MODULE 2C: MAPS AS SOURCES OF HUMAN ECOLOGICAL INFORMATION Flashcards
Recent technological advances in computerized mapping and visualization have created opportunities to visualize and explore human-environment connections that were previously invisible
Human Ecology Mapping (HEM)
Extracting HE information using analytical tools and operations in GIS
- Database query
- Map Algebra
- Distance operators
- Overlay Analysis
- Geoprocessing
- Terrain Analysis
- Slope and Aspect
- Flow direction
- Watershed
Asks a question about stored information
Database query
A syntax for retrieving and manipulating data from a relational database
Structured Query Language
Language that defines a syntax for combining map themes by applying mathematical operations and analytical functions to create a new map theme (ESRI)
Map Algebra
Set of techniques where distance is the primary concern of analysis
Distance operators
Types of Distance Operators
- Buffer
- Euclidean distance
- Thiessen Polygon
- Vector overlay
- Raster overlay
Overlay Analysis
Takes an input dataset, and returns the result of the operation as an output dataset (Used to manipulate GIS data)
Geoprocessing
Types of GeoProcessing
- Dissolve
- Merge
- Clip
- Intersect
- Union
Features of Terrain Analysis
- Terrain
- Terrain Variables
- Contour Lines
- Shaded Reliefs
- Slope and Aspect
- Flow direction
- Watershed
Vertical dimension of land surface (expressed in elevation, slope, and aspect)
Terrain
Terrain Variables
- Height
- Slope
- Aspect
- Upslope area
- Flow length
- Upslope length
connected lines in uniform elevation that run at right angles to the local slope
Contour Lines/Topographic contours
Often referred to as hillshade map, it is a depiction of the brightness of terrain reflections given a terrain surface and sun location
Shaded Reliefs
Commonly used terrain variables required in hydrology, conservation, site planning, and infrastructure development and the basis for many terrain analysis functions
Slope and Aspect
Slope and Aspect: Defined as the change in elevation (a rise) with a change in horizontal position (a run)
Slope
Calculated by estimating the aspect, which is the direction of steepest descent from a center cell to immediately adjacent cells
(Used in hydrologic analyses)
Flow direction
An area that contributes flow to a point on the landscape (basins, sub-basins, drainage, etc.)
Watershed
