GIS and Remote Sensing Lecture Notes
What does a GIS do?
store, organize, and distribute data
common to see data files in the 10-100 megabyte range, up to gigabytes
of remote sensing data.
USGS National Map or download older, small scale data files
USGS Earth Explorer (discover and download)
- allows exploration of relationships among data layers
"...high yield forage grass is most common on which rock types?"
"...how does population density relate to water quality?"
- criteria matching
"I need to find a place for an outdoor recreation specialist at the
Forest Service that is...
on public land
with gentle slope
with permeable soils (for the the privy!)
possessing nice views of the Blue Ridge
amongst shade trees
and within 50 m of a canoe-able river...
so that she can build a campsite there."
allows scenario testing
...if we moved the new landfill, would it be farther from most domestic water wells? Would it be more visible?"
"how about moving it to here?... or here?..."
CommunityViz a commercial ArcGIS extension to test land use scenarios
serves as a data handler for other analyses
e.g., passing geologic and topographic data to an erosion model of
the Appalachians, or passing water quality and groundwater levels to a
groundwater flow model
these are typically written in other languages (C++, Fortran, etc)
that can access the GIS.
- A flood inundation model (GIS holds the data couples with hydrologic model, and displays results)
- A forest fire plume model uses ArcGIS to locate fires from public data and incorporate in calculations)
- which improves understanding and pattern recognition
- & facilitates public participation in alternative
- & coordinates group decision making
- models environmental processes and outcomes
forward modeling - input known conditions to predict outcomes
inverse modeling - input known outcomes or conditions to understand causes
See for example Geostatistical modeling in ArcGIS help
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