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1. Introduction into GIS, Open Geospatial Datasets

A brief introduction to Geographical Information Systems (GIS) and a quick overview of various open geospatial datasets.

Note

More in related course: Geographic Information Systems (155GISE)

Definitions

  • GIS has multiple definitions depending on the context and application (source: Wikipedia):
    • General: GIS is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data.
    • Technical: GIS is a framework that integrates hardware, software, data, and workflows to analyze and visualize spatial relationships, patterns, and trends.
    • Academic: GIS is a multidisciplinary tool used for spatial analysis and decision-making, combining cartography, statistical analysis, and database management.
  • Geospatial data refers to any data that is associated with a specific location (typically on the Earth's surface). It includes information about:
    • physical objects,
    • events, or
    • phenomena that have a geographic or spatial component, typically represented using coordinates.

Examples of geospatial data:

  • administrative boundaries
  • rivers, lakes
  • roads
  • elevation model
  • contours
  • sattelite imagery
  • GPS data
  • weather data
  • ...

Access policies:

  • open data
  • proprietary (closed) data
    • owned by an individual or organization, protected by copyright

Open Geospatial Data - Overview

Example of global datasets:

Situation in Europe overview

How to search for open data in Europe

EU-based catalogue https://data.europa.eu/en

  • Example: NUTS1 data (keyword: NUTS territorial units publisher: Eurostat)

National catalogues:

First experience with the data

What software use to open geospatial data

GIS desktop applications:

Quick info on QGIS:

  • Open source (GNU General Public License)
  • Nowadays very popular and widespread in academia, commercial companies and governmental agencies
  • A lot of plugins

Quick info on Esri ArcGIS:

  • Proprietary
  • Most famous and widely used comprehensive GIS solution

Data manipulations

Data queries in QGIS:

Workflow example in QGIS:

  • Dissolve NUTS region by country code Vector > Geoprocessing Tools > Dissolve

    Dissolve in QGIS

  • Query NUTS layer by country code Select by Expression

    Attribute query in QGIS

  • Query NUTS layer by spatial relationship Vector > Research Tools > Select by Location

    Spatial query in QGIS

Workflow example in Esri ArcGIS Pro:

Workflow in ArcGIS

Task

Compute in ArcGIS Pro all tasks performed in QGIS.

Data examples

OpenStreetMap

General info:

Associated projects:

Data download:

Workflow example in QGIS:

First, let's add OSM as a base map:

Task

Change map window coordinate system (CRS) to EPSG:3857 and compare map distorsions with the original CRS.

Zoom to your area of interest and download vector-based OSM data using QuickOSM plugin.

Note

Install plugin by accessing Plugins > Manage and Install Plugins.

Download vector-based features of your interest (see OSM documentation):

Digital Elevation Model

International programmes:

Simple processing examples in QGIS:

  • Compute slope Raster > Analysis > Slope Slope
  • Compute aspect Raster > Analysis > Aspect Aspect
  • Compute hillshade Raster > Analysis > Hillshade Aspect

Task

Compute in ArcGIS Pro all tasks performed in QGIS.

Earth Observation data

General info:

  • Data about the physical, chemical, and biological systems
  • Natural as well as manmade environment
  • Grid-structured data with spatial, additionaly also temporal information
  • Sources
    • Remote sensing
    • Measurements
  • Examples
    • Photos
    • Radar images
    • Sonar images
    • Measurements
  • Included information
    • Spectral information from satellites
    • Thermometer measurements
    • Altimeter measurements
    • Wind gauge measurements
    • Buoy measurements

Examples of raster satellite data sources:

  • Open data
    • Global
      • Sentinel
        • https://sentinel.esa.int/web/sentinel/missions
        • Sentinel-1: Land and ocean monitoring with radar imaging
        • Sentinel-2: Land monitoring
        • Sentinel-3: Marine observation
        • Sentinel-4: Air quality monitoring (to be launched in 2024)
        • Sentinel-5: Air quality monitoring
        • Sentinel-5P: Sentinel-5 precursor
        • Sentinel-6: Sea-surface altimetry
      • Landsat
        • https://earth.esa.int/eogateway/missions/landsat
        • Landsat-1 to 5: Resolution of 60 to 80 m
        • Landsat-1: 1972 -- 1978
        • Landsat-2: 1975 -- 1982
        • Landsat-3: 1978 -- 1983
        • Landsat-4: 1982 -- 1993
        • Landsat-5: 1984 -- 1999 (limited work acquisitions until 2013)
        • Landsat-7: 1999
          • Still operational
          • Land and coastal areas, shallow waters
          • 8 bands
          • Resolution of 15 to 60 m
        • Landsat-8: 2013
          • Still operational
          • Land and coastal areas, shallow waters
          • 11 bands (9 spectral bands, 2 thermal bands)
          • Spectral bands resolution 15 to 30 m, thermal bands 100 m
      • ...
    • Areas of interest
  • Proprietary data

Sentinel-2 data:

Task

Try to fetch Sentinel-2 data using Copernicus Browser and/or QGIS SentinelHub.