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DMINews -- October 2007
Topics: • Geographic Shape to Shape Relationship Analysis • School District Demographic Change 1999-2000 to 2005-2006 • Cost of Census 2010 & FY 2008 Federal Budget Continuing Resolution Issues Geographic Shape to Shape Relationship Analysis The new CommunityViewer Shape-to-Shape (Shp2Shp) relational analysis feature provides many geospatial processing operations. Shp2Shp determines geographic relationships of shapes in two shapefiles and provides information to the user about these relationships. A simple example of a Shp2Shp operation is to answer the question -- which county(s) touch (are adjacent to) one that I specify? A more general version of this example is -- tell me which counties, places, census tracts or ZIP codes -- choose any one type of geography (that meet some query/specific condition) in one shapefile touch (are adjacent to) counties, places, census tracts or ZIP codes -- choose any one type of geography (that meet some other query/specific condition). A little more concrete example is: tell me which cities/places that have population of 25,000 or more touch a principal city in any metropolitan statistical area. Scope of geospatial relationships. Up to this point, the only relationship that has been reviewed is touching or adjacency. The Shp2Shp operations enable the user to select the type of geospatial relationship to be applied from these eight options: equals, disjoint, intersect, touches, overlap, cross, within, contains. Use/selection of the relationship option is shown in the following graphic. Click graphic for larger view then press F11 key upon display for best view. 
In the above Shp2Shp form (form at right), the relationships between the Idaho by county shapefile (with the query condition where only "county='005'" is selected) relative to all counties in the second instance of the Idaho by county shapefile (no query is applied). When the Find Matches button is clicked, these events occur: 1) the map is refreshed and shows the county (shape) in shapefile 1 (layer 1) with red diagonal lines and the counties matching the relationship in shapefile 2 (layer 2) as cross-hatched, 2) a list of shapes from layer 1 and layer 2 meeting the conditions are displayed in the lower right listbox. In this example the field selected to display is NAME; any field may be selected for display. The rows in the listbox may be optionally exported to an Excel file. In the more general case, there might be hundreds of rows and the field name displayed a geocode rather than a name. 3) a new shapefile may optionally be created that will contain shapes from layer 2 meeting the match requirements. Other Application Examples. In the above example, simple polygon shapefiles were used. Any combination of point, line, or polygon shapefiles may be used. Application examples: • Streets, pipelines, waterways, corridors passing through selected polygon area(s). • Housing structures/addresses with certain attributes contained within selected census blocks. • Census tracts intersecting a set of ZIP codes. • School districts adjacent to/intersecting/ other school districts. • Census block groups meeting certain demographic criteria wholly contained within a metro area. Repetitive matching operations may be performed using different criteria. Matching shapes may be cleared each time or accumulated. By specifying the visible extent (with respect to the map view) a small part of a shapefile with a much larger extent can be processed, accelerating match processing time. School District Demographic Change 1999-2000 to 2005-2006 Of the 13,650 U.S. regular school districts with enrollment in both school years 1999-2000 and 2005-2006, 5,734 (or 42.01 percent) experienced some growth in enrollment. How did districts of interest to you change? How did the change occur regionally? Use the new school district ranking table http://proximityone.com/dist0506.htm to view how school districts have changed throughout the U.S. since 2000. A large file, the ranking table takes a minute to display (Internet Explorer suggested). Initially displayed in alphabetical order by state, click on a header column and sort the table on an enrollment or enrollment change measure. Click the same column header again to reverse sort direction. Data in the ranking table are available in an Excel file for all 2005-06 school districts (order here) or integrated into the 2005-06 school district boundary shapefile (order here). View the data in maps as thematic patterns. Link in other data of interest to view relationships and patterns. The map files are in a ready-to-use CommunityViewer GIS project fileset. These data are updated annually. The national scope 2006-07 enrollment data will become available in mid-2008. The data are reported by state education agencies based on data reported to them by local education agencies/school districts. Cost of Census 2010 & FY 2008 Federal Budget Continuing Resolution Issues Increasing costs to carry-out Census 2010 are almost a certainty due to the FY 2008 Federal budget continuing resolution. Following the earlier House vote, on September 27, 2007, the Senate voted voted to keep the government operating through November 16, adopting an FY 2008 continuing resolution (CR) which funds government programs at fiscal 2007 levels whose authorizations lapsed September 30. This section briefly reviews the potential impact in the context of the broader Census 2010 life cycle costs. Census 2010 stakeholders should consider communicating with elected officials and others who might assist in resolution of funding restrictions in an effort to minimize cost and maximize opportunities for the best possible Census 2010. Census 2010 Life-cycle Costs. A June 2006 U.S. Government Accountability Office study (http://www.gao.gov/cgi-bin/getrpt?GAO-06-822T), reported that the Census Bureau then estimated the 2010 Census to have a full life cycle cost of $11.3 billion even after adjusting for inflation. This estimate includes the 10-year costs for American Community Survey replacement for the census long form and the costs of Master Address File/TIGER system development and maintenance. At that time, the Census Bureau estimated that the number of housing units for the 2010 Census will increase by 10 percent over 2000 Census levels. At the same time, the average cost per housing unit for 2010 was expected to increase by approximately 29 percent from 2000 levels (from $56 per housing unit to $72 per housing unit in 2000 inflation-adjusted dollars). Census 2000 Cost Over-run Experience. The Census Bureau estimated that the Census 2000 would cost approximately $4 billion if sampling was used, and a traditional census without sampling would cost around $5 billion. The final cost for the 2000 Census (without sampling) was over $6.5 billion. Updates on Census 2010 Budget, Operation and Costs. Costs and related planning issues were addressed in the July 2007 statement by the Census Bureau director before the Senate Subcommittee on Federal Financial Management, Government Information, Federal Services, and International Security. On October 16, 2007, the Census Bureau director summarized the impact of the continuing resolution on Census 2010 operation in a statement prepared for the Subcommittee on Government Management, Organization, and Procurement (of the House Committee on Oversight and Government Reform). Census 2010 will be the first in which workers going door-to-door will use hand-held computers to collect information about the public. Census needs to buy about 500,000 of the computers, which are to be tested in a large-scale dress rehearsal scheduled for next spring. The director's statement notes the computers won't be ready unless the Census Bureau starts paying the supplier soon. He said abandoning the computers and returning to paper forms would add about $1.5 billion to the cost of the census. The director also summarized plans to scale back the dress rehearsal, and could cancel it if the budget stalemate goes beyond six weeks. The continuing resolution is also affecting the Census Bureau community partner programs. The Local Update of Census Addresses was delayed one month in the summer. The Bureau expected to provide the local address and housing count review materials in September. The first of the local review materials have not yet been distributed by Census. More Information Contact Proximity for more information about any of the topics reviewed in this section. |
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