Tangible Geospatial Modeling System and GRASS GIS

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Tangible Geospatial Modeling System and GRASS GIS

• Helena Mitasova
• North Carolina State University
• Russell S. Harmon
• Army Research Laboratory, Army Research Office

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GIS and spatial simulations
Explore answers to questions What happens with
water, ecosystems, if - we change land use? -
sea level is 1m higher? - area is flooded or
trees are cut? Create new landscape
configurations in 2D using map algebra or
digitizing If the change is 3D and we need to
explore many scenarios, digitizing becomes
tedious and collaboration is limited
touch systems work in 2D
can we make changes in 3D ?
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GIS and physical 3D models
New technologies combine easy to interpret 3d
physical models of landscape with geospatial data
to facilitate communication and collaboration
Xenovision Dynamic Matrix Display 2004 and
NG Terrain Table computer controlled dynamic
3D model very expensive low 3D resolution
GISon3D static model
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MIT Illuminating Clay
Solid model provides tangible landscape
interface 3D landscape model is modified by
hand, scanned, analyzed and result is projected
over the model in near-real-time Developed by
MIT Media laboratory SENSEable City lab
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Working with Illuminated Clay
Testing with model based on real world
data, adding a checkdam, creating a depression
and watching the flow direction, profile, slope
to change
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Building TanGIS at the VISSTA lab
3D scanners projectors 3D display
workstations web cameras flexible models
System is linked to GIS GRASS, ArcGIS - both
can be used simultaneously Multipurpose facility
at VISSTA Lab at ECE NCSU Prof. Hamid Krim
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3D landscape design with TanGIS
3D laser scanner projector
flexible model with projected orthophoto
Mitasova, H., Mitas, Ratti, Ishii, Alonso,
Harmon, 2006, Real-time Human Interaction With
Landscape Models Using a Tangible Geospatial
Modeling Environment, IEEE CGApp, 26(4).
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3D landscape design with TanGIS
Modify model and scan it
3D laser scanner projector
flexible model with projected orthophoto
Compute DEM, run flow simulation, project the
results (img or animation)?
Mitasova, H., Mitas, Ratti, Ishii, Alonso,
Harmon, 2006, Real-time Human Interaction With
Landscape Models Using a Tangible Geospatial
Modeling Environment, IEEE CGApp, 26(4).
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Case study experimental watershed
Problems sediment deposition, road
flooding Design new land management alternatives
in 3D space and evaluate their impacts
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1993 photogrammetric DEM
Sediment pollution
N
N
Flooding
0 200m
2001 lidar-based DEM
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Impact of landscape modification
N
initial terrain
flexible clay model
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Impact of landscape modification
initial terrain road breaks

flexible clay model take out piece of
clay
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Impact of landscape modification
initial terrain road breaks
checkdam is added
flexible clay model take out piece of
clay add piece of clay
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Impact of landscape modification
initial terrain road breaks
checkdam is added
flexible clay model take out piece of
clay add piece of clay
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Impact of landscape modification

• Modify landscape
• add buildings, ponds, dams, roads
• change land cover properties
• Compute and project
• elevation or volume change,
• slope and aspect
• viewshed, line of sight
• flow accumulation and watershed boundaries
• soil erosion and deposition,
• solar energy potential

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Terrain with buildings in TanGIS
elevation change
Add buildings
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Terrain with buildings in TanGIS
elevation change
Add buildings
Runoff from buildings, compacted surface
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Terrain with buildings in TanGIS
elevation change
Add buildings
Runoff from buildings only
Runoff from buildings, compacted surface
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TanGIS as collaboration tool
Investigating impact of reckless design
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TanGIS as collaboration tool
Investigating impact of reckless design
Design by Army research team Note persistence
of flooding if infiltration stays the same
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Getting creative in TanGIS
Exploring various materials, testing runoff
simulations on surfaces with depressions and
various patterns of roughness
lagoon
porous parking lot
Design by USFWSUSGSNCDENR team
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Getting creative in TanGIS
Exploring various materials, testing runoff
simulations on surfaces with depressions and
various patterns of roughness
lagoon
summer solstice
porous parking lot

• the model does not crash in spite of all the
  pits and flats
• more rainfall is needed to flood the road

Design by USFWSUSGSNCDENR team
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Testing models in TanGIS
Testing runoff simulations on surfaces with
depressions and various patterns of roughness
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Solar radiation in TanGIS
Where to locate solar pannels? Analyze pattern of
solar radiation
January 16
March 30
April 30
summer solstice
winter solstice
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Teaching with GRASS6

• Updated NCSU GIS curriculum now includes Open
  Source GRASS GIS
• Geospatial Modeling and Analysis course
• Data integration, display and 3D visualization
• Proximity analysis, cost surfaces
• Terrain modeling, analysis, geomorphometry
• Flow tracing, watershed analysis, landforms
• Modeling geospatial processes, Tangible GIS

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Teaching with GRASS and TanGIS

• Tangible GIS in class
• experiment with laser scanning of different
  materials,
• process point clouds of features with different
  geometries and surface properties
• test algorithms for analysis and simulations
• explore and demonstrate spatial impacts of
  landscape change on runoff, erosion, solar
  irradiation, ...

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Open source GIS GRASS6.4 http//grass.osgeo.org
General purpose GIS 2D/3D raster and vector
data management, analysis, modeling,
visualization for Linux, Mac and
MSWindows Developed by US Army CERL
1982-1993 GPL since 1999, current development
coordinated from Trento, Italy, official OSGeo
project GRASS64RC3 available new wxPython GUI,
native MS Windows support, new and enhanced
modules
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Conclusion

Laboratory 3D laser scanning can be used for
Tangible GIS an experimental environment for
analysis of landscape change impacts and
design GRASS GIS and TanGIS now included in NCSU
GIS curriculum Geospatial Modeling and Analysis
course, more coming
Funding by the US Army Research Office and NC
WRRI is gratefully acknowledged
GRASS GIS
Open Source Geospatial
Foundation