Introduction to GIS and Spatial Analysis

Sajid Pareeth, Ph.DS.Pareeth@un-ihe.org

Department of Land & Water ManagementIHE Delft Institute for Water Education

– Concept and application of Water Productivity– Introduced case study – Kirkuk Irrigation project– Introduction to WaPOR database– Data analysis and extraction in WaPOR– You have created a login in WaPOR portal!

Your Day 2 Tasks:

– WaPOR Quiz – 23 of you attempted (Good job !)– Exercise 1: Point time series in WaPOR portal (only 16 submitted yet !)

- (Continue with this exercise, But you are getting more exciting work today !)

Remember the reading/additional materials

Have you all installed QGIS?

Recap to Day 2:

Welcome to Day 3:

Introduction to GIS and Spatial Analysis

• What is GIS?• What is Georeferencing/Projection/Coordinate Reference System (CRS)?• Spatial data – Vector vs Raster?

Discuss !

Can you answer these questions?

GIS

System

GIS

…..the system of computer software, hardware and data, and

personnel to help manipulate, analyze and present information that is

tied to a spatial location.

“G” = Geographic

Denotes the concept of spatial location on Earth’s surface

Importance of relative location (not just where you are but where you are in relation to everyone else)

“I” = Information

Database; tables of data

Transformation of table information into spatial context for analysis and visualization

Geographic Information Systems (GIS)

Data Sources

Geographical Information System (GIS)

Existing analog maps Existing tabular data

Inpu

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sing

Out

put

Satellite Image

- 7 -

Architecture !

A map is a graphic representation or scale model of spatial concepts.

It is a means for conveying geographic information.

Coordinate Systems are grids which are used to describe or identify the location of points in a space.

Maps

Latitudes and Longitudes

• Other terms – Projection, Coordinate Reference System (CRS), SpatialReference System (SRS)

• Georeferencing is defined as the assignment of coordinates of an absolute geographic reference system to a geographic feature

• In remote sensing it is process of assigning geographic coordinates to an satellite image

• Raster data is commonly obtained by scanning maps or collecting aerial photographs and satellite images which needs georeferencing to assign ground coordinates

Georeferencing

• Universal Transverse Mercator (UTM) , cylindrical projection, commonlyused projection in analysis

• Most of the global data sets are provided in Latitude and Longitude

• EPSG stands for European Petroleum Survey Group. They publish a database of coordinate system information plus some very good related documents on map projections and datums.

• Check http://spatialreference.org for details on coordinate systems andcorresponding EPSG codes

You must know !!

UTM zones

Vector

Raster

Tabular information(attribute table)

Data types

Vector data structure

Raster data structure

Raster data structure

• Many formats available for vector and raster– Most common are

- Geotiff for raster (.tif)- Shapefile (.shp)/geopackage(.gpkg) for vector

• Most global products will be in other formats like netCDF and HDF4/5

• List of raster formats here:– http://www.gdal.org/formats_list.html

• List of Vector formats here:– http://www.gdal.org/ogr_formats.html

Data formats

• Free and Open Source GIS Software– An OSGeo project– Packaged with a bunch of other open source libraries and tools– Most popular and stable

QGIS – Quantum GIS

QGIS – User interface

• Three lecture tutorials are provided to you:– Tutorial 1: Introduction to QGIS and map layers– Tutorial 2: Map layout in QGIS– Tutorial 3: Zonal statistics in QGIS

Tutorials – Self pace

You will find the tutorial here

• Follow the tutorials and prepare a population density map of Iraq Governorates:– Example map– Submit the map in .png or .jpgformat– Deadline: 15 April midnight

Exercise 2:

You will find the tutorial here

Submit your exercise here