g topography temperature rainfall population 1 1 1 1 1 1 2 2 1 1 1 2 1 1 2 2 2

G topography temperature rainfall population 1 1 1 1

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E.g. topography, temperature, rainfall, population 0 0 0 0 0 0 0 1 0 0 1 1 0 1 1 1 0 0 2 2 1 1 1 2 1 1 2 2 2 2 2 0 0: shale 1: sandstone 0: rock well exposed 1: 2: rock poorly exposed 99.2 99.5 100 99.3 99.8 100.6 100.3 99.6 100.5 Elevation Raster DEM (Digital Elevation Model) Digital Elevation Model: Any digital representation of continuous variation of relief over space.
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Value indicating classes One value per cell but can has multiple attributes per value in value attribute table (VAT) 0 0 0 0 0 0 0 1 0 0 1 1 0 1 1 1 Value Count Rock type Rock name 0 10 Sedimentary Shale 1 6 Sedimentary Sandstone
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DEMA: YesB: No For discussion: Can elevation of the area be represented by vector data model?
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What does a map look like?
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Real world features: discrete objects or continuous phenomena Models: simplified version of real world features Vector data model: points, lines, polygons Raster data model: matrix of cells Spatial data and attribute data Shapefiles and geodatabase A map represents a portion of the earth's surface Map: Representation of real world by selected information Spatial and attribute data are displayed together using map symbols and a legend.
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Scale model of Earth: globe
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Globe distance Earth distance = Graticule: Network of lines on globe or map representing latitude and longitude. Origin is at Equator/Prime Meridian intersection (0,0) Principal Scale
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Longitude line (Meridian) Range: 180 ° W 0 ° 180 ° E Latitude line (Parallel) Range: 90 ° S 0 ° 90 ° N Equator, Prime Meridian 0 ° Parallels converge as poles are approached Christopherson (2001) Graticule: Network of lines on globe or map representing latitude and longitude. Origin is at Equator/Prime Meridian intersection (0,0)
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- Geographic longitude - Geographic latitude R - Mean earth radius O Geocenter: Earth mass center A point on the surface of the Earth is referenced by its longitude and latitude values Longitude and latitude are angles measured from the Earth's center to a point on the Earth's surface Latitude values are measured relative to the equator and range from -90° at the South Pole to +90° at the North Pole Longitude values are measured relative to the prime meridian at Greenwich and range from - 180° when traveling West to 180° when traveling East from the prime meridian
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