{"id":1467,"date":"2015-07-22T13:12:24","date_gmt":"2015-07-22T13:12:24","guid":{"rendered":"https:\/\/grindgis.com\/?p=1467"},"modified":"2015-08-12T01:02:56","modified_gmt":"2015-08-12T01:02:56","slug":"create-map-and-learn-basics-about-the-qgis","status":"publish","type":"post","link":"https:\/\/grindgis.com\/?p=1467","title":{"rendered":"Quick and easy to create Map – Learn basics about the QGIS"},"content":{"rendered":"

[vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]Table of Contents:<\/span><\/strong><\/p>\n

1. QGIS installation<\/a><\/p>\n

2. QGIS Interface<\/a><\/p>\n

3. Setting up Spatial Reference System<\/a><\/p>\n

4. Adding vector data, shape files<\/a><\/p>\n

5. Moving around map and map canvas<\/a><\/p>\n

6. Layer management<\/a><\/p>\n

6.1 Layer Function<\/a><\/p>\n

\u00a06.2 Attribute table<\/a><\/p>\n

7. Layer properties<\/a><\/p>\n

7.1 General<\/a><\/p>\n

7.2 Symbol<\/a><\/p>\n

\u00a07.3 Labeling<\/a><\/p>\n

7.4 Other properties<\/a><\/p>\n

8. Preparing vector data: creating, editing and deleting shape files<\/a><\/p>\n

8.1 Creating new shape Files<\/a><\/p>\n

8.2 Editing shape files<\/a><\/p>\n

8.3 Snapping<\/a><\/p>\n

8.4 Adding X and Y coordinates to QGIS<\/a><\/p>\n

9. Geographical Analysis<\/a><\/p>\n

9.1 Spatial query<\/a><\/p>\n

9.2 Geo-processing tools<\/a><\/p>\n

9.3 Convex hull(s)<\/a><\/p>\n

9.4 Clip<\/a><\/p>\n

9.5 Buffer<\/a><\/p>\n

10. Georeference<\/a><\/p>\n

11. Map composition<\/a>[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]1.\u00a0<\/span>QGIS installation<\/span><\/strong>
\n<\/a>
\nQGIS software can be downloaded from https:\/\/www.qgis.org\/en\/site\/forusers\/download.html<\/a> .<\/a><\/p>\n

\"QGIS
\nUser can download the appropriate\u00a0version. In this tutorial, we\u00a0installed QGIS version 2.8 (64 bit) for the windows.<\/p>\n

\"QGIS<\/p>\n

\"QGIS
\nClick Finish at the end.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n2.\u00a0<\/span>QGIS\u00a0Interface<\/span><\/strong>
\nNow you will notice\u00a0QGIS and other open source software\u00a0icons are on the\u00a0desktop.<\/p>\n

\"QGIS
\nClick QGIS Desktop icon to open QGIS interface.<\/p>\n

\"QGIS
\nThere are so many\u00a0useful tools in the QGIS. Basic tools are already presen int the QGIS interface. If you need more tools then right click on the Menu bar and choose available tools.<\/p>\n

\"
\nAll toolbar icons have small description if you hover the mouse cursor over it\u00a0for a moment. This makes it easier to become familiar with the different options and tools in the QGIS.
\nSome window also contain a help button (normally in the bottom left) which\u00a0can sometimes provide helpful tips and information.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n3.<\/span> Setting up\u00a0Spatial\u00a0Reference\u00a0System<\/span><\/strong><\/p>\n

It is best practice to\u00a0define the coordinate system or projection system before you start any work.<\/p>\n

a-\u00a0<\/strong>Setting in main menu bar<\/p>\n

b-\u00a0<\/strong>Option > CRS<\/p>\n

\"Spatial<\/p>\n

c-<\/strong> Then press\u00a0\"\"\u00a0button, new window will popup where you have to select required CRS system.<\/p>\n

\"CRS[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n4.\u00a0<\/span>Adding vector data: shp files<\/span><\/strong><\/p>\n

Vector data is composed of discrete coordinates that can be used as points or connected to create lines and polygons.
\nThere are several ways to add existing vector data to the\u00a0project.<\/p>\n

a-<\/strong> Go to the layer<\/strong> in main menu bar\"Menu<\/p>\n

b-<\/strong> Select add layer<\/strong><\/p>\n

c-<\/strong> Click on add vector layer<\/strong><\/p>\n

 <\/p>\n

 <\/p>\n

Another way is from Manage layer tool box
\n\"add
\nIn Manage Layer tool bar click on Add vector Layer button<\/strong>.<\/p>\n

Another way is from the browser tool box,
\n\"browser<\/p>\n

Browse the shape file location and double click it to add.
\nIn all above\u00a0process user has\u00a0to browse the shape file location and choose file_name.shp file.<\/p>\n

\"add
\nNote: If shape file doesn\u2019t have CRS, then QGIS prompt CRS selection window.<\/em><\/strong>[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n5.\u00a0<\/span>Moving around Map and Map Canvas<\/span><\/strong><\/p>\n

Map navigation toolbox helps to explore map.
\n\"map<\/p>\n

From left to right<\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u00a0\"pan<\/td>\ngrab the map and move it about<\/td>\n<\/tr>\n
\u00a0\"pan<\/td>\nThis tool bring the selected part in the center of screen<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nZooming to the interested area<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nZooming out from the zoomed area<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nThis is basically for Raster data zooming into pixel size<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nThis will bring all map layer in screen extend<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nIt will zoom the selected part<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nIt will zoom selected layer to screen extend<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\nreturn to the last map canvas position<\/td>\n<\/tr>\n
\u00a0\"zoom<\/td>\ngo to the next canvas position<\/td>\n<\/tr>\n
\u00a0\"refresh\"<\/td>\nreload the map canvas (good if it gets stuck or does not display correctly first time)<\/td>\n<\/tr>\n
\u00a0\"identify<\/td>\nIt will show the information of clicked feature.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

To use the tool, Select the right\u00a0tool and apply to the map canvas. User need to play with this tools to get familiar with it.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n6.<\/span>\u00a0Layer Management<\/span><\/strong><\/p>\n

Where the added data goes?<\/p>\n

All your added data goes to the Layers toolbar. Layer toolbox is one of the vital\u00a0component of the QGIS\u00a0where you can play with your data.<\/p>\n

\"Layer
\nWhile working with many layers, it\u00a0should be in right order to visualize data properly. User can drag the layer and move its current position. In the below example, street is move upward. \u00a0Basic thump of rule is in layers toolbox, a polygon layer should be at the bottom, after that polyline and at the\u00a0top should be the point file.<\/p>\n

\"Layers[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>
\n6.1<\/span>\u00a0Layer\u00a0Function<\/strong>
\nThere are several\u00a0layer functions. To display\u00a0the layer function, select a desire layer and then right click.<\/p>\n

\"Layer<\/p>\n

The function are<\/p>\n

\"\":\u00a0A useful way of examining a study area is to zoom to a layer’s extent in the display. This method is a quick and easy way of zooming in to the area of concern.<\/p>\n

\"\":\u00a0The\u00a0Overview<\/em><\/strong>\u00a0window uses a box to show the extent of your display view within the total extent of your data. You can use the\u00a0Overview<\/em><\/strong>\u00a0window to navigate the map in the Data view display.<\/p>\n

\"overview
\nThe red box is the extend of the current map display in the map canvas.<\/p>\n

\"\": It will remove selected layer from the Layers toolbox.<\/p>\n

\"\": It will create a copy of selected layer in the Layers toolbox.<\/p>\n

\"\": \u00a0As name suggested, it sets the minimum and maximum scale to visualize in the map canvas.<\/p>\n

\"scale<\/p>\n

\"\":\u00a0Feature count will show the number of feature on the selected layer as shown in the figure.<\/p>\n

\"layers\"[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>6.2<\/span>\u00a0Attribute Table<\/strong>
\nTo open the attribute table of the selected layer,\u00a0right click and\u00a0\"\"<\/p>\n

\"attribute<\/p>\n

In the attribute table there are many functions and some of them are explain below
\n\"\"<\/p>\n

\"\"Editing mode: This function allow you to modify or update the attribute table.<\/p>\n

\"attribute<\/p>\n

\"attribute<\/p>\n

\"attribute<\/p>\n

\"\"Save: This button save the edit or update. Editing mode should be on.<\/p>\n

\"\"Delete: This will delete the selected row. Editing mode should be on.<\/p>\n

\"\"Selection by Expression.<\/p>\n

\"\"Deselecting<\/p>\n

\"\"Move selected feature on the top.<\/p>\n

\"\"Pan to the selected row.<\/p>\n

\"\"Zoom to the selected row.<\/p>\n

\"\"Copy the selected row.<\/p>\n

\"\"Delete column. This will prompt a window with list of attribute name. By selecting attribute name and pressing OK button will delete the selected column.<\/p>\n

\"delete<\/p>\n

\"\"Add Attribute Column<\/p>\n

\"add<\/p>\n

\"\"Field calculator:<\/p>\n

\"field<\/p>\n

On the bottom of the Attribute table\u00a0there are\u00a0filters in the drop down menu as shown in the below\u00a0figure.<\/p>\n

\"Attribute[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>7.<\/span>\u00a0Layer Properties<\/span><\/strong><\/p>\n

To go to layer properties either double click the selected layer or right click and go to properties. A layer may have different properties some are explain here<\/p>\n

7.1<\/span>\u00a0General<\/strong>
\nThe general properties show the information about layer such as layer name, layer source, CRS etc.
\n<\/a>
\n\"Layer<\/p>\n

7.2<\/span>\u00a0Symbol<\/strong>
\n<\/a>
\nSymbol is the one of the important part for the map representation. Symbol distinguish one feature from another. To symbolize your map, right click on the selected layer then properties and then style. The below figure shows the changing of polygon fill color. This example is for a single symbol for all features.<\/p>\n

\"Layer<\/p>\n

\"Layer
\nThere are many symbol style for representing different features in the same layer as shown in below figure.<\/p>\n

\"Layer<\/p>\n

The below figure shows the categorized symbol according to regions of the world map.
\n\"Layer<\/p>\n

Not only polygon can be symbolized differently but also point and line can be.
\n\"symbolize<\/strong><\/p>\n

\"symbolize
\n<\/a>
\n7.3<\/span>\u00a0Labeling<\/strong>
\nLabels can be added to the\u00a0map to show information about an object. Any vector layer can have labels associated with it. These labels rely on the attribute data of the\u00a0layer.<\/p>\n

\"Labeling\"<\/p>\n

Map composed of Symbols and Labels is the important part.
\n<\/a>
\n7.4<\/span>\u00a0Other Properties<\/strong>
\nThere are many other properties of the layer such as fields, rendering etc. User have to play with this properties to know more about layer properties.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>8.<\/span>\u00a0Preparing vector data: creating, editing and deleting shp files:<\/span><\/strong><\/p>\n

While working with vector data some time we need to create it\u00a0and\/or edit existing data.<\/p>\n

<\/a>8.1<\/span>\u00a0Creating New Shape File.<\/strong>
\nThis helps to create new vector data for eg. Digitization from the image.\u00a0 Shape file can be created by clicking
\n\"\"<\/p>\n

Alternately, Layers tab from main menu, Create Layer<\/strong> and then New Shape file Layer.
\n\"Creating<\/p>\n

This will open a new window as below
\n\"New<\/p>\n

Begin from the top, user have to first define shape file type i.e Point, Line or Polygon. Then define File encoding. After that user have to provide CRS for the new shape file. The newly created shape file might contain various attributes, this can be define in the section New Attribute. Finishing everything and clicking OK button will show up new windows where you have to give the name of the vector layer and the destination to save it.<\/p>\n

<\/a>8.2<\/span>\u00a0Editing Shape Files.<\/strong>
\nAfter creating it, you can\u00a0edit the shape file, either by right clicking the layer and \u2018toggle editing\u2019<\/strong> or highlighting the layer and choosing the \u2018edit\u2019<\/strong> button in the digitize toolbar (see below).<\/p>\n

\"Editing<\/p>\n

\"Editing<\/p>\n

When edit button pressed, the pencil sign shows up on the layer that is editable.<\/p>\n

You can then edit the shape file \u2013if you want to add to the shape file (either more points, more lines or more polygons) you click the \u2018add feature\u2019 button next to the save button on the above toolbar.<\/p>\n

You can also move it and delete parts using the tools on this toolbar.<\/p>\n

To save your edits right click once you are done and click OK on the window that pops up. You can then toggle editing off. It will prompt you to save changes if necessary.<\/p>\n

<\/a>8.3<\/span>\u00a0Snapping:<\/strong><\/p>\n

The vector files you create can snap or join to other shapes files \u2013this can be useful if you are trying to create a complete shape or tracing a feature directly.<\/p>\n

><\/strong>To set the snapping options first go to Settings\/Snapping Option.<\/p>\n

\"snapping<\/p>\n

You will get the Snapping option windows
\n\"snapping<\/p>\n

You can change the snapping mode. The snapping mode define the in which layer includes in snapping.<\/p>\n

\"snapping<\/p>\n

Set the snapping tolerance to pixels or map unit \u2013Choose a tolerance suitable for the work (5 is a good starting point).<\/p>\n

User might also enable snapping for topological editing and\/or intersection at the bottom of snapping option window.<\/p>\n

<\/a>8.4<\/span>\u00a0<\/strong>Adding X and Y Coordinates to QGIS:<\/strong><\/p>\n

Sometime user might have a set of x, y coordinates and other data tables from survey. This data need to be added into the QGIS for further analysis. To do so, if the data table is in csv format is the best. This can be achieved in Excel, by saving as .csv (Comma Delimited).<\/p>\n

The csv file can be added as
\n\"\"<\/p>\n

><\/strong>Click the layer in main menu then add layer and add delimited text layer<\/strong><\/p>\n

><\/strong>Browse for the table<\/p>\n

\"\"<\/p>\n

><\/strong>Name the layer<\/p>\n

><\/strong>Choose the file format, if you have other *.txt with different delimiters then choose custom delimiters and Specify the delimiter string \u2013such comma \u2018,\u2019, semicolon \u2018;\u2019 etc.<\/p>\n

><\/strong>X field is your Easting column, Y field is your Northing column if they are coordinates related entries. Finally you got your x, y coordinates and other data in QGIS.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>9.<\/span>\u00a0Geographical Analysis<\/span><\/strong><\/p>\n

<\/a>9.1<\/span>\u00a0Spatial Query<\/strong>
\nFor example purpose, street network from somewhere around the world is taken.<\/p>\n

\"Spatial<\/p>\n

Then a polygon mask is digitize as mentioned on the above process<\/p>\n

><\/strong>\u00a0Create new shape file<\/p>\n

><\/strong>Toggle Editing<\/p>\n

><\/strong>Add feature (Draw or digitize polygon)<\/p>\n

><\/strong>Save and exit edit mode.<\/p>\n

><\/strong>Make fill color as transparent<\/p>\n

\"Spatial<\/p>\n

\"Spatial<\/p>\n

You will get following windows<\/p>\n

\"Spatial<\/p>\n

In this windows, user have to define<\/p>\n

a.<\/strong> Source feature in which selection has to be made<\/p>\n

b.<\/strong> Spatial Condition for selection such as\u00a0\"Spatial<\/p>\n

c.<\/strong> Then user has to define the reference feature for selection<\/p>\n

d.<\/strong> Then press on apply button that\u00a0gives results as below<\/p>\n

\"Spatial<\/p>\n

Create layer of selected feature press \"\"\u00a0button and you will see one more layer name + selected. In this example streets is selected so streets selected<\/strong> is added.<\/p>\n

\"layers<\/p>\n

The added layer streets selected<\/strong> is temporary so user have to save it for permanency\u00a0by right clicking and then go to save as.<\/p>\n

<\/a>9.2<\/span>\u00a0Geo-Processing tools<\/strong>
\nWhile working with vector data, data has\u00a0to be processed to get the desired result. For this purpose QGIS provides many Geo-processing tools under vector menu<\/strong> in main menu bar.<\/p>\n

\"Geo-Processing<\/p>\n

<\/a>9.3<\/span>\u00a0Convex \u00a0hull(s)<\/strong>
\nThe Convex hull tool derive the mask of the layer data in new shapefile.<\/p>\n

\"convex<\/p>\n

In the following figure the back ground polygon is the convex hull generated for the street network shape file.<\/p>\n

\"polygon\"<\/p>\n

<\/a>9.4<\/span>\u00a0Clip<\/strong><\/p>\n

Sometimes with larger datasets, it is\u00a0useful to extract the small area for the region you are working on. This can be done by creating a new shp file \u2013polygon. Drawing a polygon over the area you want to extract then choosing the clip function in the Vector tools menu. The example is same as the spatial query.<\/p>\n

<\/a>9.5<\/span>\u00a0Buffer<\/strong><\/p>\n

Buffering<\/strong>\u00a0usually creates two areas: one area that is\u00a0within<\/strong>\u00a0a specified distance to select real world features and the other area that is\u00a0beyond<\/strong>. The area that is within the specified distance is called the\u00a0buffer zone<\/strong>.<\/p>\n

A\u00a0buffer zone<\/strong>\u00a0is any area that serves the purpose of keeping real world features distant from one another. Buffer zones are often set up to protect the environment, protect residential and commercial zones from industrial accidents or natural disasters, or to prevent violence. Common types of buffer zones may be greenbelts between residential and commercial areas, border zones between countries, noise protection zones around airports, pollution protection zones along rivers or the right of way of road.<\/p>\n

\"buffer<\/p>\n

\"buffer<\/p>\n

Generally buffer creates a polygon file.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>10.<\/span>\u00a0Georefrence<\/span><\/strong><\/p>\n

QGIS supports various kinds of raster data and Imagery such as *.tiff, *.ecw, *.jpeg etc. Most of the time these raster data need to be geo-reference to its actual ground position. Sometime Raster images comes with location data \u2013for example tiffs accompanied with .tfw files. These files should be kept together in the same folder. When the tiff image is added into QGIS, it\u00a0should drop into the correct location (assuming all projections are correct) and if it does not then we have to do Geo-referencing.<\/p>\n

There are several ways to go Geo-referencing in QGIS. One of them is<\/p>\n

\"Georefrence<\/p>\n

Main Menu>><\/strong> Raster>><\/strong> Georeferencer<\/p>\n

Which open a new window<\/p>\n

Add the raster you want to georeferenced by clicking the \u2018Add raster layer\u2019<\/strong> icon in the window that pops up. Geo-referencing can take place using control points \u2013i.e. points that the image and the actual location on the map are\u00a0in common. These can be derived from features marked on the map that correspond to known features on the image. Or survey data from a GPS or Total Station marking the corners of grids or field boundaries. The important thing is to have control points decided in advance of starting this process, depending on the number of control points that are suitable this will influence the transformation type you select (more detail on this below).<\/p>\n

\"Georefrence<\/p>\n

Add the raster you want to georeferenced by clicking the \u2018Add raster layer\u2019 icon\u00a0\"\"<\/p>\n

in the window that pops up.<\/p>\n

><\/strong>Click the \u2018add control points\u2019 icon\u00a0\"\"<\/p>\n

Then click on the first control point on the raster image you want to locate \u2013a window pops up.<\/p>\n

\"Georefrence<\/p>\n

There is the second option of determining this corresponding point by clicking on the map canvas \u2013follow the onscreen instructions and click the pencil icon labelled \u2018From map canvas\u2019<\/strong>. Then make sure to zoom in as close to this point on the map as possible and click on this point. (toggling between zoom function in main QGIS window and the second georeferencing window \u2013it often reduces to the bottom left corner of the screen)<\/p>\n

><\/strong>Click OK and the first point appears in the panel below the raster.<\/p>\n

><\/strong>Repeat this for the rest of your control points \u2013if you make a mistake at any point you can delete the control point and start it again or move the control point to the correct position using the icons on the georeferencing window toolbar.<\/p>\n

Click the green triangle icon for \u2018start georeferencing\u2019<\/strong> and a window pops up asking you to set the transformation type \u2013click OK.<\/p>\n

\"Transformation<\/p>\n

><\/strong>Transformation Type drop down menu gives you a choice \u2013linear requires 2 control points, polynomials require more depending on the degrees of transformation.<\/p>\n

(Generally it is better where possible to go for polynomial transformation in terms of increased accuracy.)<\/p>\n

><\/strong>Leave resampling method and Compression on their defaults (see figure below).<\/p>\n

><\/strong>Choose a location and name for the output raster (clicking the browse button to the left of this field)<\/p>\n

><\/strong>There is the option to check a box to create a world (.wld) file \u2013this saves the locational data and can be kept with the original raster to use as location data in future projects.<\/p>\n

><\/strong>Check the \u2018load in QGIS when done\u2019 box to display the located layer<\/p>\n

You can also save your georeferencing control points (GCP) using the save icon in this window \u2013this could be useful if you want to try different transformation types before deciding on the most useful one.[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row][vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]<\/a>11.<\/span>\u00a0Map Composition<\/span><\/strong>
\nTo compose map, go to project and new composer or press\u00a0 \"\"\u00a0new composer icon. It will show up composer title. Provide the composer title.<\/p>\n

\"composer<\/p>\n

After pressing OK button, new window will popup.
\n\"new<\/p>\n

In composer interface, there are many buttons. If you hover over the button you can see the tool-tip providing info\u00a0about it. Some of the buttons are explain here.<\/p>\n

\"\"\u00a0Add new map: This button add the QGIS canvas (the map that we want to present) to our composer.<\/p>\n

\"\"\u00a0Add image: to add image<\/p>\n

\"\"\u00a0Add new label: This button help to provide information about generated map such as Title, Author, and Date etc.<\/p>\n

\"\"\u00a0Add new Legend: This button bring the symbol from the map canvas.<\/p>\n

\"\"\u00a0Add new scale: This button provide the map scale.<\/p>\n

\"\"\u00a0Add new arrow: This button help to show north arrow in map.<\/p>\n

\"\"\u00a0Add new attribute: This will add the desired attribute table of available layer. This help to show statistics data on map.<\/p>\n

\"\"\u00a0This buttons help to print map either in hard-copy or in image or in pdf as per user needs.<\/p>\n

To compose map, first click Add new map, then draw rectangle box in working space. Note that this is your main map so present. The added map can be seen in items toolbar and its properties can be edited as per needed.<\/p>\n

\"world[\/vc_column_text][vc_separator style=”double” padding_top=”0″ padding_bottom=”0″][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":"

[vc_row layout=”normal” margintop=”0″ marginbottom=”15″ paddingtop=”0″ paddingbottom=”0″ bg_color=”#ffffff” bg_repeat=”repeat” bg_stretch=”no” en_border=”no” border_color=”#e8e8e8″][vc_column width=”1\/1″][vc_column_text]Table of Contents: 1. QGIS installation 2. QGIS Interface 3. Setting up Spatial Reference System 4. Adding vector data, shape files 5. Moving around map and map canvas 6. Layer management 6.1 Layer Function \u00a06.2 Attribute table 7. Layer properties 7.1 General 7.2 Symbol […]<\/p>\n","protected":false},"author":1,"featured_media":1497,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[316],"tags":[320,318,317,322,115,319,309,321],"class_list":["post-1467","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-qgis","tag-basics-about-qgis","tag-easy-to-create-map","tag-free-map","tag-learn-qgis","tag-map","tag-open-source-software-map","tag-qgis","tag-qgis-tutorial","entry","has-media"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/posts\/1467","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/grindgis.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1467"}],"version-history":[{"count":0,"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/posts\/1467\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/grindgis.com\/index.php?rest_route=\/wp\/v2\/media\/1497"}],"wp:attachment":[{"href":"https:\/\/grindgis.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1467"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/grindgis.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1467"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/grindgis.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1467"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}