Geodata analysis. Riccardo De Filippi.

Transcription

1 Geodata analysis Riccardo De Filippi

2 Analysis Purpose & Methods Queries and reasoning Measurements Transformation Data mining Descriptive summaries Optimization Vector analysis Raster analysis Combined analysis Hypothesis testing

3 Operations in vector What is? Attribute What is its relation to other entities? Spatial topology Where is it? Distance/location Feature analysis Select Create

4 What is it: Attribute operators Logical operations attributes of one or more entities individual entities Mathematical operations new attribute math calculation Statistical analysis descriptive stat stat software Numerical models complex sets of mathematical functions that represent physical process

5 Spatial operators Relational operators: - Testing spatial relationships between geometries - Result is a boolean value, no new geometries are created Topological operators: - Support for editing geographic features - Result is a new geometry based on a logical comparison between geometries

6 Vector analysis: Relational operators Relational operators: Equals Contains Within Crosses Overlaps Touches Disjoint

7 Vector analysis: Relational operators(3) Contains Within Zeiler (1999)

8 Vector analysis: Relational operators (4) Crosses Overlaps Zeiler (1999)

9 Vector analysis: Topological operators Topological operators: Buffer Clip Convex hull Cut Difference Intersect Symmetric Difference Union

10 Topological operators (1) Buffer Clip Zeiler (1999)

11 Topological operators (3) Difference Intersect Zeiler (1999)

12 Interaction

13 Functions vs Operators 1. Raster functions Zeiler (1999) 2. Raster operators

14 Every cell of the raster is processed Cell processing

15 Raster Map Analysis Zeiler (1999) Map query Boolean/logical operations: And, Or, XOr, Not, >, >=, =, <>, <, <=, Zeiler (1999) Map calculation Mathematical operations: +, -, /, *, Log, Exp, Sin, Cos, Sqrt,

16 Raster Functions Trigonometric sin, cos, tan,... Exponential a x, e x Logarithmic log, ln, lg, ld Relational >, <, =,,,, <>,... Statistical max, min, mean, total, SD,... Application Transformation, DTM derivatives, Hydrology,Proximity, Dispersion.

17 Raster functions: Spatial application Zeiler (1999)

18 Local functions McCoy et al. (2002)

19 rain Local function : application case Local mean or minimum

20 Focal functions McCoy et al. (2002)

21 Focal function: application case Burrough (1998)

22 Zonal functions Quelle: ArcGIS 9.0 Desktop Help

23 Global functions

24 Application function 1 First and higher derivatives - slope - aspect - plan curvature - profile curvature DTM slope aspect Quelle: ArcGIS 9.0 Desktop Help

25 Application function 2 Viewsheds, shaded relief, irradiance DTM hillshade combin ed Zeiler (1999)

26 Application function 3 Dilation, spreading, dispersion - fire spreading - oil dilation and translocation - soil solute dispersion from point source Zeiler (1999)

27 Application function 4 Spatial transformation - translocation - scaling, distension, stretching - rotation - distortion Zeiler (1999)

28 Raster analysis: application 5 Surface topology, drainage network, sun - Slope, Aspect - Hydrology - Sun radiation. flow accumulation DTM watershed & subwatersheds Sources: Weisshaidinger; Hebel

29 Application function 6 Proximity - Euclidian distance - Travel time Zeiler (1999)

30 Application function 7 Least-cost path analysis Zeiler (1999)

31 Raster Operator Arithmetic [Inlayer1] + [Inlayer2] / 2 Boolean Where <> 0 in layer1 and layer2 Relational Inlayer < 3

32 Process diagram (flowchart) Input data Process Intermediate data Output data Input Intermediate Output Data processing Process Process Line Line Selection Data processing Select

33 Process diagramms Test Area xy Modify feature Rivers Geocorrected area Roads Clip Clipped Roads and Rivers Answer 2 How many line features are within test? Update line length: quality check! not recalculated Updated length R & R Select & Statistic Bach Layer Summar 1_Klass 2_Klass 3_Klass ize Answer 5 statistics on 3 road classes? SummarizeTable.dbf Answer 3, 4, 5 Shortest, Longest, Sum of rivers?

34 Practice QuantumGIS visualization, map editing Grass data processing engine, data editing

35 References Burrough, P.A., and R.A. McDonnell, Pronciples of Geographical Information Systems. Oxford: University Press. Longley, P.A., M.F. Goodchild, D.J. Maguire, D.W. Rhind, Geographic Information Systems and Science. Chichester, UK John Wiley & Sons. Zeiler, M., Modelling our World: The ESRI Guide to Geodatabase Design. Redlands, Ca: ESRI Press.

36 References Longley, P.A., M.F. Goodchild, D.J. Maguire, D.W. Rhind, Geographic Information Systems and Science. Chichester, UK John Wiley & Sons. SNV, SN : Vermessung und Geoinformation INTERLIS Modellierungssprache und Datentransfermethode. Winterthur, CH: Schweizerische Normen-Vereinigung. Swisstopo, Bundesamt für Landestopographie. Bern, CH: Swisstopo. Avaliable at: Zeiler, M., Modelling our World: The ESRI Guide to Geodatabase Design. Redlands, Ca: ESRI Press.

37 References Department of Geography, Geographic Information Technology Training Alliance (GITTA). Zurich, CH: University of Zurich. Avaliable at: Burrough, P.A., and R.A. McDonnell, Pronciples of Geographical Information Systems. Oxford: University Press. Fischer, M., and P. Nijkamp, Geographic Information Systems, Spatial Modelling and Policy Evaluation. Berlin and Heidelberg: Springer Verlag. Longley, P.A., M.F. Goodchild, D.J. Maguire, and D.W. Rhind, Geographic Information Systems and Science. Chichester, UK: John Wiley & Sons. Tomlinson, R., Thinking about GIS: Geographic Information System Planning for Managers. Redlands, Ca: ESRI Press. Zeiler, M., Modelling our World: The ESRI Guide to Geodatabase Design. Redlands, Ca: ESRI Press.

38 References McCoy, J., K. Johnston, S. Kopp, B. Borup, J. Willison, B. Payne, Using ArcGIS Spatial Analyst, - GIS by ESRI. Redlangs, Ca: ESRI Press. Swisstopo, Bundesamt für Landestopographie. Bern, CH: Swisstopo. Avaliable at: Zeiler, M., Modelling our World: The ESRI Guide to Geodatabase Design. Redlands, Ca: ESRI Press.