Oregon and Washington

State Framework

Clearinghouse

Hydrography Data Dictionary

Physical Data Model

Version 1.1

Prepared by the

Washington and Oregon

Hydrography Framework

Technical Work Groups

P.O. Box 47600

Olympia, Washington 98504-7600

September 22, 2000

The Department of Ecology is an equal opportunity agency and does not discriminate on the basis of race, creed, color, disability, age, religion, national origin, sex, marital status, disabled veteran’s status, Vietnam Era veterans’ status or sexual orientation.

Table of Contents

Section 1 Database Overview

Background and Document Contents............................................................................ 1

Data Layer Descriptions............................................................................................... 1

Database Listing and Naming Conventions.................................................................... 3

Database File Relationships........................................................................................... 6

Database File Diagram - Watercourses................................................................ 7

Database File Diagram – Water bodies................................................................ 8

Database File Diagram – Water Shorelines........................................................... 9

Database File Diagram – Water Points............................................................... 10

Section 2 Washington Hydrography Framework Data Descriptions

Watercourse Layer Data Descriptions......................................................................... 11

Arc Attribute Table............................................................................................ 11

Section Table.................................................................................................... 13

Route Table....................................................................................................... 15

Line Type Event Table....................................................................................... 16

Name Event Table............................................................................................. 18

Feature Type Event Table.................................................................................. 20

River Reach File Event Table............................................................................. 22

Stream Flow Event Table................................................................................... 24

Feature History Event Table............................................................................... 26

Water Body Layer Data Descriptions.......................................................................... 29

Polygon Attribute Table..................................................................................... 29

Shoreline Layer Data Descriptions.............................................................................. 31

Arc Attribute Table............................................................................................ 31

Section Table.................................................................................................... 32

Route Table....................................................................................................... 34

Shoreline Type Event Table............................................................................... 36

Feature History Relate Table.............................................................................. 37

Water Point Layer Data Descriptions.......................................................................... 40

Point Attribute Table.......................................................................................... 40

Feature History Relate Table.............................................................................. 42

Section 3 Appendix

Acknowledgements.................................................................................................... 45

Data Dictionary Code Tables and Format Sheet Explanations...................................... 46

Section 1 Database Overview

Background and Document Contents

This data dictionary describes data for the Washington and Oregon Framework Hydrography data and the standard system used to identify the states surface water.

The Framework goal was to utilize an existing data model that would enable various participants to locate and identify the state's marine and fresh surface water. The system was developed to provide a standard for referencing surface water bodies and watercourses, and to provide a vehicle for cross-referencing existing surface water data between agencies and groups in both GIS and tabular formats.

It is intended that this physical data model provide the backbone whereby users may each attach and retain their own particular surface water data. The standard identifiers provided by this system will ideally facilitate data exchange on a wide scale amongst water management entities and reduce redundancy in data collection.

For additional information about Dynamic Segmentation and/or the rules and procedures for applying this model, please refer to the companion document titled “Oregon and Washington State Framework Hydrography Concepts, Rules & Procedures.”

Document Contents

Section 1 is comprised of a description of the data layers, database listings and naming conventions.

Section 2 describes the working physical data model, how system identifiers and indexing are carried, the database contents, the imbedded metadata, and an explanation of naming standards and coding structure.

Section 3 contains an explanation of the format of the data dictionary sheets and the larger detailed code tables.

Data Layer Descriptions

The Framework model allows for the storage of all hydrographic features. Successful implementation of the Framework Hydrography data model requires that participants understand the way in which the different features are modeled and that they have a common understanding of the terms and definitions contained in the document. This section addresses the way in which these features are modeled.

Hydrographic features are modeled in four layers:

Water Points (WP)

Watercourses (WC)

Water Bodies (WB)

Water Body Shorelines (WS)

The desired source scale for all layer acquisition is 1:24,000 or better. 1:100,000 data may be substituted where layers at the desired source scale have not been developed. All data is stored in NAD83 geographic coordinates, double precision.

A longitude/latitude identifier (LLID) uniquely identifies each hydrographic feature in the model. This 13-character identifier is composed of the concatenated decimal degree longitude and latitude of the feature. The identifier is unique within each layer but there is no requirement that it be unique between the layers. The geographic location used to generate the LLID varies depending on the data layer. Consult the detailed layer attribute table definitions (Section 2) to determine the location used to generate the LLID for that layer.

Each feature in the Water Point (WP), Watercourse (WC) and Water Body (WB) layers share the following attributes:

§ a unique LLID identifier.

§ a generalized classification of the hydrographic feature type (e.g. spring, stream, lake etc.)

§ a classification of the type of cartographic element. This is a more detailed classification of the feature useful for mapping or more detailed database queries.

§ a classification of seasonal, or periodic behavior of the water feature (e.g. perennial, intermittent or ephemeral)

§ a robust set of attributes that describe the history of spatial edits to each feature. See detailed layer attribute table definitions (Section 2) for a complete description of these feature history attributes.

What follows is a short description of each of the four layers present in the model, the type(s) of features included in each layer and the relationships between the related information.

The Water Point (WP) layer is the repository for springs, seeps and other hydrographic features with limited spatial extent (i.e. most easily represented by a point). This layer consists of a point coverage and a single related table. The related table describes the history of spatial edits to the feature.

The Watercourse (WC) layer consists of stream, canal, flume, pipeline and other linear hydrographic feature centerlines. Where these features (especially streams) are represented as double lined features at the source scale they will be represented in this layer by their centerline. Streams that flow through water bodies such as lakes and reservoirs will also be represented by a centerline. This feature has been modeled to allow for flow modeling. All arcs must point downstream. This layer will be routed using the LLID identifier for the stream. All associated attributes are stored as event tables on the LLID routes. The stream routes are indexed starting from 0 at the mouth of the stream to some maximum value at the headwaters. All route measures will be initially calibrated in kilometers to three decimal places. As these routes are edited, every effort will be made to keep the measure value at a given map location from shifting. This will be accomplished by stretching or shrinking the measure values to accommodate lengthening or shrinking along the route as its X,Y coordinates are edited. Thus, over time, the measures will only approximate kilometers along a watercourse or shoreline. These measures are simply an indexing scheme for linear referencing, not a stored attribute of shoreline or watercourse length.

The Water Body (WB) layer consists of sounds, bays, lakes, ponds, wetlands, reservoirs, inundation areas, the double lined portions of streams and other hydrographic features best represented as areas. For ease of managing these features they have been modeled as regions rather than simple polygons in the Framework model. However, by agreement, each water body will be stored as a non-overlapping, non-multi-part region (i.e. there will be one polygon per region). The advantages of this approach will be described in detail in document titled “Oregon and Washington State Framework Hydrography Concepts, Rules & Procedures.” Water body attributes will be stored in the WB region attribute table (PATWB.) Changes to the water body shape will be made and tracked in the water body shoreline coverage.

The Water Body Shoreline (WS) layer consists of one or more representations of the shoreline of each water body. One representation of the shoreline for each water body will be flagged in the Framework database as the “default” shoreline. This default shoreline will be coincident with the water body perimeter in the water body (WB) layer. This layer is modeled in the Framework to accommodate those instances where multiple shorelines based on different datum (e.g. mean high water, mean low water etc.) are useful, especially marine shorelines. This layer is modeled as a routed linear feature. Water will be on the right side of each route and each shoreline will be represented by one or more non-overlapping routes. However, most simple water bodies (e.g. small lakes and ponds) will likely be represented by a single route. The history of spatial edits to each water body will be stored as an event on the route(s) on the default shoreline. Our agreement is that unless there is good justification to do so, all other shoreline attributes will be stored as events on the default shoreline. Non-default shorelines are intended to accommodate specialized requirements.

Database Listing and Naming Conventions

This section contains a list of the data files and diagrams depicting the relationships that exist between the files.

Database Layers and Coverages

Layer Description	Feature Class	Attribute Table Name
Water bodies areas	Region	WB.PATWB
Water body shorelines	Route	WS.RATWS
Watercourses	Route	WC.RATWC
Water points	Point	WP.PAT

Naming Conventions

Table Names:

COVERAGE NAME . TOPOLOGY TYPE _ DESCRIPTION

Examples: WC.EVT_NAME

WS.EVT_SL_TYPE

WP.REL_FTR_HST

Lookup Table Names:

COVERAGE NAME . TOPOLOGY TYPE _ ITEM DESCRIPTION

Examples: WC.LUT_FTR_ORG_CD

Column Names or Items in Lookup Table

ITEM NAME FTR_ORG_CD

ITEM NAME_LU FTR_ORG_LU

(replace_CD with _LU for short description)

ITEM NAME_DS FTR_ORG_DS

(replace _CD with _DS for long description)

Item or Field Names:

COVERAGE NAME . DESCRIPTION _ CLASS/KEY

Example: WC.LN_TYP_CD

Table and Attribute Requirements

All tables are mandatory and must be present in order to be placed in the Clearinghouse. In Section 2, you will find a description of each table and whether the attributes or fields contained within those tables should be applied to all the features on stream network or just on a portion of the features. We refer to this as the “Attributes Extent” and it’s intended to help users identify the extent of coverage. In some cases attributes are available for only some stream/water body features, in those cases you are not required to populate the database if information is not available.

The data described below is provided in ARC/INFO format. All data is stored in NAD83 geographic coordinates, double precision.

Watercourses

Coverage/Table File Name

Coverage WC

Line attribute table WC.AAT

Section table WC.SECWC

Route attribute table WC.RATWC

Event table WC.EVT_NAME

Event table WC.EVT_LN_TYPE

Event table WC.EVT_FTR_TYPE

Event table WC.EVT_RRF

Event table WC.EVT_STRM_FLOW

Event table WC.EVT_FTR_HST

Water Bodies

Coverage/Table File Name

Coverage WB

Region attribute table WB.PATWB

Water Shorelines

Coverage/Table File Name

Coverage WS

Line attribute table WS.AAT

Section table WS.SECWS

Route attribute table WS.RATHYD

Event table WS.EVT_SL_TYPE

Event table WS.EVT_FTR_HST

Water Points

Coverage/Table File Name

Coverage WP

Point attribute table WP.PAT

Point relate table WP.REL_FTR_HST

Please refer to Section 4 for a full listing of associated code tables. There you will find the actual code tables as they're reflected in the four data coverage’s (watercourses, water shorelines, water bodies and water points) with the similarities and differences between them noted.

Database File Relationships

The following diagrams depict the relationships between the data files comprising the three layers:

Figure 1-1 Watercourse