This is the second part in working with the HCMGIS QGIS Desktop plugin that is rich with functionalities and to check out the first part of thewalkthrough click the link shown Working with HCMGIS QGIS Plugin Part 1
The walkthrough continues below with more functionalities.
Download Covid-19 Data
The third tool is for downloading Covid-19 data which can be used to create heatmaps showing and performing analysis on data with respect to covid-19. Click on Download Covid-19 Data shortcut under it select the first submenu shortcut as shown below.
This downloads and displays covid-19 data from the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University Hopkins data repository. The downloaded data appears as shown below in QGIS Desktop map canvas.
The map below shows covid-19 data for African countries with each dot representing country or sovereignty.
Below is the attribute table for the covid-19 point layer. Note the Country_Region column containing names of countries.
While still in the attribute table, identify and click on the icon on top of the attribute data that contains an epsilon label as shown below.
This opens selection window which will be used to demonstrate selection in QGIS Desktop by use of expression. For details on QGIS expressions refer to the QGIS Documentation.
The intention here is to select points representing countries with covid-19 cases that are beyond a given value. The first step will be to identify the field/column that contains the value of our interest. In this case identify the Fields and Values and double click to collapse it and select Active by double clicking on it as well.
Note that the double clicked field name will appear in the left text area containing double quotes. Note that all fields in QGIS expressions are represented like the one shown below. Add a greater than sign ‘>’ as shown below and add a value like 100000 as shown below.
Ensure that the expression window’s bottom left area is clear of any errors that can be indicated in red and then click Select Features button at the bottom right area of the window.
If the attribute table had been closed, open it and the selected fields will appear as shown below.
Similarly in the map, some of the points have been selected (in yellow) and represent countries that have active cases of over 100000.
In summary, we have been able to visualize covid-19 data using HCMGIS plugin and filtered the data to select only countries that have over 100000 active covid-19 cases. This is a case example among others that HCMGIS plugin can be used.
Download Open Data
Browsing for GIS data online, identifying it, downloading and extracting it can be time consuming and at times exhausting. HCMGIS plugin’s Download OpenData functionality can save some time on this and also provide up-to-date data for those repositories that update their data.
To download data from geofabrik, click on the first option under Download OpenData shortcut labelled OSM Data ye Country from Geofabrik. Geofabrik, as explained in a recent post on downloading geospatial data is an open street map data repository through which one can download data from.
On clicking the shortcut a windows is displayed and appears as shown below. It contains various controls for selection and buttons.
Click on the first drop down that contains representation of world regions. For this case, Africa region would suffice otherwise any other region can be selected.
The next step entails selecting a country within Africa region selected above. Sao Tome and Principe is the selected country as shown below. Note that different countries have different sizes of datasets and the bigger the data, the more the time it will take to download the data.
Use the browse button labelled … to navigate to he folder where the downloaded data will be saved. Select a suitable location in the local computer. A message will show informing on the size of data to be downloaded and that it may take time. The message is as shown below.
Once the download is complete, the download progress bar will be full and at 100% as shown below.
After download a success message will be shown as well indicating that the download has been completed successfully.
The downloaded data will automatically be loaded in the QGIS Desktop layers panel and in the map canvas as shown below. for Sao Tome and Principe.
Similar to previous steps, the attribute table of the data can also be opened and for this case, the attribute table appears as shown below.
In summary, HCMGIS plugin can be leveraged to download data from Geofabrik, an Open Street Map data repository o-the-fly into the machine and visualized.
Download GADM data
The other open data download supported include data from Global ADMinistrative areas repository which can be accessed from this link.
Click on the shortcut shown below to download data from GADM repository.
A window containing download options in controls appears as shown below. To begin, click on country drop down.
The drop down shows list of all countries in the world. Select your preferred country as in this case, the selected country is Kenya. as shown below.
A message showing the shapefile size to be downloaded and informs that the download may take time. Click Yes button to continue.
Once the download has started, the progress bar starts to change by increasing percentage value as the download continues in the background. Once the download has completed, the progress bar is at 100%.
A message is shown once the download is complete informing that the download process has completed successfully or with error. Click OK button to continue.
Another message similar to the messages above shows informing that the extraction of the data has completed successfully. Click OK to proceed.
The downloaded data is displayed in the QGIS map canvas and has several administrative levels. The one shown below is the administrative level zero of the whole country. Note that in the Layers panel there are four layers representing the administrative levels.
Disable all the layers by unchecking the checkboxes in the Layers panel except for the layer labelled gadm36_KEN_1 which will be shown in the map canvas as below. This is the administrative level 1 representing the counties of Kenya.
To view the attribute table right click on the active (checked) layer and click Open Attribute Data option shown below.
The attribute table for the layer will be displayed and appears as shown below.
In summary, the plugin saves the time that would take to navigate to download page using browser to download like in a previous procedure and also extracts and visualizes the data in QGIS Desktop.
Building Footprints from Microsoft
HCMGIS plugin supports spatial dataset download from Microsoft Building footprints data repository. The repository can be accessed through their GitHub repository. To access the functionality, click on the shortcut as shown below.
A window containing controls for country, province/state, file size and number of buildings among others appears as shown below. Click on the country drop down.
The only available option in this case is United States and under it select Alaska state. After selecting the above, then the number of buildings and file size is displayed in their corresponding text areas. Also ensure that the preferred save folder is selected. Click on Apply button to poceed.
A confirmation message similar to previous ones appears as shown below. Click Yes button to proceed.
Once the download is complete, a message box similar to others in previous steps is shown indicating that download has been completed. Click on OK button below.
After extraction another message box is shown and appears as below. Click OK button to proceed.
The downloaded data is visualized in the QGIS map canvas and appears as shown below. The data consist of buildings spanning across the state of Alaska.
Download Other Open Data
HCMGIS plugin supports dowloading of other data from the web through the Web Feature Service (WFS) which is an Open Geospatial Consortum (OGC) standard. Click on the the shortcut as shown below.
A window is displayed and contains controls based on the WFS specification such as the title and abstract which populate on selecting a supported service provider.
The supported service providers appear as shown below on clicking the Service Provider drop down.
One of the service providers is the HCMGIS OpenData and when selected, the abstract, title and WFS layers sections are populated and appear as shown below. This gives the user the chance to select an individual layer of interest for download.
Change the service provider to World Food Programme as shown below.
The WFS layers will change on changing the service provider. After selecting the provider, identify any layer on the WFS layers list. Note that the selected option is named geonode:food_insecurity at number 11.
Once that is selected, click Browser… button to point to the output folder where the data will be downloaded into.
Select SHAPE-ZIP as the output format which instructs the plugin to download data in the format of a zipped file.
The screenshot below shows the selected dataset of our interest.
Once Apply buton is clicked, the progress bar is activated and shows the download size in percentage. Once it completes, the progress bar appears as shown below, also the number of layers being downloaded is shown.
The data that has been downloaded appears in the QGIS map canvas as shown below.
The attribute table for the downloaded data appears as shown below.
In summary, the HCMGIS QGIS Desktop plugin can be leveraged in different ways based on users interest and can help achieve some user’s goals. Try the plugin for yourself and use different options and different datasets.
About HCMGIS Plugin
HCMGIS is a QGIS Desktop plugin that has been developed by Center for Applied GIS of Ho Chi Minh City and the code repository for the plugin can be accessed through this GitHub link and comprises of the following functionalities:
- Basemaps loader.
- Batch Converter for some GIS data formats.
- Downloader for Covid-19 Data.
- Downloader for datasets from various platforms.
- Downloader for Vietnam datasets.
- Geometry Processing tool.
- Calculate Field tool.
In this walkthrough we shall only look at the first four functionalities.
Installing HCMGIS Plugin
To install HCMGIS QGIS plugin, one can either download a zipped file from the HCMGIS Plugin repository or download directly from the QGIS Desktop Plugins menu. Below is a screenshot of the HCMGIS plugins repository for the HCMGIS plugin.
This walkthrough assumes that QGIS Desktop is already installed in the computer. If not, refer to the post on Installing QGIS Desktop in Windows 10 . This walkthrough has been done in Windows 10. After opening QGIS Desktop and installing the HCMGIS plugin, the plugin menu under installed section should appear as shown below.
The menu should also be visible in the QGIS menu as shown below.
When clicked the shortcuts under it appear as shown below. The items functions are as highlighted in the previous section.
Click on the BaseMap shortcut and the dropdown appears showing a list of all the basemaps supported by the plugin. Note that you require to be having an internet connection to load the basemaps as they are being loaded from the web.
Under BaseMap shortcut, click on the GoogleMaps option and a map is loaded in the QGIS Map Canvas and on the Layers Panel as a layer if active as shown below and is zoomed into Kenya’s bounds. The service is developed and maintained by Google.
When done with the above base map, close and click on the HCMGIS plugin once again and click on the Bing Virtual Earth option and the base map loads showing a terrain kind of map that looks like natural landscape with green vegetation. The free service can be used to view features on earth’s surface.
The next base map is the CartoLight base map which is maintained by Carto and can come in handy with custom data overlays or in designing a map in QGIS Desktop. There are other children of carto base maps that include Carto Dark and Carto Eco. Below is the Carto Light base map which is preferred for point data. The development repository can be accessed here.
The final base map in this walkthrough includes the WikiMedia base map which appears as shown below. There are a variety of basemaps that can be used under the HCMGIS plugin and just a few have been covered here.
After downloading the data, in the QGIS Desktop menu identify and click HCMGIS menu and if it is not visible revisit previous steps of opening the QGIS Plugin menu and activating or even re-installing the plugin otherwise, the clicking should show a dropdown that appears as shown below.
Click on the Vector Format Converter shortcut and this open a widget that appears as shown below and contains several controls; dropdowns, buttons and text fields.
Under the input format label is a drop down when clicked, shows all the supported input formats. In this case we will be working with ESRI shapefile denoted by SHP option therefore, select that option.
Similarly, under the output format label, select CSV as the option indicating that we shall be outputting our data in Comma Separated Value (CSV) file.
After selecting input and output formats, click on the Browse… button which will open an input folder window. Navigate to the folder containing the previously downloaded and extracted data and click OK button to close the window.
If pointed to the correct folder, the shapefiles existing in that folder will be shown as a list as shown below. The folder in this case contains four shapefiles.
After ensuring all above mentioned options are correct, click Apply button to proceed with the conversion.
After the conversion is complete, the progress bar will be at 100% and a label indicating number of files converted will be shown as below. If any errors occurred during conversion they will be displayed in the error log area below the progress bar.
The whole window appears as shown below after conversion.
Navigate to the output location that is similar to the input folder and additional files with a .csv extension will appear as shown below. They may be arranged by name or other field but the file type will be Comma Separated Values.
On loading the layers in QGIS Desktop and opening the attribute table, the data looks as shown below.
CSV to Point Converter
In this next step, we will select the CSV to Point shortcut as shown below.
This tool geocodes CSV data and converts them to shapefiles which is quite the opposite of what we did in the previous step only that in this step the input and output formats are fixed.
Click on Browse… button to browse to the directory containing input CSV files. The input files must contain coordinates fields in Latitude and Longitude otherwise the conversion will not take place. To mitigate this from happening, open the CSV data in a text editor or in QGIS Desktop to view the attribute data and confirm that it has coordinates.
The data used in this procedure can de downloaded from ArcGIS Hub data repository and is as listed below:
Once the data has been downloaded navigate in the browse window shown below to the folder containing the files and click Select Folder button to close.
Now that the input folder has been selected, the next step entails identifying the latitude and longitude fields. At times the plugin automatically detects the fields and lists them as shown in the screenshot below but at times the user may be forced to click on the drop downs below the Latitude Field and Longitude Field consecutively to identify the actual field name containing the coordinates.
Once selected every control as required, click Apply button to begin the conversion process. Once the process is complete the progress bar will be at 100% and the number of converted files will be shown in bold above the progress bar.
The previously existing files in CSV can be identified as shown below.
The newly created ESRI shapefiles can be identified as shown below.
To add the layers, click on the Add Vector Layer… shortcut as shown below.
The Data Source Manager window is displayed as shown below with the Vector option highlighted. Click on the button labelled … to browse the file system.
A file browser window similar to previous file browser windows is displayed as shown below. Point it to the files of interest and note that they end in .shp extension indicating that they are shapefiles and then click Open button.
The shapefiles are loaded as vector layers and displayed in the QGIS map canvas as shown below.
In the QGIS Desktop Browser panel, identiy XYZ Tiles and double click on it to collapse it and among the options identify OpenStreetMap that comes with QGIS by default.
This loads an Open Street Map base map however it appears on top of the vector layer therefore hiding the points and it is necessary to correct that.
In the layers panel shown below, drag the OpenStreetMap layer shown below by clicking and holding the mouse button downwards below the other two layers and it will appear as shown below.
And also for the map, the points will be seen to appear on top of the basemap.
In the above steps the conversion of datasets has been summarized and this shows that the HCMGIS plugin can come in handy and remove the repetitive process of converting multiple files by loading them into the QGIS Desktop and exporting them manually.
QGIS Desktop plugins extend the base functionalities of the GIS desktop software. On its own, QGIS Desktop can help users achieve a lot of tasks from digitizing, connecting to a database and creating of maps among others. Plugins enrich QGIS Desktop functionality and in this post we shall see our first example plugin that is the QuickMapService plugin. The tutorial highlights how to download, install and use the plugin.
QuickMapServices is a QGIS Desktop plugin that comprises of several web services, datasets and basemaps that can be used as a help to digitizing, comparing vector feature locations, change detection studies among many other tasks. It has been developed by NextGIS and its code repository can be accessed using this link. To install a plugin in QGIS Desktop, one can either download a zipped file from the QGIS Python Plugins repository or download directly from the QGIS Desktop Plugins menu. Below is a screenshot of the QGIS Plugins repository.
This tutorial assumes that QGIS Desktop is already installed in the computer. If not, refer to my post on Installing QGIS Desktop in Windows 10 and if using Ubuntu Linux refer to Installing QGIS Desktop in Ubuntu Linux this tutorial uses Ubuntu. Run the QGIS Desktop by clicking on the shortcut either pinned in the GNOME taskbar as shown below.
Alternatively, the QGIS Desktop shortcut can be accessed by clicking the home key in the keyboard (could be marked as a windows key) and type in the search area QGIS and the shortcut shall appear as shown below as long as one has QGIS installed in the computer.
After clicking the QGIS Desktop shortcut, then the splash screen is displayed for few seconds and appears as shown below. Note that the splash screen differs with the QGIS Desktop version installed in the computer.
After the splash screen disappears, the QGIS Desktop user interface is displayed and contains different controls and menus. The screenshot below shows the user interface in its default state and may differ with others if user interface settings have been customized. To understand the QGIS Desktop user interface, view my post on Exploring the QGIS Desktop User Interface .
In the Menu Bar at the top just below the black title bar lies all the menus that are shown in the QGIS by default. Some plugins once installed populate or insert additional menus. Identify the Plugins menu that is between Settings and Vector menus above and click on it and the drop down containing a list of two menus pops down as shown below.
Click the Manage and Install Plugins… shortcut which triggers a connection to the QGIS Plugins Repository shown at the beginning of this post but from the QGIS user interface.
If the connection is successful then the plugins widget appears as shown below containing all the install-able plugins from the plugin repository. Otherwise a message box showing error in connection is displayed and the plugins menu shown will only have the QGIS core plugins under the Installed tab menu.
Click in the search bar at the top and type QuickMapService and the plugins will be filtered as typing continues and will finally show the plugin of our interest as shown below.
Click on the Install Plugin button at the bottom right of the widget. If already installed then the buttons will be labelled Uninstall Plugin and another one labelled Re-install Plugin. Ensure that connection to the internet is working as it downloads the plugin files from the internet.
Once installed, ensure that the left checkbox is checked as shown below for the QuickMapServices plugin meaning that it will be active in the QGIS Desktop user interface.
Close the plugin widget and in the QGIS Desktop user interface, there will be a docked widget which for now can be closed since it is not being used in this task.
Identify and click the Web menu in the menu bar area and a dropdown appears as shown below. Hover the cursor on top of the QuickMapServices.
The drop down shows only five services however these could be very few for most usages and tasks. Therefore there would be need to add more services.
Luckily, instead of using an additional plugin or looking for web map services’ urls on the web which could be time consuming, QuickMapServices plugin has settings to add these extra services if they appear as shown above. On the plugin menus just below the services shown above, identify and click settings which is highlighted below.
The settings comprise of a number of tabs in which the More Services tab is of our interest therefore click on it if not active and the contents will appear as shown below. Click on the button labelled Get contributed pack below.
The additional services are installed from the internet and this process will only be successful if there is working internet connection otherwise an error in connection message will be shown.
Click OK above and in the settings widget click on save button shown as below.
To show the added services, click on the QuickMapServices menu under Web QGIS menu and they will appear as shown below.
We shall begin by loading a Google Satellite base map by selecting the options as shown below.
By clicking on the Google Satellite option, the layer from Google Satellite is loaded on the QGIS map canvas area and on the layers panel all as shown below.
One can also zoom into the image and an example of the layer display after zooming in appears as shown below. The area shown is a part of Lake Victoria located in western part of Kenya in East Africa region.The second service to load will be ESRI Satellite basemap that appears under the ESRI option as shown below.
On selecting the ESRI Satellite option, the basemap is loaded as a layer in the QGIS map canvas just like in the previous step. It may seem somewhat similar but also with some differences to the previous but the provider (ESRI in this case) is different.
The final service that we will load in this tutorial will be Stamen Terrain whose options appear as shown below.
On selecting Stamen Terrain, the layer is visualized in the QGIS map canvas layer and is as shown below. As it can be noticed, the style of the layer below is different from the previous layers.
We have been able to install QGIS plugin named QuickMapServices and can come in handy for tasks such as having a base map layer for map, digitizing of features from layer and Geo-referencing tasks just to mention a few. This plugin is also flexible on the number of services that on e can work with therefore give it a try.
Installing QGIS Server in Windows 10
This tutorial or walkthrough is curated for those people who might want to install QGIS Server in their machines containing Windows 10 operating system or those that might be encountering challenges in installing the same. It consist of a step-by-step procedure with explanations that the usual setups and installation wizards might have or the information provided is little to make one understand.
QGIS Server is a an open source Geographic Information Systems (GIS) server that leverages on the Open Geospatial Consortium (OGC)’s services which include:
- Web Map Service (WMS)
- Web Feature Service (WFS)
- Web Coverage Service (WCS)
The above services have been well described in a previous post here. QGIS Server can be deployed in both Windows 10 and the steps below show how one can deploy/install the robust GIS server. A standard QGIS Server does not have specifications per-se and for such one can make reference to GIS StackExchange
Navigate to QGIS Installers web page at Download QGIS page using your browser. The web page looks as shown below.
Similarly, navigate using your browser to XAMPP Download Page that appears as below.
Click on the Download button. Note that there are only 64-bit downloads in the page above and this will also start a download process in the browser. Once the downloads are complete, the files appear in the file systam as shown below.
In this procedure, we will start with installing QGIS Server using the network installer. Double click the osgeo4w setup or right mouse click and select open option. This makes the installer wizard to appear as shown below.
Ensure the Advanced Install radio button is the selected one as above. This option grants the liberty to install individual Desktop and Server packages unlike the other two and in this case we only want to install the QGIS Server. Click Next button to proceed to the next wizard page shown below.
The option Install from Internet is for initial download (first run) which instructs the setup to download files from the internet into the computer and this is the step that we shall use. The option Download Without Installing just download files from the internet and does not install. The third option, Install from Local Directory is used when one has downloaded the files into a folder in local computer. (One needs to know there the files have been downloaded) Click Next to proceed.
The Root Directory above is the ‘installation folder’ that hosts the installed/extracted files and by default the path is as shown in the white text input above as C:\OSGeo4W64 . One can change by clicking the Browse… button though we will leave it as is. For the users section, All Users ensures that all users in the computer can access the OSGeo4w software while for the Just Me option only the current user (one who is installing and must have administrative rights) has access to those files. Click Next to proceed.
The Local Package Directory is the folder in which the contents of QGIS Server and other supporting files (not installed files) downloaded from the internet will be saved and the Start menu name is the name that will appear in Windows Startup Programs as shortcut. Just lke the previous one can click on the Browse… button to select a custom location. When Browse… button is clicked, the following Windows Browse window appears as shown below.
Once you select the preferred folder, click OK button to close. Below page shows a custom location that has been selected.
Once the custom location is selected, click Next to proceed.
In the above page, the way with which the setup connects to the internet must be configured. By default the Direct Connection option is selected. Use IE5 Settings uses Internet Explorer 5 connectionconfiguration while the Use HTTP/FTP Proxy option is used where the network is behind a proxy. In this the default option is left as is. Click Next to proceed.
There are various download site URLs that are listed above and the setup downloads from the user selected option. Select one of the links to activate the Next button or one can also add a custom URL in the User URL text field and click Add button. When the existing URL is clicked it appears as shown below.
Once the URL has been selected or a custom URL has been input, the Next button is activated and can be clicked to continue.
There are many packages that can be downloaded and installed by the osgeo4W installer and they are listed in the above page. Since the installation is for QGIS Server, click the + sign next wo Web option and it collapses with 5 more options. Click on the Skip option for qgis-server and a version number will appear just as shown above. The rest of the options can be left as is. Click Next button to continue.
The page shown above displays a list of the packages and libraries that will be installed. Click Next button to proceed.
This page initializes a download of the packages from the URL that was selected earlier. Some libraries are shipped with End User License Agreements (EULA) that one must accept to continue as some also have licenses for free, non-commercial usage and et cetera. After accepting these licenses and agreements, click Next to continue.
A page with active progress bars (in green above) appears and the percentage download progress is also displayed at the title bar above. The first progress bar shows the download progress for the individual package being downloaded, the second shows the overall/total download progress of the packages and the third progress bar shown the computer disk size. This process should not be interrupted and it is dependent on internet speed/network latency once complete i.e. at 100% then the following final page is shown. If there are errors in download, then the download failure will be shown in a rather similar fashion. Click Finish button to close the installer wizard.
Next procedure entails installation of XAMPP. XAMPP is a free and open source web application server that is cross-platform and has been developed by Apache Foundation. It consists of Apache Web Server, MariaDB database and Hypertext Preprocessor (PHP) and Perl interpreters among othets. Let’s begin by double clicking the xampp setup that was downloaded in the beginning steps.
The setup wizard appears as shown above. Click Next button to proceed.
Above are the packages that are shipped with the XAMPP setup. For the purposes of QGIS Server, only the Server > Apache is required therefore the rest can be unchecked to match the case above. A breakdown of the main components required for the QGIS Server installation include:
- Apache Server – The role of this server in QGIS Server is to provide Hypertext Transfer Protocol (HTTP) in which the OGC services mentioned in the beginning of this post are dependent on. QGIS Server uses FastCGI protocol that is an Apache module therefore the importance of the server is realized in this.
- PHP – This comes tightly coupled with the web server therefore cannot be unchecked (at least for version 8.0.3)
Click Next button to continue.
The page shown the default path/folder in which the selected components of XAMPP will be installed in. By default it installs in the Windows’ system/OS drive i.e. C:\Xampp and to change this click on the icon on the right side of the path field and it opens the file system for one to select their preferred installation location. Once the preferred location is clicked, click Next button to continue.
Select the preferred language and click Next to proceed.
On this page, some info on the developers of the installer, if not interested in the info, uncheck the checkbox as above and by click Next button to continue.
Click Next button to begin installation of the components.
A progress wizard similar to those in osgeo4W installer appears in the middle of the page below the XAMPP welcome image. The installation should not take a lot of time but also depended on hardware specifications. Once the installation is complete, Next button is activated and can be clicked to proceed.
This informs that the installation has completed successfully. Ensure the checkbox in the page is checks so that it can open the XAMPP control panel. Click Next button to proceed.
The control panel assists in enabling and disabling the services listed. In the case above, only Apache has been installed therefore, it is the only active row while the rest are inactive (greyed out). Click on the Start button in the first row for Apache.
The control panel shown above indicates that Apache Server module is running and is assigned the Process Identification (PID) 7036, 150028 and running on port(s) 80, 443. Click on the Admin button.
A browser page is opened with the URL pointing to the localhost and it confirms that apache in deed is running.
Once both XAMPP and QGIS Server are installed, we have to configure some settings in the default apache configuration file. By default, the apache configuration file (for XAMPP 3.0.8) is located in C:/xampp/apache/conf/httpd.conf
The file shown above can be opened with a text editor like notepad or any other editor that is installed and contains settings/configurations for the apache server and one has to be careful not to remove or insert wrong information in the file as it may affect the working of apache server.
The apache configuration file appears as shown above in Notepad++ text editor.
Let’s confirm hat the file qgis_mapserv.fcgi exists in the bin folder of the qgis app in folder shown above. If it exists then we
Edit the line shown above for the Script Alias (highlighted in grey) to point to the bin directory shown in the previous diagram. Note that the original line has been commented by adding a # before it.
Similarly add a directory directive as shown above (in grey) to point to the same bin folder as the previous and inside it a number of statements that allows apache server permissions to access the folder and also execute the relevant scripts.
Add an .exe handler in order to enable server to execute the QGIS Server executable files.
Finally, add the following lines as shown above and ensure that the paths in the lines shown above actually exist otherwise there might be errors when attempting to run QGIS Server.
After the above procedures, open XAMPP from the Windows start menu if not running and it will display the control panel and ensure that apache server is already running. Navigate using your browser to http://localhost/cgi-bin/qgis_mapserv.fcgi.exe?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities which opens a an XML (eXtensible Markup Language) page showing the WMS capabilities of the server.
A Web Map Service (WMS) is a standard leveraged in serving maps that are georeferenced through the web. The WMS standard is maintained by the Open Geospatial Consortium (OGC). The WMS request URL or link consists of a number of request parameters among them includes GetCapabilities and GetMap requests. For more on these refer to the OGC WMS Specification document. WMS output formats include:
- Portable Network Graphic (PNG)
- Joint Photographic Experts Group (JPEG)
- Tag Image File Format (TIFF), GeoTIFF
- Scalable Vector Graphics (SVG)
- Portable Document Format (PDF)
- Keyhole Markup Language (KML)
- KMZ – This is a zipped KML
A Web Feature Service (WFS) is a standard for serving Geographic Information commonly referred to as features across the web. Similarly to the previous standard, is maintained by the Open Geospatial Consortium (OGC). The WFS request URL or link consists of a number of request parameters among them includes GetCapabilities, DescribeFeatureType and GetFeature requests among others. For more on these refer to the OGC WFS Specification document. WFS output formats include:
- Geography Markup Language (GML)
- ESRI Shapefile
- Comma Separated Values (CSV)
Geospatial is a term that has been trending for a while now and one that has caught the eye of many with the recent events and trends on space exploration, climate change and digital journalism just to mention a some as this list can be endless. In my own context, this term can be split into two sub-terms;
- Geo – Relating to earth or ‘has Earth component’.
- Spatial – Relating to space or ‘has space component’.
For one to analyze data with relation to location then one must get data that has location component and this location has a ‘geo’ and ‘spatial’ component therefore termed geospatial data. There are a gazillion sources of data at a time that we are struggling with handling of big data of all sorts, location-based data being one of them.
I compiled a list of freely available data sources at this time which includes the following:
- OpenStreetMap This contains crowdsourced and compiled data of regions and the whole world that is updated at various intervals, some daily, weekly, hourly etc. The data consists of way-points, points of interest (POIs), roads and road names and buildings. It also provides an application programming interface (API) through which one can query and download data using other software. For country and other extracts, check here and for the whole world check here.
- Natural Earth This is a data repository for vector and raster data that is published at different scales and it is supported by North American Cartographic Information Society (NACIS).
- UNEP Environmental Data Exlporer Data source repository provided by the United Nations Environmental Programme (UNEP) that consist of geospatial datasets related to global and local weather, watershed boundaries, average monthly temperatures etc. To obtain data, one must search either using keywords or the provided filters for searching specific datasets.
- Copernicus Open Access Hub This access hub provides free access to Sentinel satellite datasets and is managed by the European Commission. One must register and sign in to download data from this repository. The type of datasets to expect from this hub include data related to marine environment, forest cover, wetlands, atmospheric data on solar radiation and pollution among others.
- USGS Earth Explorer Provides access to earth science data from various satellites such as Landsat through an interactive user interface and is managed by U.S Geological Survey.