USING GIS IN GEOMORPHOLICAL STUDIES

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USING GIS IN GEOMORPHOLICAL STUDIES
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Background

• Need for dealing with massive data.
• GIS
• Visualize and analysis of spatial data.
• GIS can assist in carrying out geomorpholocial
  study in easier and more accurate manner.

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Objective

• To develop a GIS-based systematic approach for
  conducting a geomorphological study and its
  relevant analysis procedures.

• Methodology
• Assessing existing manual approaches.
• Identifying the main steps of building GIS for
  geomorphological studies.
• Highlighting the main advantages of GIS-based
  approach compared to manual ones.

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Manual approach

• Data collection
• Topographic maps
• Aerial photographs
• A filed survey
• Build a number of base maps
• Geological map
• Drainage map (Network)
• Contour map
• Data calculation and tabulation.
• Data analysis.
• Producing final maps and graphs.

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GIS-BasedApproach
Definition required data
Maps
Data collection from secondary source of data
Previous studies
Field survey
AutoCad
Map digitizing
Transformation of AutoCad drawing files
Construct topology
ArcInfo
No errors
Check errors
Errors
Correct errors
Spatial data editing
Map registration
Data entry
Building Data base
ArcView
Data analysis
Data analysis and output
Data visualization and output
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Maps
Geologic map
Topographic map
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Map digitizing
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Building data base
Type Name Feature
Polygon Geology Geologic units
Line Structure Structure
Polygon Basin Watershed
Line Network Drainage
Point Level Levels points
Line Road Transportation roads
Point Well Water wells
Polygon Study area Study area border
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Spatial data editing
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Attribute data entry
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Analysis capabilities

• Inquiry functions.
• Table
• View (Map)
• Surface analysis
• Building DEM
• Creating contour map
• Carrying out most morphometric analysis
• Overlap functions
• Interrelationships between various factors.

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Inquiry function
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DEM and Contour Map
DEM
Contour Map
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Morphometric analysis
Network
Overlap Identify streams of the selected basin
Watershed Select a basin
Inquiry Number and length of streams 1st, 2nd,
3rd, 4th order
Editing attribute table of watershed
Frequency
Drainage density (stream length/ drainage basin
area)
Stream bifurcation
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Manual Vs. GIS-based approach
GIS-Based approach Manual approach Item
Requires less time Consuming time process Time
Hard work in building the system Hard work process in all stages Efforts
More accurate Less accurate Accuracy
Applicable Not applicable Amendments

• Moreover, GIS-based approach has more advantages
• High analytical capabilities.
• Producing maps and charts.
• Providing database for further research and
  application

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Conclusion

• GIS is not a system for producing maps.
• The analytical capabilities is the most important
  characteristics of GIS
• The great potentials of GIS-based approach to be
  applied in geomorphological studies.
• The efficiency of the suggested approach
  requires
• Capacity buildings activities
• Training
• Networking
• More arguments on morphometric analysis