Difference between revisions of "QGIS"

Latest revision as of 14:48, 22 July 2020

QGIS

QGIS (previously known as Quantum GIS) is a free and open-source cross-platform, desktop geographic information system (GIS) application that supports viewing, editing, and analysis of geospatial data. QGIS functions as geographic information system (GIS) software, allowing users to analyse and edit spatial information, in addition to composing and exporting graphical maps. QGIS supports both raster and vector layers; vector data is stored as point, line, or polygon features. Multiple formats of raster images are supported and the software can georeference images. QGIS integrates with other open-source GIS packages, including PostGIS, GRASS GIS, and MapServer. Plugins written in Python or C++ extend QGIS's capabilities. Plugins can geocode using the Google Geocoding API, perform geoprocessing functions, which are similar to the standard tools found in ArcGIS, and interface with PostgreSQL/PostGIS, SpatiaLite and MySQL databases.

The Spoken Tutorial Effort for QGIS has being contributed by Dr. Snehalatha Kaliappan from IIT-Bombay and Prajwal.M from NIT Suratkal.

The scripts for these tutorials were reviewed by Prof. Pennan Chinnasamy, CTARA, IIT-Bombay

https://script.spoken-tutorial.org/skins/common/images/button_bold.png

Basic Level

1. Installation of QGIS

• System requirements to install QGIS
• Add QGIS repositories on Ubuntu Linux OS
• Installation of QGIS on Ubuntu Linux OS
• Visit the Official QGIS Website
• Download QGIS installer for Windows 10
• Installation of QGIS on Windows 10
• Download QGIS installer for Mac OS X
• Installation of QGIS on Mac OS X
• Open and show QGIS interface

2. Downloading GIS Datasets

• Basic introduction to GIS
• Download open source vector datasets from Natural Earth Data website
• About geospatial data
• About vector data
• View vector data in QGIS
• Save the map in .qgs format
• Download raster dataset from Bhuvan website
• About raster data
• View raster data in QGIS

3. Coordinate Reference Systems

• Add layers to the projections in QGIS
• Change the color of the layer
• Resize the panels on the canvas
• View metadata information for layers in QGIS
• Save selected features from a layer to a new layer
• Re-project and overlay data layers of different projections together
• Delete a layer from the dataset

4. Digiiizing Map Data

• Create Point and Polygon shape files
• Digitize Point and Polygon shape files
• About Toggle editing and Add Feature tools
• Open attribute table for Point feature
• Open attribute table for Polygon feature
• Change style and color for Point and Polygon features

5. Importing Spreadsheets

• Import speadsheets in CSV format to create a Point layer
• Convert Point layer to a Polyline layer
• About QGIS Geoalgorithm
• About WMS layers
• Select a WMS map from Bhuvan website
• Load WMS (Web Map Service) layers in QGIS

6. Vector Data Styling

• Load vector data in QGIS
• Open attribute table for the layer
• Learn to style vector layers using,

Single symbol styling Categorized styling Graduated styling

• Show how to Label features

7. Geometric Properties of Vectors

• Show attribute table for a shapefile layer
• Show selected features from attribute table on the map
• Change the CRS of the layer
• Add columns to the attribute table
• Calculate statistics for the attributes using Field Calculator tool

8. Raster Data Styling

• Information about download and save example files from the Code files link
• Change Coordinate Reference System for the given layer
• Use Identify Features tool to view the pixel value
• Change the style of the raster map
• About raster properties
• View metadata information
• Write an expression in the raster calculator

9. Creating a Map

• Information on how to download the example files given in Code files link
• Add vector layer on the canvas
• Show labels for the cities on the map
• About Print Composer tool
• Show how to show and hide panels
• Create a map using Print Composer
• Add map elements in the composer (add a new map, grid, images, label, scale, inset map)
• Export the map

10. Creating Dataset using Google Earth Pro

About Google Earth Pro program Download and install Google Earth Pro on Ubuntu Linux 16.04 Navigate Google Earth Pro Create a point dataset for a few locations in Maharashtra Use Google Earth Pro to create a boundary layer for Maharashtra state About Kml and Kmz file formats Save the layers in Kml format Open the points layer and boundary layer in QGIS

11. Plugins

• Information about the Plugins
• Enable Core Plugins
• Install an External Plugin
• Locate a Plugin on QGIS interface
• Install QuickMapServices Plugin
• Download OpenStreetMap data
• Use QuickOSM Plugin to convert OSM data to a shapefile
• View 3D visualization of a map layer using Qgis2threejs Plugin
• Settings in the Plugins menu

Intermediate Level

12. Table Joins and Spatial Joins

• Load vector layer on QGIS canvas
• Open attribute table for the layer
• About different types of combining attribute data
• Add Delimited Text Layer on QGIS canvas
• Join the attribute tables of two data sets having common field (Table Join)
• Join the attribute tables of two data sets having same spatial data (Spatial Join)
• Save the Project

Advanced Level

13. Nearest Neighbour Analysis

• Open shapefiles showing locations of volcanoes and cities on QGIS canvas
• Open attribute table for the layers
• About Nearest Neighbour Analysis
• Statistical analysis using Distance matrix method
• Save Distance matrix analysis as a layer in CSV format
• Open attribute table for the Distance matrix layer
• Run Nearest Neighbour Analysis algorithm
• Analysis of results after running the Nearest Neighbour Analysis algorithm
• Save the project

14. DEM Analysis

• About Digital Elevation Model (DEM) analysis
• Open Shuttle Radar Topography Mission (SRTM) data website
• Download DEM data from SRTM data website
• Save DEM data from SRTM data website
• Open SRTM data file with .tif extension in QGIS
• Show Hillshade of DEM
• Show Symbology for the DEM layer

15. Create Contour Lines

• Add DEM on QGIS map canvas
• Clip area in DEM using Clipper tool
• About contour lines
• Show contour lines for the DEM
• Change the color of the contour lines
• Open the attribute table for the contour layer
• Mark the highest elevated area on the contour map
• Save the project
• Show Symbology for the Hillshade layer

16. Interpolation

• About Interpolation
• Methods of interpolation
• Load the vector layer on QGIS canvas
• Label the Point features on the map
• Enable Interpolation Plugin
• About Inverse Distance Weighting (IDW) method
• Interpolation of Point layer using IDW method
• Save the Interpolated map
• About Triangulated Irregular Network (TIN)
• Interpolation of Point layer using TIN method