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Explore the relationship between geographic reality and social constructs through the lens of geographical ontology, delving into the nature of objects, boundaries, and representations in spatial data systems.
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Geographical Ontologies: An Overview Gilberto Camara National Institute for Space Research, Brazil Licence: Creative Commons ̶̶̶̶ By Attribution ̶̶̶̶ Non Commercial ̶̶̶̶ Share Alike http://creativecommons.org/licenses/by-nc-sa/2.5/
Hic sunt leones et dragones What’s out there?
What’s out there? fonte: Carlos Nobre
What’s out there? Reality
Data Data GIS A GIS B FormatB Format A What’s out there? Lake Habitat
The realist perspective (John Searle) 1. There is a real world that exists independently of us, our experiences, our thoughts and our language. 2. We have direct perceptual access to that world through our senses and our measurement devices. 3. Words in our language can be used to refer to real objects in the world. 4. Our statements are typically true of false depending on whether they correspond to the facts in the real world. 5. Some features of the world exist independently of us, such as mountains and lakes. Some features of the world are dependent on a socially-constructed agreements, such as boroughs and land parcels.
Humans before language: cave paintings 17,000 BCE, Lascaux, France
It all begins with observations… What’s out there? We use words in our language to describe the world
mobile devices • social network • Mobile devices, crowdsourcing, massive Earth observation sets: new technologies, new challenges sensorseverywhere ubiquitousimagery
Geoinformatics enables crucial links between nature and society Nature: Physical equations Describe processes Society: Decisions on how to Use Earth´s resources
From data to computer representations X,Y,Z X,Y,Z X,Y,Z X,Y,Z X,Y,Z EVENTS / POINT SAMPLES SURFACES / REGULAR GRIDS AREA DATA / POLYGONS FLUX DATA / NETWORKS
Digital spaces: Social exclusion in São Paulo iex 1991 2000
Representation The Medieval King has in him two Bodies: a Body natural, and a Body politic. Representations of the King fulfill a key political function
Representation The King had two bodies: Otho III, holding a royal orb, inside a mandorla. Vivet et non vivit
Representation "Mosaic in the Martorana at Palermo, representing the coronation of King Roger II at the hands of Christ, where the desired effect of making the God manifest in the king was achieved by a striking facial resemblance between Roger and Christ." Ernst H. Kantorowicz, The King's Two Bodies: A Study in Mediaeval Political Theology (Princeton: 1957) 65
System designer view of spatial data Spatial Data Natural Domain Human Domain INFRASTRUCTURE -roads -utilities -dams CADASTRAL DATA -parcels -streets -land use CENSUS DATA -Demographics -Economics IMAGES -planes -satellites ENVIRONMENTAL DATA -topography -soils -temperature -hidrography -geology
A geographical ontology Geographical reality Natural objects Social objects identity boundaries properties
Geographical reality identity Geo-objects observations boundaries Natural objects Social objects properties attributes Fields
It all begins with observations… What’s out there? The continuously changing landscape of the Earth (topography) Mountains with names (Alps, Mont Blanc)
It all begins with observations… What’s out there? Fields (coverages) objects The continuously changing landscape of the Earth (topography) Mountains with names (Alps, Mont Blanc)
What about objects? Mont Blanc Objects are language constructs, built upon observations They require both an external reality and a conscious act to identify their existence
Objects as mental constructions derived from physical reality Mont Blanc “Mont Blanc” is a socially-accepted name for a specific topographic feature Where does “Mont Blanc” start and “Dôme du Goûter” end?
Objects as mental constructions derived from physical reality Walrus W1 To understand animal behaviour, we tag them and assign them an identity
Objects as mental constructions derived from physical reality Walrus W1 To understand animal behaviour, we tag them, assign them an identity and track their movements
Objects as mental constructs derived from social reality “Germany (1914)” is a geographical object whose existence is defined by laws and treaties Die Proklamation des Deutschen Kaiserreiches 1871
Objects as mental constructs derived from social reality “Germany (2013)” is a geographical object whose existence is defined by laws and treaties Einigunsvertrag 1990 Two-plus-Four Agreement 1990
Was Germany a nation before it were a state? Germania, in a 1834 fresco. When did Germany start to exist? What were the boundaries of Germany when Goethe lived?
Boundaries of natural and social objects may coincide (but are not the same) The boundaries of the Republic of Cuba are not the boundaries of the island of Cuba (think of Guantánamo)
Natural objects: we measure properties in reality… Map showing main topographical features in Europe.
…but always inside a bounding space… Where is Europe in this map? Map showing main topographical features in Europe.
The natural world has continuous spatial variation Temperature, Waterph, soilacidity...
Properties of natural objects can be continuous For every point inside Europe, there is a height measurement Map showing main topographical features in Europe.
Soils map of Europe How real are those boundaries?
Fields as a Generic Data Typefor Big Spatial Data Gilberto Camara, Max J. Egenhofer, KarineFerreira, Pedro Andrade, Gilberto Queiroz, AlberSanchez, Jim Jones, and LubiaVinhas image: INPE