Connecticut Regional Drainage Basins Line

+ Resource Description

Citation

Information used to reference the data.

Title: Connecticut Regional Drainage Basins Line

Originators: State of Connecticut, Department of Environmental Protection (data compiler, editor and publisher)

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Other citation details: The State of Connecticut, Department of Environmental Protection is the collector of the data (compiler), the creator and maintainer of the data layer (editor), and producer (publisher) of this information for use. Data compiled and digitized from the 1:24,000-scale compilation sheets for the 1:125,000-scale Natural Drainage Basins in Connecticut Map, McElroy, 1981. The 2006 Edition includes the same basin features originally published in 1988 with some minor corrections and improvements made to feature attribute information. Previously undetected errors have been corrected and are included in this 2006 edition. This data is not updated. Source map scale is 1:24,000.

Larger Work Citation

Title: Natural Drainage Basins in Connecticut

Originators: Marianne McElroy, State of Connecticut, Department of Environmental Protection, Natural Resources Center

Series name: Connecticut Natural Resources Atlas Series

Series identification: Drainage Basins Map

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 1981

Data type: map

Data location: http://cteco.uconn.edu/map_catalog/maps/state/Natural_Drainage_Basins_In_Connecticut.pdf, http://cteco.uconn.edu/map_catalog/maps/state/Natural_Drainage_Basins_In_Connecticut_250K.pdf

Other citation details: The Natural Drainage Basins in Connecticut map is published by the State of Connecticut, Department of Environmental Protection, Natural Resources Center in cooperation with the U.S. Geological Survey. The map was funded in part by the Water Resources Council. Map scale 1:125,000.

Description

A characterization of the data, including its intended use and limitations.

Abstract: Connecticut Regional Drainage Basins is 1:24,000-scale, polygon and line feature data that define Regional drainage basin areas in Connecticut. These large basins mostly range from 40 to 400 square miles in size and make up the even larger major drainage basin areas. Connecticut Regional Drainage Basins includes drainage areas for all Connecticut rivers, streams, brooks, lakes, reservoirs and ponds published on 1:24,000-scale 7.5 minute topographic quadrangle maps prepared by the USGS between 1969 and 1984. Data is compiled at 1:24,000 scale (1 inch = 2,000 feet). This information is not updated.

Polygon and line features represent drainage basin areas and boundaries, respectively. Each basin area (polygon) feature is outlined by one or more major and regional basin boundary (line) feature. These data include 85 regional basin area (polygon) features and 529 regional basin boundary (line) features.

Regional Basin area (polygon) attributes include major and regional basin number, and feature size in acres and square miles. The regional basin number (RBAS_NO) uniquely identifies individual basins and is 2 characters in length. There are 44 unique regional basin numbers. Examples include 43, 60 and 61. The first digit (column 1) designates the major basin and the first two digits (columns 1-2) designate the regional basin. Note, there are slightly more regional basin polygon features (85) than unique regional basin numbers (44) due to coastal regional basins defined by series of polygon features located along the Connecticut shoreline.

Regional basin boundary (line) attributes include a drainage divide type attribute (DIVIDE) used to cartographically represent the hierarchical drainage basin system. This divide type attribute is used to assign different line symbology to individual major and regional drainage basin divides. For example, major basin drainage divides are more pronounced and shown with a wider line symbol than regional basin drainage divides.

Connecticut Regional Drainage Basin polygon and line feature data are derived from the geometry and attributes of the Connecticut Drainage Basins data.

Purpose: The polygon features define the contributing drainage area for individual reservoirs, lakes, ponds and river and stream reaches in Connecticut. These are hydrologic land units where precipitation is collected. Rain falling in a basin may take two courses. It may both run over the land and quickly enter surface watercourses, or it may soak into the ground moving through the earth until it surfaces at a wetland or stream. In an undisturbed natural drainage basin, the surface and ground water arrive as precipitation and leave either by evaporation or as surface runoff at the basin's outlet. A basin is a self-contained hydrologic system, with a clearly defined water budget and cycle. The amount of water that flows into the basins equals the amount that leaves. A drainage divide is the topographic barrier along a ridge or line of hilltops separating adjacent drainage basins. For example, rain or snow melt draining down one side of a hill generally will flow into a different basin and stream than water draining down the other side of the hill. These hillsides are separated by a drainage divided that follows nearby hilltops and ridge lines.

Use these basin data to identify where rainfall flows over land and downstream to a particular watercourse. Use these data to categorize and tabulate information according to drainage basin by identifying the local basin number for individual reservoir, lake, pond, stream reach, or location of interest. Due to the hierarchical nature of the basin numbering system, a database that records the 2-digit regional basin number for individual geographic locations of interest will support tabulations by major and regional basin as well as document the unique 2-digit regional basin identification number. To identify either all upstream basins draining to a particular location or all downstream basins flowing from a particular location, refer to the Gazetteer of Drainage Basin Areas of Connecticut, Nosal, 1977, CT DEP Water Resources Bulletin 45, for the hydrologic sequence, headwater to outfall, of drainage basins available at http://cteco.uconn.edu/docs/wrb/wrb45_gazetteer_of_drainage_areas_of_connecticut.pdf

Not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.). Not intended for analysis with other digital data compiled at scales greater than or more detailed than 1:24,000 scale. Use these data with 1:24,000-scale hydrography data also available from the State of Connecticut, Department of Environmental Protection.

Supplemental information: A standardized mapping of natural drainage basins in Connecticut was completed in 1981 by the Connecticut Department of Environmental Protection. This drainage basin system divided Connecticut into 8 major basins, 45 regional basins, 337 subregional basins, 2,898 local basins, and 7,067 small drainage basin areas. Major basins are subdivided into regional basins. Regional basins are subdivided into subregional basins. Subregional basins are subdivided into local basins. Local basins are subdivided into smaller drainage basin areas for impoundments and river reaches.

A pair of 1:24,000-scale polygon and line feature classes is available for all basin levels. These data are named Connecticut Major Basins, Connecticut Regional Basins, Connecticut Subregional Basins, Connecticut Local Basins, and Connecticut Drainage Basins. Connecticut Drainage Basins includes the most detailed information upon which the other basin datasets are based.

A hierarchical drainage basin number was assigned to uniquely identify drainage basin areas. Drainage basin areas are numbered sequentially beginning upstream and proceeding downstream. The first digit (column 1) identifies the major basin, the first two digits (columns 1-2) identify the regional basin, the first 4 digits (columns 1-4) identify the subregional basin, and the first seven digits (columns 1-7) identify the local basin. Below are examples of the hierarchical drainage basin numbers.

Basin Numbers:

4 = Major drainage basin number, MBAS_NO (column 1)

43 = Regional drainage basin number, RBAS_NO (columns 1-2)

4302 = Subregional drainage basin number, SBAS_NO (columns 1-4)

4302-04 = Local drainage basin number, LBAS_NO (columns 1-7)

4302-04-1-R12 = Basin drainage identification number, BASIN_NO (columns 1-13)

Stream Order (column 9):

4304-00-1 = Stream order value of 1 represents a headwater basin.

4304-00-2 = Stream order value > 1 denotes the complexity of the drainage basin morphology.

Mapping Status Element (column 10):

4302-00-2- = Ending with minus sign (-) denotes detail mapping at 1:24,000 scale for entire basin.

4302-00-2+ = Ending with plus sign (+) denotes detailed mapping not performed at 1:24,000 scale for the entire drainage basin. The Stream Order value will not reflect the complexity of the drainage basin morphology.

4302-00-1* = Ending with asterisk sign (*) denotes a headwater basin containing a delineated impoundment into which a delineated drainage basin outlets.

Reach-Impoundment Identifier (column11) and Number (column 12-13):

4302-00-1-L1 = The value for the Reach-Impoundment Identifier for an impounment basin is L (for lake). It is followed by the Reach-Impoundment Number (1).

4302-04-1-R12 = The value for the Reach-Impoundment Identifier for a stream reach basin is R (for reach). It is followed the Reach-Impoundment Number (12).

Dataset credit: Tom Nosal, State of Connecticut, Department of Environmental Protection, for the final compilation and delineation of 1:24,000-scale drainage basin boundaries, assignment of drainage basin numbers, and conversion to digitial format. Basin boundaries were manually delineated at 1:24,000-scale by visually interpreting the 10 feet contour elevation lines and waterbody features appearing on 1:24,000-scale 7.5 minute USGS topographic quadrangle maps for Connecticut published between 1969 and 1984. The metadata abstract includes a brief description of a drainage basin obtained from material written by Jim Murphy in an article entitled Reading the Landscape published in the Citizen's Bulletin, a CT DEP monthy magazine.

Language of dataset: en

Point Of Contact

Contact information for the individual or organization that is knowledgeable about the data.

Organization: State of Connecticut, Department of Environmental Protection

Person: Tom Nosal

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@ct.gov

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106-5127

Country: USA

Data Type

How the data are represented, formatted and maintained by the data producing organization.

File or table name: depgis.DEP.REGIONAL_BASIN_LINE

Data type: vector digital data

Data format: SDE Feature Class

Native dataset environment: These data are maintained by the State of Connecticut using ArcGIS software developed by Environmental Systems Research Institute (ESRI) in a Microsoft Windows operating system environment.

Time Period of Data

Time period(s) for which the data corresponds to the currentness reference.

Date: 1988

Currentness reference: publication date

Status

The state of and maintenance information for the data.

Data status: Complete

Update frequency: None planned

Key Words

Words or phrases that summarize certain aspects of the data.

Theme:

Keywords: drainage basin, drainage area, watershed, basin divide, major, regional, subregional, local, gazetteer

Keyword thesaurus: None

Theme:

Keywords: elevation, inlandWaters

Keyword thesaurus: ISO 19115 Topic Category

Place:

Keywords: United States, Connecticut, CT

Keyword thesaurus: U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of The United States, and Associated Areas (Federal Information Processing Standard 5-2): Washington, DC, National Institute of Standards and Technology.

Place:

Keywords: United States of America, USA

Keyword thesaurus: U.S. Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions (Federal Information Processing Standard (FIPS) 10-4): Washington, D.C., National Institute of Standards and Technology.

Data Access Constraints

Restrictions and legal prerequisites for accessing or using the data after access is granted.

Access constraints: None. The data is in the public domain and may be redistributed.

Use constraints: No restrictions or legal prerequisites for using the data. The data is suitable for use at appropriate scale, and is not intended for maps printed at scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet). Although this data set has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection as to the accuracy of the data and or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut, Department of Environmental Protection in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata. When printing this data on a map or using it in a software application, analysis, or report, please acknowledge the State of Connecticut, Department of Environmental Protection as the source for this information. For example, include the following data source description when printing this layer on a map: Basins - From the Regional Drainage Basins layer, compiled and published by CT DEP. Source map scale is 1:24,000.

Cross Reference

Information about other, related data sets that are likely to be of interest.

Title: Gazetteer of Drainage Basin Areas of Connecticut

Originators: Tom Nosal, Department of Environmental Protection, State of Connecticut (compiler and publisher)

Series name: Water Resources Bulletin

Series identification: No 15

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 19970101

Data type: document

Other citation details: Gazetteer of Drainage Basin Areas of Connecticut is organized by the eight major drainage basins covering Connecticut. The individual basins that comprise each major basin are listed in hydrologic sequence, headwater to outfall, with drainage basin number, description, basin area, and cummulative drainage area listed for each individual basin.

+ Graphic Example

Browse Graphic

Graphic illustration of the data.

Browse graphic 1

Open - Full view of Connecticut Regional Drainage Basins - Regional Drainage Basin line features are symbolized by the Drainage Basins Divide (DIVIDE) attribute to illustrate the basin hierarchy.

Browse graphic 2

Open - Detail view of Connecticut Regional Drainage Basins - Regional Drainage Basin polygon features are labeled with the 2-digit regional basin number. Regional Drainage Basin line features are symbolized by the Drainage Basins Divide (DIVIDE) attribute to illustrate the basin hierarchy. Watercourses are shown in the background.

+ Spatial Reference Information

Horizontal Coordinate System

Reference system from which linear or angular quantities are measured and assigned to the position that a point occupies.

Projected coordinate system:

Name: NAD 1983 StatePlane Connecticut FIPS 0600 Feet

Map units: survey feet

Geographic coordinate system:

Name: GCS North American 1983

Coordinate System Details

Map projection

Map projection name: Lambert Conformal Conic

Standard parallel: 41.200000

Standard parallel: 41.866667

Longitude of central meridian: -72.750000

Latitude of projection origin: 40.833333

False easting: 999999.999996

False northing: 499999.999998

Planar Coordinate Information

Planar coordinate encoding method: coordinate pair

Coordinate representation:

Abscissa resolution: 0.000250

Ordinate resolution: 0.000250

Planar distance units: survey feet

Geodetic model

Horizontal datum name: North American Datum of 1983

Ellipsoid name: Geodetic Reference System 80

Semi-major axis: 6378137.000000

Denominator of flattening ratio: 298.257222

Vertical Coordinate System

Reference system from which vertical distances (altitudes or depths) are measured.

Altitude system definition:

Altitude resolution: 1.000000

Altitude encoding method: Explicit elevation coordinate included with horizontal coordinates

Spatial Domain

The geographic areal domain of the data that describes the western, eastern, northern, and southern geographic limits of data coverage.

Bounding Coordinates

In Projected or local coordinates

NAD 1983 StatePlane Connecticut FIPS 0600 Feet

Boundary	Coordinate
Left	727909.125000 (survey feet)
Right	1345854.250000 (survey feet)
Top	1145219.750000 (survey feet)
Bottom	539975.750000 (survey feet)

In Unprojected coordinates (geographic)

GCS North American 1983

Boundary	Coordinate
West	-73.760405 (longitude)
East	-71.465712 (longitude)
North	42.603944 (latitude)
South	40.936173 (latitude)

+ Data Structure and Attribute Information

Overview

Summary of the information content of the data, including other references to complete descriptions of entity types, attributes, and attribute values for the data.

Entity and attribute overview: Drainage basin information is comprised of a set of polygon and line features that together describe different types of drainage basins and drainage basin divides.

Part 1 - Drainage Basin Polygon Features

Information encoded for drainage basin polygon features generally includes drainage basin number and name. Below is a brief explanation of the drainage basin identification number. Use the BASIN_NO attribute to uniquely identify drainage basins. The BASIN_NO is a unique number assigned to each polygon feature. However, in a few instances, two adjacent basin polygon features are assigned the same BASIN_NO when separated by a drainage basin line feature encoded as a Water diversion point divide (DBARC_COD = 10).

Basin Numbers:

4 = Major drainage basin number, MBAS_NO (column 1)

43 = Regional drainage basin number, RBAS_NO (columns 1-2)

4302 = Subregional drainage basin number, SBAS_NO (columns 1-4)

4302-04 = Local drainage basin number, LBAS_NO (columns 1-7)

4302-04-1-R12 = Basin drainage identification number, BASIN_NO (columns 1-13)

Stream Order (column 9):

4304-00-1 = Stream order value of 1 represents a headwater basin.

4304-00-2 = Stream order value > 1 denotes the complexity of the drainage basin morphology.

Mapping Status Element (column 10):

4302-00-2- = Ending with minus sign (-) denotes detail mapping at 1:24,000 scale for entire basin.

4302-00-1* = Ending with asterisk sign (*) denotes a headwater basin containing a delineated impoundment into which a delineated drainage basin outlets.

Reach-Impoundment Identifier (column11) and Number (column 12-13):

4302-00-1-L1 = The value for the Reach-Impoundment Identifier for an impounment basin is L (for lake). It is followed by the Reach-Impoundment Number (1).

4302-04-1-R12 = The value for the Reach-Impoundment Identifier for a stream reach basin is R (for reach). It is followed the Reach-Impoundment Number (12).

Part 2 - Drainage Basin Divide Line Features

Information encoded for line features categorizes drainage basin divides (boundaries) for cartographic purposes. Use the AV_LEGEND or IMS_LEGEND attribute to classify and symbolize boundary lines on a map. The AV_LEGEND attribute classifies basin boundary features into the same categories as DBARC_COD and DIVIDE. It is included for convenience. Unlike the IMS_LEGEND attribute, it does not condense features into broader categories. When symbolizing drainage basins arc features on AV_LEGEND values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: AV_LEGEND <> "No Show". The IMS_LEGEND attribute condenses the 9 drainage basin line feature types (DBARC_COD values) into 6 broader categories (Major, Regional, Subregional, Local, Shoreline, and No Show). When symbolizing drainage basins arc features on IMS_LEGEND values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: IMS_LEGEND <> "No Show". Use the AREA_SQMI and ACREAGE attributes to determine drainage basin polygon feature size. These values reflect the area of the respective polygon feature. They do not reflect the cumulative (upstream) drainage area for each basin. Note, ACREAGE and AREA_SQMI values are not automatically updated after modifying feature geometry (shape). These values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc.

Direct spatial reference method: Vector

Indirect spatial reference method: Connecticut DEP Major Basin Number, Regional Basin Number, Subregional Basin Number, Local Basin Number, Basin Number

Attributes of Connecticut Regional Drainage Basin Line

Detailed descriptions of entity type, attributes, and attribute values for the data.

Name: depgis.DEP.REGIONAL_BASIN_LINE

Type of object: Feature Class

Geometry type: Polyline

Number of records: 529

Description: Drainage basin linear features outline all drainage basin polygon features. These line features typically represent drainage basin divides between major, regional, subregional, local, stream reach, and smaller lake impoundment basins. However, some features are not true drainage basin divides. For example, line features that coincide with the coastline enclose coastal basins that drain into Long Island Sound. These line features that follow the coast are encoded as shoreline features.

Source: State of Connecticut, Department of Environmental Protection

Attributes

OBJECTID

Definition: Internal feature number.

Alias: OBJECTID Type: OID Width: 4 Precision: 10 Scale: 0

Attribute values: Sequential unique whole numbers that are automatically generated.

Attribute definition source: ESRI

DBARC_COD

Definition: Drainage Basin Arc Code - A numeric code that describes the type of drainage basin divide. There are 9 drainage basins arc code values, one for each type of feature. For example, a drainage basin line feature that forms the boundary between two Major drainage basins has a Drainage Basin Arc Code value of 1 (DBARC_COD = 1); a drainage basin line feature that forms the boundary between two Regional drainage basins in the same Major basin has a Drainage Basin Arc Code value of 2 (DBARC_COD = 2); a drainage basin line feature that forms the boundary between two Subregional drainage basins in the same Regional basin has a Drainage Basin Arc Code value of 3 (DBARC_COD = 3); and so on. Not all linear features represent true drainage basin divides between drainage basins. Some line feature types are introduced in order to close certain polygon features along the data limit or along the coast. For example, line features that are not true drainage basin divides or features that follow the geometry of the (coastal) shoreline have DBARC_COD values of 0 and 8, respectively. When symbolizing drainage basins arc features on DBARC_COD or DIVIDE values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: DBARC_COD > 0.

Alias: DBARC_COD Type: SmallInteger Width: 2 Precision: 5 Scale: 0Output width: 3

Attribute domain values

Value	Definition
0	Not a drainage basin divide
1	Major drainage basin divide
2	Regional drainage basin divide
3	Subregional drainage basin divide
4	Local drainage basin divide
5	Stream reach basin divide
6	Lake impoundment basin divide
8	Shoreline - Not a true drainage divide. This line feature is coincident with the shoreline and introduced to close coastal basins draining into Long Island Sound.
9	State Boundary
10	Water diversion point divide

Attribute definition source: State of Connecticut, Department of Environmental Protection

DIVIDE

Definition: Drainage Basin Divide - Text values that correspond to numeric DBARC_COD attribute values. DIVIDE is the English language equivalent of (decodes) the DBARC_COD field. When symbolizing drainage basins arc features on DBARC_COD or DIVIDE values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: DIVIDE <> "Not a drainage basin divide".

Alias: DIVIDE Type: String Width: 40 Precision: 0 Scale: 0Output width: 40

Attribute values: See Enumerated Domain Value Definitions for DBARC_COD attribute.

Attribute definition source: State of Connecticut, Department of Environmental Protection

AV_LEGEND

Definition: ArcView Legend. A text field for symbolizing the different types of drainage basin divides on a map. The AV_LEGEND attribute classifies basin boundary features into the same categories as DBARC_COD and DIVIDE. It is included for convenience. Unlike the IMS_LEGEND attribute, it does not condense features into broader categories. When symbolizing drainage basins arc features on AV_LEGEND values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: AV_LEGEND <> "No Show".

Alias: AV_LEGEND Type: String Width: 20 Precision: 0 Scale: 0Output width: 20

Attribute domain values

Value	Definition
Lake Impoundment	This category includes DBARC_COD value 6
Local	This category includes DBARC_COD value 4
Major	This category includes DBARC_COD value 1
No Show	This category includes DBARC_COD value 0
Regional	This category includes DBARC_COD value 2
Shoreline	This category includes DBARC_COD value 8
Stream Reach	This category includes DBARC_COD value 5
Subregional	This category includes DBARC_COD value 3
Water Diversion	This category includes DBARC_COD value 10

Attribute definition source: State of Connecticut, Department of Environmental Protection

IMS_LEGEND

Definition: Internet Mapping Software Legend - A text field used to classify and symbolize basin boundary features into broad categories, more suitable for use with Internet mapping applications. The IMS_LEGEND attribute condenses the 9 drainage basin line feature types (DBARC_COD values) into 6 broader categories (Major, Regional, Subregional, Local, Shoreline, and No Show). When symbolizing drainage basins arc features on IMS_LEGEND values, be sure to exclude features not intended to be shown on the map by using the following layer definition query: IMS_LEGEND <> "No Show".

Alias: IMS_LEGEND Type: String Width: 20 Precision: 0 Scale: 0Output width: 20

Attribute domain values

Value	Definition
Local	This category includes DBARC_COD value 4
Major	This category includes DBARC_COD value 1
No Show	This category includes DBARC_COD values 0, 5, 6, and 10
Regional	This category includes DBARC_COD value 2
Shoreline	This category includes DBARC_COD value 8
Subregional	This category includes DBARC_COD value 3

Attribute definition source: State of Connecticut, Department of Environmental Protection

LENGTH_MI

Definition: Calculated length of feature in miles. Note, LENGTH_MI values are not automatically updated after modifying feature geometry (shape). Values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc.

Alias: LENGTH_MI Type: Double Width: 8 Precision: 38 Scale: 8Output width: 8

Attribute values: Numeric value

Attribute definition source: State of Connecticut, Department of Environmental Protection

SHAPE

Definition: Feature geometry.

Alias: SHAPE Type: Geometry Width: 4 Precision: 0 Scale: 0

Attribute values: Coordinates defining the features.

Attribute definition source: ESRI

SHAPE.len

Alias: SHAPE.len Type: Double Width: 0 Precision: 0 Scale: 0

ESRI Feature Description

Description of spatial objects in the data using the Environmental Systems Research Institute (ESRI) terminology.

Environmental Systems Research Institute (ESRI) terms

depgis.DEP.REGIONAL_BASIN_LINE

ESRI feature type: Simple

Geometry type: Polyline

Topology: FALSE

Feature count: 529

Spatial index: TRUE

Linear referencing: FALSE

SDTS Feature Description

Description of point and vector spatial objects in the data using the Spatial Data Transfer Standards (SDTS) terminology.

Spatial data transfer standard (SDTS) terms

depgis.DEP.REGIONAL_BASIN_LINE

Type: String

Count: 529

+ Data Quality and Accuracy Information

General

Information about the fidelity of relationships, data quality and accuracy tests, omissions, selection criteria, generalization, and definitions used to derive the data.

Logical consistency report: Polygon features conform to the following topological rules. Polygons are single part. There are no duplicate polygons. Polygons do not self overlap. Polygons do not overlap other polygons. Lines are single part. Line features conform to the following topological rules. There are no duplicate lines. Lines do not self overlap. Lines do not overlap other lines. Lines intersect only at nodes, and nodes anchor the ends of all lines. Lines do not overshoot or undershoot other lines they are supposed to meet and intersect. In general, there are no duplicate features, unresolved intersections, overshooting lines, open polygons, sliver polygons, or unlabeled (unattributed) polygons. The tests of logical consistency were performed by the State of Connecticut using ESRI ArcInfo software to maintain feature topology in ArcInfo coverage format. The data is topologically clean. The ArcInfo Clean function was repeatedly used following edits to verify topology and enforce a minimum distance between vertices of 4 feet (fuzzy tolerance) and a minimum allowed overshoot length of 0 feet (dangle length).

Completeness report: The data reflects the content of the data source, which is a set of 1:24,000 scale mylar sheets used to compile and publish the 1:125,000-scale Drainage Basins in Connecticut Map, McElroy, 1982. All major, regional, subregional, local and smaller basin divides were digitized from these 1:24,000-scale mylar compilation sheets. This data is not updated.

Attribute Accuracy

Accuracy of the identification of data entities, features and assignment of attribute values.

Attribute accuracy report: The Drainage Basins layer retains the feature types and information identified on the 1:24,000-scale compilation sheets for the Natural Drainage Basins in Connecticut map, McElroy, 1981. All attributes have valid values. Values are within defined domains. There are no duplicate LBASIN_NO values except where expected (see definition of LBASIN_NO attribute).

The RBASIN_NO is derived from the first 2-digits of BASIN_NO so the accuracy of the RBASIN_NO is dependent on that for the BASIN_NO. For polygon features, the accuracy test for the BASIN_NO attribute values was conducted by visually comparing the basin number information depicted on the source Mylar overlays with 1:24,000-scale check plots or interactive displays of the digital data on a computer graphic system. These check plot maps and computer displays labeled polygon features with BASIN_NO values and differentiated line features based on DBARC_COD values for comparison with the original source Mylars. Subsequently, four additional fields (MBAS_NO, RBAS_NO, SBAS_NO, LBAS_NO) were added and populated based on the first, first 2, first 4, and first 7 columns of the BASIN_NO attribute. The MAJOR, REGIONAL, and SUBREGION attributes store drainage basin names based on MBAS_NO, RBAS_NO, SBAS_NO values, respectively. Basin names were attributed by joining basin name lookup tables to the polygon features base on MBAS_NO, RBAS_NO, SBAS_NO key values and populating the corresponding fields. These basin names are from the Natural Drainage Basins in Connecticut map, McElroy, 1981. The AREA_SQMI (area in square miles) and ACREAGE (area in acres) field were automatically calculated for each polygon feature based on computer generated feature area in square feet.

For line features, the DBARC_COD attribute was populated through a combination of automated and manual processes that compared the BASIN_NO attribute value of the polygon on each side of the line. For example, if the two polygons are in different major basins (MBAS_NO on the left <> MBAS_NO on the right), then the line feature represents a Major basin drainage divide and is assigned a DBARC_COD value of 1. If the left and right polygons are in the same Major basins but in different regional basins (RBAS_NO on the left <> RBAS_NO on the right), the line feature is a Regional basin drainage divide and is assigned a DBARC_COD value of 2, and so on. DIVIDE is the English language equivalent of (decodes) the DBARC_COD attribute value and was populated by joining a lookup table to the line features instead of manually attributing these values for each line feature. AV_LEGEND and IMS_LEGEND values were also attributed through table joins.

Positional Accuracy

Accuracy of the positional aspects of the data.

Horizontal accuracy report: The horizontal positional accuracy of this data complies with the United States National Map Accuracy Standards for 1:24,000 scale maps. According to this standard, not more than 10 percent of the locations tested are to be in error by more than 1/50 inch (40 feet) measured on the publication scale of a USGS 7.5 minute topographic quadrangle map.

Drainage basin boundaries were interpolated from 10 FT elevation contours and surface water body (hydrography) information published on a set of USGS 1:24,000-scale, 7.5-minute topographic quadrangle maps that cover the State of Connecticut. Natural drainage basin boundaries were manually delineated by interpolating elevation and water body information found on topographic quadrangle maps published by the USGS between 1962 and 1984.

+ Data Source and Process Information

Data Sources

Information about the source data used to construct or derive the data.

Data source information

Source 1 - Source Materials

Title: drainage basin compilation sheets

Originators: State of Connecticut, Department of Environmental Protection

Publication date: Unpublished Material

Data type: stable base mylar

Map scale denominator: 24000

Media: stable-base material

Source contribution: Basins compiled on 1:24,000-scale 7.5 minute USGS quadrangle area mylar overlays.

Source 2 - Drainage Basins

Title: Connecticut Drainage Basins

Originators: State of Connecticut, Department of Environmental Protection

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Map scale denominator: 24000

Media: disc

Source contribution: Connecticut Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is BASIN.

Date: 1988

Currentness reference: publication date

Source 3 - Regional Drainage Basins

Title: Connecticut Regional Drainage Basins

Originators: State of Connecticut, Department of Environmental Protection

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Map scale denominator: 24000

Media: disc

Source contribution: Connecticut Regional Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is RBASIN. These polygon and line feature data were subsequently converted to geodatabase feature format and named REGIONAL_BASIN_POLY and REGIONAL_BASIN_LINE, respectively.

Date: 1988

Currentness reference: publication date

Process Steps

Information about events, parameters, tolerances and techniques applied to construct or derive the data.

Process step information

Process Step 1

Process description: Feature digitizing and attribution (digitizing tablet method) - Using ESRI ArcInfo software, basin boundary line features were digitized by registering the individual compilation sheets to the digitizing tablet and using the crosshairs of the digitizer's mouse to manually capture the geometry (location) of features drafted on the map. The corners of the USGS 7.5 minute topographic quadrangle maps are used as registration points and are depicted on the source map. The source map was registered to the digitizing tablet by digitizing (entering) the locations of four quadrangle corner registration points shown on the map. ArcInfo software compared the values of the digitized coordinates with the actual (true) values for the quadrangle corner (tic) features. The Root Mean Square (RMS) error generated by the ArcInfo software indicated the amount of error involved in transforming coordinates from the registered map to the digital layer. RMS errors higher than 0.004 were not acceptable and required re-registering the source map by digitizing the tic locations again. With a correct registration, basins boundaries features were manually digitized off the source map. Where necessary, additional minor corrections (edits) to feature geometry were manually digitized on the screen (heads-up digitizing) at display scales greater than 1:24,000. Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to attribute value on the computer screen and on hard copy paper maps, and comparing this information to the orginal source data. These check plot maps were printed at the same scale as the source maps in order to visually inspect digitizing quality and the assignment of attribute values.

Individual quadrangle level basin boundary coverages were appended and edgematched along quadrangle boundaries to create a statewide layer in ArcInfo Coverage format having both polygon and line features. Polygon label points were created and assigned BASIN_NO values that uniquely identified each polygon feature. Most other related polygon and line feature attributes were assigned through automated procedures based on the format and hierarchical nature of the BASIN_NO value. Four additional fields (MBAS_NO, RBAS_NO, SBAS_NO, LBAS_NO) were added and populated based on the first, first 2, first 4, and first 7 columns of the BASIN_NO attribute. The MAJOR, REGIONAL, and SUBREGION attributes store drainage basin names based on MBAS_NO, RBAS_NO, SBAS_NO values, respectively. Basin names were attributed by joining basin name lookup tables to the polygon features base on MBAS_NO, RBAS_NO, SBAS_NO key values and populating the corresponding fields. These basin names are from the Natural Drainage Basins in Connecticut map, McElroy, 1981. The AREA_SQMI (area in square miles) and ACREAGE (area in acres) field were automatically calculated for each polygon feature based on computer generated feature area in square feet. The GAZRECNO attribute was manually assigned to each basin polygon feature.

Organization: State of Connecticut, Department of Environmental Protection

Person: Tom Nosal

Phone: 806-424-3540

Fax: 860-424-4058

Hours of service: Mondy to Friday, 8:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 1988

Process software and version: ArcInfo 5, 6

Data Source used

Source 1 - Source Materials

Title: drainage basin compilation sheets

Originators: State of Connecticut, Department of Environmental Protection

Publication date: Unpublished Material

Data type: stable base mylar

Map scale denominator: 24000

Media: stable-base material

Source contribution: Basins compiled on 1:24,000-scale 7.5 minute USGS quadrangle area mylar overlays.

Data Source produced

Source 2 - Drainage Basins

Title: Connecticut Drainage Basins

Originators: State of Connecticut, Department of Environmental Protection

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Map scale denominator: 24000

Media: disc

Source contribution: Connecticut Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is BASIN.

Date: 1988

Currentness reference: publication date

Process Step 2

Process description: Create Regional Drainage Basins - Using ArcInfo Workstation software, removed the BASIN_NO, LBAS_NO, SBAS_NO and SUBREGION polygon feature attributes, calculated the ACREAGE and AREA_SQMI polygon attributes to zero, and dissolved polygon features on the remaining RBAS_NO, MBAS_NO, REGIONAL, and MAJOR attribute values to create regional drainage basin polygon features. Using the ArcInfo Dissolve command, this step merged the smaller basin polygons into the larger regional basin polygon features. Line features were preserved as part of the dissolve process and were merged using the ArcInfo Unsplit command afterwards. The ACREAGE and AREA_SQMI attributes were recalculated based on the new feature geometry, and ArcInfo coveage topology was re-established with the Build command.

Organization: State of Connecticut, Department of Environmental Protection

Person: Tom Nosal, Howie Sternberg

Phone: 860-424-3540

Fax: 860-424-4058

Hours of service: Mondy to Friday, 8:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 1988

Process software and version: ArcInfo 6

Data Source used

Source 2 - Drainage Basins

Title: Connecticut Drainage Basins

Originators: State of Connecticut, Department of Environmental Protection

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Map scale denominator: 24000

Media: disc

Source contribution: Connecticut Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is BASIN.

Date: 1988

Currentness reference: publication date

Data Source produced

Source 3 - Regional Drainage Basins

Title: Connecticut Regional Drainage Basins

Originators: State of Connecticut, Department of Environmental Protection

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut USA

Publication date: 1988

Edition: 2006

Data type: vector digital data

Data location: http://www.ct.gov/deep

Map scale denominator: 24000

Media: disc

Date: 1988

Currentness reference: publication date

+ Data Distribution Information

General

Description of the data known by the party from whom the data may be obtained, liability of party distributing data, and technical capabilities required to use the data.

Resource description: Connecticut Regional Drainage Basins Line

Distribution liability: Although this data set has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection as to the accuracy of the data and or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut, Department of Environmental Protection in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata.

Technical prerequisites: Geographic information sytem (GIS), computer-aided drawing or other mapping software is necessary to display, view and access the information.

Distribution Point of Contact

Contact information for the individual or organization distributing the data.

Organization: State of Connecticut, Department of Enviromental Protection

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@ct.gov

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106-5127

Country: USA

Standard Order Process

Common ways in which data may be obtained.

Digital form:

Format name: Shapefile, Feature Class, ArcInfo Coverage

Format version number: ArcGIS

File decompression technique: Zip file

Digital transfer option:

Online option:

Computer information:

Network address:

Network resource name: http://www.ct.gov/deep

Fees: An online copy of the data may be accessed without charge.

Custom Order Process

Description of custom distribution services available.

Custom order process: The data distributor does not provide custom GIS analysis or mapping services. Data is available in a standard format and may be converted to other formats, projections, coordinate systems, or selected for specific geographic regions by the party receiving the data.

+ Metadata Reference

Metadata Date

Dates associated with creating, updating and reviewing the metadata.

Last updated: 20120125

Language of metadata: en

Metadata Point of Contact

Contact information for the individual or organization responsible for the metadata information.

Organization: State of Connecticut, Department of Environmental Protection

Person: Tom Nosal, Howie Sternberg

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@ct.gov

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106-5127

Country: USA

Metadata Standards

Description of the metadata standard used to document the data and reference to any additional extended profiles to the standard used by the metadata producer.

Standard name: FGDC Content Standards for Digital Geospatial Metadata

Standard version: FGDC-STD-001-1998

Time convention: local time

Metadata profiles defining additonal information:

Profile: ESRI Metadata Profile

Online linkage: http://www.esri.com/metadata/esriprof80.html

FGDC Plus Metadata Stylesheet

Stylesheet: FGDC Plus Stylesheet

File name: FGDC Plus.xsl

Version: 2.2

Description: This metadata is displayed using the FGDC Plus Stylesheet, which is an XSL template that can be used with ArcGIS software to display metadata. It displays metadata elements defined in the Content Standard for Digital Geospatial Metadata (CSDGM) - aka FGDC Standard, the ESRI Profile of CSDGM, the Biological Data Profile of CSDGM, and the Shoreline Data Profile of CSDGM. CSDGM is the US Federal Metadata standard. The Federal Geographic Data Committee originally adopted the CSDGM in 1994 and revised it in 1998. According to Executive Order 12096 all Federal agencies are ordered to use this standard to document geospatial data created as of January, 1995. The standard is often referred to as the FGDC Metadata Standard and has been implemented beyond the federal level with State and local governments adopting the metadata standard as well. The Biological Data Profile broadens the application of the CSDGM so that it is more easily applied to biological data that are not explicitly geographic (laboratory results, field notes, specimen collections, research reports) but can be associated with a geographic location. Includes taxonomical vocabulary. The Shoreline Data Profile addresses variability in the definition and mapping of shorelines by providing a standardized set of terms and data elements required to support metadata for shoreline and coastal data sets. The FGDC Plus Stylesheet includes the Dublin Core Metadata Element Set. It supports W3C DOM compatible browsers such as IE7, IE6, Netscape 7, and Mozilla Firefox. It is in the public domain and may be freely used, modified, and redistributed. It is provided "AS-IS" without warranty or technical support.

Instructions: On the top of the page, click on the title of the dataset to toggle opening and closing of all metadata content sections or click section links listed horizontally below the title to open individual sections. Click on a section name (e.g. Description) to open and close section content. Within a section, click on a item name (Status, Key Words, etc.) to open and close individual content items. By default, the Citation information within the Description section is always open for display.

Download: FGDC Plus Stylesheet is available from the ArcScripts downloads at www.esri.com.