The District of Columbia

Land Use - Existing (ExistingLandUse)

Land Use - Existing (ExistingLandUse)

by Office of Planning on 05/05/2005

Keywords
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Taking place at: Washington DC, District of Columbia, DC, DC GIS, DCGIS

Abstract

Existing Landuse

This Spatial Data contains 2004 Existing Land Use delineations for Washington District of Columbia. The layer was developed to support in the Comprehensive Plan review process currently underway by the DC Office of Planning Long Range Planning Division. The layer boundaries are a combination of 1999 planimetrics, DC Property Square Index boundaries that were manually split along scanned, raster tax lot boundaries.

Purpose


This data is used for the planning and management of Washington by local government agencies.

Stereotype areas using DC Office of Tax and Revenue (OTR) owner points and use codes as the first step; supplement with additional data layers and corrections based on manual review as needed. The end product should be a land inventory and associated maps sufficiently accurate to indicate for planning purposes how lands are currently being used in DC. This effort is launched in advance of the availability of digitized lot boundaries for DC, and will be revised when they become available.

Access constraints

None.

Use constraints

Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.

Point of contact


in DC Office of Planning

801 N Capitol St, NE # 4000
Washington DC, 20002, USA

phone: 202-442-7600
fax: 202-442-7637
hours: 8:30 am - 4:30 pm

Data accuracy

Accuracy
Data believed to be complete and accurate, subject to change.

Completeness
Data believed to be complete and accurate, subject to change.

Lineage / Sources

  • Owner Points Light (OwnerPtLt)
    vector digital data,
    Owner Points Light
    by DC Office of Tax and Revenue (OTR), 04/10/04
  • Property Square Index (PropSqrPly)
    vector digital data,
    Property Square Index
    by DC Office of Tax and Revenue, 03/29/2004
  • Tax Map Scans
    raster digital data,
    Tax Map Scans
    by DC Office of Tax and Revenue, 06/21/2001
  • Road Bondaries (RoadPly)
    vector digital data,
    Road Bondaries
    by National Capitol Planning Commission (NCPC), 03/31/2001
  • NPS-Managed Parks (NpsParks_dc10_03)
    vector digital data,
    (NpsParks_dc10_03)
    by National Parks Service, 01/09/2004
  • DC-Managed Parks (RecPly)
    vector digital data,
    RecPly
    by DC Parks and Recreation, 03/01/2004
  • Hope IV Removed Properties (Vacant)
    vector digital properties,
    OwnerPtLight622 (Hope IV Removed Properties)
    by DC Office of Planning
Lineage / Processes
John Codd
in DC Office of Planning

801 North Capitol St, NW # 4000
Washington DC, 20002, USA

phone: 202-442-7600
fax: 202-442-7637

Phase 1 of the Existing Land Use develoment process is layer creation. 1999 Planimetric Water features and Roads features (roads, intersection, medians, traffic circles, alleys) and DC OTR property square boundaries were unioned to create a base layer that contained attributes from each of the input source layers. The resulting geodatabase covered all of DC land including water features. Some, but not all of the Planimetrics outside of the DC property squares retained the geography of the original planimetrics layer. In the union process, the planimetric alley polygons cut into and/or split the DC property squares. This decision was made to assist in the process of further splitting the DC property squares by tax lots that were not conforming Existing Land Use categories. Whole or partial DC property squares were automatically assigned Existing Land Use catgories based on the Office of Tax and Revenue (OTR) Public Extract ownership database.

GIS specialists at the DC Office of Planning conducted further manual splitting of the tax lots within the DC Property squares. Tax lots or aggregates of contiguous tax lots automatically received an Existing Land Use category when a pre-approved percentage of land were assigned a homogenious Existing Land Use category.

Prepare spatial analysis tools

? Build ArcGIS scripts to support one-time categorization of lands and interactive re-categorization of lands as needed.
? Test and revise as needed

Prepare tables characterizing land use by OTR Use Codes

? Generate a set of categories to be distinguished via use code data
? Identify the maximum allowable proportions of other uses within an area we will designate as homogeneous (i.e., how much LMDR is ok within LDR.)
? For "Government", also try to distinguish "Federal" by examining owner name

Process OTR data

? Begin with square (block) boundaries
? Split them into "square segments" to the extent practicable using alley centerline data
? Process square segments in bulk, identifying a designated land use classification if the predominant use covers the entire segment or if the other uses are sufficiently limited and consistent with the predominant use.
? Revisit all square segments that are not automatically classified using a semi-automated process:
o Begin with test areas in each ward of the city; revise the process if necessary before proceeding further
o The software will highlight all non-classified square segments
o Zoom to each in turn and show owner point data color-coded by use and the tax lot boundaries
o Operators will split segments as needed to separate distinct uses; the software will automatically re-evaluate each newly-split segment and classify it (removing the highlighting) if it now meets the rules for automatic classification.

Additional Bulk Processing Steps:

? Separate Government areas into Federal/District/undetermined
o ? via owner point ownership info
o ? via other sources
? Separate Commercial areas, identifying neighborhood commercial areas distinctly (using boundaries provided by LRP staff)
? Separate areas that are:
o Alleys
o Sidewalks
o Road surfaces
o Parking lots ?
? Tag other areas (outside of squares) known to be parkland (NPS)
? Tag other areas (outside of squares) believed to be managed by Parks and Rec
? Tag areas known to be military
? Tag areas known to be Federal
? Tag areas known to be water (Potomac/Anacostia/other)

Initial Manual Review

? Print large-format maps for in-house review by OP planners (possibly with orthos as faint overlays)
o Any corrections must be vouched for by a specific planner, whose name will be recorded as the source of that information

Pictometry Review

? Focus on suspect areas, and use oblique aerial photos to resolve as needed

Windshield Review

? For areas of particular concern - and a random sample of areas we think are ok -- review in the field
? We won't know how extensive this is until we see the interim products

IMPLIED DATA HIERARCHY

? Street polygons
? Sidewalk polygons
? Alley polygons
? Parking lots *** not in squares ***
?
? Separately QC'D military base boundaries
?
? Squares/owner points
o Owner name = United States xxx or District of xxx supercedes use code
o Use codes thereafter
? (separate designation) Parking lots *** in squares only ***
? (separate designation - CHECK ) Parks and rec parks *** in squares ***
? National park boundaries (from NPS)
? Separately prepared and QC'd boundaries for Mall, Zoo, other fed lands as needed
? Parks and rec parks *** outside of squares ***

in DC Office of Planning



Phase 2 of the Existing Land Use development is the review process. The Long Range Planning Division drew up strict review guidelines. Neighborhood Planning staff, Development Review staff and Historic Preservation staff each reviewed 36x48 hardcopy, Ward maps of the Existing Land Use layer. Reviewers marked polygons that were assigned incorrect Existing Land Use categories with correct attributes. GIS specialist staff updated the geodatabase to reflect the marked changes.

Distribution

Distribution liability
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.

Distributed by

in DC Office of Planning

801 N Capitol St, NW # 4000
Washington DC, 20002, USA

phone: 202-442-7600
fax: 202-442-7637
hours: 8:30 am - 5:30 pm

Entity

DCGIS.ExistingLandUse / DC Office of Planning (DCOP)
Existing Landuse

Attributes

  • OBJECTID / ESRI
    Internal feature number.
  • OP_LAYER
    Source Planimetrics
  • CNT_OP_LAYER
    Original polygon count.
  • MIN_DXF_LAYER
  • AREAKM
    Area of The District of Columbia in square kilometers
  • AREAMILES
    Area of The District of Columbia in square miles
  • WAT
    Original Planimetric Water Feature
  • WAT_ID
    Original Planimetric Water Feature Object ID
  • WAT_CODE
    Original Planimetric Water Feature Code
  • WAT_NAME
  • DXF_LAYER
    Original Planimetric Water Feature DXF_Layer Attribute
  • SQRSUF / Real Property Tax Assessors (RPTA) public extract database
    DC Property Square number and suffix where one occurs
  • WARD_ID
    Original Polygons assigned a ward number (1-8).
  • GIS_ID
    DC Property Square number
  • SQR_NUM
    DC Property Square number
  • LU_CODE
    Current Existing Land Use attribute
  • QCFLAG
    Flag field for Phase 2 Review and Editing process
  • OLD_LU_CD
    Last LU_CODE before change
  • ISVACANT
    Tracks vacant polygon (lot or lots)
    • y / The polygon (lot or lots) is vacant
    • Null / The polygon (lot/lots) is not vacant
    • blank / The polygon (lot/lots) is not vacant
    •  
  • HASBLDG
    Tracks vacant polygon (lot or lots) structure status
    • y / a building or sturucure is present
    • n / a building or structure is not present
    •  
  • SHAPE / ESRI
    Feature geometry.
  • VACTYPE
    Vacant polygon (lot or lots) type
    • V / Vacant Land
    • VB / Vacant Building or structure
    •  
  • SHAPE.AREA
  • SHAPE.LEN

Metadata

FGDC Content Standards for Digital Geospatial Metadata / FGDC-STD-001-1998 as of 12/14/2007

Provided by

in DC Office of Planning

801 N Capitol St, NE # 4000
Washington DC, 20002, USA

phone: 202-442-7600
fax: 202-442-7637
hours: 8:30 am - 4:30 pm