t UNITED STATES PARTMENT OF COMMERCE PUBLICATION *1* TO 'Cq y '""•Vis o» ' DAD No. 33 (Series CG-3) August 1973 U.S. DEPARTMENT OF COMMERCE Social and Economic Statistics Administration BUREAU OF THE CENSUS \G\Q~ ** data access descriptions 1970 Census Geography: Concepts, Products, and Programs Sr 4TES Of U. S. DEPARTMENT OF COMMERCE Frederick B. Dent, Secretary Sidney L. Jones, Assistant Secretary for Economic Affairs Social and Economic Statistics Administration Edward D. Failor, Administrator BUREAU OF THE CENSUS Vincent P. Barabba, Director Robert L. Hagan, Deputy Director DATA USER SERVICES OFFICE Robert B. Voight, Chief ACKNOWLEDGMENTS Data Access Descriptions are developed in the Data User Services Office under the direction of Michae! G. Garland, Chief, Data Access and Use Laboratory. Ann D. Casey, User Information Services, is responsible for general supervision. Editorial supervision was provided by Valerie McFarland. This report was prepared by Gerald O'Donnell. Any suggestions, comments, or inquiries from users of Data Access Descriptions will be appreciated by the Bureau. Letters should be addressed to the Director, Bureau of the Census, Washington, D.C. 20233. For sale by Publications Distribution Section, Social and Economic Statistics Administration, Washington, D.C. 20233. Subscription price $5.50 for 4 to 6 issues of Data Access Descriptions (issued occasionally), along with 12 monthly issues of Small-Area Data Notes. Single copies vary in price. Price this issue 50 cents. 1970 Census Geography: Concepts, Products, and Programs o 4) o CONTENTS Page Introduction 1 1970 Census Geographic Areas 1 Geographic Reference Products 2 Census Maps 2 Geographic Code Schemes 6 Address Coding Guides 9 Geographic Base (DIME) Files .... 10 The CUE Program for GBF/DIME File Management 11 Computer Programs for Geographic Applications 12 Reference Materials 15 Acquisition of Geographic Reference Products and Computer Programs. Further Information Appendixes 16 16 17 INTRODUCTION The objective of this Data Access Description is to explain the geographic aspects of the 1970 census. Special emphasis will be given to the census geographic products which assist users in their analysis of small-area data. Geography played a crucial role in every stage of planning, enumerating, and tabulating the 1970 Census of Population and Housing. Identification of geographic areas was the basis for adminis- trative control in taking the 1970 census and processing the returned questionnaires. Census tabulations were prepared for specific geo- graphic areas-- whether the entire United States or a city block. Without the ability to assign or relate data to specific areas, the data collected from a census would be of little value other than for furnishing national totals. Statistics which present characteristics for States, counties, cities, and smaller areas make the censuses important to most data users. The geographic work for a census basically involves determining boundaries, coding geo- graphic areas, and preparing maps. However, additional geographic work was required for the 1970 census in the development of mailing lists of residential addresses for the metropolitan areas which were enumerated by mail rather than by census takers. Work relating to geography resulted in several products, such as new types of census maps, geographic code schemes, and address coding guides, which are of value to census data users as well as the Bureau of the Census. 1970 CENSUS GEOGRAPHIC AREAS In the 1970 census substantial improvements have been made in providing tabulations for small geographic areas. Although there is no precise definition of "small areas," for the purpose of this Data Access Description geographic areas at the State level and below are considered "small- areas." (Examples include standard metro- politan statistical areas (SMSA's), counties, cities, census tracts, and blocks.) Small-area census data are used by the Federal govern- ment in the development of national policies. State and local governments use small-area census data for planning and implementing many of their programs. Semipublic agencies, uni- versity faculties, and the business community also are interested in small-area census data. Boundaries of the geographic areas for which the Bureau of the Census collected and tabulated 1970 census data were established in several ways. Boundaries of political areas--States, congressional districts, counties, minor civil divisions, incorporated places, and city wards- are based on information received from the appropriate authorities. Boundaries of sta- tistical areas are determined by groups with special interests, often with the advice and as- sistance of the Bureau of the Census. For ex- ample, the Office of Management and Budget of the Executive Office of the President, with the assistance of other Federal agencies, defines standard metropolitan statistical areas. Bound- aries of functional or administrative areas are defined outside the Census Bureau by the appropriate agency, such as the ZIP code areas defined by the U.S. Postal Service. In addition, the Bureau of the Census established the boundaries of several sets of geographic areas for which it tabulated 1970 census data-- urbanized areas, census county divisions, un- incorporated places, census tracts (in cooper- ation with local census tract committees), enu- meration districts, block groups, and blocks. Census county divisions and unincorporated 1 places are defined with local assistance at several levels of government. To meet the processing and tabulation re- quirements of the 1970 census, numeric codes were used in lieu of names to identify areas for which census data were summarized. The geo- graphic codes were derived primarily from a master coding scheme prepared by the Bureau, and they appear on the 1970 census summary tapes and related geographic products. Each level in the census geographic hierarchy, from the State down to the block, has an associated code scheme, with individual codes ranging in length from one to six digits. In appendix A, definitions are presented for the key geographic areas for which 1970 census data are tabulated. The definitions specify the unique characteristics of the geographic area, the number of units of each type of area (example: 50 States, 3,141 counties), and the type of geo- graphic code used to identify the area (example: minor civil divisions are assigned a 3-digit numeric code according to their alphabetic sequence within county). Figure 1 shows how most of the geographic areas relate to each other (e.g., census tracts are subdivisions of standard metropolitan statistical areas). Data from the 1970 census have been tabulated for all of the geographic areas described in appendix A and are available in several different series of summary computer tapes and many printed reports derived from the tapes. It may be difficult for a user to determine where data for a given geographic area can be found. Figure 2 is designed to help reduce this problem by showing the geographic areas associated with each of the summary tape series and printed reports and microfilm derived from the tapes. For example, a user interested in data for census blocks can see that this information will be found on the Third Count Summary Tape and in the printed report series HC(3). General information on the summary tapes and printed reports can be found in Data Access Descrip- tions Nos. 18 and 27, respectively, which are available on request from the Data User Services Office, Bureau of the Census, Washington, D.C. 20233. GEOGRAPHIC REFERENCE PRODUCTS A number of geographic reference products have emerged from the 1970 census. These products are essential to the effective use of small-area data. For example, census maps show the boundaries of each census tract, enu- meration district, and block. Geographic code schemes are required to permit identification of census geographic areas contained on the sum- mary tapes. Address coding guides and geo- graphic base (DIME) files provide a means of relating local data to census geographic areas. (DIME is an acronym for Dual Independent Map Encoding.) Descriptions of the various geo- graphic reference products are presented below. Census Maps Census maps are necessary for virtually all uses of small-area census data; they are needed in locating specific census geographic areas and in analyzing their areal relationships. There are basically five kinds of census maps which delineate small areas: The Metropolitan Map Series, county maps, place maps, county sub- division maps, and tract outline maps. The Metropolitan Map Series (MMS) generally covers the urbanized areas of standard met- ropolitan statistical areas and shows, in great detail, the location of place and MCD/CCD boundaries, census tracts, congressional dis- tricts, enumeration districts, and blocks, and identifies the features which form the boundaries of these areas. These maps are at a common scale of 1 inch = 2,000 feet, with portions of some sheets enlarged to 1 inch = 800 feet. There are approximately 200 map sets in the series (one or more urbanized areas may be in a map set) comprising approximately 3,200 map sheets (each sheet including an area of 5 by 7 miles); the number of sheets in a set range from 2 to 144. The Metropolitan Map Series covers a total area of approximately 110,000 square miles. This coverage includes about two-thirds of the Nation's population. The series is available as part of the Block Statistics reports for urbanized areas, series HC(3) of the 1970 census reports. Each report is accompanied by a set of metropolitan maps for the urbanized area concerned. An HC(3) report for a medium- size urbanized area can be purchased for less than $5 from the Super- intendent of Documents, U.S. Government Print- ing Office, Washington, D.C. 20402. The metropolitan maps contained in the HC(3) reports use color and shading to emphasize selected boundaries. The county maps, which generally are re- productions of standard State highway depart- ment maps, show the boundaries of minor civil divisions or census county divisions, places, tracts, and enumeration districts for portions of counties not covered by the Metropolitan Map Series, as well as for all counties outside of S MSA's. It is important to note that the county maps show only a range of enumeration district (ED) numbers for places which contain more than one ED and do not identify the ED boundaries within places--place maps are used for this purpose. County maps are generally at a scale of 1 inch = 2 miles. There are usually one or two map sheets for each county except for those counties larger in area. County maps are not published in any census reports. Copies may be obtained at a price of $1 and up for each sheet from the Data User Services Office, Bureau of the Census, Washington, D.C. 20233. Place maps are available for every incor- porated and unincorporated place which was reported in the 1970 census but not included in the Metropolitan Map Series. These maps, which are usually reproductions of maps supplied to the Bureau of the Census by local agencies, identify streets and show boundaries for enumeration districts, tracts where applicable, and blocks if the place was under contract with the Bureau for preparation of block statistics. Place maps generally vary in scale from 1 inch = 400 feet to 1 inch = 1,500 feet. There is normally one map sheet for each place. Most place maps are not a part of any census report. They are sold individually by the Data User Services Office at a price of $1.50 and up per map sheet, depending upon the size of the sheet. Place maps appear in the HC(3) reports for places participat- ing in the contract block statistics program; how- ever, these maps do not show ED's. County subdivision maps of States show boundaries for counties and subdivisions of counties (minor civil divisions or census county divisions) as well as the location of all places which were recognized in the 1970 census. There is normally one map sheet for each State with the exception of a few States that have been combined on one sheet. The scale used for most of the county subdivision maps is 1 inch = 12 miles. The maps are priced at 20 cents per State and may be obtained from the U.S. Govern- ment Printing Office. Copies of the county sub- division maps on a smaller scale appear in sectionalized form in Number of Inhabitants, series PC(1)-A, of the 1970 census reports. Tract outline maps show the boundaries of census tracts, counties, and all places with populations of 25,000 or more. Names of features which constitute tract boundaries are included on these maps except for very short segments. The scale of tract outline maps varies according to the size and complexity of the SMSA and, therefore, may range from 1 inch = 1/2 mile to 1 inch = 10 miles. Generally, there are two tract outline map sheets per SMSA. These maps are included as part of the Census Tract reports for SMSA's, series PHC(l) of the 1970 census reports. Most PHC(l) re- ports cost less than $2 and are available from the U.S. Government Printing Office. In addition to the census maps already described in this section, there are two other kinds of maps published by the Bureau of the Census. These are the urbanized area maps and the United States Maps. Urbanized area maps show the extent and components of the urbanized area by means of shading. Copies of these maps, at a scale of 1 inch = 4 miles, appear in Number of Inhab- itants, series PC(1)-A, and in General Housing Characteristics, series HC(1)- A, reports, which can be obtained from the U.S. Government Printing Office. These maps can only be obtained by purchasing the reports. More detailed infor- mation on urbanized area boundaries can be found in the Metropolitan Map Series. The United States Maps (the GE-50 map series) are statistical maps which show the geographic distribution, by county, of various social and economic data from the 1970 census as well as earlier censuses. Different color schemes are used to depict values of the data; county names and boundaries are easily seen through the color. Each map is a single sheet (generally 42" x 30" in size) at an approximate scale of 1 inch = 80 miles. Copies of these maps sell for 25 to 50 cents each. An order form listing the various maps in the GE-50 series is available upon request from the Publications Distribution Section, Social and Economic Sta- tistics Administration, Washington, D.C. 20233. To facilitate map acquisition, the Bureau of the Census has compiled an inventory of the Metropolitan Map Series, county maps, and place maps. The census map inventory lists the cost and the required number of map sheets for each State, county, and place for maps maintained and sold by the Bureau. Names and the relevant geographic codes for these areas are included. The inventory covers all 50 States and the District of Columbia. By checking the census map inventory for any State, county, or place, a person can quickly determine the required map sheets and their cost. The inventory is most useful when ordering place maps and county maps containing enumeration district and other census boundary designations that are not found in any 1970 census reports. The U.S. Department of Commerce district offices and the Census Bureau and its regional Data Collection Centers have the census map inventory for the entire Nation on hand to assist users. The inventory can be purchased at a price of $2 for individual States and $75 for the complete set from the Data User Services Office. Figure 1.— Census Geographic Areas AREA STANDARD METROPOLITAN STATISTICAL AREA AND COMPONENT AREAS (central city of 50,000+ population and the surrounding metropolitan county(s)) Central City ■ Urbanized Area (shaded area) Place ■ Minor Civil Division County CENSUS TRACT (small, homogeneous, relatively permanent area; all SMSA's are entirely tracted) n~r °%zh I — 'Li v ' IOs| I06 I - ." * „,„„■ ;,-' ■.*+««! 113 111 ,„ .' M* ,,,,', . , * '!' J- ... ,'.". 1 £.2'. '": ' ': — •_ 71 ». .. j ■ '■' I X H" i ■ ■! ■H ii H POPULATION SIZE At least 50,000 Average 4,000 BLOCK GROUP OR ENUMERATION DISTRICT (subdivisions of census tracts, places, and minor civil divisions) BLOCK (identified in all urbanized areas and some selected areas) 301 10 302 PINE 305 ST. 306 Q 2 CN 307 PINE 303 1- tsi 304 308 O UJ 317 _J i O O 316 SPR H (/) 313" UCE 309 ST 312 315 314 311 310 Average 1,000 Average 100 ts 3 "O O i_ Q. CO 4-* CO Q 3 CO CO 0> Q. CO o 0) CsJ 3 CM < X CJ X 3 O Q U K X c_) s. ■ > E S K X X E & 3 "* n _, o X X 3 O s JZ ft X X X X X D. 2 | O X * X X * o X 3 o CJ LL. ~ x X X XX ^ u a. s 6 g. < u u CJ 3 *"" ^ „ CJ X S X -o h- | Q. E 2 X "£. to -_ CJ X X X a. < £ 3 X X X X X CJ o X ^ o CO ft x * X X XX CJ a. > E 9- < ca ca ca ca ca co ca CC E 2 co -^ > y. X X X CJ X < ^ y X X CJ 3 Q_ o u " ■3 X X X X X X * * is ^ i 0. < ca Of pa a ca ca CO to Li w « c O w X >> c S u c co >. >> d a u O -H r-i c h -H > c C *H < L> tt — ^H C £ co ■H -O a CO 'J > c h a t V3 ■a ■-« c . -H >> a c CO Q. tf ■O -M a h Of c *j c 0" fc d c t — 3 ib u a CJ A A A =) a -O *■ ■O C CO 0) d C a U T- U V N CO "O U r- 3 CO ca a X +. a 1- c V J O £ : s- m 1 0) Of c c ■O +■ c u & c CJ c d = C CC a bC c e a ca a 3 a c d +. £1 E c c a C C a --H CJ C u c 4-> 1/ O a M t. a 5 a a. a. L 5 CA 3 O u Cs CO -P O A rt o o u o i-H t« •h a «H C ■ u 1 -M o d jo -a : U C o « 1 a > > o d . ; co -c cq O -D nH C x> o d o >, o - J3 - CO •o -H t. -H u a -h +j - 01 3 iH d O -M C -H «M D. d CU •H ■*-> U ^H E d d o -w D. *j f-t £ > d - c 3 -w d x: -o o o o. m jn 4J cy t-t a o co >. d d 4J 3 t. O u a CU £ ■*-* CI at j; -. p-< •p^-. Users who submit frequent census map orders or copy and distribute large quantities of these maps will find the inventory to be of value. Geographic Code Schemes All geographic areas are identified on the 1970 census computer tapes only by their numeric codes--names are not used. Users, therefore, require some form of a geographic code scheme to associate the codes for geographic areas with their area names. Codes and the corresponding names for census geographic areas are contained in the following Census Bureau products: The Master Enumeration District List (MEDList), the Geographic Area Code Index (GACI), and the Geographic Identification Code Scheme (GICS). The Master Enumeration District List , or MEDList, is a listing of the names of political and statistical subdivisions and related geo- graphic codes from the State down to the county subdivision and place level. It also provides codes for unnamed areas below the county sub- division level — tracts, enumeration districts (ED's), and block groups--as well as population and housing total counts for most areas. (See figure 3 for an example of the MEDList.) The MEDList is designed to serve two basic purposes: (1) Furnish area and place names corresponding to the geographic codes which are used on the 1970 census summary tapes and (2) provide official population and housing unit counts for enumeration districts, block groups, and other areas. A special version of the MEDList containing the latitude and longitude coordinates for the estimated population center points for each of 242,000 enumeration districts and block groups has also been prepared by the Bureau of the Census. The center points, or centroids, were visually estimated from census maps. Co- ordinate values were then assigned to the points by an electronic digitizer. The coordinates are expressed in decimal degrees carried to four places. The MEDList without coordinates is available for the United States on three reels of tape for $210; the MEDList with coordinates is sold on aState-by-Statebasis (one tape reel for each State) at a cost of $70 per reel. Both products are available from the Data User Services Office, Bureau of the Census. not appear. The GACI is useful for persons not requiring all of the information included in the MEDList. The GACI for the entire United States is available from the Data User Services Office on one reel of tape for $70 or on one reel of microfilm for $8. The 1970 Geographic Identification Code Scheme (GICS) is a four-volume guide to the geographic codes for the component parts (county subdivision and larger areas) of each State. Each volume reports on a different region of the country (Northeast, North Central, South, and West). The information published in the GICS is also available from the MEDList and GACI computer tapes. For each State within a region the GICS presents two tables. Table 1, arranged by counties within the State, shows the following codes, as appropriate, for counties, county sub- divisions, and places: State, county, SMSA, MCD or CCD, place, place description, and place size. Table 2 presents alphabetically all the places within the State with their corresponding county, county subdivision, and place codes. A third table, shown once for each volume, presents SMSA and urbanized area codes for the entire United States. (See figure 4 for illustration of tables.) Copies of the GICS may be purchased from the U.S. Government Printing Office for the following prices: Northeast, $1; North Central, $1.75; South, $1.50; and West, 60 cents. Some of the codes included in the MEDList, GACI, and GICS are codes that have been standardized for use by all Federal agencies in the exchange of computer- readable information. The Federal standard codes in the Bureau products noted above include State, SMSA, county, and congressional district. (The Bureau of the Census includes this last code only in the MEDList). These codes are published by the National Bureau of Standards, U.S. Department of Commerce, in a series known as the Federal Information Processing Standards Publications (FIPS PUB) and are sold by the U.S. Govern- ment Printing Office. The titles and prices for these reports are: FIPS PUB 5-1 State Codes 20 cents FIPS PUB 6-1 County Codes 45 cents FIPS PUB 8-2 SMSA Codes 30 cents FIPS PUB 9 Congressional District Codes 10 cents An abbreviated version of the MEDList, called the Geographic Area Code Index (GACI), is a source of names and related geographic codes for States, counties, places, and county sub- divisions (MCD's/CCD's). No area smaller than the county subdivision and place is referenced in the GACI. Population and housing unit counts do For some users, the FIPS PUB series might be more suitable as a source of geographic codes than the Census Bureau's geographic code schemes, especially if a user is interested in only one set of codes (such as codes for all counties in the Nation) rather than several sets of codes for each State and its component parts (SMSA, minor civil division, and place). o n CM rH rH oo oo in in oo o o •" o o m o «— 0) O O O r- r> oo f» rH CO 01 CM in CO CM rH 8 c/> •dod en Csj eft rH 00 CO CM rH in m oo CM CM rH in rH C7> rH rH rH tD CO T-1 6 cz w " ■"j- o rH CJ E rH O O O CO CO o CM rH rH o o CM o m T CO m m o CO CO o rH CM oo co tt r- to to rH «3 cr> 8uisnoH QO 00 ID CM ^J" CD CD CM CO rH in ih cm LJ- 01 'jsip '8uoq — 01 01 oi Ol Ol Ol ai Ol 01 Ol 01 Csl O O o O O 0,00000 PJBM Osl lejni/'qjfi in Csl r-i rH o o o rH rH rH rH O O a xmns Csj CM CO rr in to r» apoo CO Csj O O O O o o rl* tj* tj* ^ O O O O •dj8 "MIS Csj Csl rH CM CO r-< CM u xijjns CSJ Ol Ol CM O > >> ' — -* •P P ss •H -H bo S (0 u u £ 2 - — - CO rH > 4> 4) (A V) es « i-\ cd X 0) -P ■H aao CO rH rH i-h rH rH rH rH rH rH rH rH dS3 § O O m in o o o in o O in O V3S UD ID CO to to — ' o o o o CM CM CM CM 03 apoo UT> ID (0 O O ID O to o "f= CO CO CO co =3 XIJ3Jd s lH T-i rH rH O O O O E3JE papeii CM CM CM CM CO CO in in CO in CO in eaje paziueqjfi Csj O CM CO in ^, o o o O VSWS ^J CM CM CM CM ' CO CO m m CO in CO m V3S s u CO 3ZIS CM o to o 'DS3Q CO * r» * r» m m 3P0Q •— CM CM CO CM 033, 03W 1> o o 01 Ol Ol O O O m m O) o o o O 333 u-> rH rH rH rH rH r-t H •qej jo AiunoQ 5 AjunoQ ro f-H •-< rH ^ rH rH . 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F O rH tjuh a c D -— o o ft. ■- !h o a> *~~^ p W T3 Q 0) o s 4) •• o o p M ^' T3 CO S >> "- 1 -p p G CO CO •H c o -o P 3 -n C CO O 01 rt • * •H O -H +-> CJ > > CO - 0> rH -H Sh CO Q •- CJ ■a u -^ xi -p >, < CO co c -P o 11 new 4 O 3 — bO C •- O to rH •H C 0) CO no Ih (J Tl 01 Si CO CO T3 > rH C 4> •H 3 4) P c C XI O CO 3 E CO \ T3 3 E-i '"^ -H rH Q H , H c CO •- -H CO C >, Q P rH to P CO CO rH C CJ O, 3 rH •- •rl X -H C *J W U > 00 •H -H •rH •a o p p •• h a CO 41 CO -H •P p -o U U co c o o Z CO c to c P -H 4> CO S Q a ■>-> 8 Figure 4.— Illustrations of 1970 Geographic Identification Code Scheme (GICS) Tables TABLE 1 COUNTIES, COUNTY SUBDIVISIONS AND PLACES UTAH GEOGRAPHIC COOES NAME GEOGRAPHIC CODES NAME y £ " s o ~ z < Q S ij u " z < ™ 1", < s 1* < *-* 1 A S o S 5> < LJ <\ •*, 1 ""' ~ «/> °- °- a - 49 001 113 03 BEAVER 49 49 013 013 113 113 03 0.1 010 015 0185 4 03 DUCHESNE MYTON DIV 49 001 113 03 005 BEAVER DIV 49 013 113 03 015 0645 4 01 MYTON 49 001 113 03 005 0050 4 03 BEAVER 49 013 113 03 020 ROOSEVELT DIV 49 001 113 03 010 MILFORD-MINERSVILLE DIV 49 013 113 03 020 0840 4 OS ROOSEVELT (PART) 49 001 113 03 010 0590 4 03 MILFORD 49 013 113 03 025 TABIONA DIV 49 001 113 03 010 0600 4 01 MINERSVILLE 49 013 113 03 025 0985 4 00 TABI0NA 49 003 112 01 BOX ELDER 49 015 113 03 EMERY 49 003 112 01 005 BEAR RIVER DIV 49 015 113 03 005 CASTLE DALE-HUNTINGTON DIV 49 003 112 01 005 0045 4 01 BEAR RIVER 49 015 113 03 005 0090 4 0? CASTLE DALE 49 003 112 01 005 0160 4 01 CORINNE 49 015 113 03 005 0140 4 01 CLEVELAND 49 003 112 01 005 0210 4 01 ELWOOD 49 015 113 03 005 0200 4 Ofl ELMO 49 003 112 01 005 0260 4 01 FIELDING 49 015 113 03 005 0360 4 00 HIAWATHA (PART) 49 003 112 01 005 0295 4 03 GARLAND 49 015 113 03 005 0385 4 02 HUNTINGTON 49 003 112 01 005 1005 4 06 TREMONTON 49 015 113 03 005 0710 4 02 ORANGEVILLE- 49 003 112 01 010 BENCHLAND DIV 49 015 113 0.1 010 EMERY-FERRON DIV 49 003 112 01 010 0175 4 01 DEWEYVILLE 49 015 113 03 010 0215 4 01 EMERY 49 003 112 01 010 0375 4 02 HONEYVILLE 49 015 113 03 010 0255 4 02 FERRON 49 003 112 01 015 BRIGHAM CITY DIV 49 015 113 03 015 GREEN RIVER DIV 112 01 015 0080 4 0B __aRLGH£M_CITY 1 -0_L5j 113 03 015 0325 4 03 GREEN RIVER (PART) ~ , ■ TABLE 2. ALPHABETIC LIST OF PLACE NAMES UTAH GEOGRAPHIC CODES NAME GEOGRAPHIC CODES NAME COUNTY MCD PLACE COUNTY MCD PLACE 049 006 0005 ALPINE 053 015 0410 IVINS 013 005 0010 ALTAM0NT 041 010 0415 JOSEPH 025 010 0015 ALTON 031 005 0420 JUNCTION 005 020 0020 AMALGA 043 010 0425 KAMAS 049 006 0025 AMERICAN FORK 025 005 0430 KANAB 041 015 0030 ANNA6ELLA 021 010 0435 KANARRAVILLE 017 020 0035 ANTIMONY 027 010 0440 KANOSH 041 020 0040 AURORA on 005 0445 KAYSVILLE 003 005 0045 BEAR RIVER 035 035 0450 KEARNS (U) 001 005 0050 BEAVER 031 005 0460 KINGSTON 055 010 0055 BICK NELL 041 005 0465 KOOSHAREM 035 005 0060 BINGHAM CANYON 033 005 0470 LAKETOWN 037 005 0065 BLANDING 053 010 0475 LA VERKIN 017 005 0072 BOULDER on 005 0480 LAYTON on 010 0075 BOUNTIFUL 027 005 0485 LEAMINGTON 003 015 0080 BRIGHAM CITY 053 010 0490 LEEDS 017 020 0085 CANNONVILLE 049 015 0495 LEHI 015 005 0090 CASTLE DALE 023 010 0500 LEVAN 007 005 _DinJ 0095 • CASTLE GATE 005 ' 010 __!)06_ 0505 JJ5iflJ LEWISTON oaj J — -^ ^ ~- __ — — TABLE 3 STANDARD METROPOLITAN STATISTICAL AREAS AND URBANIZED AREAS GEOGRAPHIC CODES NAME GEOGRAPHIC CODES NAME SMSA UA SMSA UA 0040 0080 0120 0160 0200 0240 0280 0320 0360 0400 0440 0460 0480 0520 0560 0600 0040 0080 0120 0160 0200 0240 0280 0320 0400 0440 0459 0480 0520 0560 0600 _ 0620 ABILENE TEX AKRON. OHIO ALBANY GA ALBANYSCHENECTADYTROY.N.Y ALBUQUERQUE. N MEX ALLENTOWN-BETHLEHEM-EASTONPA-N J ALTOONA.PA AMARILLO.TEX ANAHEIM SANTA ANA GARDEN GROVE. CALIF ANDERSON. IND ANN ARBOR MICH APPIETON.WIS APPLETON-OSHKOSH.WIS ASHEVILLE.N C ATLANTA. GA ATLANTIC CITY N J AUGUSTA.GASC AURORA. ILL . AJJSTINJEJL__ __ J 2920 2960 3000 3040 3080 3120 3160 3200 3240 3280 3320 3360 3400 3440 •uao 3000 3040 3080 3119 3160 3199 3230 3240 3280 3300 3320 3360 3400 3440 3480 GALVESTON-TEXAS CITY.TEX. GARY-HAMMONO-EAST CHICAGO. IND. GRAND RAPIOS.MICH GREAT FALLS.MONT. GREEN BAY, WIS GREENSBORO. NC GREENSBORO-WINSTON-SALEM-HIGH POINT, NC. GREENVILLE.SC HAMILTON. OHIO HAMILTON-MIDDLETOWN.OHIO HARLINGEN-SAN BENITO.TEX. HARRISBURG.PA HARTFORD. CONN. HIGH POINT. NC HONOLULU. HAWAII H0UST0N.TEX HUNTINGTON-ASHLAND. W VA.-KY -OHIO HUNTSVILLE.ALA INDIANAPQl"" L Address Coding Guides Figure 5.— Typical Block Faces In conducting the 1970 Census of Population and Housing, two different enumeration methods were used: the mail-out/mail-back type of canvass, taken primarily in the large urban areas of the country, and the conventional house- to-house visit by enumerators in the remainder of the country. In 145 of the then 233 standard metropolitan statistical areas and in certain adjoining areas the mail-out/mail-back procedure was used. Approximately 60 percent of the Nation's popu- lation were canvassed by mail rather than by an enumerator's visit. Householders were asked to complete the census questionnaire in the privacy of their own home and mail it back to a local Census Bureau office. The remainder of the country was enumerated by the conventional house-to-house canvassing procedure which closely resembled enumeration methods of the 1960 and earlier censuses. Census takers visited every housing unit in their assigned ED's and obtained the required information asked on the questionnaires. Census geographic codes for each household were determined and coded on the questionnaire by the enumerator. In the 145 SMSA's in which the mail-out/mail- back technique was used, a method of assigning specific census geographic codes to a mailing list address was needed. The solution decided upon called for the development of a master computer file for each area which would contain the information necessary to "geocode" the addresses. The file developed for this purpose was named the Address Coding Guide (ACG). The ACG, in essence, performed one of the functions of an enumerator by providing the "census geography" of each address. Address Coding Guides are simply computer listings which contain block face records for all streets within the city postal delivery area (which roughly corresponds to the urbanized area) of an SMSA. A block face is one side of a street between two intersections; a block face for a dead-end street is one side of a street from its beginning intersection to the dead end. Other features such as municipal boundaries, rivers, and railroad tracks are not included since there were no housing addresses for units associated with them. Figure 5 illustrates some typical block faces. Each ACG record identifies a single block face by street name, a range of addresses, the block number, and tract, place, and other geographic codes. Census data users have found the Address Coding Guide valuable as a reference source for LARMON ST. BF- MAINST. BF = block face assigning census geographic codes to local records containing addresses. This geographic coding can be performed by using an address matching program (such as the Census Bureau's ADMATCH program described on page 12) which matches individual addresses contained in local record files to address ranges in the ACG. Once a local record has been linked to its appropriate ACG record, all desired census geographic codes are then assigned to the local record file. (This operation represents computerization of the manual process of looking up geographic codes in a printed street index and posting appropriate codes to records, application forms, etc.) For example, crime incidence records may be coded to census tracts, which would permit a cor- relation study between crime and census socio- economic data for tracts. The ADMATCH pro- gram would match each individual address of crime occurrence to the appropriate address range in the ACG and, upon a match, assign the desired census tract code contained in the ACG to the crime incidence record. The ACG can be used in the assignment of codes other than census geographic codes. If local areas (i.e., police precincts, planning districts, neighborhoods) are defined in terms of blocks and/or tracts, codes for these local areas can be added to the ACG. (The addition of any local area codes to the ACG is the responsibility of local users.) The ADMATCH program will assign the local area codes to records containing addresses in the same manner that it assigns census geographic codes. Address Coding Guides are available on computer tape (IBM- compatible format) at $70 per tape reel from the Data User Services Office, Bureau of the Census. Most areas covered by the ACG are on one or two reels. The ACG's are also available as computer printed listings 10 on 11- by 14-inch paper. No pricing has been established for the printout version; however, the cost is normally two to three times that for tape versions. Geographic Base (DIME) Files After preparation of the Address Coding Guides was well underway (and the 1970 census date was too near to permit a change in the system), an improved version of the ACG was developed. The improved ACG, which is known as a geographic base file, was developed by the Census Use Study (a small area data research group in the Census Bureau) using a technique called Dual Independent Map Encoding or DIME. The geographic base (DIME) file, commonly referred to as GBF/DIME, is characterized by: (1) An editing capability which improves the accuracy of the files and (2) an increased utility to local users as a result of added features. The concept underlying the creation of the GBF/DIME files is derived from graph theory. Each street, river, railroad tract, municipal boundary, etc., that bounds a census block can be considered as one or more straight line segments; curved streets or other features can be divided into series of straight line segments. Where streets or other features intersect or change direction, node points are identified. Figure 6 illustrates street segments and nodes. While an Address CodingGuide is constructed on a block face basis, a GBF/DIME file is con- structed on a street segment basis. Therefore, while each ACG record contains the appropriate census geographic codes for one side of a street between two intersections, each GBF/DIME segment record contains the appropriate codes for both sides of a street between two nodes. By uniquely identifying each segment (including segments that are not along streets) and each node point, and their geographic relationships, a geographic description which can be checked bv computer for accuracy is made possible. The GBF/DIME concept also serves a further and equally important function. By digitizing the node points (that is, assigning x-y coordinates), graphic outputs either in the form of geographic data displays or map images can be produced by applying computer mapping techniques. The construction of a GBF/DIME file involves the transcription by local agencies of geographic information (i.e., street patterns, address ranges, area identifiers) from metropolitan maps and other sources into a form that can be read and manipulated by computer. Clerks enter the various types of geographic information o n Figure 6.— Street Segments and Nodes NODES worksheets which are then keypunched and entered into the computer. After the computer editing, appropriate correction, and insertion of coordinates, the GBF/DIME file is ready for use. Essentially the same information is contained in both the ACG and GBF/DIME files: Street name, address ranges, block numbers, tract, place, and other geographic codes. The GBF/ DIME file has three additional codes: (1) The left-right orientation code separating the census geographic codes for areas on each side of the street segment, (2) the identification numbers of the node points at each end of the segment, and (3) the x-y coordinates of each node point ex- pressed in State plane coordinates (measured in feet relative to the State plane grid system), latitude and longitude (measured in degrees and ten-thousandths of a degree based on distance from the equator), and map set miles (measured in miles and thousandths of a mile from an arbitrary point at the southwest corner of the Metropolitan Map Series sheets.) The GBF/ DIME file also contains block boundaries that do not follow streets; these are not contained in the ACG's. (See figure 7 for an example of a GBF/DIME file record.) Originally, GBF/DIME files were created for 79 of the 88 nonmail SMSA's for use in assigning tract and block numbers to the work- place responses from the place of work question on the 1970 census questionnaire. The Census Bureau and other Federal and local agencies recognized that it would be desirable to add the GBF/DIME features to the already existing ACG's. Each of the 145 SMSA's included in the original ACG program was contacted and invited to participate in the development of a GBF/DIME file; 115 SMSA's agreed to do so. In total, 194 SMSA's (plus part of the San Juan, Puerto Rico 11 SMSA and the new SMS A of Appleton-Oshkosh, Wis.) participated in the Census Bureau program to develop such files. Of the remaining S MSA's, 32 participated only in the original ACG program and six did not participate in either the ACG or GBF/DIME programs. (See appendix B for a list of SMSA's by their ACG or GBF/DIME status.) In addition to the geocoding capability de- scribed for the ACG's, there are other uses for the GBF/DIME files, as the following examples demonstrate. (1) Since a GBF/DIME file as- sociates coordinates with computerized geo- graphic records, it provides one of the essential elements for computer mapping. Regardless of the computer mapping system being used, spatial identifiers such as the coordinates found in the file are required. (2) A GBF/DIME file can be used in street network analysis. Street networks of varying degrees of detail are required for computerized study and design of routes for garbage trucks, ambulances, and other service vehicles. (3) Computer programs that are designed to allocate resources to facilities can also take advantage of a GBF/DIME file. For example, the file can be used in allocating people to community fallout shelters or children to schools, determining logical service areas for community health facilities, and evaluating al- ternative sites for new retail outlets. The GBF/DIME files are available on com- puter tape (IBM- compatible format) at $70 per tape reel, with most areas on one or two reels. These tape reels can be purchased from the Data User Services Office, Bureau of the Census. Printed listings of the files can also be obtained on a cost reimbursable basis--the cost is normally two to three times that for tape versions. The CUE Program for GBF/DIME File Management The GBF/DIME files contain a large amount of geographic information. Unfortunately, they Figure 7.— GBF/DIME File Record For each street segment A GBF/DIME record contains ^ Street Name Street Type Lt Addresses Rt Addresses Left Block Left Tract Right Block Right Tract Low Node X-Y coordinate High Node X-Y coordinate A MAIN ST 101-199 100-198 138 9 131 9 123 155000 232000 124 156000 234000 12 have some errors in them and like the associated source maps (Metropolitan Map Series) from which the files were constructed, they are becoming out of date. Both of these products reflect local urban geography as it existed immediately prior to the 1970 census. To be of most use to local agencies and the Census Bureau, the files and appropriate maps must be updated as well as corrected. To accomplish this, the Bureau has established the CUE pro- gram, referring to the Correction, Update, and Extension of the GBF/DIME file. The purposes of the CUE program are as follows: All of these computer programs are avail- able from the Data User Services Office, Bureau of the Census, Washington, D.C. 20233. Unless otherwise stated, the pro- grams are sold on computer tape for $70. DIME (Dual Independent Map Encoding). -- DIME is a computer program package designed to aid local users in the creation of GBF/DIME files for nonmetropolitan cities. The package consists of a clerical procedures manual and a set of computer programs for file creation. 1. To make corrections as necessary to produce a complete and accurate GBF/DIME file and Metropolitan Map Series (MMS) for the SMSA's having an existing file. 2. To extend the GBF/DIME files and MMS to cover the entire SMSA. (At present only the urban core of SMSA's are covered.) 3. To establish GBF/DIME files and MMS for those SMSA's where GBF/ DIME files and MMS do not cur- rently exist. 4. To develop procedures by which each SMSA can systematically main- tain current and accurate GBF/ DIME files and MMS series. Parts of the CUE program are now operational and many local agencies are beginning to cor- rect and update their GBF/DIME files using computer programs developed by the Census Bureau. (See p. 14 for descriptions of the FIXDIME and UPDIME computer programs.) Further information on the CUE program can be obtained from the Geography Division, Bureau of the Census, Washington, D.C. 20233. COMPUTER PROGRAMS FOR GEOGRAPHIC APPLICATIONS In addition to the 1970 census geographic reference materials previously described, a number of computer programs for geographic applications, most of which pertain to effective use of the geographic base (DIME) files, are available from the Bureau of the Census. Descriptions of these computer programs are presented in this section. Figure 8 shows the relationship between many of these programs. The FIXDIME and UPDIME programs are not shown in figure 8 because they represent a different stage of application. The manual supplies complete information on the clerical coding operation including personnel and space requirements, materials, training and supervising of coders, coding procedures, and problem resolutions. The set of computer pro- grams converts the coded data to a master file for machine use, validates the completeness and accuracy of the clerical work, modifies the master file to correct errors and omissions, and inserts coordinates into the file. The programs are written in ANSI standard FORTRAN IV for users of almost any computer system with a minimum core storage of 100K bytes. ADMATCH (Address Matching ) . - - ADM ATCH is a package of computer programs and docu- mentation designed to assist in the assignment of geographic codes to computerized data records containing street addresses. Geographic codes for areas such as census tracts and blocks can be readily assigned to records in local data files using ADMATCH. ADMATCH compares the individual street addresses of local data files to the address ranges in the ACG or GBF/DIME records and upon a match, attaches the desired geographic codes contained in these files to the local data records. Local data records on crime incidents, school dropouts, new construction, or other matters can then be aggregated to census geographic areas for study in relation to the census data available for these areas. Users need not be restricted to studying only census geographic areas. By creating equiv- alency tables that relate census tracts or blocks to local areas such as health districts, traffic zones, and school districts, the codes for these local areas can be added to an ACG or GBF/ DIME file. Then ADMATCH can be used to assign these local area codes to records in local files in the same manner that it assigns census geo- graphic codes. 13 Figure 8.— Relationship of Computer-Programs for Geographic Applications Split segment records into block face records and strip out nonstreet records NICKLE or T-GUIDE Program Derived Area* Boundaries & Coordinates *Tracts, ED's, blocks and local areas Alternate approach for areas that do not have aGBF/DIME file Tabulation Programs Mapping Programs (GRIDS, C-MAP) 14 The ADMATCH program package is written in IBM System/360 Assembler Language. Separate versions are available for use under 16K Disk or Tape Operating Systems (DOS or TOS) and under the Operating System (OS). The minimum core storage requirement is 32K bytes, and a line printer and three magnetic tape or disk units are needed. NICKLE .--The NICKLE program is designed to split the street segment records of the GBF/ DIME file into block face records. (To use ADMATCH or any other type of computer matching program, individual block face records rather than street segment records are re- quired.) The program reads the GBF/DIME file, drops the nonstreet records, and then splits the segment records, thus creating a record for each side of the street (block face) much like records in the Address Coding Guide. The block face records may then be used for input to the ADMATCH program. NICKLE is written for the IBM 360/40 (DOS) in COBOL. A program listing and record layout for the resulting NICKLE file can be obtained at no cost. T-GUIDE. --The T-GUIDE program was de- veloped to produce a street index at the census tract level from a GBF/DIME file. The index produced from applying T-GUIDE consists of all streets within each census tract included in the GBF/DIME file, indicating low and high address ranges for each side of the street. The program reads the file, drops all nonstreet records (such as railroad tracts, streams, etc.), splits the street segment records, thus creating a record for each side of the block, and then collapses the address ranges of the block side record along the length of the street within each census tract. This results in an approximate 60-percent reduction in the size of the GBF/DIME files and thereby allows for manual, as well as speedier mechanical, geocoding of census tracts to local data records. The T-GUIDE program is written for the IBM 360/40 (DOS) in COBOL. A program listing and record layout for the resulting T-GUIDE file can be obtained at no cost. new records. All items in the files, with the exception of coordinate values, may be corrected. The FIXDIME program is written in COBOL Level D for the IBM 360 system under DOS. UPDIME .--Qnce the GBF/DIME files have been corrected using FIXDIME, the updating process of the CUE program can begin. As with the correction process, updating the files can only be carried out by the local agencies. To assist the local agencies in this effort, the Bureau has prepared a FORTRAN IV program called UPDIME. UPDIME makes possible the addition of new street segments to the file as well as the x-y coordinates for the new segments. It also contains a block chaining edit which detects the structural defects (e.g., missing street seg- ments) in the GBF/DIME file. The UPDIME program is expected to be available in mid- 1974. GRIDS .- -The Grid Related Information Display System (GRIDS) is a generalized com- puter graphics system capable of performing a wide variety of mapping tasks. It produces density, shading, and value maps within a grid pattern. A routine supplied with the system allows GBF/DIME file street networks to be printed displaying segments, city and census tract boundaries, and nodes. GRIDS is written in ASA Basic FORTRAN IV and will run on any computer system with a suitable FORTRAN compiler and sufficient storage, regardless of computer word size or operating system. GRIDS will operate on a machine as small as an IBM System/360 Model 30 computer with 32K bytes of storage. C ~_ MAP ( Cn P£°P leth Mapping) . --C-MAP is a simplified FORTRAN computer mapping pro- gram distributed by the Census Bureau to users who have small computers. Data for geographic areas (i.e., States, counties, census tracts) are printed on the map according to a classification of their statistical values. The user specifies the number and limits of the statistical classes and their perspective printer characters. Shading is achieved by overprinting two or more printer characters. (See figure 9 for a sample choropleth map.) FIXDIME . --The FIXDIME program was de- veloped in conjunction with the Bureau's CUE program. FIXDIME enables local agencies to perform correction operations upon GBF/DIME files. The program deletes erroneous records, makes corrections in existing records, and adds Punchcards are presently the input medium; however, the program can be modified for com- puter tape or disk input. A program listing and the procedures for preparing the necessary punchcards for the input process are available at no cost. 15 0069996969*888(1 UG0l9bbbob9BB UUGUIJCGBdbBBbbb OUOGGUt OBdbBbBBi GUUUOUOCOObBdBBB ■ 000GIGCOOB 888888 laitilJlk oaaaaaaaaaaaaj 8*8*8888 BB«88xXX> lluuxm xxxxxxxxx xxxx XX XX X. .. .0 CLASSIF 1CATI0N 0. 100GC. 00 xxx xxx 2500C. 00 COG uuo 50000 00 B68 ob8 100000, 00 ■ ■1 ■ ■1 2 50000. 00 Figure 9.— Sample Choropleth Map 11110000 MMijoQoooooeeeaes MiM ****** )0999HB-iHBB89 ■■■■■■■■■■uoouoHbeBe^ueeHeo liantJtl Jl -■--- - i* iii mum iid-UHhHHHHMH,!', lOGOBBaBBOGGOGOGOUGOOGOuJL'OCOGUOOOOOOGUOOO I' it C.iOBBOJOGOOOOO DOOJ0UO0OOOG0OO00O0GUOOO0 3GuUCGOGUGUGoUU!JU30G30UOOOOOOuiH];)G KjU 00000 GOJOUGGOOOUOOOUOXXXXXXXXXXUOOGGOOOOOOOOOOO xuouuuuao loaoooiixxxxxxxxxxoooouoooacouooeie C00UGOOG0OO0G)G00XXXXXXXXXX0O0r>000UU0B6898 DOC OLGJUilJOOOOUJOX AXXXXXXXxOUOOUOOXXXXXXHB XL)L(0OGO0U0L)00O0OUHxmHi0Gl)GO']OC