How to Convert a Matrix in a Geospatial Tiff in QGIS with PyQGIS - Tutorial

Raster are matrices with geospatial reference. In order to make a finite difference model or any other model compatible with QGIS we have to process the matrix with its parameters to be represented as a spatially referenced raster. The process involves some Python scripting on the QGIS console, processing time is low and the process can be applied for many matrices without visual representation of intermediate files that saves computational time and resources.

This tutorial show the complete process of matrix construction, parameter calculation and spatially representation in the Python console of QGIS.

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How To Create Line From Points in QGIS with PyQGIS and Pandas - Tutorial

Python scripting allows us to enhance the data management and spatial analysis in QGIS. Most times, spatial data comes from a variety of data providers in a sort of formats and data types that we have to be adapted to the GIS standard. Big data and continuos monitoring create large datasets that have to indexed, sorted and manipulated in a effective way.

QGIS has a Python console and the capability to install external Python packages that run on QGIS session. This time we have installed Pandas in QGIS to handle the data from a sensing device made on a Raspberry Pi 3 and then we have defined the path as a succession of points with PyQGIS scripting.

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Spatio-Temporal Hurricane Tracking in the Gulf of Mexico with QGIS and PyQGIS - Tutorial

This tutorial show a mixed procedure with native QGIS tools and PyQGIS commands for the data representation, styling and plotting with spatio-temporal criteria with the TimeManager plugin. Data for this tutorial was downloaded from the National Hurricane Center's Tropical Cyclone Reports that contains information as six-hourly positions and intensities. You can access the whole hurricane database o

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How to add multiple Vector Layers and group them in QGIS with PyQGIS - Tutorial

QGIS is a great software for the processing/analysis of spatial data, Python is a clear, powerful programming lenguaje; together they can enhance the spatial analysis to solve more complex or more dedicated problems in less time. PyQGIS is the Python environment inside QGIS with a set of QGIS libraries plus the Python tools with the potential of running other powerful libraries as Pandas, Numpy or Scikit-learn. 

This tutorial shows the whole procedure to upload multiple files from a certain pattern and group them on the Layer Panel using PyQGIS commands.

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How to Upload a Shapefile in QGIS with PyQGIS - Tutorial

QGIS is a great software for the processing/analysis of spatial data, Python is a clear, powerful programming lenguaje; together they can enhance the spatial analysis to solve more complex or more dedicated problems in less time. PyQGIS is the Python environment inside QGIS with a set of QGIS libraries plus the Python tools with the potential of running other powerful libraries as Pandas, Numpy or Scikit-learn. This tutorial show the basic procedure to upload a shapefile in QGIS with PyQGIS.

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How to join tables in QGIS - Tutorial

QGIS is a powerful open source software for spatial analysis and management of spatial data. User experience with QGIS is great and most users find QGIS easier to use than other free and commercial GIS software. This time we will show how simple is the process to join tables in QGIS. Spatial data of sanitary quality of beaches in Lima was used to show the join table process.

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Introduction to PyQGIS, the Python environment in QGIS

QGIS is a great software for the processing/analysis of spatial data, Python is a clear, powerful programming lenguaje; together they can enhance the spatial analysis to solve more complex or more dedicated problems in less time. PyQGIS is the Python environment inside QGIS with a set of QGIS libraries plus the Python tools with the potential of running other powerful libraries as Pandas, Numpy or Scikit-learn. This tutorial shows the main parts of the Python environment and has some practical cases of vector data layers.

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Tutorial: Georeferencing Historic/Ancient Maps with QGIS

Working with spatial data on many environments requires an historic perspective of the land use, urban development and other changes on earth surface. Some times (or most times) the only data available is on printed form with or without a system of reference that makes this data of limited use for a spatial analysis. Afortunately, QGIS can handle the georeferenciation of ancient maps on a smooth and quick way based on the functionality of its tools.

Anyone can overlay an historic map on the map canvas on few steps. This tutorial shows the whole procedure to georeference a map of Lima city from 1856 in QGIS.

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Tutorial: Determination of Glaciers and Lakes from Sentinel 2 Images with QGIS and SCP Plugin

Any object on the earth has a "signature" on a different bands or ranges on the visible and invisible spectrum. Base on the values and trends on this "spectral signature" one can classify different types of land cover as lakes, soils, wetlands, exposed rock and glaciers from many free and available multispectral satellite images as Sentinel 2, Aster, MODIS, and Landsat. QGIS is a very powerful open geographical information system software and its plugin Semiautomatic Classification Plugin gives QGIS many capabilities for the download, preprocess, classification and analysis of satellite imagery without using another desktop software. This tutorial deals with the whole procedure for the supervised classification of lakes and glaciers on a clipped Sentinel 2 image and its vectorization as polygons.

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Tutorial: Direct Landsat Imagery Dowload in QGIS with SCP Plugin

Based on the review from our followers, we have noticed that the download procedure to download images from the NASA and USGS web servers had changed. It is not clear the current method to download the selected files, even if you have your username and password set up correctly. Luckly there is an alternative way to download those files with QGIS and the Semiautomatic Classification Plugin (SCP). This tutorial covers the whole procedure to sign up, select, previsualize and download a Landsat 8 in QGIS with the SCP Plugin.

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Tutorial: Water Surplus Evaluation at Basin Scale with QGIS and Remote Sensing Data

The current availability of strong open source GIS software together with remote sensing data and specific data products as high resolution precipitation and evapotranspiration makes possible the assessment at global scale on short processing time of certain parts of the water cycle. Water surplus is the difference in between precipitation and actual evapotranspiration, that can be translated to the difference in between IMERG imagery (precipitation) and MOD16 imagery (actual evapotranspiration). This raster algebra calculation could be implemented in open source software as QGIS with a set of specific procedures as reprojections, temporary files and raster calculators. This tutorial deal with the water surplus calculation for a andean basin for year 2015.

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Tutorial: Area of Study AsterDEM Download and Basin - Stream Delineation in QGIS

QGIS is a open source software for spatial analysis and data representation. There are many tools from QGIS for the hydrological/hydrogeological evaluation and modeling. This time we have made a tutorial with the whole procedure of the download process for a AsterDEM only on the extension of an area of study. The DEM was later reprojected on QGIS and processed to get the channel network and drainage basins. The tutorial has the purpose to show how simple is the process of working with QGIS and Processing.

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Tutorial to Georeference Google Searches with Python and QGIS

To carry out a series of studies and investigations we have to know both name and location of certain places. This may be available through some web pages, however the use of data is limited and advance geoprocessing tools on softwares as QGIS can not be used. There are several services or APIs that can bring you the spatial location of Google searches. In this tutorial we will use the Google Maps API for the location of Hospitals in a radius of 5 kilometers from a point in Miraflores, Lima. Only open source software tools have been used for this tutorial.

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Determination of Mining Projects Areas with Satellite Imagery and QGIS

Our current working conditions require access to spatial information in short periods of time. Work planning tasks or quoting of services require data of distances, areas, proximities, medium elevations, among others. The data can be given by clients, organizations or by field monitoring, but they may not be available at the required moment. The use of geoprocessng tools of satellite imagery reduces the required time to have this information. Since QGIS is open source and the Landsat, MODIS and Aster images are free, this type of geoprocessing is versatile, economic and friendly for any user with basic/intermediate QGIS knowledge.

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VIDEO: Webminar on Satellite Imagery Analysis with QGIS - May 10, 2017

Satellite Imagery has developed a new dimension in the evaluation of water resources, environment, land planning, atmosphere and climate change. There are many satellites and imagery available, many of them being free of cost. At the same time, powerful open source tools for spatial analysis and representation are available.

This webminar wants to give a perspective on search, manage and interpretation of satellite imagery, through practical exercises using QGIS.

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How to represent Sentinel 2 Bands in a False Color Image with QGIS

False color images are used to enhance certain cover types as vegetation on the image representation. This tutorial show the procedure represent the bands of a False Color image from Sentinel 2 bands in QGIS. 

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