Q-GIS-AN OPEN SOURCE SOFTWARE DEMONSTRATION
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The document provides a comprehensive overview of QGIS, an open-source software used in geographic information systems. It details the process of georeferencing and digitization of geographic data, including step-by-step instructions for using QGIS features. The author, Bhupen Barman, emphasizes the importance of accurate coordinate systems and provides guidance on creating layers and maps.
Q-GIS-AN OPEN SOURCE SOFTWARE DEMONSTRATION
- 1. See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/331258248 QGIS-OPEN SOURCE SOFTWARE Bhupen Barman Assistant Professor in Geography Presentation · February 2019 DOI: 10.13140/RG.2.2.32331.64806 CITATIONS 0 READS 92 1 author: Some of the authors of this publication are also working on these related projects: A Study on Child Working Population in India View project Bhupen Barman Tufanganj Mahavidyalaya 8 PUBLICATIONS 2 CITATIONS SEE PROFILE All content following this page was uploaded by Bhupen Barman on 21 February 2019. The user has requested enhancement of the downloaded file.
- 2. QGIS-OPEN SOURCE SOFTWARE Bhupen Barman Assistant Professor in Geography Tufanganj Mahvidyalaya Cooch Behar bhugeo12@gmail.com
- 3. Q GIS= Quantum GIS Developed By: free and open-source software (FOSS) community Present Version: 3.4.1 "Madeira" (November 2, 2018;) Initial release: 2012 It is an open Source Software. It takes less space. It can run any platform means operating system. Open QGIS Desktop Icon. Now, install the QGIS; Simply search on Google….’’QGIS”
- 6. Just Simply click and install based on your computer operating system, i.e 32 bit or 64 bit.
- 7. Now, open QGIS Desktop 2.14.3 (as per your installed version)
- 10. Georeferencing means that the internal coordinate system of a map or aerial photo image can be related to a ground system of geographic coordinates. Georeferencing means to associate something with locations in physical space. The term is commonly used in the geographic information systems field to describe the process of associating a physical map or raster image of a map with spatial locations. Georeferencing may be applied to any kind of object or structure that can be related to a geographical location, such as points of interest, roads, places, bridges, or buildings. WHAT IS GEOREFERENCING?
- 11. HOW TO GEOREFERENCE? Click on Raster → Georeferencer → Georeferencer → Open Raster → Select file → Open your map → see the co ordinate reference system tool → select datum WGS84 → ok Click on add point (for giving the latitude and longitudinal value) → type longitude at X and latitude value at Y → minimum 3 co-ordinate are required for georeferencing → If you have other georeferenced map like in .tif file or in .kmz file you can add this. Click on setting → transformation Setting (for georeferencing there are many method but but we select polynominal 1) → transformation type: Polynominal 1 → Resampling: Nearest neighbour → Type SRS: by default → close the window → click on the check box × load in your own QGIS folder → ok. (Here in the table residual error is less than one. When you will be expert in that field the error will be zero and if error is more than again you have to georefer the image.) Click on georeferencing → save GCP → ok. Now the georeferencing is done. Close the window Again open the QGIS Desktop → click on add raster → open the .tif file Now find out co ordinate of the given 3 point. Select your project scale at the bottom of the window.
- 25. Digitization is the process of converting information into a digital format . In this format, information is organized into discrete units of data (called bit s) that can be separately addressed (usually in multiple-bit groups called byte s). It is the process of converting geographic data either from a hardcopy or a scanned image into vector data by tracing the features. During the digitzing process, features from the traced map or image are captured as coordinates in either point, line, or polygon format. WHAT IS DIGITIZATION?
- 26. HOW DO WE DIGITISE POINT, LINE& POLYGON? For creating layer or shape file: Here for each object (point, line, polygon) one individual shape file is created. For polygon or area feature Click on Layer tab → create layer → create shape file → select polygon for area feature → click on toggle editing for digitizing → click on add feature → active the layer then → click on start digitizing. For common boundary: Click on setting → snapping → advanced → click on every check box → apply → ok. After complete the digitization → click on toggle editing → save. Same process you can digitize the point. For line feature Click on layer → create shape file → new shape file → click on add field box give the features name like road or river → click on toggle editing → digitize the feature → click on Save.
- 45. HOW TO LAYOUT A MAP? For Thematic mapping: Click on polygon feature → column → select pop density → classify → apply → ok. Layout: Click on project → new print composer → for page setup click on composition tab → click on orientation → portable/landscape → add new map and drag into the page → click on move for moving the map → for scale click on scale → for legend click on legend For north line: add image → item properties → search directory → add north line → click on grid → add interval → draw co ordinate (for putting value) → format → degree minute → ok → for heading → click on text → click on export image → export image in bmp or jpg or pdf format.
- 55. HOW TO ADD ATTRIBUTE IN SHAPE FILE?
- 60. Thank you View publication statsView publication stats