filled starting with 1 for the various mouth points of the major basins. For example, the Housatonic has 2 mouth points, so the files in this directory include 21001us.odb, 21001ds.odb, 21002us.odb, 21002ds.odb. These files are for delineation processing purposes and cannot be viewed by the user.

shps directory: This directory contains ESRI shapefiles for the basin. Shapefiles contain three component files: subbas.shp, subbas.shx, and subbas.dbf, referring to the subbasin boundaries for the tile. These subbasins were taken from the BASIN library (basin.sub_basins USGS subbasins), and modified slightly for technical reasons so that the watershed tools would complete delineations properly. Subbasins with no centerline were dissolved into adjacent subbasins, and some subbasin outlines were slightly modified so that the centerline was entirely contained within the subbasins. The small differences between the original subbasins coverage and the centerline coverage result from each dataset having been derived from different revisions of the USGS topographic maps.

grds directory: This directory contains 5 raster data files in ARC/INFO GRID format:

• clsg – A raster version of the cl_ centerline coverage. Cell size is 10m. Integer grid. Values are 1 (centerline cells) and NODATA.
• dir2 – A flow-direction grid developed by Pete Steeves of the USGS Water Resources Division, Northborough, Mass. Flow-direction data provides the direction in which the water flows from a cell. This grid was created from altered USGS elevation grids using a special process to "burn in" the centerline, essentially altering the terrain to better represent the hydrographic features. Cell size is 10m. Integer grid. Values include: 

  1 = East
  2 = Southeast
  4 = South
  8 = Southwest
 16 = West
 32 = Northwest
 64 = North
128 = Northeast
 
• elev – Elevation grids, derived from 1:25,000 USGS DEM data. Cell size is 30 meters, represented in standard feet values.
• slope250 – Contributed by Pete Steeves of the US Geological Survey, Northborough, Mass. Derived from 1:250K DEM data. Slope is in percent. Cell size is about 94 meters.
• strg – A flow-accumulation grid created from the dir2 grid by the ARC/INFO GRID command strg = flowaccumulation(dir2). Cell size is 10m. Floating point grid.

These data datalayers are maintained by MassGIS. For information on data updates please contact Philip John by email at Philip.John@state.ma.us or by phone at (617) 626-1185. 

For the latest data available for use in the Watershed Analyst, please see the current Status Map. 

When ordering a MassGIS Data Viewer that includes the above datalayers, choose the Data Viewer with Watershed Data option.

Last Updated 1/14/2008
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