During the last few years researchers and environmental planners have carried

on their preliminary studies following an interdisciplinary approach. One of the

main issues in this approach is the sustainability of economic development. As a

matter of fact, the importance of the studies related to the distribution and the

limits of natural resources is widely recognized. This can be accomplished more

easily than in present by the use of extremely powerful computer application.

The purpose of this contribution is to demonstrate the usefulness of an integrated

approach of the GIS and of the RS to planning in complex problems of decision

making. Many GIS applications are suited to the input of remote sensing and the

integration of these techniques is now accepted in landscape planning. By means

of GIS and RS, environmental information can be integrated with administrative,

political, social and economic data. GIS, RS and fuzzy logic techniques are used

to assist environmental compatibility studies and decision makin

De Montis, A.

Manca, Germana

P-arch

Land Planning through GIS, RS andmulticriteria decision analysis.A case study in Sardinia.G. Manca and A. De MontisCRS4 Centro di Ricerca, Sviluppo e Studi Superiori inSardegna, via Nazario Sauro, 10 - 09123 Cagliari, Italy -Tel.: +39 70 2796218; Fax: +39 70 2796216E-Mail: gmanca@crs4.itDipartimento di Ingegneria del Territorio, SezioneUrbanistica, Università di Cagliari - piazza d'Armi 16 09123Cagliari, Italy - Tel.: +39 70 675 5209 Fax.: +39 70  6755215E-Mail: ademonti@vaxca1.unica.itAbstractDuring the  last few years researchers and environmental planners have carriedon their preliminary studies following an interdisciplinary approach. One of themain issues in this approach is the sustainability of economic development. As amatter of fact, the importance of the studies related to the distribution and thelimits of natural resources is widely recognized. This can be accomplished moreeasily than in present by the use of extremely powerful computer application.The purpose of this contribution is to demonstrate the usefulness of an integratedapproach of the GIS and of the RS to planning in complex problems of decisionmaking.  Many GIS applications are suited to the input of remote sensing and theintegration of these techniques is now accepted in landscape planning. By meansof GIS and RS, environmental information can be integrated with administrative,political, social and economic data. GIS, RS and fuzzy logic techniques are usedto assist environmental compatibility studies and decision making.As a case study, an area located in the central part of Sardinia is analyzed. Thisarea is especially interesting because of the presence of industrial andagricultural resources and infrastructures.1 IntroductionThe relative weakness of the Sardinian economy is the basis under whichthe European (EU) considers Sardinia to be a “lagging behind region -objective 1”.  Many measures of economic strength have demonstratedthe disparity between the Sardinian economy and the greater Italian andEuropean economies. Even today it is clear that the weakness of theSardinian economy can be attributed to this geographic separation. Thehigh cost of transportation to and from the island, as well as within theisland itself is the most pressing problem to be addressed when factorylocation decisions are being made.1.1 The crucial geographic position of MacomerThe primary road crossing the island of Sardinia is State Highway (S.S)number 131, also known as Carlo Felice, which links the capital city -Cagliari - in the south to the other major population and industrial center -Sassari - in the north.  The town of Macomer is located at the intersectionof the S.S. 131 and another important artery - known as the SardinianCentral Way - which links the larger centers on the western side of theisland, such as Bosa, to the interior eastern regions in the Nuoro’sProvince.  This geographic situation is ideal for those industries thatchoose to minimize transportation costs: the immediate access to themain highways of the island constitutes a positive externality andgenerates economies of scale. For this reason Macomer’s economicdevelopment has been based mainly on industrial settlements. A model ofindustrial development includes the development of medium and smallsized factories producing a wide variety of products, such as textiles,dairy-products, food, garments, and structural steel.  This “soft” modelbased on a strategy consisting of the diversification of production isdescriptive of Macomer’s industrial complex. Considering that the hardindustry is currently in a state of crisis, and is now being re-constructedwith respect to its organization and means of production, the soft modelof Macomer in its industrial zone “Tossilo” seems to guarantee a higherlevel of output and of employment.1.2 Urban and environmental planning proceduresThe Commune of Macomer in the 1970’s showed a population of morethan 10.000 residents. According to the main urban planning national lawn. 1150/42, in 1975 its General Regulatory Plan (P.R.G.) was approved.In 1995 the Commune of Macomer, according to landscape andenvironmental requirements set forth by the main regional law number45/89, published the executive summary of the new P.R.G., called theUrban Communal Plan (P.U.C.). All of the aforementioned documentsfocus on the development of industrial plants as an important economicopportunity for the territory. In large part, they describe the industrialexpansion in Bonurtau and at the new site Tossilo.1.3  Sector planning and general strategic indicationsThroughout the period of the 1960s and the 1970s, sector planning inSardinia has influenced the entire system of planning procedures for theterritory as a whole. Specifically, the Territorial Coordinated Plan(P.T.C.), provided for by the national law n. 1150/42, corresponds closelyto the plan of the Middle Sardinia Industrial Development Area (A.S.I.).In other words, that regional economic strategic plan is largely composedof the local industrial development scenarios.The relatively new field of landscape planning and environmentprotection procedures asserts that the diversification of land use is acrucial element of successful economic development.  However, theimportance of a well chosen site for a particular industrial settlement, andthe access of that site to transportation routes is universally accepted asthe most influential element in a successful territorial land use plan.In spite of the recent trend away from mono-cultural development, thenewest developments in the study region are, without exception,expansions of the industrial zones in the commune of Macomer:1. Under the plans described above, the first settlements were located atthe periphery of the town, in close proximity to the existing urbaninfrastructure;2. A second an industrial “D” zone was planned at Bonutrau in thewestern part of the territory of Macomer;3. Thirdly the industrial zone of Tossilo was settled in the southern partof the territory of the commune.As the importance of the system at Tossilo grew rapidly, the number ofindustrial settlements at Bonutrau have diminished.  As a result, the localplanners have indicated that the expansion zone should be locatedbetween Bonutrau and Tossilo, and in the area of Bonutrau itself, througha special renewal plan known as a Recovery Plan (P.d.R).1.4 Population forecast and industrial settlementEmployment and population forecasts serve two particular purposes.First, they are the basis for estimating future space requirements.  Spacerequirement for housing are estimated by converting population forecastsinto the number and types of households demanded by that population.The second application of population and employment forecasts is theprojection of the need for transportation infrastructure and service,community facilities, and public services.The changing geographic distribution of the population of Macomer hasreflected regional trends.  The 1981 urban area population was 11.083,and the most recent census established that there were 11.395 urbanresidents. There has been virtually no urban population  growth.  Thistrend is common to all the island towns, with few exceptions. This trendreflects the attraction and migration to the largest regional centers,accompanied by a regional decline in the birth rate.Population trends may also be recognized through qualitative analysis.One method of doing so involves an assessment of the varying styles ofbuildings in different geographic regions. In Macomer a natural divisionexists between the traditional or historic city center and the urban-ruralfringe surrounding the city. Macomer is divided into two parts by therailway, and by the main street, represented by the former highway(ss131). The historic area is a mixture of architectural styles reflecting avariety of different cultures and economic classes. This area is wellrestored and the employment rate is high. In an attempt to cope with thelack of housing in urban areas, recent urban planning efforts havepromoted the concept of residential area delineation. The 1979 P.R.G.defined three expansion areas. The large majority of the land within theseareas has been dedicated to the construction of the popular building.More recently, however, the P.U.C of 1995 includes a new expansionarea.The renewed interest in local authority accountability has placed issues ofresource allocation firmly back on the political agenda. The localcouncillors have to consider three principal characteristic of populationand economy, especially relevant for land use planning purposes; size,composition, and spatial distribution.When determining the size orpopulation number, it is necessary to apply a forecast approach.  Theforecasting method used here is a joint economic-population technique.This approach projects population and employment in a coordinatedprocedure.  The population projection is based on employment analysis,and the economic projection is based on labor force-populationindicators.The industrial settlement of  Tossilo shows many signal of employmentgrowth. The consortium controlling the industrial area has received manyrequests from firms which would like to locate inside that industrial area.The renewed industrial strategic plan makes a provision for 158 ha,assigned to new installations, but  - in actuality - the land use plan hasassigned substantially less area (approximately 90 ha), than what wasestimated by the plan.  The average size of the new industries that wouldlike to locate in this area, is approximately 10 ha. Considering thisdimension of each free area, the ratio between the area available and theaverage size for new enterprise gives the number of new plants (equal to9 new industries).  Assuming that these new firms will employ an averageof 200 workers, multiplying the number of the new plants times thenumber of workers, results in the  amount of population increase for thecity.  Considering the unemployment ratio (around 15%), 300 workersshould be absorbed by new industries, but the remainder must find newhousing - ideally close to the work place.An assessment of the “Composition” of the population is made bydetermining the size of specific age groups, households types, andsocioeconomic levels. Moreover, economic activity may be distinguishedby industry and type of firm. The largest group of employees is composedof labour-workers.The spatial distribution of population and economic activity must beconsidered. Italian law has defined several criteria to calculate the potentialsize area for expansion; the regional law “decreto Floris”, fixes for eachperson, a volume of 100 mc.  Consider that the expected new employmentwill increase the city population by 1500 workers.  These workers will likelybring their families with them.  The average Italian family is composed of twomembers.  Multiplying this factor by the number of new workers, results in atotal city population increase of 3.000. However, it is reasonable to assumethat not all of the families will live in Macomer, and it is expected that 30%will live close to - but out of the city limits of - Macomer. Subtracting thispercentage and the number of unemployed persons absorbed by the newemployment, the resulting population increase is approximately 1.500persons.  Multiply this number by 100 mc for each person, and the result is150.000 mc.  This value is divided then by the edification index (1.5 mc/mq)to obtained a residential space requirement of 10 ha.2 Description and construction of thealternativesTo find out an alternative fitting the requests of the environment and politics,it has been carried out a suitability analysis. The suitability analysis identifieslocation within the planning area that are best suited to locate the “C” area.The following is a list of some criteria that ought to be considered whensetting out to derive a fair assessment of “C” are:Natural endowed value, Polical geography value, Slope, Increasingpopulation, Soil, Distance, Landuse, Political Agenda, Topography,Sentiment.Doing this analysis it has been built an environmental inventory. It is acoordinate “package” of information on individual environment features.This package generates a suitability scores for all sites within theplanning jurisdiction for a “C” area.The two alternatives have been built by computer calculation, while theothers two come from the town’s plan of the ’79.The procedure to build the two alternatives is the following:• Creation of a map containing the percent degree of slope• Reclassification based on a value of slope.• Creation of a map of landuse.• Reclassification based on the natural resource. From the landuse,derived from the TM and aerial photos classification, it has beenextracted a suitability score map. The scale arises from one to five.• Overlay summing procedure has been carried out to obtain asuitable map. Firstly the town boundary has been clipped from theresult overlaid map; after having created a buffer of rivers,inaedificandi area, streets and railway (mostly taking into account thelaw constraints), these have been clipped too.  The sum of the valuescan tell how many positive factors occur at the location. In this casethe highest value shows the best allocation. The area whom belongsto a value higher than five, should be a good solution for location ofthe “C” area. After having reclassified the area with a value higherthan five, it has been searched an area bigger than 10 hectares. TheGIS software mapped out two areas.2.1  Identification of the “C zone” and multicriteria evaluationThe major steps in developing and using a model of this type for multiplecriteria evaluation are:1.identification of  the alternatives to be evaluated.The alternatives to be considered are represented by the “C” area, thosealready in the urban plan of 1979, and the new area, created by the computer’scalculation and designed by an urban planner.2.Identification of relevant criteria and structuring a hierarchy of criteria.It has been also identified a number of relevant criteria, thus establishinga base for evaluation:♠ neighbourhood to “B” area♠ nearness to principal street♠ population dynamics♠ square meters for “C” area♠ land price for the passage from “E” to “C” area♠ slope♠ landscape fruition♠ visual impactHaving identified the above collection of criteria they need to bestructured in an appropriate way. The structure is a hierarchies of criteria.3)  Evaluation of alternatives with respect to criteria (scoring).The aim of scoring is to assign values to each alternative reflecting theirperformance on each criterion. The function is an utility function. For thecriterion neighbourhood to “B” area the scale is quantitative. So less isthe distance better is the performance of the criterion. The secondcriterion is the real distance from the principal communication way(ss131). The population dynamics is a quantitative criterion. A growingnumber of person is a positive aspect, because, as explained before,means a raising economy and industrial development. It’s related to thenumber of person that should be allocated inside the area. The squaremeters is also a quantitative criterion linked directly with the abovecriteria.  The cost for a new area is calculated by “Naples’s Law” (marketvalue + income from agricultural land / 2). The two last criteria should beincluded into one criteria “quality of life”. The landscape position isstrictly linked with the position of the area “C”. The area worked bycomputer out is in a wonderful area, very interesting for the nature  andbeautiful visual impact. The country around the new area is green andcolorful during the spring. A high quality level of vegetation is presentthere. The scale is between 1 and 8 where 8 is the best performance.Slope is a quantitative criterion. A scale from 1 up to 5 has been scored,where the value equal to five is the best while 1 is the worst. One is theslope over 5%, 3 is between 2 and 5%, and 5% is between 0 and 2%.4.Evaluation of the relative importance of criteria (weighting)The different criteria it has been assigned the following value:♦ 10  ⇒ neighbourhood♦ 15  ⇒ nearness to the street♦ 15  ⇒ population dynamics♦ 10  ⇒ square meters for “C” area♦ 25  ⇒ land price from “E” to “C”♦ 5    ⇒ slope♦ 20  ⇒ quality of life5)  Sensitivity analysis.The chart “Multicriteria Analysis Result” represents the overall scores foreach of the alternatives. The bottom chart is the profile of criteriaweights. The best alternative is 4A. But if the weight of the criterion costwill be a few points more, the alternatives classification changes. Life-quality and cost determine the modification of the dominance. The toppart of the chart is a bar representing the score at the selected level ofhierarchy for each of the alternative in the selected criteria. To concludethe analysis provides an ordering of the alternatives.3 ConclusionTo cope with the problematic situation of landscape planning, the plannershave to impose some order, taking into account the multiple aspects ofenvironment and of politics, and to achieve a right decision. In order to pursuethis goal all kinds of distinctions, classifications and other judgement might beconsidered. These methods and techniques and further the integration assistthe planner to inventory, classify and feasibly arrange the information neededfor a choice, giving a tool that enables to take a decision as responsibly aspossible.The integration of GIS data and multicriteria analysis it is now possible,thanks to new available softwares. The chosen software is Arcview3. Theinteroperability provided by ArcView, for communicating withexecutable DOS files, have allowed to run a multicriteria program and tolook at the results inside an ArcView project.The future development will be the complete integration of two differentroutines; the consequences of this integration will allow to control andcheck the results of multicriteria directly in the view, in order toappreciate the different solutions in the map.4 ReferenceAmadori G., Ciuffini F.M., Moro B. (1993), Prospettive urbanistichedell’agglomerato industriale di Tossilo in rapporto alle direttrici disviluppo della città. Relazione tecnica, Comune di MacomerComune di Macomer (1975), Piano Regolatore Intercomunale. Normetecniche di attuazione, Delibera C.C. n° 66 del 1996, MacomerComune di Macomer (1977), Piano Regolatore Generale, RelazioneUrbanistica di Modifica, Ufficio Tecnico del Comune di MacomerComune di Macomer (1995), Piano Urbanistico Comunale. Fase dimassima Relazione tecnica per la riunione del consiglio comunale apertodel 24 luglio 1995, Ufficio Tecnico del Comune di MacomerGoodchild M.F., Parks B.O., Steyaert L.F. (1993), Environmentalmodeling with GIS, Oxford University PressRiunione dei Ministri dell’Assetto del Territorio degli Stati Membridell’Unione Europea (1997) Schema di Sviluppo dello spazio europeo.Prima bozza ufficiale, Noordwijk, 9 e 10 giugno 1997Roy B.(1996), Multicriteria Methodology for Decision Aiding, KluwerAcademic Publishers

Land planning through GIS, RS and multicriteria decision analysis. A case study in Sardinia

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Land planning through GIS, RS and multicriteria decision analysis. A case study in Sardinia

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