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GIS - EN version
Transcript of GIS - EN version
Colorado State U. http://www.cnr.colostate.edu/class_info/nr502/lg1/map_projections/
Kang-tsung Change, 2003, Introduction to Geographic Information Systems (2nd Edition), McGraw-Hill Higher Education press.
Paul A. Longley et al., 2001, Geographic Information Systems and Science, John Wiley & Sons press.
Keith C. Clarke, 2003, Getting Started with Geographic Information System (4th Edition), Prentice Hall press.
Spatial analysis: determining how places are related
Temporal analysis techniques
Why use and create metadata
Simple data structure
Various kinds of spatial analysis
Uniform size and shape
Large amount of data
Projection transformation is difficult
Different scales between layers can be a nightmare
May lose information due to generalization
Raster – Advantages and disadvantages
Good representation of reality
Compact data structure
Complex data structures
Simulation may be difficult
Some spatial analysis is difficult or impossible to perform
Vector – Advantages and Disadvantages
Digital spatial data
Property tax assessment
Planning and economic development
Spatial Analysis: Making Predictions
Spatial Analysis: Detecting and Quantifying Patterns
London cholera epidemic 1854
Raster and vector data models
Two basic data models
GIS: a simplified view of the real world
real world locations
to be digitally represented and stored in a database so that they can be abstractly presented in
(analog) form, and can also be worked with and
to address some problem
Natural resource management
Spatial Analysis: Finding the Best Locations and Paths
Dr John Snow is known as the ‘
father of modern epidemiology
’ and the ‘
father of GIS
’ because of the famous case of the 1854 Cholera outbreak in London’s Broad Street region.
In the 1850s, cholera was very poorly understood and massive outbreaks were a common occurrence in major industrial cities. An outbreak in London in 1854 in the Soho district was typical of the time, and the deaths it caused are shown in the map on the right.
Data is organized by
layers, coverages or themes
with each layer representing a common feature.
on the earth’s surface, thus geographic location is the organizing principal.
axis representating the
Geographic integration of information
The convergence of technological fields and traditional disciplines
Geography and related
Knowledge base for GIS
What - When - Where
Why is GIS unique?
The GIS data model
Flights and baits drops in Poland and Romania
What stands GIS for?
Geographic / Geospatial
The locations are known
in terms of
The data may be organised as
, but also as
statistical graphics, tables
on-screen responses to
make up GIS.
data capture, input, manipulation, transformation, visualization, combinations, query, analysis, modeling and output
patterns and processes
in geographical data
automation of time-consuming tasks
(too tedious, expensive or inaccurate if performed by hand)
hardware and software:
for capturing, managing, analyzing and displaying all forms of geographical data
...defining Geographic Information Systems
GIS: understanding and managing our Earth
Earth surface: Topo, Ellipsoid, Geoid
real earth surface (ground)
a map of average sea level
a mediate sea level-MSL surface
The Geoid, exaggerated to illustrate the complexity of its' interface
can be treated as uniform.
Mountains and valleys
vary a lot vertically.
A simple mathematical model can not be considered.
Two main reference surfaces have been established to approximate the shape of the earth:
Flat earth models
: radius < 10 km
For short distances.
Spherical earth models
: radius 6371 km, meridian and parallels.
For short range navigation and global distance approximations.
Ellipsoidal earth models
For accurate range and long distance calculations.
Earth shape models
Laying the earth flat?
measuring and comparing
distances, directions, areas, shapes.
Enable measuring in
meters or feet
>> Not in degrees of latitude & longitude
>> 1:24,000 globe would have diameter of ~ 13 m
>> Typical globe has scale of ~ 1:42,000,000
Laying the earth flat?
curved earth (Latitude and Longitude) to a flat map (rectangular coordinates)
Distorsion distance, area, shape, direction.
The Mercator projection
Viewing the world as a smashed orange
Universal Transverse Mercator (UTM) coordinate system
World Geodetic System (WGS)
is a standard for use in cartography, geodesy, and navigation. It comprises a standard coordinate system for the Earth, a standard spheroidal reference surface (the datum or reference ellipsoid) for raw altitude data, and a gravitational equipotential surface (the geoid) that defines the nominal sea level.
The latest revision is
), established in 1984 and last revised in 2004.
is currently the reference system being used by the Global Positioning System (
). It is geocentric and globally consistent within ±1 m.
The World Geodetic System (WGS)
European Terrestrial Reference System 1989
ECEF (Earth-Centered, Earth-Fixed) geodetic Cartesian reference frame, in which the Eurasian Plate as a whole is static.
The coordinates and maps in Europe based on ETRS89 are not subject to change due to the continental drift.
ETRS89 is the
frame of reference for geodata for Europe.
Longitude and latitude
60 sixty longitudinal UTM zones of
6 degrees wide, and 20 bands of 8 degrees wide from 80° S to 84° N.
UTM Zone Numbers
Representation of the coordinates
of any point
equal in length
imaginary line joining points
having same longitudes.
passing through the Royal Observatory, Greenwich, London known as
Imaginary lines running between the geographical poles of the Earth.
Equator is the
longest parallel and
taken as a reference (
zero latitude line
of parallels goes on
The parallels at the poles are
angle formed by the Prime Meridian and the median passing through a point.
From East or West, with 0 to 180 degrees for the East, and 0 to -180 degrees for the West.
angle between the equatorial plane and the line connecting a point to the center of the Earth.
From North and South angles, +90 degrees for North and -90 degrees for South
: a transverse-secant cylindrical projection, division of the surface of the Earth into 6 degree zones with a central meridian in the center of the zone.
UTM conformal projection
: no distortion of small features (all distances, directions, shapes, and areas are reasonably accurate ).
: in meters, easier and more accurate calculations of short distances between points (error is less than 0.04%)
Angular measurement is always done in degrees (°), minutes (') and seconds (").
Given below are the coordinates of Brussels in 3 commonly used systems:
Degrees, Minutes and Seconds
: 50°51'00" N, 4°21'00" E
Degrees and decimal Minutes
: 50°51' N, 4°21' E
Decimal degrees Lat Long
: 50.8500° N, 4.3500° E
Relation between map distance and ground distance.
For example, on a 1:100000 scale map, 1cm on the map equals 1km on the ground.
Water quality and availability
International and national security
Routing analysis (
e.g. animal transport distance and timing
Natural hazards: seismicity, weather events
e.g.: road, river
(zone): two dimensions
e.g.: city, lake
Raster spatial data model
Define space as an array of equally sized cells arranged in rows and columns. Each cell contains an attribute value and location coordinates
Individual cells as building blocks for creating images of point, line, area, network and surface
Vector spatial data model
Use x-, y- coordinates to represent point, line, area, network, surface
Example: continuous raster
Attribute data is about “what” of a spatial data and is a list or table of data arranged as rows and columns
Rows are records
Columns are fields
Intersection of a column and a row
shows the values of attributes, such as color, ownership, magnitude, classification…
Metadata is an
Metadata is the
who, what, when, where, why
How, when, where, and by whom the data was collected
availability and distribution information
its projection, scale, resolution, and accuracy
its reliability with regard to some standard.
To help organize and maintain an organization's spatial data
To provide information to other organizations and clearinghouses to facilitate data sharing and transfer
To document the history of a spatial data set
Spatial Information in Europe (INSPIRE)
is a European directive 2007/2/EC of 25/04/2007.
Its goal is for an Internet-accessible infrastructure of technologies and permissions to tie European geospatial information producers and users together into a single geospatial information-sharing community to improve decision making and operations in service of a productive and sustainable Europe.
(Spatial Information in Europe)
INSPIRE metadata is based on the ISO 19115 (dataset) and ISO 19119 (services) standard.
European Open Source Metadata Editor
Dr. John Snow
During the 1854 massive cholera in three days over 120 people died from the disease. Dr. John Snow plotted the locations of the deaths on a map and found they clustered around a pump in Broad Street – he suggested that the pump be taken out of service – thus helping to end the epidemic. This then helped him formulate his theory of the spread of cholera by dirty water.
This analysis is famous as it is often considered to be:
The first epidemiological analysis of disease – trying to understand the spread of cases by factors in the environment
The first geographical analysis of disease data – plotting points on a map and looking for relationships
The ability of GIS to
"overlay" different entities
based on their common geographic occurrence makes it a very
valuable tool in epidemiological research.
The idea that place and location can influence health is a very old and familiar concept in Western Medicine.
As far back as the time of Hippocrates, (460-370 BC), the father of Modern Medicine, physicians have observed that certain diseases seem to occur in some places and not in others.
The Hippocratic concept of health and disease stressed the relation between man and his environment.
GIS for health
GIS and health
GIS for health
GIS is a valuable tool to assist in health research, in health education, and in the planning, monitoring and evaluation of health programmes and health systems.
Data has both a
spatial and a temporal context
everything happens someplace and occurs at some point in time.
can be used to assess the management and prevention of infectious diseases and other epidemiological phenomena.
The process of examining the locations, attributes, and relationships of features in spatial data through overlay and other analytical techniques in order to
address a question or gain useful knowledge
Spatial analysis extracts or creates new information from spatial data.
Spatial analysis is how we understand our world—mapping where things are, how they relate, what it all means, and what actions to take.
Which rivers are within 10 miles of a pipeline?
Have other crimes occurred at this location? Answering spatial questions often requires an understanding of
proximity, coincidence, intersection, overlap, visibility
Whether you're looking for the
best route to travel
, the best corridor to build a pipeline, or the best location to site a new store, spatial analysis helps you make more informed decisions about the best locations and paths.
Where are clusters of high expenditures on electronic goods?
Where are the hot spots of cancer deaths?
patterns in data
can be used to find hot spots and outliers, find natural data clusters, and
How will a forest fire spread based on vegetation and wind?
How will store size and travel distance attract or detract customers?
Spatial analysis lets you use powerful modeling techniques to make predictions and
better understand our world.
Buffer Zones Creation
Example of pinewood nematode (Bursaphelenchus xylophilus) in Valverde del Fresno
DG Health and Food Safety
Tel.: +32 2 297 63 50
Imaginary circles parallel to the
Head of TRACES Sector, Dr Didier CARTON