Integration of advanced GIS technologies for decision support

Introduction

Data

Remote sensing data

Free satelite images: Landsat, Sentinel browsers:

The Copernicus Open Access Hub (previously known as Sentinels Scientific Data Hub) provides complete, free and open access to Sentinel-1, Sentinel-2, Sentinel-3 and Sentinel-5P user products

Copernicus Open Access Hub -

Landsat, SRTM and much more data provider:

EarthExplorer

GIS data

Data preparation

Coordinate System (CS) of the features

XYZ Tiles in QGIS - base maps are available

OSM CS geographical
DTM SRTM CS geographical

NO projection, only coordinate on the elipsoid! Problem!!!

CS of the project

QGIS is possible to change CS on-the-flight

CS EPSG codes

rys1

Change CS of the feature

We would like to avoid geographicala CS. In QGIS you can transform the data coordinates during export !!!!

right klick on the feature in legend-Export-Save feature as

you can:

change CS
data extent (clip to the zoomed window)

if you clip raster you can change spatial resolution (pixel size), but take care QGIS cheats, check in feature properties and correct coordinates of map extent

Changing CS:

vector: 1. coordinate's transformation
raster: 2. coordinate's transformation, 3. resampling

Vector analysis

attribute query
- Working with the Attribute Table
- Query by attribute
buffering, Vector-Geoprocessing Tools
overlaying, Vector-Geoprocessing Tools

Vector analysis - case study - site location

conditions:

We are looking "barriers=gates"
10 m around residential streets

How we realize it?

Query by attribute: SQL (osmpoints) SELECT * FROM osmpoints WHERE BARRIER='GATE'
Query by attribute: SQL (osmlines) SELECT * osmlines WHERE HIGHWAY='RESIDENTIAL'
Buffering Vector-Geoprocessing-Buffer (selected feature only), 10, round, dissolved result = condition1
Overlaying 1 by 3 Vector-Geoprocessing-Intersection osm_points selected overlay on canditon1=condition2