GUIDELINES FOR DIGITAL REPRESENTATION OF KANSAS SURFACE WATERS January, 1996 Submitted to Kansas GIS Policy Board Technical Advisory Committee By KANSAS DEPARTMENT OF HEALTH AND ENVIRONMENT BLDG 740 Forbes Field Topeka, KS 66620 and GEOGRAPHIC RESEARCH, APPLICATIONS AND INFORMATION LABORATORY Department of Geography Lindley Hall University of kansas Lawrence, KS 66045 ACKNOWLEDGMENTS Dr. Robert Wiseman, Director Geographic Research, Analysis, and Information Laboratory University of Kansas, Lawrence, KS 66045 A. J. Thomas, Research Associate Geographic Research, Analysis, and Information Laboratory University of Kansas, Lawrence, KS 66045 Richard D. Miller, GIS Coordinator Kansas Department of Health and Environment BLDG 740 Forbes Field, Topeka, KS 66620 Michael K. Butler, Hydrologist Kansas Department of Health and Environment BLDG 740 Forbes Field, Topeka, KS 66620 Steve Brown, GIS System Administrator Data Processing Section, Office of Information Systems Kansas Department of Health and Environment BLDG 740 Forbes Field, Topeka, KS 66620 FORWARD The Surface Waters Information Management System (SWIMS) has been designed to meet multi-agency hydrologic database needs for Kansas. The SWIMS pilot project was initiated and funded by the Kansas GIS Policy Board in 1992 to (1) develop an enhanced digital, attributed hydrologic network for a portion of the State and (2) integrate selected water quality, regulatory, and monitoring datasets with the hydrologic network. The SWIMS feature hydrologic dataset is based on the Environmental Protection Agency's River Reach 3 (EPA-RF3) digital hydrologic database. Supplemental SWIMS hydrologic data include information from the National Pollution Discharge and Elimination System (NPDES) permits, Kansas Department of Health and Environment (KDHE) surface and lake monitoring networks, and other agency environmental activities. This report describes and documents the SWIMS feature hydrologic database. Additional information on the SWIMS project is available in the Kansas GIS Policy Board SWIMS proposals, reports and a publication, Surface Waters Information Management System, Proceedings of the Thirteenth Annual ESRI Users Conference, 1993. The SWIMS source data, EPA-RF3, is a generally accepted and readily available digital cartographic hydrologic database depicting surface water features in Kansas. SWIMS was designed to provide agency participants in the Kansas GIS Initiative with a standard set of hydrologic databases that will enable (1) multi-agency water-related database integration, (2) agency specific geo-referencing, (3) standard cartographic management, and (4) support for all GIS analyses including network analysis and hydrologic modeling. This report contains guidelines used to develop the SWIMS/RF3 hydrologic database across the entire state. Specifically, the report describes: (1) the current state of and documentation available on RF3; (2) procedures employed in identifying editing operations required to correct and enhance the EPA-RF3 files to meet design parameters of SWIMS; and (3) file structure, data dictionary, and metadata for the final SWIMS databases. SWIMS HYDROLOGIC DATABASE REFERENCE SECTION I. INTRODUCTION An integral part of the Surface Waters Information Management System (SWIMS) project is the creation of a state-level surface-water digital data resource based on Environmental Protection Agency's (EPA) River Reach Files. The adaptation of EPA's River Reach Files (EPA-RF3) has been based on the premise that these source materials were to be optimized for use with hydrologic modelling capabilities found in the GIS software, ARC/INFO , used by many state agencies working with computerized geographic data. The original EPA-RF3 files contained two datasets per hydrological cataloging unit. One file contains the graphic elements; the second, tabular data characterizing each graphic element. For the SWIMS project, the EPA graphics file was reorganized into three file sets, one per type of water feature (water networks, water-related points, other water reference features, and water bodies). Each SWIMS file set contains graphic elements, a limited set of descriptive fields, and cross-reference capabilities back to the original EPA-RF3 data. The chart below summarizes the SWIMS file sets and their contents. A more complete description of the SWIMS hydrologic files is included in Appendix B. FILE TYPE FILE PREFIX FILE SUFFIX(S ) DESCRIPTION EPA-RF3 B .AAT Arc coverage of EPA's RF3 linear graphic elements .DS2 Tabular file containing EPA RF3 feature descriptions, relatable to SWIMS data sets via RF3RCHID WATER NETWORK WN .AAT Arc coverage of SWIMS linear network graphic elements, relatable to .DS2 via RF3RCHID WATER POINT WP .PAT Point coverage of water-related points, relatable to .DS2 via RF3RCHID WATER REFERENCE WR .AAT Arc coverage of water network-related features, relatable to .DS2 via RF3RCHID WATER BODY WB .PAT Polygon coverage of water-body features WATER CORRECTION WC .ACODE REFERENCE ONLY. Relatable tabular file of linear graphic updates .PCODE REFERENCE ONLY. Relatable tabular file of point graphic updates WATER ARCHIVE WA .AAT REFERENCE ONLY. Arc coverage of linear graphic updates .PAT REFERENCE ONLY. Point coverage of point graphic updates The following documentation describes the various procedures implemented to produce the digital hydrologic data resource for the SWIMS project. These guidelines have been compiled for use as reference material for the development of a state-wide digital hydrologic data resource. Each reference section is summarized below: Section II provides an overview of terminology used throughout the subsequent sections. This section has been included to reduce potential confusion among various naming conventions for hydrologic features. Sections III through VI focus on optimization procedures to alter EPA's River Reach Files. These sections include:  Description of EPA's surface-water digital file  Review procedures and protocol used to adapt EPA's surface-water digital files  Outline enhancements developed for SWIMS hydrologic database  Examination of the archival system linking EPA's and SWIMS surface waters files Section VII discusses more general issues related to overall state planning for water-related digital resource development. Some of these themes may already exist in standardized form, but to insure consideration, a full range of subject matter was included. Appendices A and B hold data dictionary information on the original EPA-RF3 file structure and on the SWIMS hydrologic file sets. SECTION II. TERMINOLOGY The following terminology encompasses most of the technical vocabulary used throughout this guide to describe the SWIMS surface waters data. Arc: A representation of a line in the ARC/INFO GIS program. ARC/INFO : The GIS software for which most of these guidelines have been developed. Registered trademark of ESRI. BLM: Bureau of Land Management. Coverage: A naming convention referring to ARC/INFO graphic and tabular data sets. Feature One of a set of graphic elements found in a coverage sharing similar characteristics, i.e., point, line, polygon. GIS Geographic Information System, a computer-based set of procedures used to store and manipulate geographically referenced data. HUC Hydrologic Unit Code (Seaber, et al) derived at a 1:2,000,000 scale. "These divisions are not accurately correlated to topography and do not always correspond directly to true watersheds as they are more administrative in function" (Dulaney). Linear feature: Water represented only by lines (e.g., small streams). Point feature: Water represented as points (e.g., spring, gaging station). Polygonal feature: Water represented as polygons, or areas (e.g., lakes, ponds). RF3: The third revision of EPA's surface-water digital database rendered at a scale of 1:100,000. Surface-water: Rivers, streams, lakes, ponds, and wetlands. USGS: United States Geological Survey. Segment: All or part of a stream branch referenced by a unique identification number. Reach: The section of natural stream channel lying between two divergent points on a stream. Connector: Line(s) added through lakes, rivers, and wetlands to create a continuous linear hydrologic network as shown in Figure 1. Dam: Man-made flow control structure. Island: Sand bar or semi-permanent land feature surrounded by water. Label: a. Identifier for each polygonal feature present in the SWIMS surface waters database. b. Identifier for hydrologic point features, either natural or man-made, i.e., hydrologic gaging stations, wells, and springs. Lake: All standing water bodies, regardless of size, are generically referred to as lakes. River: River, as represented here, is composed of dual banks, i.e., two- line hydrological feature. Stream: Single-line water channel. Wetland: Swamp or inundated areas not considered lakes. Loop: A linear water feature composed of either a natural oxbow bend or an artificial canal on one side and one or more natural water segments on the other side. SECTION III. EPA-RF3 HYDROLOGIC DATABASE A digital database of surface-water, including rivers, streams, lakes and ponds, is important in natural resources management, community and regional planning and other land-management activities. At the national level, EPA is proceeding with the development of a 1:100,000- scale surface-water database referred to as River Reach Files. This digital resource has evolved from versions Reach File 1 (RF1), developed from 1:500,000-scale NOAA aeronautical charts, and Reach File 2 (RF2), enhanced with data from the Geographic Names Information System (GNIS), to the current version (RF3). This latest version, RF3, expanded the surface-water network to include features from the 1:100,000-scale digital line graphs (DLG) developed by USGS. The Reach File series serves as the digital resource file for many of EPA's mainframe hydrologic-modelling programs. The feature infrastructure of this surface-water digital resource can serve as an important base from which to build state-level surface-water digital maps. The USGS 1:100,000-scale DLGs that were incorporated into the latest revision of EPA's Reach File dataset represent the cumulative efforts of several conversion procedures. Most prominent among these was a raster-vector photo reduction of USGS and BLM maps, augmented by manual editing. The standard data source for the nation-wide DLG compilation was 1:100,000-scale material. However, in instances across the nation where similarly-scaled data was not available, larger-scale sources were substituted. The standard projection for the DLG database was the Universal Transverse Mercator. Upon completing the hydrologic network densification, EPA reorganized the RF3 data by USGS HUC-8 units to facilitate data handling as well as hydrologic modelling. Further enhancements were then completed to improve hydrologic connectivity using an automated program to link linear features within each hydrologic unit separated by approximately 100 feet. Gaps not closed during this automated procedure were manually corrected by trained analysts. To maintain the reach indexing system established for RF2 and RF1, the hydrologic feature numbering system devised for RF3 is comprised of three elements: a cataloging unit, segment number and a mile figure. This numbering system was devised not only to maintain the characteristics of earlier Reach File versions but also to provide for new inclusions derived from the DLG files and, more importantly, to act as a link to other EPA databases, i.e. STORET (Storage and Retrieval of U.S. Waterways Parametric Data), DRINKS (Drinking Water Supplies), IFD, GAGE (Stream Gage/Flow), WBS (Water Body System), and DAMS (Technical Doc D, p1). The extensive cross-referencing system (see Appendix A) developed in RF3 makes it possible to execute hydrologic modeling algorithms without the presence of physical connectivity between each feature in the hydrologic network. In contrast, though, network modelling algorithms in ARC/INFO , which substitutes cumbersome cross-referencing indexing for inherent topological relationships, demands a fully integrated hydrologic network. Both organizational structures provide advantages depending upon how the files are used and how programs access the surface-water database information. SECTION IV. RF3 ASSESSMENT Before corrective work for the SWIMS surface waters databases was initiated, a conscientious effort was made to assess the viability of RF3 as a source database for this project. This assessment also lent itself to the development of optimization protocols for a hydrologic database structure acceptable to the SWIMS project objectives. The assessment process incorporated a rigorous documentation search for RF3 development and application. This collection was reviewed and summarized. Based on this reference collection, a series of inquiries were then conducted to evaluate the quality of RF3 hydrologic data for application in the SWIMS project and develop the optimal configuration of graphics and data to be included in the SWIMS datasets. Documentation describing the EPA Reach File series is limited since this database has not been officially released for public access. Most of the information concerning these databases comes second-hand through articles written by early Reach File users and developers or through personal contact with researchers currently examining the capabilities of this hydrologic database. Official technical documentation of Reach Files from EPA has been compiled, but as of this writing, it is still in draft form. Since its inception in 1982, the Reach File series has been upgraded from a variety of resources, i.e. 1:500,000 NOAA aeronautical charts, the USGS Geographic Names Information System (GNIS), and the 1:100,000 USGS Digital Line Graphs (DLGs). The opinions expressed in research articles written across this time-frame, concerning the quality of the EPA-Reach Files, have been mixed. These mixed reactions appear to be associated with several factors. One obvious factor is the timeliness of the articles accessible for inclusion in this review. Articles date from 1982 with a heavier concentration around 1990. A second, perhaps not so obvious factor, may have been the physical location of the attempted application, since the integrity of the Reach File database is said to be of poorer quality in areas of complicated hydrology, such as coastal or low-lying areas (Kerski; Howe). Other contributing factors could have been cumulative error carryover from earlier update resources, the appropriateness of RF3 to the specific application being conducted, or variation among user expectations. From a review of the research efforts and EPA's technical documentation, a list was compiled summarizing the potential database omissions in the RF3 hydrologic database (see Table 1). Given the mixed reactions of researchers using the Reach File data along with the acknowledged set of potential database omissions referenced in Table 1, a preliminary review of the quality of RF3 graphic and tabular data for this region of the continent seemed appropriate. As a result, several inquiry procedures, including those described in the following sections, were conducted to evaluate the RF3 data for inclusion in the SWIMS project. Concern was expressed over the effect of the coordinate truncation error identified by EPA during the RF3 revision process. In calculating latitude/longitude coordinates for RF3 features, geographic values were truncated, thus compromising spatial accuracy. The truncation produced a non-systematic displacement that 'shifted' feature coordinates to the extent of 1/1000th of a degree (Olsen). Since the error was non-systematic, the effect of the truncation could vary significantly from region to region. To assess the effect of this shift within the project area, position coordinates from USGS DLG datasets (original source material for the RF3 revision) were compared to similar feature coordinates contained in the EPA RF3 datasets. Several USGS DLG source files were imported into ARC/INFO as line coverages. Positional coordinates from randomly sampled node locations from both datasets were compared. Coordinate shifts averaged 8(ñ2) meters along the Y-axis and 4(ñ1) meters along the X-axis. These values are comparable to the allowable National Map Accuracy tolerances, and as such were deemed acceptable for the prototype phase of the project. The integrity of the hydrologic network was another concern, since much criticism has been voiced regarding network-feature omissions and flow-direction indicators. Used in conjunction with database algorithms that 'walk the network' by means of sequential feature- identification number, these RF3 database omissions are not problematic. However, if used with programs dependent upon a linked network, such as ARC/INFO network programs, they pose significant problems. Several routing programs available in the ARC/INFO NETWORK module were used to assess the extent of these omissions and to identify those segments not physically connected to the network. A network CENTER was located at the outlet of the hydrologic unit, and linked stream segments were then allocated to this center. WRITEALLOCATE was then used to tag those arcs networked together, as well as those arcs disconnected from the network. ALLOCATE was also used to identify consistent flow direction within the database structure. Following a procedure, outlined by Jacqz (1992), WRITEALLOCATE was used to record information on flow direction conflicts. For the hydrologic units examined here, most of the directional conflicts appear to result from the data conversion rules established by EPA. According to these conversion parameters, water-body shorelines were digitized in a counter-clockwise direction. Accordingly, one shoreline for every water-body feature appears to flow in the opposite direction from all other hydrology contained in the file. SECTION V. GUIDELINES FOR EPA-RF3 DATABASE CONVERSION Concurrent with the assessment phase, numerous conversion routines were developed for adaptation of RF3 for use in the SWIMS project. These routines, developed in cooperation with KDHE hydrologists, maintain the initial integrity of the RF3 attribute database where possible, while minimizing vector structure adjustments to achieve hydrologic connectivity and database correction. The 1:100,000 USGS map series was established as the reference source for the conversion routines to produce the SWIMS hydrologic databases. Paper-base renditions of this map series were chosen for use in this project, since purchase of mylar separates exceeded the project budget. To minimize the effects of media shrink/swell, 15-minute subsections of these products were converted to raster scans. Scan resolution and color were optimized to reduce map noise while still maintaining the integrity of the hydrologic network. Nine reference points based on the 7.5-minute grid coordinates were used to register and rectify the raster images. This set of reference scans served as a backdrop for most of the anticipated database adjustments. A combination of manual and computer procedures were used to audit the RF3 database features and attributes. RESELECT commands were used to isolate attribute information deemed important to future applications work. Attribute information such as intermittent, shoreline, shoreline in combination with intermittent, and other was queried out of the RF3 files and plotted for review. These products were manually checked against USGS quad sheets for miscoded and extraneous or omitted features. In addition, oxbows, canals, springs, and swamps were sorted out for special processing specific to SWIMS database needs. HYDROLOGIC UNITS ( USGS HUC-8 Codes) 1027 0101 1027 0102 1027 0103 1027 0207 1025 0016 TOTALS Oxbows and swamps 2 8 33 1 16 60 Miscode intermittent as perennial 3 57 53 21 13 147 Miscode perennial as intermittent 2 23 10 9 0 44 Omitted lakes 6 51 7 2 2 68 Omitted segments 12 26 20 7 11 76 Extraneous lakes 1 13 12 1 5 32 Extraneous segments 9 19 14 4 47 93 Totals per HUC 35 197 149 45 94 520 Table 2. Reach File Omission Summary The intent of this process was not to replicate the quality assurance/quality control procedures previously conducted by EPA contractors, but rather to identify those elements that would require adaptation to meet the SWIMS project specifications. Within the scope of the pilot project, database updates were itemized for five of the nine hydrologic units in the Lower Republican, representing approximately 80 percent of the study basin area (see Table 2, previous page). The numbers in Table 2 suggest that approximately 100 omissions can be expected per HUC-8 watershed. The greatest number of problems were occurrences of perennial coding erroneously tagged as intermittent segments. Headwater areas pose the next most frequent problem, with omitted lakes and reach segments. These problems are widely acknowledged to exist (see Table 1). The Reach File audit did not uncover any unexpected problems. With these anticipated omissions, a series of decision rules were developed to update the EPA-RF3 files. Many of these decisions were developed as data conflicts were encountered. The underlying premise applied throughout the development of these decision rules was to retain, as much as possible, the integrity of the original dataset. Presented in the following section, Figures 2 through 26 and related text describe the corrective actions established as part of this pilot project. SWIMS RF3 Decision Rules Segments improperly assigned to adjacent hydrologic units (Figure 2, segments A,B) are identified by local hydrologists and reallocated to correct USGS-HUC unit. Figure 3 shows an isolated stream segment (A). Cross-reference to USGS source document verifies that this feature is not directly connected to the main network system. Segment A will be retained as a hydrologic feature within the stream network file but will not be connected to the hydrologic network. Figure 4 represents an instance where branch stream segments (B,C) were not connected to the main channel (A). Cross-reference to USGS quads verifies network linkage among these branches. To establish a valid network representation, segment A was subsequently split (see Figure 5; sections A1, A2, A3) to accept branch segments B, C, and the end-points of branch B and C were extended to join with the main channel sections (A1, A2, A3) Figure 6 represents two original RF3 segments, A and B, constituting a single natural reach. Segment A is designated intermittent; Segment B intermittent. Although in some instances, it may have been beneficial to represent this reach as a single hydrologic structure, the original RF3 designations were deemed more important to retain. No changes are made. Figure 7 shows an oxbow (loop) feature B. Segment A, the shortest segment of the feature, will be retained as part of the stream network. Segment B is retained for cartographic representation and carries a special-purpose code. This code provides users a means of temporarily removing this feature for network analysis. Figure 8 represents an oxbow (loop) feature split by a branch stream (segments B, C, D). Where segments A1, A2, A3, B, and D are equal stream-order, segment A2 contains the special purpose code for temporary removal during network processing. Where segments A1, A2, A3 are higher stream-order values, segment B contains the special purpose code for temporary removal during network processing. Figure 9 depicts a gap in the stream network between segments A and B. The downstream segment A is extended to bridge the gap. First, the gap is filled with a new segment2 (see Figure 10, segment A2) The intervening node between segments A1 and A2 (Figure 10) is then removed so that the altered segment A (see Figure 11) carries the reference information associated with the original reach A. In effect, this procedure moved the upper end of the downstream segment to meet the next upstream segment. Figure 12 represents a stream network gap occurring downstream from a divergence. The position of the divergence is retained throughout subsequent file modifications. Figure 13 shows segment A2 being added to bridge the network gap, and Figure 14 depicts the removal of the intervening node between segments A1 and A2 of Figure 13. By doing so, the original feature attributions are associated with revised segment A in Figure 14. Figure 15 shows a stream network gap occurring upstream from a divergence. The position of the divergence is retained as the stream network is modified to bridge the gap. Figure 16 shows the addition of segment A2, filling the gap. The intervening node between segment A1 and A2 is removed as shown in Figure 17 and the original RF3 reference information is associated with the altered segment A. Compared to USGS reference documents, the headwater reach (segment A, Figure 18) changes from perennial to intermittent half-way along the reach length. Rather than break this segment into two reaches, losing continuity with RF3 numbering sequence, this coding omission will not be changed. This decision was also based on the knowledge that class assignment on the USGS reference documents is subjective. Figure 19 represents an isolated headwater lake. The relationship between stream channel and lake feature will be retained as shown on USGS source document. No artificial connector will be used to link an isolated waterbody to the stream network. Figure 20 represents a waterbody feature present in the original RF3 file. The dual bank representation of this feature does not lend itself to ARC/INFO network modeling. To insure a viable hydrologic network, the waterbody feature is replaced with an artificial tree structure (see Figure 21, segments B, C, and D). The segments are designated 'connectors' to distinguish them from natural channel features. If the natural submerged drainage channel is designated on the USGS source document, the connector replicates this drainage network channel. Otherwise the connector follows the approximate centerline (or interpreted path of maximum flow) between the furthest upstream inlet and the outlet. Confluences of connectors, such as that depicted in Figure 21 are created by extending side branches (segment C and D) to their relatively natural conjunction with the main branch (segment B). Figure 22 represents the omission of a waterbody feature along a stream segment. Depicting the presence of this polygonal feature would require the segment B to be divided (B1, B3) and a connector (B2) added as depicted in Figure 23. Rather than break the existing segment and thus lose original RF3 feature attribution, the linear hydrologic segment is not broken. However, a digital representation of lake edge (feature A) is added to the polygonal water-feature database. For all ponds, lakes, or wetlands areas which terminate a stream network, a connector (feature A, Figure 24) is added upstream to the point on the shore furthest from the polygon outlet. Dashed box (A) in Figure 25 identifies a channelized network within the stream drainage system (C). The interconnecting canals of this feature are replaced with a single artificial connector (Figure 26, section B) to form a hydrologic network suitable for processing with ARC/INFO. SECTION VI. ADDITIONAL ENHANCEMENTS Edit History The work conducted under the context of Edit History served two purposes, edit control and edit archive. To insure greater consistency in the RF3 file updates a series of ARC/INFO aml (advanced macro language) programs were developed to control the type of SWIMS surface waters edit procedures described in SECTION V. In conjunction with these update actions, additional amls were developed to preserve the spatial and tabular records of original RF3 stream segments affected by SWIMS database updates, storing these references in an edit archive. Edit Control The corrections described in SECTION V were performed within the framework of multiple ARC/INFO aml programs compiled for the pilot project. For each type of correction, an aml was developed which performs a specific correction. All editing activities were performed within the framework of the amls thus focusing the activities of the operator upon assessment of error types described in SECTION V. Once error identification was completed, the related corrective aml was initiated and database manipulation was executed in as automated a fashion as possible. The edit-control amls utilized several ARC/INFO coverages to temporarily record and effect update processes before recording verified changes into the SWIMS surface waters database. When a correction was made to a feature, a copy of the original feature was placed into a temporary "holding" coverage, and the feature was edited in the working coverage. After making the correction, the operator verified that the correction should be accepted. If the operator accepted the correction, the original feature was moved from the holding coverage into the "archive" coverage, and the modified feature was retained in the working coverage. If the operator rejected the correction, the modified feature was removed from the working coverage, and the original feature was moved from the temporary holding coverage back to the working coverage. The working coverage eventually became the final updated SWIMS surface waters database. Edit Archive In addition to standardizing operator editing, the aml programs executed archival procedures specific to an edit function, transferring historical references of the changes to the edit archive coverage. This preservation measure was established to retain linkages to the original EPA-RF3 files if in the future these files were used in other efforts requiring source information. These historical records were also established to provide conversion references if as the SWIMS surface waters databases are developed that new revised EPA hydrologic files become available. Federal plans to update EPA-RF3 files are expected to continue. These updated files, however, may or may not be available in their most correct form before further work on a statewide hydrologic database is undertaken. The Edit Archive aml programs were developed to maintain continuity with the original EPA RF3 files. This was achieved by creating separate historical records for edits performed on each USGS HUC-8 Reach Files. In general, the Edit Archive contains records of approved edit operations and cross-references to EPA's feature identification numbering system, as described below. In order to track the sequence of approved edit operations on a feature a "VERSION" field was added to the attribute database. Each time an individual feature, was edited, its VERSION field was incremented by 1. Additional fields were added corresponding to the correction types as described in Appendix B. These numeric fields were used to record the correction activities performed on each feature and count the corrections performed on each feature. The Edit Archive coverage and file series (WA and WC ) tracks an individual RF3 feature through multiple update actions to the current feature representation included in the SWIMS coverage. Association between features was controlled via the RF3RCHID field (defined in Appendix B) present in the original RF3 datasets developed by EPA. The RF3RCHID value which is unique to each feature and is retained throughout each revision of a feature's graphic or tabular update. Strahler Stream-order Development A series of 'C', dBase, and ARC/INFO procedures were used to develop Strahler stream-order numbers to the SWIMS hydrologic dataset. EPA has developed Strahler numbers for the RF3 datasets, but given the many changes included in the SWIMS updates, Strahler values were reassigned throughout the SWIMS stream network within the State boundaries. Strahler values from upstream HUC8's were inherited by downstream hydrologic units in insure progressive value assignments. Please note that stream segments across the state border contain Strahler values formulated by EPA. These have been included to provide the most up-to-date information available. The procedures used to derive Strahler numbers were developed on the basis of the following rules: 1. A headwater is assigned a Strahler number of 1. 2. If a reach has a single connecting upstream reach, the reach is assigned the Strahler number of the upstream reach. 3. If a reach has two converging upstream reaches, the Strahler number is: a. The higher order number of the two upstream reaches, if the Strahler numbers are not equal. b. An order number one greater than that of the upstream reaches if the two upstream reaches have equal Strahler numbers. SECTION VII. SWIMS SURFACE WATERS STANDARDS ISSUES Listed below are some of the many important concepts regarding the generation and management of a surface-water digital file that are suggested for inclusion in the development of the state's surface-water standards prior to extension of SWIMS database across Kansas. Database Objectives. Decisions regarding current and future objectives of the surface- water database will significantly impact the state's standards. Decisions regarding the optimal scale desired for agency use (i.e. 1:100,000 versus 1:24,000) will help prioritize other issues. Database Structure. The database structure must be flexible for use in a variety of applications, from cartographic display to network analysis. The database structure can be established as a single file structure where the digital files contain all the physical feature records along with characteristic information. Otherwise, the database may consist of two record sets linked by a common attribute reference, one record for the physical features with elementary characteristics and a second record with more extensive characterization. Where extensive characterization along linear features is present, relationships between the physical feature record and the characteristic database may be easier to maintain with a new facility available in the ARC/INFO GIS software, dynamic segmentation, that uses a linear measurement from a known starting point as the pointer record relating the linear feature with the characteristic rather than the previously described common attribute link. Hierarchical Coding of Arcs. Surface-water coding schemes often include extensive hierarchal coding systems. Each arc, or stream reach, is assigned a unique code. This coding scheme must be sufficiently dynamic to compensate for surface-water database adjustments (i.e. scalar or feature change) yet maintain the integrity of the original hierarchial scheme. If chosen carefully this database attribute can act as the crucial "link" if a two-set feature database scheme is selected as the State standard (reference Database Structure) Database Tiling System. To aid hydrologic modelling, the most efficient and meaningful tiling system is the hydrologic unit. The USGS HUC-8 is generally accepted for this purpose. Feature Attributes. An agency review of current hydrologic modeling and planning activities, along with computer program input requirements, may identify the variables and related data most beneficial for state planning purposes. The results of this review could help define the most efficient form of data structure for agency use. Redundant Maintenance. Surface-water data are widely used for a variety of applications, making data maintenance potentially complex. With use, identification of changes and improvements to the surface-water database will naturally occur. Database alterations should be restricted to a central repository agency. Alternatively, the records of individual agency alterations could be reported back to the central repository for inclusion in the official surface-water database. In either case, quality control and quality assurance regulations should be established and implemented by those parties held responsible for the updating process. A notification procedure to minimize redundant corrections or notification of corrections among those agencies cooperating in the improvement of this data resource is also recommended. Quality Assurance/Quality Control. Decisions regarding acceptable reference media, hardware, processing methods, resolution tolerances, and feature interpretation should be established for proper maintenance control of the database standards. Coordinate System. The surface-water standard coordinate system should be selected with respect to the coordinate system of the reference material from which much of the data will be updated and with regards to the most efficient coordinate system for archival purposes. In cases where USGS material will be used as the source for updating, the Universal Transverse Mercator projection will provide the least scale factor distortion between the digital and source data. Space consumption and ease-of-use are factors that may affect the final selection of the archival projection. As in the case of the Census Bureau TIGER files, geographic coordinates have been employed thus foregoing any specific projection system. SWIMS Surface Waters Coverages. The surface-water spatial data will be distributed as three separate ARC/INFO coverages; linear features, point features and polygon features. The linear feature coverage will include all single line stream and river features and artificial connector features added to the database to aid hydrologic modelling. The point features will include spring, wells, and other water-related point features. The polygon feature coverage will include lakes, islands, and dual channel elements that are identified with a polygon label along with artificial dummy lines (see Figure 1 for further definition). Coincident Features. Surface-water arcs are often coincident with other GIS digital data features tied to the land (e.g., soil delineations or landuse boundaries). When combining different digital files together, as in map compilation or data modeling, mismatches between coincident features require additional effort to reconcile. Early development of application standards for data resource precedence may assist future efforts incorporating duplicate data resources. SECTION VIII. REFERENCES Armstrong, M.P. and Hopkins, L.D. "Data Structure Design for Surface Water Resources Information." URISA Journal 3(2):12-24,. Fall 1991. Bondelid, T.R., Hanson, S.A., and Taylor, P.L. "Technical Description of the Reach File." U.S. Environmental Protection Agency. 1990. Bower, S.T., and Scott, D. "Vermont GIS Draft Standards for Surface Waters Data." Proceedings of the Twelfth Annual ESRI User Conference. Palm Springs, CA, 1992. Department of Interior U.S. Geological Survey. Digital Line Graphs from 1:100,000-scale Maps. Reston, VA, 1989. Department of Interior U.S. Geological Survey. Geographic Names Information System. Reston, VA, 1987. Dulaney, R.A. and Hewitt III, M.J. "GIS Technical Memorandum, RF3-ARC/INFO Bridge." U.S. Environmental Protection Agency Geographic Resources Information and Data System. Gregory, K.J. and Walling, D.E. Drainage Basin Form and Process. New York: John Wiley & Sons. Hanson, S.A., Deffenbaugh, B., Horn, B., and McKay, C. River Reach File (RF3), Update and Quality Control, Standards, Procedures and Management, 1992. Howe, B. St. Johns River Water Management District, Palatka, FL. Interview, 21 January 1993. Jacqz, C. "Developing a Cost-effective Hydrological Network Coverage." Proceedings of the Eleventh Annual ESRI Users Conference, Palm Springs, CA, 1991. Kerski, J.J. "Hydrologic Analysis: DLG, TIGER, or RF3?" Unpublished paper, 1992. Nebert, D. "River Reach-to-ARC Conversion for Hydrologic Analysis in ARC/INFO." Discussion Document, 1991. Olsen, Mark. USEPA EMSL-LV, Las Vegas, Nevada. Interview, 7 January 1993. Puterski, R. "Using Dynamic Segmentation with the Reach File 3 Stream Database." Proceedings of the Twelfth Annual ESRI User Conference. Palm Springs, CA, 1992. U.S. Environmental Protection Agency. An Introduction to the Reach File and the Reach File Directory, 1982. U.S. Environmental Protection Agency. "Reach File." EPA Regional Forum on Water Information, 1991. USGS Rocky Mountain Mapping Center. NAWQA Digital Cartographic User's Guide, 1992. Seaber, P.R., Kapines, E.P., and Knapp, G.L. "Hydrologic Unit Maps." U.S. Geological Survey Water-Supply Paper 2294, 1987. Vermont Center for Geographic Information, Inc. VGIS Handbook, 1993. Zack, J.A. and Sieh, D.R. "The Colorado River Simulation System/Multiple Objective Decision Making System: GIS and the Decision Support System." Proceedings of the Twelfth Annual ESRI User Conference. Palm Springs, CA, 1992. APPENDIX A EPA-RF3 File Structure (Bondelid, et al) Field Name catunit segm mi upmi seqno rflag owflag tflag sflag reachtype lev junc divergence startcu strtsq stopcu stopsq usdir termid trmblv pname pnmcd cname cnmcd owname ownmcd dscu dsseg dsmi ccu cseg cmile cdir ulcu ulseg ulmi urcu urseg urmi segl rforgflag altpnmcd altownmc dlat dlon ulat ulong Type I I N N N C C C C C I I I I N I N C I I C C C C C C I I N I I N C I I N I I N N I I I N N N N Length 8 4 5.2 5.2 11.6 1 1 1 1 1 2 2 1 8 4 8 4 1 5 1 30 11 30 11 30 11 8 4 5.2 8 4 5.2 1 8 4 5.2 8 4 5.2 6.2 1 8 8 8.4 8.4 8.4 8.4 Description Cataloging Unit (CU) Segment Number (SEG) Mile Point (MI) Upstream Mile point Hydro Sequence Number Reach Flag (0,1) Open Water Flag (0,1) Terminal Flag (0,1) Start Flag (0,1) Reach Type Code Level Junction Number Divergence Code Start CU Start SEG Stop CU Stop SEG Upstream Direction Terminal Stream ID Terminal Base Level Primary Name Primary Name Code Common Name Common Name Code Open Water Name Open Water Name Code Downstream CU Downstream SEG Downstream MI Complement CU Complement SEG Complement MI Complement Direction Upstream Left CU Upstream Left SEG Upstream Left MI Upstream Right CU Upstream Right SEG Upstream Right MI Reach Length (Miles) RF Origin flag (1,2,3) Alt.Primary Name Code Alt.OW Name Code Downstream Latitude Downstream Longitude Upstream Latitude Upstream Longitude Field Name minlat minlong maxlat maxlong ndlgrecs ll1key1 ll2key1 ll1key2 ll2key2 ll1key3 ll2key3 ll1key4 ll2key4 ll1key5 ll2key5 ll1key6 ll2key6 ll1key7 ll2key7 ll1key8 ll2key8 ll1key9 ll2key9 ll1key10 ll2key10 ln1at2 ln2at2 area1 area2 ar1at2 ar1at4 ar2at2 ar2at4 update1 updtcd1 updtsrc1 update2 updtcd2 updtsrc2 update3 updtcd3 updtsrc3 filler Type N N N N I N N N N N N N N N N N N N N N N N N N N I I I I I I I I C C C C C C C C C Length 8.4 8.4 8.4 8.4 4 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 4 4 4 4 4 4 4 4 6 8 8 6 8 8 6 8 8 30 Description Minimum Latitude Minimum Longitude Maximum Latitude Maximum Longitude Number of DLG Records Starting DLG LL Key 1 Ending DLG LL Key 1 Starting DLG LL Key 2 Ending DLG LL Key 2 Starting DLG LL Key 3 Ending DLG LL Key 3 Starting DLG LL Key 4 Ending DLG LL Key 4 Starting DLG LL Key 5 Ending DLG LL Key 5 Starting DLG LL Key 6 Ending DLG LL Key 6 Starting DLG LL Key 7 Ending DLG LL Key 7 Starting DLG LL Key 8 Ending DLG LL Key 8 Starting DLG LL Key 9 Ending DLG LL Key 9 Starting DLG LL Key 10 Ending DLG LL Key 10 DLG Line Attribute 1 DLG Line Attribute 2 DLG Area ID 1 DLG Area ID 2 DLG Area attribute DLG Area attribute DLG Area attribute DLG Area attribute Update Date #1(mmddyy) Update Type Code #1 Update Source #1 Update Date #2(mmddyy) Update Type Code #2 Update Source #2 Update Date #3(mmddyy) Update Type Code #3 Update Source #3 Filler for future use I = Integer C = Character N = Numeric B = Binary 5.2 = Five digits, two decimals including decimal point APPENDIX B The table below indexes the ARC/INFO coverages developed for the SWIMS project. Each HUC unit contains a set of six files. The remainder of this addendum contains data dictionary and reference information for each coverage type. EPA-RF3 WATER NETWORK WATER POINT WATER REFERENCE WATER BODY WATER CORRECTION WATER ARCHIVE PHASE I LOWER REPUBLICAN B10250016 WN10250016 WP10250016 WR10250016 WB10250016 WC10250016 WA10250016 B10250017 WN10250017 WP10250017 WR10250017 WB10250017 WC10250017 WA10250017 B10270101 WN10270101 WP10270101 WR10270101 WB10270101 WC10270101 WA10270101 B10270102 WN10270102 WP10270102 WR10270102 WB10270102 WC10270102 WA10270102 B10270103 WN10270103 WP10270103 WR10270103 WB10270103 WC10270103 WA10270103 B10270104 WN10270104 WP10270104 WR10270104 WB10270104 WC10270104 WA10270104 B10270205 WN10270205 WP10270205 WR10270205 WB10270205 WC10270205 WA10270205 B10270206 WN10270206 WP10270206 WR10270206 WB10270206 WC10270206 WA10270206 B10270207 WN10270207 WP10270207 WR10270207 WB10270207 WC10270207 WA10270207 PHASE II MISSOURI NORTHEAST B10240005 WN10240005 WP10240005 WR10240005 WB10240005 WC10240005 WA10240005 B102400007 WN1024007 WP10240007 WR10240007 WB10240007 WC10240007 WA10240007 B10240008 WN10240008 WP10240008 WR10240008 WB10240008 WC10240008 WA10240008 B10240011 WN10240011 WP10240011 WR10240011 WB10240011 WC10240011 WA10240011 MISSOURI SOUTH B10300101 WN10300101 WP10300101 WR10300101 WB10300101 WC10300101 WA10300101 MARIAS DES CYGNES B10290101 WN10290101 WP10290101 WR10290101 WB10290101 WC10290101 WA10290101 B10290102 WN10290102 WP10290102 WR10290102 WB10290102 WC10290102 WA10290102 B10290103 WN10290103 WP10290103 WR10290103 WB10290103 WC10290103 WA10290103 B10290104 WN10290104 WP10290104 WR10290104 WB10290104 WC10290104 WA10290104 B10290108 WN10290108 WP10290108 WR10290108 WB10290108 WC10290108 WA10290108 NEOSHO B11070201 WN11070201 WP11070201 WR11070201 WB11070201 WC11070201 WA11070201 B11070202 WN11070202 WP11070202 WR11070202 WB11070202 WC11070202 WA11070202 B11070203 WN11070203 WP11070203 WR11070203 WB11070203 WC11070203 WA11070203 B11070204 WN11070204 WP11070204 WR11070204 WB11070204 WC11070204 WA11070204 B11070205 WN11070205 WP11070205 WR11070205 WB11070205 WC11070205 WA11070205 B11070206 WN11070206 WP11070206 WR11070206 WB11070206 WC11070206 WA11070206 B11070207 WN11070207 WP11070207 WR11070207 WB11070207 WC11070207 WA11070207 SALINE B10260001 WN10260001 WP10260001 WR10260001 WB10260001 WC10260001 WA10260001 B10260002 WN10260002 WP10260002 WR10260002 WB10260002 WC10260002 WA10260002 B10260003 WN10260003 WP10260003 WR10260003 WB10260003 WC10260003 WA10260003 B10260004 WN10260004 WP10260004 WR10260004 WB10260004 WC10260004 WA10260004 B10260005 WN10260005 WP10260005 WR10260005 WB10260005 WC10260005 WA10260005 B10260006 WN10260006 WP10260006 WR10260006 WB10260006 WC10260006 WA10260006 B10260007 WN10260007 WP10260007 WR10260007 WB10260007 WC10260007 WA10260007 B10260008 WN10260008 WP10260008 WR10260008 WB10260008 WC10260008 WA10260008 B10260009 WN10260009 WP10260009 WR10260009 WB10260009 WC10260009 WA10260009 B10260010 WN10260010 WP10260010 WR10260010 WB10260010 WC10260010 WA10260010 SOLOMON B10260011 WN10260011 WP10260011 WR10260011 WB10260011 WC10260011 WA10260011 B10260012 WN10260012 WP10260012 WR10260012 WB10260012 WC10260012 WA10260012 B10260013 WN10260013 WP10260013 WR10260013 WB10260013 WC10260013 WA10260013 B10260014 WN10260014 WP10260014 WR10260014 WB10260014 WC10260014 WA10260014 B10260015 WN10260015 WP10260015 WR10260015 WB10260015 WC10260015 WA10260015 UPPER REPUBLICAN B10250001 WN10250001 WP10250001 WR10250001 WB10250001 WC10250001 WA10250001 B10250002 WN10250002 WP10250002 WR10250002 WB10250002 WC10250002 WA10250002 B10250003 WN10250003 WP10250003 WR10250003 WB10250003 WC10250003 WA10250003 B10250004 WN10250004 WP10250004 WR10250004 WB10250004 WC10250004 WA10250004 B10250009 WN10250009 WP10250009 WR10250009 WB10250009 WC10250009 WA10250009 B10250010 WN10250010 WP10250010 WR10250010 WB10250010 WC10250010 WA10250010 PHASE III VERDIGRIS B11070101 WN11070101 WP11070101 WR11070101 WB11070101 WC11070101 WA11070101 B11070102 WN11070102 WP11070102 WR11070102 WB11070102 WC11070102 WA11070102 B11070103 WN11070103 WP11070103 WR11070103 WB11070103 WC11070103 WA11070103 B11070104 WN11070104 WP11070104 WR11070104 WB11070104 WC11070104 WA11070104 B11070106 WN11070106 WP11070106 WR11070106 WB11070106 WC11070106 WA11070106 WALNUT B11030017 WN11030017 WP11030017 WR11030017 WB11030017 WC11030017 WA11030017 B11030018 WN11030018 WP11030018 WR11030018 WB11030018 WC11030018 WA11030018 UPPER ARKANSAS B11020009 WN11020009 WP11020009 WR11020009 WB11020009 WC11020009 WA11020009 B11030001 WN11030001 WP11030001 WR11030001 WB11030001 WC11030001 WA11030001 B11030002 WN11030002 WP11030002 WR11030002 WB11030002 WC11030002 WA11030002 B11030003 WN11030003 WP11030003 WR11030003 WB11030003 WC11030003 WA11030003 B11030004 WN11030004 WP11030004 WR11030004 WB11030004 WC11030004 WA11030004 B11030005 WN11030005 WP11030005 WR11030005 WB11030005 WC11030005 WA11030005 B11030006 WN11030006 WP11030006 WR11030006 WB11030006 WC11030006 WA11030006 B11030007 WN11030007 WP11030007 WR11030007 WB11030007 WC11030007 WA11030007 B11030008 WN11030008 WP11030008 WR11030008 WB11030008 WC11030008 WA11030008 LOWER ARKANSAS B11030009 WN11030009 WP11030009 WR11030009 WB11030009 WC11030009 WA11030009 B11030010 WN11030010 WP11030010 WR11030010 WB11030010 WC11030010 WA11030010 B11030011 WN11030011 WP11030011 WR11030011 WB11030011 WC11030011 WA11030011 B11030012 WN11030012 WP11030012 WR11030012 WB11030012 WC11030012 WA11030012 B11030013 WN11030013 WP11030013 WR11030013 WB11030013 WC11030013 WA11030013 B11030014 WN11030014 WP11030014 WR11030014 WB11030014 WC11030014 WA11030014 B11030015 WN11030015 WP11030015 WR11030015 WB11030015 WC11030015 WA11030015 B11060001 WN11060001 WP11060001 WR11060001 WB11060001 WC11060001 WA11060001 B11060001 WN11060001 WP11060001 WR11060001 WB11060001 WC11060001 WA11060001 B11060002 WN11060002 WP11060002 WR11060002 WB11060002 WC11060002 WA11060002 B11060003 WN11060003 WP11060003 WR11060003 WB11060003 WC11060003 WA11060003 B11060004 WN11060004 WP11060004 WR11060004 WB11060004 WC11060004 WA11060004 B11060005 WN11060005 WP11060005 WR11060005 WB11060005 WC11060005 WA11060005 CIMARRON B11040002 WN11040002 WP11040002 WR11040002 WB11040002 WC11040002 WA11040002 B11040003 WN11040003 WP11040003 WR11040003 WB11040003 WC11040003 WA11040003 B11040004 WN11040004 WP11040004 WR11040004 WB11040004 WC11040004 WA11040004 B11040005 WN11040005 WP11040005 WR11040005 WB11040005 WC11040005 WA11040005 B11040006 WN11040006 WP11040006 WR11040006 WB11040006 WC11040006 WA11040006 B11040007 WN11040007 WP11040007 WR11040007 WB11040007 WC11040007 WA11040007 B11040008 WN11040008 WP11040008 WR11040008 WB11040008 WC11040008 WA11040008 B11050001 WN11050001 WP11050001 WR11050001 WB11050001 WC11050001 WA11050001 B11100102 WN11100102 WP11100102 WR11100102 WB11100102 WC11100102 WA11100102 Water Network Features The Water Network (WN) file series contains the updated continuous stream channel features within the State borders represented on the 1:100,000 USGS map series. The file also contains detached stream segments and either natural or artificial interconnecting stream features (i.e. oxbows, canals, irrigation ditches, diverted stream channels). A notable change from the original RF3 source files is that the flow direction runs downstream. Update activity was executed on all water features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. The following data dictionary references the fields in the Water Network.Arc Attribute Tables (WN.AAT). The RF3RCHID field of the WN.AAT file can be used to relate characterizations from EPA's B.DS2 tables for graphic elements that were retained or updated from the original RF3 source files. HUC's crossing state boundaries contain both corrected and uncorrected feature and attribute information. Users should take this into consideration when using boundary HUC's in GIS analysis. Out-of-State features may contain values inconsistent with field definitions included below for TYPE and CLASS. Out-of-State network features have not been corrected into a continuous network and reflect the structure of the original RF3 source files. To prepare these data sets for network analysis, it is recommended that water network feature types 11, 13, and 70 (see TYPE definition below) be removed prior to trace operations. In accordance with ESRI recommendations for maintaining data similar to the SWIMS hydrologic datasets that use tolerances lower than the default coverage settings, users should combine adjacent datasets with an APPEND, BUILD sequence of ARC/INFO commands. Altering files through ARC/INFO commands, MAPJOIN or CLEAN, may inadvertently collapse or delete graphic elements. Outlet/Inlet arcs across HUC boundaries have been adjusted to share node locations. If multiple WN files are combined, an APPEND, BUILD, MATCHNODE sequence is recommended to adjoining stream segments across HUC boundaries. WN.AAT FIELD NAME TYPE WIDTH DESCRIPTION FNODE# B 4 Each line segment in the coverage is characterized by a user- defined flow direction (i.e. flowing 'from' one point 'to' a second point). This field contains the reference for the 'from' node of the line segment. TNODE# B 4 This field contains the reference for the 'to' node of the line segment described in the comment line above LPOLY# B 4 The topological data model in ARC/INFO provides reference information for space adjacent to a line feature. This field contains reference information for space to the left of the line segment oriented in the from-to direction. RPOLY# B 4 This field contains reference information for space to the right of the line segment as described in the comment line above. LENGTH F 4 Line segment length is provided in units defined in the coverage projection WN# B 4 An internal reference number controlled by the ARC/INFO program WN-ID B 4 A user-defined reference number for each line segment TYPE I 5 Feature type was redefined for purposes of the SWIMS project from original EPA-RF3 data. For water network features, the following type definitions appear in this field: 10 - Regular Reach 11 - Other Interconnect Feature 13 - Canal Interconnect Feature 30 - Waterbody Connector 99 - Unknowns CLASS I 5 Feature class was redefined for purposes of the SWIMS project from original EPA-RF3 data. For water network features, the following class definitions appear in this field: 10 - Intermittent 20 - Perennial 99 - Unknown SWIMSID B 4 Unique ids. This field cross-references to correction (WC) and archive (WA) datasets. RF3RCHID C 17 This field is a concatenation of the EPA-RF3 fields, cu, seg, and mile. The redefined field provides a relational link to EPA-RF3's .ACODE tabular database, containing descriptive data PREVARC B 4 Downstream reference STRAHLER I 5 Stream-order values Water-related point features The Water-related Point (WP) file series contains label elements identifying a range of point features including wells, springs, seeps, windmills, and gaging stations. These features have been converted from degenerate arcs features in the EPA-RF3 files. Update activity was executed on all water point features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. The following data dictionary references the fields in the Water-related Point.Point Attribute Tables (WP.PAT). The RF3RCHID field of the WP.PAT file can be used to relate characterizations from the B.DS2 tables for graphic elements that were retained or updated from the original RF3 source files. HUC's crossing state boundaries contain both corrected and uncorrected feature and attribute information. Users should take this into consideration when using boundary HUC's in GIS analysis. Out-of-State features may contain values inconsistent with field definition included below for TYPE and CLASS, reflecting the structure of the original RF3 source files. In accordance with ESRI recommendations for maintaining data similar to the SWIMS hydrologic datasets that use tolerances lower than the default coverage settings, users should combine adjacent datasets with an APPEND, BUILD sequence of ARC/INFO commands. Altering files through ARC/INFO commands, MAPJOIN or CLEAN, may inadvertently collapse or delete graphic elements. WP.PAT FIELD NAME TYPE WIDTH DESCRIPTION AREA F 4 ARC/INFO includes this field in the point attribute tables, though no information is recorded regarding point features PERIMETER F 4 ARC/INFO includes this field in the point attribute tables, though no information is recorded regarding point features WP# B 4 An internal reference number controlled by the ARC/INFO program WP-ID B 4 A user-defined reference number for each line segment TYPE I 5 Feature type was redefined for purposes of the SWIMS project from EPA-RF3 data field, reachtype. For water-related point features, the following type definitions appear: 40 - spring, seep 41 - geyser 42 - riser 50 - nonflowing well 51 - windmill 60 - gaging station 61 - pumping station 62 - water intake 63 - canal lock 64 - flood gate 65 - siphon 99 - Unknown CLASS I 5 Feature class was redefined for purposes of the SWIMS project from EPA-RF3 data field, reachtype. For water-related point features, the following class definitions appear: 30 - Natural structure 40 - Manmade structure 99 - Unknown SWIMSID B 4 Unique ids. This field cross-references to correction (WC) and archive (WA) datasets. RF3RCHID C 17 EPA-RF3 cross reference, see WN.AAT field for extended description Water Reference The Water Reference (WR) file series contains all of the water-related feature information present on the 1:100,000 USGS map series. The WR.AAT files contain line segments for dual-channel rivers or streams and swamp features in addition to pond and lake boundary line segments that served as a base for the Water Body (WB) file series, . Update activity was executed on all water-related features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. The following data dictionary references the fields in the Water Reference.Arc Attribute Tables (WR.AAT). The RF3RCHID field of the WR.AAT file can be used to relate characterizations from EPA's B.DS2 tables for graphic elements that were retained or updated from the original RF3 source files. HUC's crossing state boundaries contain both corrected and uncorrected feature and attribute information. Users should take this into consideration when using boundary HUC's in GIS analysis. Out-of-State features may contain values inconsistent with field definition included below for TYPE and CLASS. Out-of-State water reference features have not been corrected for omitted or invalid water-reference features and reflect the structure of the original RF3 source files. In accordance with ESRI recommendations for maintaining data similar to the SWIMS hydrologic datasets that use tolerances lower than the default coverage settings, users should combine adjacent datasets with an APPEND, BUILD sequence of ARC/INFO commands. Altering files through ARC/INFO commands, MAPJOIN or CLEAN, may inadvertently collapse or delete graphic elements. WR.AAT FIELD NAME TYPE WIDTH DESCRIPTION FNODE# B 4 Each line segment in the coverage is characterized by a user- defined flow direction (i.e. flowing 'from' one point 'to' a second point). This field contains the reference for the 'from' node of the line segment. TNODE# B 4 This field contains the reference for the 'to' node of the line segment described in the comment line above LPOLY# B 4 The topological data model in ARC/INFO provides reference information for space adjacent to a line feature. This field contains reference information for space to the left of the line segment oriented in the from-to direction. RPOLY# B 4 This field contains reference information for space to the right of the line segment as described in the comment line above. LENGTH F 4 Line segment length is provided in units defined in the coverage projection WR# B 4 An internal reference number controlled by the ARC/INFO program WR-ID B 4 A user-defined reference number for each line segment TYPE I 5 Feature type was redefined for purposes of the SWIMS project from original EPA-RF3 data. For water network features, the following type definitions appear in this field: 21 - Swamp shoreline 22 - Water-body shoreline 23 - Reach shoreline 70 - Other feature 99 - Unknown CLASS I 5 Feature class was redefined for purposes of the SWIMS project from original EPA-RF3 data. For water network features, the following class definitions appear in this field: 10 - Intermittent 20 - Perennial 99 - Unknown SWIMSID B 4 Unique ids. This field cross-references to correction (WC) and archive (WA) datasets. RF3RCHID C 17 This field is a concatenation of the EPA-RF3 fields, cu, seg, and mile. The redefined field provides a relational link to EPA-RF3's .ACODE tabular database, containing descriptive data Water Body Features The Water Body (WB) file series contains all of the water body features such as lakes and ponds present on the 1:100,000 USGS map series. This polygon coverage was created from feature types = '22' contained in the Water Reference (WR) series. Update activity was executed on all water body features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. The following data dictionary references the fields in the Water Body.Polygon Attribute Tables (WB.PAT). Default Arc/Info characteristic information is available for these features associated with a unique label contained within each water body feature. Corrected water body features and attribute information were developed within the State boundaries. HUC's crossing state boundaries exclude water bodies outside the State boundaries . In cases where a water body straddles two HUCs, an artificial boundaries has been inserted to close the feature to establish polygon file structure integrity. Adjacent water bodies across HUC boundaries have been adjusted to share node locations. If multiple WB.PAT files are combined an APPEND, BUILD, MATCHNODE sequence along with an ARCEDIT session to remove artificial water-body segment is recommended to combine these datasets. Users should take these noted exceptions into consideration when using boundary HUC's and in- state HUCs in GIS analysis involving area calculations. In accordance with ESRI recommendations for maintaining data similar to the SWIMS hydrologic datasets that use tolerances lower than the default coverage settings, users should combine adjacent datasets with an APPEND, BUILD sequence of ARC/INFO commands. Altering files through ARC/INFO commands, MAPJOIN, UNION or CLEAN, may inadvertently collapse or delete graphic elements. WB.PAT FIELD NAME TYPE WIDTH DESCRIPTION AREA F 4 Area in square units as defined in the coverage projection PERIMETER F 4 Perimeter length of the polygon boundary in units as defined in the coverage projection WB# B 4 An internal reference number controlled by the ARC/INFO program WB-ID B 4 A user-defined reference number for each polygonal feature SWIMSID B 4 Unique ids. This field cross-references to correction (WC) and archive (WA) datasets. Water Correction and Archive (Arc Features) The information contained in Water Correction (WC.ACODE) file for linear (arc) features and the Water Archive (WA) arc/linear series have been retained for reference only. The WC.ACODE file contains references for the last updates performed on the water network graphic elements and can be reassociated with the WN coverages through the SWIMSID. Earlier corrections to the linear graphic elements were written to the Water Archive.Arc Attribute Table (WA.AAT) coverage files. These corrections include information on reshaped, revised, or deleted features, including duplicate and intersecting arcs. The graphic features contained in this coverage series use the original UTM projection from the USGS map series which is the basis for all of the SWIMS corrections. The projection of this file will not be changes to retain as much of the coordinate integrity as possible. At some future time, it may be possible to use the information in these files to report feature updates back to EPA for national database revision. Note that these file has been included for the exclusive purpose of reporting update activity to EPA and are not for use by the general public. Update activity was executed on all linear (arc) water features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. WC.ACODE and WA.AAT FIELD NAME TYPE WIDTH DESCRIPTION FNODE# B 4 From node, see similar description WN.AAT TNODE# B 4 To node see similar description WN.AAT LPOLY# B 4 Left Poly see similar description WN.AAT RPOLY# B 4 Right Poly see similar description WN.AAT LENGTH F 4 Length see similar description WN.AAT WC/WA# B 4 An internal reference number controlled by the ARC/INFO program WC/WA-ID B 4 A user-defined reference number for each line segment CU I 8 reference EPA-RF3 field description, Appendix A SEG I 4 reference EPA-RF3 field description, Appendix A MILE N 5 reference EPA-RF3 field description, Appendix A UP B 4 reference EPA-RF3 field description, Appendix A DOWN B 4 reference EPA-RF3 field description, Appendix A TYPE I 5 Feature type, see WN.AAT field for extended description CLASS I 5 Feature type, see WN.AAT field for extended description SWIMSID B 4 Appearing only in WC.ACODE dataset. Unique ids. This field cross-references to correction (WC) and archive (WA) dtasets. RF3RCHID C 17 EPA-RF3 cross reference, see WN.AAT field for extended description RCHTYPE C 1 reference EPA-RF3 field description, Appendix A LN1AT2 I 4 reference EPA-RF3 field description, Appendix A LN2AT2 I 4 reference EPA-RF3 field description, Appendix A LEVEL I 2 reference EPA-RF3 field description, Appendix A PNAME C 30 reference EPA-RF3 field description, Appendix A OWNAME C 30 reference EPA-RF3 field description, Appendix A CODECORR I 5 Change type or class P_DROP I 5 Partial drop indicator. Part of feature is removed. F_DROP I 5 Full drop indicator. Complete feature is removed SPLIT I 5 Split indicator. Feature has been split to intersect with other features ADJSPLIT I 5 Adjacent split indicator. LINK I 5 Link indicator. Extension of feature to join adjacent feature TOHUC I 5 HUC number where arc has been moved FRHUC I 5 HUC number where arc has been transferred from ADDFEATURE I 5 Add arc indicator. New feature added to file FLIP I 5 Flip indicator. Change of flow direction. VERSION I 5 Version indicator. Number of alterations FXDD N 8 X-coordinate of From node in decimal degrees FYDD N 8 Y-coordinate of To node in decimal degrees TXDD N 8 X-coordinate of From node in decimal degrees TYDD N 8 Y-coordinate of To node in decimal degrees FRNODE N 11 Original from node number TONODE N 11 Original to node number POSITION I 5 Working field for strahler procedure PREVARC B 4 Downstream arc STRAHLER I 5 Strahler value Water Correction and Archive (Point Features) The information contained in Water Correction (WC.PCODE) for point (label) features and the Water Archive (WA) point/label series have been retained for reference only. The WC.PCODE file contains references for the last updates performed on the point graphic elements and can be reassociated with the WP coverages through the SWIMSID. Earlier updates and corrections to the point graphic elements were archived in the Water Archive.Point Attribute Table (WA.PAT) coverage files. These corrections include information on repositioned, revised, deleted or duplicate points. The graphic features contained in this coverage series use the original UTM projection from the USGS map series which is the basis for all of the SWIMS corrections. The projection of this file will not be changes to retain as much of the coordinate integrity as possible. At some future time, it may be possible to use the information in these files to report feature updates back to EPA for national database revision. Note that these file has been included for the exclusive purpose of reporting update activity to EPA and are not for use by the general public. Update activity was executed on all point (label) water features within the State boundaries. These changes were executed through controlled AML edit sessions. Batch editing such as that executed through the ARC/INFO command CLEAN were not acceptable for these procedures as such automated processing may have resulted in loss of data. Given these conditions, fuzzy and dangle tolerance values, though defined, were not invoked in any processing and will appear as non-verified parameters. WC.PCODE and WA.PAT FIELD NAME TYPE WIDTH DESCRIPTION AREA F 4 Arc/Info default field. Not applicable on point coverages PERIMETER F 4 Arc/Info default field. Not applicable on point coverages WC/WA# B 4 An internal reference number controlled by the ARC/INFO program WC/WA-ID B 4 A user-defined reference number for each line segment N# B 4 A reference number vrom node/point conversion process FNODE# B 4 From node reference from node/point conversion process TNODE# B 4 To node reference from node/point conversion process LPOLY# B 4 Left Poly reference from node/point conversion process RPOLY# B 4 Right Poly reference from node/point conversion process LENGTH F 4 Length reference from node/point conversion process N-ID B 4 A reference number vrom node/point covnersion process CU I 8 reference EPA-RF3 field description, Appendix A SEG I 4 reference EPA-RF3 field description, Appendix A MILE N 5 reference EPA-RF3 field description, Appendix A UP B 4 reference EPA-RF3 field description, Appendix A DOWN B 4 reference EPA-RF3 field description, Appendix A TYPE I 5 Feature type, see WP.AAT field for extended description CLASS I 5 Feature type, see WP.AAT field for extended description SWIMSID B 4 Appearing only in WC.PCODE dataset. Unique ids. This field cross-references to correction (WC) and archive (WA) datasets. RF3RCHID C 17 EPA-RF3 cross reference, see WP.AAT field for extended description RCHTYPE C 1 reference EPA-RF3 field description, Appendix A LN1AT2 I 4 reference EPA-RF3 field description, Appendix A LN2AT2 I 4 reference EPA-RF3 field description, Appendix A LEVEL I 2 reference EPA-RF3 field description, Appendix A PNAME C 30 reference EPA-RF3 field description, Appendix A OWNAME C 30 reference EPA-RF3 field description, Appendix A CODECORR I 5 Change type or class P_DROP I 5 Partial drop indicator. Part of feature is removed. F_DROP I 5 Full drop indicator. Complete feature is removed SPLIT I 5 Split indicator. Feature has been split to intersect with other features ADJSPLIT I 5 Adjacent split indicator. LINK I 5 Link indicator. Extension of feature to join adjacent feature TOHUC I 5 HUC number where arc has been moved FRHUC I 5 HUC number where arc has been transferred from ADDFEATURE I 5 Add arc indicator. New feature added to file FLIP I 5 Flip indicator. Change of flow direction. VERSION I 5 Version indicator. Number of alterations FXDD N 8 X-coordinate of From node in decimal degrees FYDD N 8 Y-coordinate of To node in decimal degrees TXDD N 8 X-coordinate of From node in decimal degrees TYDD N 8 Y-coordinate of To node in decimal degrees FRNODE N 11 Original from node number TONODE N 11 Original to node number POSITION I 5 Working field for strahler procedure