Keywords

Theme: Freshwater Mussel, Freshwater Fish, Diversity, Endangered Species, Stronghold Watershed, Rare Species

Place: Maryland, Prince George's County

Description

Abstract

Stronghold watersheds are the places where rare, threatened, or endangered freshwater fish, amphibians, reptiles, or mussel species have the highest numbers (abundance and number of occurrences). This file contains the results of multiple analyses for conserving watersheds that are important for the conservation of freshwater aquiatic biodiversity in Maryland. In 2005, MBSS and NHP analyzed watershed-level data to determine stronghold watersheds for individual rare, threatened or endangered freshwater aquatic species. In 2006, NHP analyzed watershed-level data to determine stronghold watesheds based on species richness and rarity-weighted richness. In 2007, strongholds for stream-related amphibians and reptiles were included. ** The Maryland-National Capital Park and Planning Commission, Countywide Planning Division, Prince George's County Planning Department, Special Projects Section has edited the original data so that it only encompasses Prince George's County.

Purpose

Originally, to develop a more comprehensive stronghold watershed provide to MD Dept of Planning for the statewide Land Preservation, Parks & Recreation Plan (LPPRP). Since then it is intended for use by any land conservation programs within government agencies or private conservation organizations.

Supplementary Information

Version 3 includes data from the Corsica River watershed, which was missing from version 2. Version 4 (2007) includes additional data for stream-oriented amphibians and reptiles. Version 5 (2009) includes updates to the data based on more intensive reviews.

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Status of the data

Complete
Data update frequency: As needed

Time period for which the data is relevant

Beginning date and time: late 1970's at time unknown

Ending date and time: 20070829 at time 000000

Description:

publication date

Publication Information

Who created the data: MD DNR, MD Biological Stream Survey & Natural Heritage Program

Date and time: 20070829 at time 000000

Contact

Name: Lynn Davidson

Title: Conservation Technology Program Manager

Organization: MD DNR-WHS, Natural Heritage Program

Phone: 410-260-8563

email: ldavidson@dnr.state.md.us

Hours of Operation: M--F 8:30 am to 4:30 pm

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Constraints on accessing and using the data

Access constraints: None

Use constraints:

None

Details about this document

Contents last updated: 20131217

Contents last reviewed: 20090724

Who completed this document

Lynn Davidson
MD DNR-WHS, Natural Heritage Program
mailing and physical:

Tawes Office Bldg, E-1

Annapolis, MD 21401

410-260-8563 (voice)
ldavidson@dnr.state.md.us

Hours of service: M--F 8:30 am to 4:30 pm

Standards used to create this document

Standard name: FGDC Content Standard for Digital Geospatial Metadata
Standard version: FGDC-STD-001-1998
Time convention used in this document: local time

Horizontal coordinate system

Details

Map Projection Name: NAD 1983 StatePlane Maryland FIPS 1900 Feet

Standard Parallel: 38.3
Standard Parallel: 39.45
Longitude of Central Meridian: -77.0
Latitude of Projection Origin: 37.66666666666666
False Easting: 1312333.333333333
False Northing: 0.0

Planar Coordinate Information

Planar Distance Units: Foot_US

Coordinate Encoding Method: coordinate pair

Coordinate Representation

Abscissa Resolution: 0.00025600000023841865

Ordinate Resolution: 0.00025600000023841865

Geodetic Model

Horizontal Datum Name: D North American 1983

Ellipsoid Name: GRS 1980

Semi-major Axis: 6378137.0

Denominator of Flattening Ratio: 298.257222101

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Bounding coordinates

Horizontal

In decimal degrees

West: -79.5055

East: -74.9579

North: 39.7295

South: 37.8676

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Lineage

Feature and Attribute Updates

Update 1

Edit Description: Presence of freshwater fish and mussel species considered by DNR to be of "greatest conservation need" (GCN) per 12-digit watershed was determined by overlaying recent extant collection locations. Total species count was added as an attribute. Scores were determined by a scoring matrix based on global and state rarity ranks for each species (i.e. G1S1 = 500; G5S5 = 1). Scores for all unique species within each watershed were added (max score= 885). The MBSS 12-digit strongholds were all included as Tier 1 watersheds to the "Combo_Tier" column. Also Tier 1 are those that have 6 or more species or a richness score of at least 150. Tier 2 watersheds have either 5 species or a richness score of about 70-149. Some watersheds with only 1 or 2 species and a score of 70 or 75 have been removed. Two new fields, Comments and Updated, were added to document reasons for changes and dates that changes were made.

Sources

Source 1

Media: None

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Spatial data description

Vector data information

SDTS description

Feature class: SDTS feature type, feature count

Feature class: GT-polygon composed of chains, 75

Details for ARCDBA.Stronghold_Watershed_MDP_Py

Attributes

OBJECTID

Definition:

Internal feature number.

Definition Source:

ESRI

Shape

Definition:

Feature geometry.

Definition Source:

ESRI

SWSH987F_

Definition:

This is an internal field set up by ARC/INFO and contains unique numbers.

SWSH987F_I

Definition:

This is an internal field set up by ARC/INFO and contains unique numbers.

MAJOR1

Definition:

Hydrologic Units Map

MINOR1

Definition:

Region code

Definition Source:

Hydrologic Units Map

ACRE

Definition:

This field contains the acres of the Watershed polygon. It was calculated by dividing the AREA by 43,560 (square feet per acre).

X_COORD

Definition:

The x coordinate for the centroid of the Watershed polygon. The fields were created by running addxy; a PC ARC/INFO function that adds the x, y coordinates to the database. The units were originallty in State Plane 1927 feet. These are in State Plane NAD1983 meters.

Y_COORD

Definition:

The y coordinate for the centroid of the Watershed polygon. The fields were created by running addxy; a PC ARC/INFO function that adds the x, y coordinates to the database. The units were originallty in State Plane 1927 feet. These are in State Plane NAD1983 meters.

MDE6DIGT

Definition:

This field contains the Maryland Department of Environment (MDE) six digit Watershed code representing nineteen Watersheds for Maryland. This field was filled manually by DNR using Watershed codes in the original Watershed file from the Maryland Office of Planning (OP) and from hardcopy maps of the Watershed from MDE and directions given by MDE staff.

Definition Source:

Maryland Department of Environment (MDE)

MDE6NAME

Definition:

This field contains names from the hardcopy MDE Watershed code book. Data was entered manually using hard copy maps from MDE and joined to the polygon data base using MDE6DIGT as the joining key.

MDE8DIGT

Definition:

This field contains the MDE eight digit Watershed code representing one hundred thirty eight Watershed for Maryland. This field was filled by intersecting the old Watershed polygon code from OP then visually comparing attributes to hard copy maps and OP stream file.

MDE8NAME

Definition:

This field contains abbreviated names from the hardcopy MDE Watershed code book. Data was entered manually using hard copy maps from MDE and joined to the polygon data base using MDE8DIGT as the joining key.

SHEDNUM

Definition:

This field contains a four digit unique code for each watershed. Each polygon is not always a complete watershed. Watersheds around Washington D.C. were split by the Maryland State line. Theses polygons contain one code for the watershed. This method of numbering watersheds will continue when watersheds from the surrounding states are received. This unique number was manually entered into each polygon to place continuous numbers inside each each MDE6DIGT and MDE8DIGT watershed.

DNR12DIG

Definition:

This field contains a unique twelve digit watershed code that was created byjoining MDE8DIGT to SHEDNUM. This code maintains MDE watershed codes to the third order watersheds.

WHOLE

Definition:

This field contains a code that defines whether or not the watershed in HUA14 is maintained as one watershed in SHED1998. If the watershed is the same in both files the field is filled with """"W"""". If the polygon is split in SHED1998 the field is filled with letters """"A"""", """"B"""", """"C"""", """"D"""", or """"E"""" to denote a piece of HUA14 watershed. This was filled manually by visual inspection.

MARYLAND

Definition:

This field contains a code defining whether or not the entire watershed is contained inside Maryland's state line. The field is filled with """"M"""" if the watershed is inside the State of Maryland and """"O"""" if the watershed terminates at the State of Maryland boundary. This field was filled manually by visual inspection.

LAND

Definition:

This field contains a code defining whether or not the watershed is land or water (water may include some islands). It is filled with """"W"""" for water and """"L"""" for land. This field was filled by manual inspection.

Definition:

This field contains a code defining whether or not the watershed is contained within the boundaries of Washington D.C. This field is filled with """"""""Y"""""""" if in D.C. and """"""""N"""""""" if in Maryland. This field was filled by manual inspection.

STRACODE

Definition:

This field contains a unique number representing the 10 Tributary Strategy watersheds for the State of Maryland. Those areas which do not have a Tributary Strategy Code are filled with """"0"""". Each of the other numbers represent a watershed. This was filled by manual inspection.

STRANAME

Definition:

This field contains the common name for each Tributary Strategy watershed. This file was hand keyed and joined to the database by the STRACODE.

HUA14

Definition:

This field contains the fourteen digit watershed code from U.S. Natural Resources Conservation Service (NRCS) watershed file HUA14. These codes were added to SHED1998 by intersecting the two watershed files (HUA14 and SHED1998).

HUA11

Definition:

This field contains the eleven digit watershed code from U.S. Natural Resources Conservation Service (NRCS) watershed file HUA11. These codes were added to SHED1998 by intersecting the two watershed files (HUA11 and SHED1997).

HUA8

Definition:

This field contains the eight digit watershed code from U.S. Natural Resources Conservation Service (NRCS) watershed file HUA8. These codes were added to SHED1998 by intersecting the two watershed files (HUA8 and SHED1998).

STFIPS

Definition:

This field contains a code which represents the Federal Information Parcel Standard (FIPS) code for the State. It is necessary to use the STFIPS and CNTYFIPS together to make a unique code. This data was manually entered to the State Highway Administration (SHA) county file and then intersected with the watershed file. Washington D.C. is """"11"""" and Maryland is """"24"""".

CNTYFIPS

Definition:

This field contains a code that represents the FIPS county code for the watershed. This data was manually keyed to the SHA county file then intersected with the watershed file. Where watersheds cross county boundaries the county FIPS codes were added together, comma delimited.

Definition:

This field contains a two digit alpha county code for the watershed. This data was manually keyed to the SHA county file and then intersected the watershed file. Where watersheds cross county boundaries the county codes were added together, comma delimited.

COMBO_TIER

UPDATED

SHAPE.AREA

SHAPE.LEN

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Overview

Any non-zero score in Combo_Tier indicates a stronghold watershed.