u11-SPATIAL OBJECTS AND DATABASE MODELS

u11-SPATIAL OBJECTS AND DATABASE MODELS - UNIT 11 - SPATIAL...

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Sheet1 Page 1 UNIT 11 - SPATIAL OBJECTS AND DATABASE MODELS <toc.html#UNIT11> UNIT 11 - SPATIAL OBJECTS AND DATABASE MODELS Compiled with assistance from Timothy L. Nyerges, University of Washington # A. INTRODUCTION <#SEC11.1> # B. POINT DATA <#SEC11.2> # C. LINE DATA <#SEC11.3> * Network entities <#SEC11.3.1> * Network characteristics <#SEC11.3.2> * Attributes <#SEC11.3.3> * Networks as linear addressing systems <#SEC11.3.4> # D. AREA DATA <#SEC11.4> * 1. Environmental/natural resource zones <#SEC11.4.1> * 2. Socio-economic zones <#SEC11.4.2> * 3. Land records <#SEC11.4.3> * Areal coverage <#SEC11.4.4> * Holes and islands <#SEC11.4.5> # E. REPRESENTATION OF CONTINUOUS SURFACES <#SEC11.5> * General nature of surfaces <#SEC11.5.1> * Data structures for representing surfaces <#SEC11.5.2> * Spatial interpolation <#SEC11.5.3> # REFERENCES <#SEC11.6> # EXAM AND DISCUSSION QUESTIONS <#SEC11.7> # NOTES <#SEC11.8> This unit continues the development of basic concepts about representing reality as spatial data. Here we look at how the representation of reality in the form of entities is handled with the spatial objects points, lines and areas. UNIT 11 - SPATIAL OBJECTS AND DATABASE MODELS Compiled with assistance from Timothy L. Nyerges, University of Washington A. INTRODUCTION <#OUT11.1> * the objects in a spatial database are representations of real-world entities with associated attributes
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Sheet1 Page 2 * the power of a GIS comes from its ability to look at entities in their geographical context and examine relationships between entities * thus a GIS database is much more than a collection of objects and attributes * in this unit we look at the ways a spatial database can be assembled from simple objects o e.g. how are lines linked together to form complex hydrologic or transportation networks o e.g. how can points, lines or areas be used to represent more complex entities like surfaces? B. POINT DATA <#OUT11.2> * the simplest type of spatial object * choice of entities which will be represented as points depends on the scale of the map/study o e.g. on a large scale map - encode building structures as point locations o e.g. on a small scale map - encode cities as point locations * the coordinates of each point can be stored as two additional attributes * information on a set of points can be viewed as an extended attribute table o each row is a point - all information about the point is contained in the row o each column is an attribute o two of the columns are the coordinates overhead - Point data attribute table o here northing and easting represent y and x coordinates * each point is independent of every other point, represented as a separate row in the database model C. LINE DATA <#OUT11.3> Network entities <#OUT11.3.1> * infrastructure networks o transportation networks - highways and railroads o utility networks - gas, electric, telephone, water o airline networks - hubs and routes * natural networks o river channels Network characteristics <#OUT11.3.2>
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This note was uploaded on 10/05/2010 for the course GEO 591 taught by Professor Davidm.mark during the Fall '10 term at SUNY Buffalo.

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u11-SPATIAL OBJECTS AND DATABASE MODELS - UNIT 11 - SPATIAL...

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