Filtering data from PostGIS database in QGIS

Filtering data from PostGIS database in QGIS

Geo-databases, QGIS, Slider, Software
Hello, Today, I wanted to share a very short article with you regarding spatial data queries in QGIS from a PostGIS database. This is an approach widely used by developers, analysts and other professionals in the GIS sector in trying to achieve their objectives.Loading spatial data from a remote server or node, at times, requires more bandwidth and more time to completely load the datasets on your GIS enviroment.To avoid this, one can use a way that filters and loads data records that are  require and leave the rest. Such is in QGIS with the help of the postgisQueryBuilder . This plugin enable us to accomplish tasks as described above. In relation to this, I have recorded a short video that will guide you towards achieving the desired results. Watch…
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The good news in QGIS 2.14.0 – Essen

The good news in QGIS 2.14.0 – Essen

General, GIS, QGIS, Slider, Software
In the last few years, QGIS has really grown in a huge collection of tools, algorithms tackling various tasks in its environments.The Dev team has really given QGIS a new look and feel and also power to roar in the GIS world. Tools tackling simple to complex processes have now been developed and been released for use by the wider community. QGIS 2.14.0 was released and comes with really great functionality that were missing in previous releases. Follow along as I unwrap some of  the functionality for you. Added Styling Options This new version of QGIS comes with new and great styling options for layers, either point, line or polygon. Styles in QGIS 2.14.0 Zoom to Feature (By Right Clicking on feature in attribute table)  This gives an easier access…
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The amazing sections in QGIS

The amazing sections in QGIS

Highlight, QGIS, Software
Recently, I posted a photo here about the styling effects found in QGIS for vector layers.This quite caught many eyes into the issue of the awesomeness found in QGIS and today, I want to explore some of this awesomeness.First, I will start with the issue mentioned above; Draw effects in style section Often, we do make beautiful maps in our projects and we glad about them.But, ever wondered how it would look like if some extra hype was added into the symbology capabilities in QGIS?...probably yes.The "Draw effects" capabilities comes in handy to help in such.The section helps add glow and other effects to the vector data available in the project. Below is an example; This is done from this window in QGIS Symbol levels In a GIS, the three…
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3D visualization of Data in QGIS

3D visualization of Data in QGIS

Highlight, Tutorials
Well, this is a topic that I have always wanted to write about but have been a little bit reluctant.I think this has been attributed to the fact that I didn't find people who wanted to use this feature.Last week, I found someone who really wanted this in their project.Here is the thing, if you want to have a 3D view of your data, QGIS provides an out-of-the-box plugin (Qgis2threejs) that really helps us in doing this.Take a look. Steps Load you data in QGIS canvas.In my case am using data for Nairobi buildings with a height attribute. We will be creating a 3D view of our buildings as an overlay on OpenStreetMap baselayer. Launch the Qgis2threejs plugin from the Web Menu.(Web > Qgis2threejs > Qgis2threejs) if you have Qgis2threejs…
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Using QGIS Layer Styles in GeoServer

Using QGIS Layer Styles in GeoServer

GIS, QGIS, Software, Tutorials
GeoServer provides us with the functionality of styling our layers to match our preferences. However, many are the times that many GeoServer users face problems while publishing their layers. Styling in GeoServer should be an easy task when doing web applications or publishing your GIS layers via GeoServer. [caption id="attachment_181" align="aligncenter" width="390"] Expected Results[/caption] Today, I will focus on how to apply same styles for layers in GeoServer as in your QGIS project. Here are a few steps that can be followed to achieve the expected results. Load a PostGIS layer in the map canvas in QGIS using the Add PostGIS layers option in Manage Layers toolbar.   The Add PostGIS tabledialog box appears and it gives the option to add a connection to our PostGIS tables Add connection Fill…
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Generating Contours from  DEM in QGIS

Generating Contours from DEM in QGIS

GIS, QGIS, Software, Tutorials
      A few weeks ago I wrote a post on “Generating DEMs from Contours” which was quite a straight forward process as explained.In this post , I will show how to “reverse engineer” the process and generate contours from DEMs. This time round am also going to demonstrate how to clip our dataset to work with the area of interest instead of working on the whole dataset. Lets begin: Assumption: You have the DEM on your local machine. If not so, data can be downloaded from either USGS EarthExplorer or from GeoComm Steps: Launch QGIS 2.X and Load our Raster Layer (DEM) i.e. Ken_dem (sample data for this tutorial) [caption id="attachment_187" align="aligncenter" width="640"] Load DEM in QGIS[/caption]   Go to Raster > Extraction > Clipper (This will help us in…
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Maps for the Color blind

GIS, QGIS, Software
We are living in an era of digital maps.We've evolved from static maps to dynamic maps where different formats(icons,pictures) of information are being developed and shared by a large group of people globally.When mapping,less often do we consider the color blind.How do you paint a picture or develop a map when the color blind is waiting to see the results.Over a long period, this has been a difficult area to tackle but thanks to QGIS.QGIS introduced the "Preview Mode" (Simulate Color Blindness (Protanope/Deuteranope)) which help GIS Analysts to create maps that will be perceived by all. To Do: In QGIS 2.4 (Windows) Go to "VIEW" > Preview Mode > (select either Simulate Color Blindness Protanope / Deuteranope ) The outputs for various modes have the visual difference as the images…
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Adding layers from GeoServer in QGIS

Adding layers from GeoServer in QGIS

GeoServer, GIS, QGIS, Software, Web-GIS
In a GIS, the ability to handle more data formats is of key priority while developing the system. This gives the GIS users a wider variety of formats to choose from during their analysis. QGIS has implemented this by allowing users to add data from many sources and in many formats. Loading a WMS, WFS or a WCS is one of the vital abilities for users carrying out web mapping operations with their data. The three formats of data can be loaded easily directly from GeoServer into QGIS. First we need to establish a secure connection between QGIS and GeoServer. Load the WMS/WMTS dialog window at Layers >> Add WMS/WMTS Layer on the Menu (QGIS) or by selecting the Add WMS/WMTS layer from the Manage layers toolbar. Select “New” to…
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