Gis samenvatting
GIS = Geographic information systems
Science
Studies
Definition GIS:
A set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from
the real world for a particular set of purposes.
Topics GIS answers questions about
Locations – where is the nearest…?
Patterns – where do high concentrations of students live in this city?
Trends – where have glaciers retreated in European Alps?
Conditions – where can I find a holiday surf camp within 1 km of the beach?
Implications – if I move how far will I be from gym, school etc?
Elements
Data – location on earth (geographic)
Software – visualize & analyse arcgis, excel etc
Rules & procedures – metadata, standards, iso
Hardware – laptop, GPS device
People/organization – you, me, ICT, manager, VHL
Data forms
1. Vector
- x, y, z coordinates
- Lines, points, polygons
- Features, topographic maps, GPS
2. Raster
- Rows and collums of cells with values
- Resolution, digital elevation
3. Storage
- Folder
- Geodatabase
Type of maps
1. Paper maps (for soil type and geology)
2. Contour maps (for topography)
3. Ecological field maps (for drainage conditions)
4. Remote sensing (for land use)
Workflow
1. Spatial problem
2. Data input
3. Data maintenance
4. Data analysis
5. Data output
6. Presentation
, GIS = Thinking in layers
Raster Vector
Data collection Rapid Slow
Area analysis Good Average
Data volume Large Small
Graphic treatment Average Good
Data structure Simple Complex
Generalization Simple Complex
Geometrical accuracy Low High
Exam question:
What are differences between vector and raster data with respect to:
1. Cartography (making nice looking maps)
Vector is way more detailed and geometrical accurate. The graphic treatment of vector is
good and from raster average.
2. Data volume & storage
Raster has a large data volume where as vector has a small one.
3. Data collection
Raster is very rapid where as vector is very slow.
4. Speed of data analysis
Raster is faster where as vector has a normal speed.
Data sources
1. Analogue
- Paper maps
- Tables
- Printed arial photos
- Ideas
2. Digital
- Maps
- Digital arial photos
- Satellite
- Loggers/sensors
- GPS
Why editing data?
To remove errors
Data is in wrong coordinate system
Data is not collected at the scale
Update the dataset
Always check quality of source
Who collected it?
Is it recent data?
At what scale is it?
GIS = Geographic information systems
Science
Studies
Definition GIS:
A set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from
the real world for a particular set of purposes.
Topics GIS answers questions about
Locations – where is the nearest…?
Patterns – where do high concentrations of students live in this city?
Trends – where have glaciers retreated in European Alps?
Conditions – where can I find a holiday surf camp within 1 km of the beach?
Implications – if I move how far will I be from gym, school etc?
Elements
Data – location on earth (geographic)
Software – visualize & analyse arcgis, excel etc
Rules & procedures – metadata, standards, iso
Hardware – laptop, GPS device
People/organization – you, me, ICT, manager, VHL
Data forms
1. Vector
- x, y, z coordinates
- Lines, points, polygons
- Features, topographic maps, GPS
2. Raster
- Rows and collums of cells with values
- Resolution, digital elevation
3. Storage
- Folder
- Geodatabase
Type of maps
1. Paper maps (for soil type and geology)
2. Contour maps (for topography)
3. Ecological field maps (for drainage conditions)
4. Remote sensing (for land use)
Workflow
1. Spatial problem
2. Data input
3. Data maintenance
4. Data analysis
5. Data output
6. Presentation
, GIS = Thinking in layers
Raster Vector
Data collection Rapid Slow
Area analysis Good Average
Data volume Large Small
Graphic treatment Average Good
Data structure Simple Complex
Generalization Simple Complex
Geometrical accuracy Low High
Exam question:
What are differences between vector and raster data with respect to:
1. Cartography (making nice looking maps)
Vector is way more detailed and geometrical accurate. The graphic treatment of vector is
good and from raster average.
2. Data volume & storage
Raster has a large data volume where as vector has a small one.
3. Data collection
Raster is very rapid where as vector is very slow.
4. Speed of data analysis
Raster is faster where as vector has a normal speed.
Data sources
1. Analogue
- Paper maps
- Tables
- Printed arial photos
- Ideas
2. Digital
- Maps
- Digital arial photos
- Satellite
- Loggers/sensors
- GPS
Why editing data?
To remove errors
Data is in wrong coordinate system
Data is not collected at the scale
Update the dataset
Always check quality of source
Who collected it?
Is it recent data?
At what scale is it?
