BRIEF HISTORY OF GEOGRAPHICAL INFORMATION SYSTEMS

BRIEF HISTORY OFGEOGRAPHICALINFORMATIONSYSTEMS

Ian McHarg (1920-1981)the “Father of GIS ” IanL. McHarg was born and raised inScotland. He came to the United States afterWorld War II to get a master’s degree in 1952In 1954 he took a position as Professor of LandscapeArchitecture and Regional Planning at the University ofPennsylvania and came to be recognized worldwide forintroducing ecological concerns into land planning fromthe mid-1960s onward. An ardent environmentalist andwriter, he was one of the prime movers in organizing thefirst Earth Day in 1970. He was a partner in the landscapearchitecture and environmental planning firm Wallace,McHarg, Roberts and Todd.

Ian McHarg (1920-2001) is credited with being the fatherof map overlays, which had a major impact onGeographical Information SystemsHe was a Professor of Landscape Architecture andRegional Planning at the University of Pennsylvania from1954-2001He wrote Design with Nature in 1969

McHarg saw industrial centers as urban plight, filled with pollution thatultimately damaged one’s soul as well as health

McHarg felt thatmass grading byengineers createdsterile man-madeenvironments devoidof aesthetic buffers intheir rush to massproduce the maximumnumber of units in aminimum space. Hefelt hat this wasinevitably unhealthyfor society at large Before(1971) and after (1977) developmentviews of Deep Canyon in Los Angeles

Ian McHarg described engineersas those individuals “who, byinstinct and training, were especiallysuited to gouge and scar landscapeand city without remorse”

McHarg’s starting point was usually a physiographicsection, like that shown here. He argued that “form mustnot follow function, but must also respect the naturalenvironment in which it is placed.” Note the placement ofstructures in the forested slopes which made them almostunnoticeable.

McHargtook landscape principles of aesthetics and applied these to maps

McHarg’sBasicAmenity Mapportrayed slopeswith wooded coveras a valuableasset, akin to a citypark. Earthshelteredstructures couldbe constructed onthe slopes if theywere embeddedinto the rock with aminimal loss oftree cover. Hencethe term “urbancamouflage”, or“designing withnature”

McCargusuallybegan with aPhysiographicFeatures Map.This examplecompared forestcover, aquiferrecharge, 50-yrflood plain,streams, slopes 25% andimpervious soils ina master overlay. Inthe early yearsthese hybrid mapswere constructedof acetate overlayson a cadastralbase map.

McCarg’sOptimal LandUse Mapcombinedphysiographicfeatures withexistinginfrastructure,developmentand zoningrestrictionswhich wereweighted tothe taste oflocal residentsand regulatoryboards.

McHargpioneeredthe use of mapoverlays to highlightintrinsic naturalfeatures, thatcommonly includedflood zones, wetlands,woody vegetationstands, slopes,drainages, aquiferrecharge zones, areasunder cultivation andman-made features.Each asset could beassigned an arbitraryvalue, depending onsocietal input.

Physiographicfeatures werecatalogued asseparate maps.McHarg wouldthen overlay theseto create acomposite mapillustratingphysiographicobstructions.Areas containingmultiple featureswould appear asthe darkest mightbe valued morethan lightercolored areas.

McHarg alsodemonstrated that aplethora of societaltraits could berepresented on mapsas well, and overlainin much the samemanner as compositephysiographicobstructions. Thesetended to mimicproperty values.

McHarg’s map overlay method gained nationalrecognition in a consulting project for a 5-mile stretchof the controversial Richmond Parkway on StatenIsland in 1968

McHarg’shybrid mapincludedecological,political andaestheticrankings thatwerecombined withphysicalattributes toselect atransportationcorridor thatwould havethe leastimpact on theresidents

McHarg’s Map Layering ConceptMcHarg’s four M”s: Measurement, Mapping, Monitoring andModeling. GIS allows a limitless combination of mapableattributes to be arbitrarily weighted and electronicallycombined to create hybrid “maps”; which are simply spatialrepresentations using the Earth’s surface as their datum

Raster and vector data files emanate from differingmethods of data collection and creation. Raster datafiles handle complex curvature typical of naturalfeatures while vector files favor linear, man-madefeatures.

SPATIAL DATA MODELS GIS has evolved with computing technology. Today,raster and vector data can be combined withincreasingly sophisticated digital imagery, manipulatinglarge data files

GLOBAL POSITIONING SYSTEMNavstar launched in 1982; requires aminimum of 18 operable satellites, 6in 3 orbital planes spaced 120degrees apart at 12, 660 milesContact with 5 to 8 satellitesrequired to provide fix

By March 1994 all 24 satellites were orbiting Earth.In May 2000 NOAA turned off selective availability, allowing publicto receive GPS fixes within 10 m under good conditionsWorldwide, GPS industry nets 16 billion annuallyGPS allows inexpensive location fixing using hand-held receiversand palm pilots, with electronic data transfer

Ian McHarg (1920-1981) the “Father of GIS ” Ian L. McHarg was born and raised in Scotland. He came to the United States after World War II to get a master’s degree in 1952 In 1954 he took a position as Professor of Landscape