Use of Geographic Information Systems to Explore and Communicate Transportation and Land Use Relationships in Iowa

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1 Ue of Geographic Information Sytem to Explore and Communicate Tranportation and Land Ue Relationhip in Iowa David J. Plazak, Tranportation Policy Analyt Mark B. elon, Tranportation Specialit Tim R. Strau, Tranportation Specialit Dawn K. Robert, Graduate Reearch Aitant Center for Tranportation Reearch and Education, Iowa State Univerity, 2625 orth Loop Drive, Suite 2100, Ame, IA Summary Urban prawl and prime farmland converion are important public policy concern in the tate of Iowa at preent. In 1997, the Iowa General Aembly convened an Interim Study Committee to make recommendation regarding potential legilative and tate agency initiative to addre land ue and prawl iue. The Iowa Department of Tranportation (Iowa DOT) i a major haper of urban growth due to it ability to invet or not invet million of dollar in roadway infratructure. The Center for Tranportation Reearch and Education (CTRE) at Iowa State Univerity ha been conducting a public policy reearch and education project on tranportation and land ue on behalf of the Iowa DOT and organization it partner with, for intance metropolitan tranportation organization (MPOS) and regional planning commiion (RPCS). The intent of thi project i to provide the Iowa Tranportation Commiion, the DOT taff, and their partner agencie with a more complete undertanding of their impact on land ue and farmland converion. CTRE i utilizing ArcView 3.1 geographic information ytem oftware to integrate a variety of econdary patial data ource and viualize pat and likely future tranportation and land ue trend around the tate. Particular emphai i being given to thoe countie included in and adjacent to Iowa eight metropolitan area. Topic that are being tudied uing GIS include: Pat trend ( 1980 and 1990) in term of demographic, houing, retailing, manufacturing and indutrial development, agriculture, land ue, chool enrollment, and tranportation ytem ue and development. Key economic relationhip among variable, for example the tradeoff between houing rent and value and commuting ditance. Pat cropland lo to urbanization and it relationhip to improvement to the tranportation network. Likely future cropland loe given demographic, economic, and tranportation trend and forecat. CTRE i uing a wide variety of econdary data ource in thi project; many ueful data ource are in the public domain. Key data ource being ued include: Federal agency data uch a Cenu data, County Buine Pattern, Bureau of Economic Analyi (BEA) economic forecat, and US department of Agriculture (USDA) agricultural production data. State agency data, uch a property tax aement data, houing permit data, chool enrollment data, and land ue claification from everal point in time originally collected to ae wildlife habitat.

2 Tranportation activity, ytem characteritic, and ytem invetment data. The Iowa DOT maintain a large tranportation management information ytem, much of which can be depicted in a GIS. Proprietary data ource uch a Wood and Poole population and employment forecat and buine and indutrial directorie. Local government property taxation and parcel record are alo available for ue in ome countie. A key outcome of thi project will be more informed deciion regarding the land ue and prawl implication of major tranportation invetment on the part of [be Iowa Tranportation Commiion, the Iowa DOT management and taff, tranportation planning organization, and other. The Public Policy Iue In ovember 1998, the Iowa Legilature Commiion on Urban Planning, Growth Management of Citie and Protection of Farmland iued a report and a propoal for legilation deigned to overhaul land ue planning in the tate. The Commiion wa etablihed during 1997 to: Study iue relating to land ue and planning, and particularly policie and trend which affect development, including but not limited to iue involving the tatu of farmland and the converion of farmland into reidential, commercial, or indutrial ue; aociated problem facing citie; the effectivene of local planning and zoning law; and a review of model legilation and tudie in tate which have undertaken reform effort and have effective land ue policie. Throughout the Urban Planning Commiion report development proce, concern were expreed about the critical role tranportation invetment play in haping urban growth, urban prawl, and farmland converion. Several public participant expreed the opinion that the Iowa DOT need to take the potential land ue impact of it project into account more and that the DOT hould become more involved in local and metropolitan land ue planning activitie. The Iowa Tranportation Commiion ha recognized that land ue will be an important policy iue for the agency during the next decade. In May, 1998, the Commiion held a workhop on tranportation and land ue that involved not only the Commiion, but land developer, realtor, regional planner, zoning official, farming, and environmental conervation group. The main concluion of thi workhop were that there i a need for better undertanding of the land development proce and land ue in general by tranportation official and planner and that communication between tranportation agencie and land ue planning agencie need to be improved. Reearch and Education Project Overview The Center for Tranportation Reearch and Education (CTRE) at Iowa State Univerity wa contracted to develop an educational program for the Iowa Tranportation Commiion, Iowa Department of Tranportation taff, and metropolitan and regional tranportation planner on the role tranportation invetment play in haping land ue pattern in Iowa. Thi project i being conducted in cooperation with a complementary project managed by the Public Policy Center at the Univerity of Iowa that i reearching pat impact on land ue pattern of tranportation invetment in Iowa. Introduction to GIS A geographic information ytem (GIS) i an information ytem that procee patial data. Spatial data are any data that have ome tie to a feature on the earth a county, a treet addre, or a zip code, for intance. It i etimated that ome 80 percent of all data have ome ort of patial component. Thi fact make GIS very valuable in term of data integration. GIS can be ued to bring together a variety of data ource that have been gathered previouly for other purpoe and apply them to a public policy iue uch a tranportation and land ue. Arc View 3.1 i a commonly-ued dektop GIS application. The idea behind a dektop GIS i that it allow the average uer of a high-end peronal computer to bring together patial data ource, analyze them, and diplay them viually.

3 Arc View and ome of it extenion allow a number of viual diplay technique to be ued, including imple thematic map and 3-D urface derived from data. Key Iowa Trend Iowa i a relatively low-growing tate. US Cenu Bureau projection how Iowa a the 39th or 46th fatetgrowing tate in term of population between 1995 and 2025 depending on which projection method (Serie A or B) i ued. The Cenu Bureau expect Iowa to have between 200,000 to 300,000 new reident by 2025 and a total population of 3.0 to 3.1 million. Iowa low growth i in harp contrat to many other tate, which are expected to have million of new reident during the next twenty-five year. Iowa rate of growth i expected to be rough] y one-third to one-fourth of the national rate of population growth. Iowa ha been following a low path from rural to urban over the pat century. Farm conolidation ha been a trend that ha perited ince about 1910, when mechanization of agriculture accelerated. At thi point, virtually all of the population growth in Iowa i concentrated in it metropolitan area and countie immediately adjacent to the metro countie. In fact, only ten countie in Iowa (out of a total of 99) will likely account for 95 percent of the growth over the next twenty-five year. Many rural countie in Iowa are loing population and now have death rate that exceed their birth rate. Some of thee countie actually achieved their peak Cenu population value a early a the 1910 Cenu or before. For thee countie, land ue change i not a particularly alient iue. However, in a few countie and three high-growth region in particular, land ue change and how tranportation invetment drive it and hape it, i a key planning iue. Thee three high growth area, all located along Intertate 80, are: The De Moine/Ame area in central Iowa, The Cedar Rapid/Iowa City area in eat central Iowa, The Quad Citie (Davenport, Bettendorf, Rock Iland, Moline) area, which i partly located in Illinoi. In 1997, about 70 percent of all the new houing permit activity in the entire tate of Iowa occurred in thee three area, which comprie a handful of the tate countie. Very little new houing contruction activity i occurred in the ret of the tate. Another area that ha not grown rapidly in the pat but that i projected by Wood and Poole Economic to grow relatively quickly in the next 20 year i the Sioux City metro area in northwet Iowa; thi area alo extend into ebraka and South Dakota. Thee demographic and houing trend are alo reflected in a number of other trend. Median houing value figure for Iowa reflect a urface that i ubtantially higher in thee few growth center than elewhere. K-12 chool enrollment and retail trade activity are alo quickly conolidating in Iowa into thee growth area.

4 Incorporated Place Population e * ?93!S7 Highway ~lntertate Other Primary U county Home Value urface Brealdl ne Hard on Elevation Range 9?11t.11* l14,1t1 iii $ m ,333 u ,444 ~ :~~ : :~ ; - 28S8S.8S _ ,889 \\, -- E + School Ditrict Poitive Enrollment Change, Urbanized Area School Enrollment Chenge. ldot=5 m County Highw8y ~lntertate w + E Prime Farmland in Iowa Iowa ha one of the larget extent of prime farmland of any US tate. Almot half of all farmland in Iowa i conidered prime, veru about one quarter in the nation a a whole. However, prime farmland i not uniformly ditributed within the tate. Mot prime farmland in Iowa i located north of Intertate 80, which biect Iowa from eat to wet. Mot, but certainly not all, of the major population center of Iowa are located within region made up of prime farmland. On the other hand, the non-prime region of the tate (e.g. outhwetern Iowa) tend to be parely populated. Thi reflect that fact that Iowa originally

5 developed a a farm tate and that agricultural production and proceing are till major driver of the economy. Iowa Prime Farmland Highway A/ I.tertate Farm Land m ot Prl.e = Prime _ Prl.e - Prime - Prime M108 w-4+e Pattern of Land Ue Change in Iowa Land ue change in Iowa i very much an iue confined to metropolitan and adjacent countie. In 1995 through 1997, 13 countie in Iowa had more than 500 acre of cropland moved out of production. A total of net acre went out of production in thoe countie. Almot half that change (over acre) occurred in and around the three-county De Moine metropolitan area. Another 7600 acre went out of production in three countie around Cedar Rapid and Iowa City and another 5400 acre in three countie around the Quad Citie. To place thoe figure into perpective, acre i about 77 average-ized Iowa farm. On the other hand, many rural countie in Iowa not adjacent to metro area had ubtantial increae in cropland acre between 1995 and Almot 40 countie in Iowa (out of 99 total) had cropland acreage increae from 400 to 2500 acre during that period (or the equivalent of one to even average-ized farm.) Thi hift appear to have been due to change in federal agriculture program, epecially the Conervation Reerve Program (CRP). The long-term change in land ue in and around Iowa metro area i not generally attributable to the expanion of incorporated citie through incorporation. From 1982 through 1992, the rural land area of Iowa dropped by only acre, or Ie than one percent. What ha driven land converion in Iowa i the change of land outide of incorporated citie from cropland and patureland to other ue. Two type of land ue converion eem to be driving thi. One i the proliferation of rural ubdiviion within commuting ditance of major employment center. The other i converion from private ue (e.g. farming) to public ue (e.g. parkland and highway right of way.) The Role of Tranportation in Fotering Land Ue Change in Iowa Tranportation literature deem highway infratructure to be a neceary, but not ufficient condition for development. Thoe major tranportation invetment mot likely to generate land ue change are thoe aociated with adding new capacity (mile or lane-mile) to the ytem in place that have coniderable growth potential (e.g. conumer and buine demand for land and building). Thee type of project include: Major capacity improvement along ational Highway Sytem (HS) or other arterial corridor. Bypae or highway located along new alignment.

6 Iowa, like many other tate, ha planned extenive improvement to it HS route over the next 20 year, particularly in the central and eatern part of the tate, where much of the tate traffic growth i concentrated. Project that eentially rebuild ection of the highway ytem, eliminate pot afety problem, or preerve pavement or tructure are likely to have little impact on land ue pattern at a regional level. The other type of project that i unlikely to have a great impact on land ue i a major project built in an are that ha little economic and demographic growth potential. Example of Tranportation and Land Ue Interaction Illutrated Uing GIS GIS technology i quite valuable for integrating a variety of econdary data ource and then viualizing them. Secondary data ource are ource gathered for a purpoe different original purpoe. For intance, data originally developed for property tax aement purpoe might later be ued to explore land ue change. A good example of a tranportation invetment impact on land ue i the large amount of new urban development (lack rectangle) that occurred new a new bypa of fat-growing Iowa City, Iowa between Land Ue Change ear Bypa of Iowa City,, Highway Land Ue Urban?-4 W-E * Mle v about 1984 and On the other hand, a very imilar tranportation invetment near low-growing Webter City, Iowa at about the ame time led to very little land ue change (black rectangle).

7 Land Ue Change ear US 20 Bypa Highway 1984 Land Ue ~] Urban w- E + Rural ubdiviion exhibit imilar pattern ofrelationhip withrepect tohighway facilitie. Inrapidly growing Dalla County, Iowa, many rural ubdiviion are popping up within five mile of Intertate 80 in area with hilly topography and water feature. Intertate 80 i the main commuting route into the wetern part of the De Moine metro area, which i located jut eat of Dalla County. By contrat, there ha been a much lower rate of rural ubdiviion development in low-growing Monroe County. Mot of thee ubdiviion are located near the northeat corner of the county, which i near a major highway corridor and a major indutrial job generator. ew Rural Subdiviion In Dalla County, Iowa n I.c.rporated P+ace county ational Hbhww Plainetwork i? Doila Converion%,6, Rdltoad% /\/ Rwet25 ToD025 w4$=e Mile v

8 ew Rural Subdiviion In Monroe County, Iowa w -+ E Public Policy Implication The illutration for Iowa ugget that the literature i indeed correct. Tranportation invetment are permiive with repect to land ue. A ubet of programmed major highway invetment are likely to have ignificant effect on future land ue pattern. Thee are capacity improvement, new alignment, and bypae in area that alo have a great deal of demographic momentum. There are only ix countie in Iowa that are expected to have or more net new reident by the year Thee countie, plu the countie adjoining them are where tranportation project are likely to generate land ue change of a ignificant magnitude. In thee few core and adjacent countie, project that run near or cro over and extend beyond exiting urbanized area boundarie are the mot likely to generate wholeale land ue change. Thee area can be identified with a GIS uing map overlay.

9 Programmed Improvement Overlayed On FutureCounty Growth Ink w + E On the other hand, many of the Iowa DOT major future project will be located in countie that are likely to continue declining in population or at leat are in countie projected by Wood and Poole to have very low growth rate. In thi type of ituation, wholeale land u change are very unlikely. Planned Highway Improvement Overlayed On Prime Farmland Area \ P&,d:Kv... h? WR.utdB,.,, IS *W Inunm w m t.. Land., P,, m. Prim. Prim. Pm. PIim., w E MI*S +- Conidering tranportation improvement, demographic momentum, and prime farmland location all at once indicate that only a few major tranportation invetment programmed by the DOT will be likely to generate major land ue change. For intance, in the rapidly growing central Iowa (De Moine metro and Ame) area, thoe project that radiate outward from De Moine to the wet, north and eat are the mot likely to generate farmland converion concern. Improvement planned to the outh of De Moine hould be of le concern, ince that area ha far le prime farmland.

10 Central Iowa Tranportation and Land Ue Overlay w + E