Data formats

Vector - most popular shape format

created by ESRI

*.shp – shape format; the feature geometry itself

*.shx – shape index format; a positional index of the feature geometry to allow seeking forwards and backwards quickly

*.dbf – attribute format; columnar attributes for each shape, in dBase IV format

other extension:

*.sbn *.sbx – a spatial index of the features

*.atx – an attribute index for the .dbf dBase created by ArcCatalog

*.ixs *.mxs – a geocoding index for read-write datasets

*.prj – projection description, using a well-known text representation of coordinate reference systems

*.xml – geospatial metadata in XML format, such as ISO 19115 or other XML schema

QGIS extensions

*. qpj – projection for shp

*.qix – own spatial index

*.cpg – file coding

Raster - most popular tif format in GIS geotiff format

One tif file:

*.tif (header meta data, CS) - any number

*.gpkg geopackages - only byte

Two files, world file created by ESRI

*.tif - image *.tfw - metadata

32.0

0.0

0.0

-32.0

691200.0

4576000.0

Text file - the most popular ESRI ascii format

*.asc

ncols 2265

nrows 2344

xllcenter 564845.00

yllcenter 241993.00

cellsize 1.0

nodata_value -9999

Need to define coordinate system CS!!!!

FOSS4G

FOSS4G is the acronym for Free and Open Source Software for Geospatial. It is the annual recurring global event hosted by OSGeo since it's inception in 2006. Its predecessors were rooted in the GRASS and MapServer communities and can be traced back to the beginning of this millennium. Find all recent conference web sites under the year followed by foss4g.org

OSGeo Open Source Geospatial

Shapefile, GeoPackage czy PostGIS in pl.

GeoPackage

Data source Geoportal

DEM, DSM, Lidar data

Download *.asc

Define CS i QGIS!!!!

EPSG: 2180, PUWG 1992

Task 1.

1. Calculate the difference between Diff=DSM-DEM
2. Slope
3. Aspect

DEM

DSM

SLOPE

ASPECT

Diff=DSM-DEM

Database of topographical object BDOT10k

Buildings PL.PZGiK.283.1261OTBUBDA OTBUBDA

Task 2

1. "Flood" zone, show me the area h<205 m
2. Show me the buildings in "flood" area
3. How many building are in risk zone and how big is the area of the building in risk zone

"flood" area - use raster calculator

Buildings PL.PZGiK.283.1261OTBUBDA OTBUBDA (93795 objects, right mouse klik - show feature count) - clip this layer to DEM (export-save as.... we already dane it), after clipping - 2791 objects

Ad. 2 Show me the buildings in "flood" area - you have to change the model raster to vector or vector to raster

• Raster - Conversion - Poligonize (Raster to vector)
• Intersection (PL.PZGiK.283.1261OTBUBDA OTBUBDA overlay on flood) - an error - processing - toolbox - vector - fix geometry, then it works

Ad. 3 How many building are in risk zone and how big is the area of the building in risk zone - working with attribute table (build_flood) - we had problems during the class, try as follow:

• calculate area PL.PZGiK.283.1261OTBUBDA OTBUBDA
• again intersection (PL.PZGiK.283.1261OTBUBDA OTBUBDA overlay on flood)
• calculate area of build_flood

• calculate percentage of the flooded area of the buildings

• Show me the buildings in "flood" area

• How many building are in risk zone and how big is the area of the building in risk zone

Answer - 2082 building are in 100% flooded