Geospatial Analysis and Modeling: Introduction

1
Geospatial Analysis and Modeling Introduction

• Geospatial Analysis and Modeling
• Assignment notes
• Helena Mitasova, NCSU MEAS

2
Outline

• Tasks and instructions
• Workspaces
• Dataset
• Software
• Getting started

3
Tasks and instructions

• Select PC-POD that you will be using for this
  course
• Login using unity ID
• Open web browser and go to MEA592 website
• courses.ncsu.edu/mea.html
• the mouse is wireless you may need to hold it
  longer to get a response

http//skagit.meas.ncsu.edu/helena/lteachtest/GIS
T.html
4
Tasks and instructions

• General tasks description on Assignment main
  page
• Step-by-step instructions provided in text form,
  done in GUI for both
• GRASS and ArcGIS

5
Homework

• Report 300-600 word 1-2 pages images/maps
• Problem, task, background
• Approach, methodology - general description,
  no need to repeat step-by-step instructions
• Results maps, images, graphs, numbers with
  brief comments
• Discussion observations in results, method
  issues, point to problems in assignment
• Conclusion - 1-2 sentences what you have
  learned
• Due on Tuesday (lecture class)?

6
Workspace on PODs

• Workspace and data available on PC-PODs
• c\workspace\MEA592_003
• create folders with your unity ID
• copy data from C\GRASS\GISDATABASE to your
  folder
• GRASS GISDATABASE nc_spm
• ArcGIS Geodatabase
• ncrast_geodatabase_15_08_08
• ncshape_geodatabase_15_08_08
• you have to use the same PC-POD to get to this
  workspace but the display is faster

7
Dataset

• Data are provided at three hierarchical levels
• entire NC state with raster data at 500m
  resolution
• South-west Wake County with raster data at
  resolutions 30m-10m
• small watershed in rural area with data
  resolutions of 1m-3m
• See more at
• http//www.grassbook.org/data_menu3rd.php

8
Software

• GRASS6.3 Free and Open source GIS
  grass.osgeo.org
• Works on Mac, Linux, and MS Windows, the last one
  is experimental
• ArcGIS9.2 leading proprietary GIS by ESRI
  www.esri.com
• Links to manuals, virtual campus on the Assigment
  web page

9
GRASS GIS data management

• Designed for team work in a given region, focus
  on analysis
• LOCATION is a project that has common coordinate
  system.
• Each LOCATION can have several MAPSETS, one is
  called PERMANENT to store baseline data, others
  are set by users. You can modify the data only in
  your current MAPSET, but you can view or copy
  data from other MAPSETS.

10
GRASS GIS data management

• DO NOT MANIPULATE FILES and DIRECTORIES IN GRASS
  Database always use GRASS commands to create,
  copy, delete MAPSETs, layers, etc.

11
ArcGIS data management

• Designed for quick viewing, organization of data
  is less restrictive
• Raster and vector data in separate geodatabase

12
Getting started in GRASS

• Instructor
• open GRASS, select gisdatabase, location and
  mapset
• display elevation
• change region to elevation 10m
• nviz elevation
• display elevation elevation_shaded
• display roadsmajor and schools

13
Getting started in GRASS

• Several modes of running commands
• GUI select command from menus, fill-in options,
  Run
• type in command name, Run(GUI), fill-in options,
  Run
• type or paste (Shift-Insert) entire command, Run
• add command button, type in command, Run
• type or copy commands in unix shell
• Run d. commands through GUI

14
Getting started in GRASS region

• GRASS performs commands on computational region
  spatial extent set by g.region (pre-defined area,
  area given by raster or vector layer, ..)
• Region can be different from viewing area or map
  layer spatial extent.
• Viewing area is controled by zoom functions
• GRASS does not automatically extend viewing
  region to map extent

15
Getting started in ArcGIS

• Instructor
• Programs-ArcGIS-ArcMap
• Add Data Select ncrast.mdb/elev
• Change color elev-Properties-Symbology
• select bgo, invert, stretch none
• Add Data - Select ncrast.mdb/elev_sh
• Change transp. elev_sh Properties Display
• set Transparency to 70

16
Getting started in ArcGIS

• ArcScene
• Add Data - ncrast.mdb/elev
• Change color- elev - properties- symbology
• Base heights - from elev, zunit 10
• View scene properties - light

17
Homework Section 1 comments

• What is XY coordinate system
• elipsoid/datum projection
• Datum defines the placement (origin, orientation)
  of the geographic coordinate system (lat/long)
  upon the elipsoid, this lat/long system is then
  projected to a plane

18
Homework Section 1 comments

• XY coordinate system elipsoid/datum projection
• Our coordinate system NC State Plane NAD83
  grs80 lambert conformal conic projection (lcc)
• ArcGIS output that describes XY coordinate system
  is confusing (PRJ file info is OK)
• XY coordinate system Name
• Lambert conformal conic ???
• Projections are often used in coordinate system
  names, e.g. UTM zone 17, but there are many
  coordinate systems that use LCC

19
Homework Section 1 comments

• Name
• Lambert conformal conic that is projection
• But In details it provides description of
• - NC state plane coordinate system
• AND
• Geographic coordinate system (lat/long) from
  which it was projected, but the data are not in
  the geographic coordinate system
• (did they mean geodetic reference system?)

20
Portfolio

• Set of homework reports in pdf format
• Slides for the presentation in ppt, pdf or odp
  format, improved based on the feedback will be
  graded based on peer review
• Research paper project report graded based on
  my review

21
Workspace server

• Workspace available on server
• \\yellowstone.cnr.ncsu.edu\class\MEA592_003
• GRASS GISDATABASE North-Carolina
• ArcGIS Geodatabases for the same data
• workspace studentwork with your folders
• copy Geodatabases to your folder
• this space is available from any computer on
  campus, but the display is slower