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Application of GIS in hydrology and water resource management
Application of GIS in hydrology andwater resources management
University of Stuttgart – ENWAT
Part 1: July 24 – 26, 2007Part 2: ?
Dietrich SchröderUniversity of Applied Sciences [email protected]
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Application of GIS in hydrology and water resource management
Objective:• Almost everything that happens, happens
somewhere. • 80% of all decisions in policies are spatial
related.• Geographical Information Systems are today
state-of-the-art tools for supporting any kind of spatial related modelling and decisions.
• This holds in particular in hydrology and water resource management.
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Application of GIS in hydrology and water resource management
Aims of the course (part 1):• Theoretical background of handling
spatial related data• Basic principles of GIS• Handling of a GIS by example ArcGISin the context of water resource management
=> GIS is still (and will remain) an expert system!! (which is impossible to learn in a 2.5-day seminar)
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Application of GIS in hydrology and water resource management
Aims of the course (part 2):
• GIS in hydrology– DEM– GIS and surface hydrology– GIS and groundwater models– Case studies
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Application of GIS in hydrology and water resource management
Part 1: 24 July – 26 July 2007
Tuesday, 24th JulyMorning session: lecturesAfternoon session: exercises in the lab
Wedneday, 25th July: Morning session: lecturesAfternoon session: exercises in the lab
Thursday, 26th July:Afternoon session: exercises in the lab
Examination: test
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Application of GIS in hydrology and water resource management
Outline Part 1 • Overview of GIS• Data modeling• Spatial referencing: Coordinate
systems, geodetic datum, and map projections
• Georeferencing of images• Design of Thematic maps• Analysis of spatial data
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Application of GIS in hydrology and water resource management
What is Geographic Information System?
A GIS is a computer-based information system that enables
– capture, – modeling, storage, – retrieval, – sharing, – manipulation, – analysis, and – presentation
of geographically referenced data
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Application of GIS in hydrology and water resource management
• Don‘t mix it:– The software package (e.g. ArcGIS)– The application (e.g. hydrological analysis
tools)
You can apply the same software product for many different applications (and of course use different software for the same application!)
GIS and GIS Application
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Application of GIS in hydrology and water resource management
Software: ArcGIS, GeoMedia, ILWIS, Smallworld, GRASS,...
Application: Forestry IS, DSS for urban planning, utility management system, hydrological analysis system,...
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Application of GIS in hydrology and water resource management Development of GIS:
from specialist system to Multi-Purpose GIS
mapping(cartography
)
utility management
(network) environmental GIS
(areal analysis)
...
multi-purpose GIS
remote sensing (raster)
• Integrated
• Multi-discipline approach
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Application of GIS in hydrology and water resource management
Components of GIS
Data Management
Data Analysis
Data Visualization
• Hardware (computer, periphery like digitizing devices, high-end plotters)
• Software (including generic procedurs for analysis)
• Data
• User (his or her expert knowledge
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Application of GIS in hydrology and water resource management
Life time of the components
H hard-ware
computer, periphery (digitizer, scanner, plotter)
~ 4 years
S soft-ware
programs, extensions, tools, methods
~ 7 years
D data data, rules, knowledge ~ 25 years
U user
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Application of GIS in hydrology and water resource management
The GIS Cost Pyramide
Hard-ware
Software
Staff / Users
Data
~ 10 %
~ 15 %
~ 25 %
~ 50 %
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Application of GIS in hydrology and water resource management
Galery of GIS Applicationshydrologycadastreagricultureenvironment geo-sciencesforestry emergency servicespublic services (utilities) navigation regional/local/rural/urban planningtourism...
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Application of GIS in hydrology and water resource management
Classical Application: Cadastre
Cadastral data is the geo base data for many large scale applications!
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Application of GIS in hydrology and water resource management
Cadastral data Germany:• ALK (Automatisierte Liegenschaftskarte)• Whole coverage of Germany• Scale level 1:1000 to 1:10 000• Accuracy some centimeter• Content: land parcel (with land use) and
buildings
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Application of GIS in hydrology and water resource management
Flood inundation mapping for risk evaluation of building insurances
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Application of GIS in hydrology and water resource management
ZÜRS (Zonierungssystem für Überschwemmung, Rückstau und Starkregen)Zoning system for inundation, backwater, and strong rain
1 river bed
2 Susceptibility class 3 (10 years)
3 Susceptibility class 2(10 – 50 year)
4 Susceptibility class 1(> 50 year)
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Application of GIS in hydrology and water resource management
Utilities: Sewerage Network
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Application of GIS in hydrology and water resource management
Utility Network and Orthophoto
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Application of GIS in hydrology and water resource management
Geo base data 1: 10 000 to 1:50 000 (ATKIS Authorative Topographic-Cartographic
Information System)
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Application of GIS in hydrology and water resource management
ATKIS- Object-based structure- Whole coverage of Germany- Scale level 1:10 000 to 1:50 000- Accuracy 3 m (as TK25)- Polygons, lines, and points with
attributes- Land use, river, transportation, etc.
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Application of GIS in hydrology and water resource management
Hydrography from ATKIS
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Application of GIS in hydrology and water resource management
Analysis of networks is a common task for GIS:rivers, utilities, transportation, …
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Application of GIS in hydrology and water resource management
Land use
Soil
Geology
Elevation
Soil depth
…
Result: HRU
Combining different maps
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Application of GIS in hydrology and water resource management
Actual Trends
• 3D landscape visualization and animation
• 3D city models• Mobile GIS• Spatial enabled database systems• Web Services (SOA)
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Application of GIS in hydrology and water resource management
3D landscape visualization
e.g. ArcGis 9.3, G-Graphix (Freiburg), Skylinesoft (Israel)
Vierwald-stätter See
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Application of GIS in hydrology and water resource management
3D City Model Hamburg
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Application of GIS in hydrology and water resource management
3D City Model Stuttgart
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Application of GIS in hydrology and water resource management
Mobile GIS
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Application of GIS in hydrology and water resource management
Tablet (rich client) to smart GPS receiver (thin client)
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Application of GIS in hydrology and water resource management
In recent years more and more functionality has moved from GIS to database systems like Oracle (locator and spatial)
Spatial enabled database systems
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Application of GIS in hydrology and water resource managementOracle Spatial• linear referencing system• Over 400 Spatial functions such as centroids and
aggregate functions (e.g. unions• and user defined aggregates)• GeoRaster data type that natively manages
georeferenced raster imagery • A data model to store and analyze network (graph)
structure• A data model and schema to persistently store and
update topology• Spatial analytic functions• • 3-dimensional data type support for terrain and city
models and virtual worlds,• support for LIDAR-based map production• Spatial web services support (WFS 1.0, WFS-T 1.0, CSW
2.0, OpenLS 1.1, web
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Application of GIS in hydrology and water resource management
Web Services (Service oriented Architecture)
From desktop GIS to server GIS
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Application of GIS in hydrology and water resource management
GIS Classification• Professional GIS (full functionality)• Desktop GIS (reduced functionality, mainly for visualization of spatial data)• CAD GIS (program with GIS functionality based on a CAD)• Internet-GIS (GIS Server) (Client-Server architecture with a Web-Browser and an application server)• Business-Map-GIS (simple cartographic tool with some
GIS functionality)• Mobile-GIS (for mobile use, in particular for data collection and updating)
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Application of GIS in hydrology and water resource management
Top Ten 2004 per seats (professional GIS)
ArcGIS ESRI 240 000
GeoMedia Professional
Intergraph 196 000
Erdas Imagine Geosystems 140 000
GRASS GRASS Developer team
30 000
Smallworld GE Network Solution 30 000
Geomatica – EASI/Pace
CGI Systems 12 000
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Application of GIS in hydrology and water resource management
Top Ten 2004 per seats (desktop GIS)
ArcView 3.3 ESRI 1 200 000
GeoMedia Intergraph 515 000
MapInfo Professional
MapInfo 300 000
MicroImages TNTAtlas + TNTlite
GIS Team 20 000
Sicad Spatial Desktop
Sicad Geomatics 10 000
…
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Application of GIS in hydrology and water resource management
Top Ten 2003 per seats (others)
Autodesk Map Autodesk
170 000 (?)
CAD GIS
Geograf/Ingrada
HHK / Softplan
12 500 CAD GIS
MicroStation Geographics
Bentley Systems
6700 CAD GIS
Mappoint Microsoft ? Business GIS
Regio Graph Macon AG
25 000 Business GIS
…
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Application of GIS in hydrology and water resource management
Summary• GIS for visualization• GIS for integration• GIS for analysisof spatial data
In both surface water and groundwater modeling, data management plays a major role. The compilation, analysis, and formulation of model input are the major phases of any modeling study, as is the creation of high-quality, graphical model output.Much of the data required for model development, including land use maps, soil types, production well locations, basin delineation, water quality, recharge, evapotranspiration, parcel data, etc. are being made available in the form of GIS coverages. A GIS allows users to take advantage of the vast quantity of data available today for water resource applications.
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Application of GIS in hydrology and water resource management
Literature• M. Gurnell, D. R. Montgomery (Editors): Hydrological Applications of GIS (collection of papers)• J. Fürst: GIS in Hydrologie und Wasserwirtschaft, Wichmann (in German but with many references)• D.R. Maidment: ArcHydro, ESRI Press• D.R. Maidment: Hydrologic and Hydraulic Modeling Support with GIS (HEC-Ras related)
• M.N. DeMers: Fundamentals of Geographic Information Systems, Wiley&Sons
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Application of GIS in hydrology and water resource management
Spatial Modeling
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Application of GIS in hydrology and water resource management
Outline• Modeling the real world• Discrete objects and continuous fields• Vector and raster representation• Managing spatial and attributive data• Object based data models• Process modeling• Dimensions• Topology
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Application of GIS in hydrology and water resource management
Modeling the real world
real world
Perception of the world:
models of geographic phenomena
database
representation
process model
map
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Application of GIS in hydrology and water resource management
What is our „model“ of the river Neckar?• A polyline on the a map 1:100 000?• A polygon on a map 1:1000?• A trench in the earth surface?• A habitat for animals and plants?• Is it a waterbody exactly defined by its
channel banks?• Is it a continuous varying field of the
river bed‘s elevation?
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Application of GIS in hydrology and water resource management
Moving from the real world through various data models to model output requires transformations in both information structure and information content. These transformations from the real world to binary representations include:•abstraction, generalization and selection of relevant concepts, processes and relationships in the real world •conceptual modeling of the relationships between abstract entities •mathematical modeling of the relationships between defined entities •physical sampling of the real world •storage of data in computers - may or may not include the necessity to model space •transformation of data between different representations (models).
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Application of GIS in hydrology and water resource management
Geographic Phenomena
Something of interest that
• Can be named or described
• Can be georeferenced
• (Can be assigned a time (interval) at which it is/ was present)
What is present? building, river,…
Where is it? coordinates
(When was it present time interval)
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Application of GIS in hydrology and water resource management
Types of geographic phenomena
• A geographic field is a geographic phenomenon for which, for every point in the study area, a value can be determined.
• Geographic objects populate the study area, and are usually well-distinguishable, discrete, bounded areas. The space between them is potentially empty.
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Application of GIS in hydrology and water resource management
Continuous Fields: elevation
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Application of GIS in hydrology and water resource management
Continuous Fields: rainfall
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Application of GIS in hydrology and water resource management
Continuous Fields: pH-value
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Application of GIS in hydrology and water resource management
Geographic Objects: Utility network•Sewage canal
•Manhole
•Valve
•Building
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Application of GIS in hydrology and water resource management
Geographic Objects: river network
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Application of GIS in hydrology and water resource management
Discrete Fields: Land use classification
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Application of GIS in hydrology and water resource management
Discrete Fields: rainfall classes
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Application of GIS in hydrology and water resource management
Conceptual Representations
real world
raster representation
vector representation
model of geographic phenomena
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Application of GIS in hydrology and water resource management
Raster: For Continuous Fields
X Y Z3532500. 5379500. 688.83532500. 5379550. 688.63532500. 5379600. 688.43532500. 5379650. 689.03532500. 5379700. 690.73532500. 5379750. 692.93532500. 5379800. 693.53532500. 5379850. 693.13532500. 5379900. 693.83532500. 5379950. 696.03532500. 5380000. 697.7
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Application of GIS in hydrology and water resource management
1 ... n 1 . . .
n
cell(35,67)
columns
rows
• imaginary grid over the study area
• only “inner” coordinates
for each cell
• whole grid has to be georeferenced
• stores information on the interior of areal features
• boundaries only implicit
Raster representation
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Application of GIS in hydrology and water resource management
• location,• value,• resolution, and • appearance
2424
location: 535020E, 3642640Nvalue: 24resolution: 10m appearance: RGB(255,0,0)
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Application of GIS in hydrology and water resource management
• In GIS usually squares are used as cell form• Location of each cell as inner coordinates,
specified are the coordinates of the upper left corner of the whole grid and ist direction towards north, e.g. for cell(35,45):x35=xul+35*resolutiony45=yul-45*resolution
• The meaning of the value depends on the application, e.g.– Intensity in a RADAR or LASER image– Classification of an RGB satellite image (range of
values) for land use– Calculated combination of different band of a
satellite image like NDVI (Normalized Difference Vegetation Index) using infra red
– Elevation above sea level– …
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Application of GIS in hydrology and water resource management
NDVI from NOAA-AVHRR satellite for February and May 1997 showing the photosynthetic activity
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Application of GIS in hydrology and water resource management
Floating point versus integer grids
1 forest
2 Farmland
3 grassland
Value land cover
•Only integer grids can have a VAT (value attribute table)
•Some operations only work on integer grids
•Integer grids are mainly used for discrete fields like land use
•Floating point grids are used for continuous fields like elevation (DEM)
VAT
grid
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Application of GIS in hydrology and water resource management
Raster Resolution
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Application of GIS in hydrology and water resource management
Cell raster: the value is an average value for the whole cell
Point raster: the value is the (interpolated) value of the cell center point
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Application of GIS in hydrology and water resource management
Advantages of the grid or raster representation
• simple concept• easy management within the computer; many computer languages deal effectively with matrices, e.g. MatLab • map overlay and algebra is simple: cell by cell• native format of satellite imagery and scanned images• modeling and interpolating is simple, because the grid is dense and complete
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Application of GIS in hydrology and water resource management
Disadvantages of the grid or raster representation
•fixed resolution, can’t be improved. So when combining maps of various resolutions, you must accept the coarsest resolution•information loss at any resolution, increasingly expensive storage and processing requirements to increase resolution•large amount of data especially at high resolution•not appropriate for high-quality cartography (line drawing)•slow transformations of projections (must transform each cell)•some kinds of map analysis (e.g. networks) is difficult or at least not ‘natural’•no correspondence to real world objects, i.e. difficult to link additional attributive data
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Application of GIS in hydrology and water resource management
Rasterizing Continuous Fields
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Application of GIS in hydrology and water resource management
Rasterizing Discrete Objects
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Application of GIS in hydrology and water resource management
Cell size of the raster determines ist resolution: cell size max. 50% of the smallest object to be recognized
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Application of GIS in hydrology and water resource management
Vector Data
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Application of GIS in hydrology and water resource management
point
line
area
Vector representation
Geometric primitives
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Application of GIS in hydrology and water resource management
Vector data and attributive data• Can be easily linked to additional
information
River segment:
Name, Code, Length, quality, …
Gage station:
Name, Code, temperature, discharge,…
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Application of GIS in hydrology and water resource management
Advantages of the vector representation
•precision is only limited by quality of the original data•very storage-efficient, since only points about which there is information or which form parts of lines and boundaries are stored•structuring the data logically is very easy•explicit topology makes some kinds of spatial analysis easy•high-quality output
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Application of GIS in hydrology and water resource management
Disadvantages of the vector representation
•not suitable for continuous surfaces such as scanned or remotely-sensed images and models based on these•time consuming capturing (digitizing, field survey)
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Application of GIS in hydrology and water resource management
Continuous fields in vector representation
TIN (Triangulated irregular network)
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Application of GIS in hydrology and water resource management
TIN as a Delaunay Triangulation
Non overlapping triangles, no other point in the outer circle of a triangle
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Application of GIS in hydrology and water resource management
Contour lines
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Application of GIS in hydrology and water resource management
Vectorizing rasters
lines polygons
Additional smoothing algorithm necessary!
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Application of GIS in hydrology and water resource management
Data Types in vector GIS
• Geometry Datae.g. 3433989.35/5399102.09
3433060.42/5398073.89
• Graphical Description (symbology) e.g. width: 3mm
color: bluepattern: dotted
• Graphic Data: Geometry + Graphical Description
X
X
X
X
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Application of GIS in hydrology and water resource management
• Attributive Data e.g. Type: ephemeral river length: 2 km Name: Thirsty Creek
• Topology Information e.g. upID: 23 downID: 56
• Other Datae.g. Multimedia data
ID Type Length_km
Name
…
34 Ephemeral 2 Thirsty Creek
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Application of GIS in hydrology and water resource management
The feature representation of geographical objects
OID Geometry topology timestamp attributes (neighboring polygons) landuse owner
12456 x1,y1 122423 1. Jan. 2000 forest Smith ... 435666 xn,yn 655680
A feature
• has an object identity
• has a property set (attributes)
• usually has a geometry, i.e. one of the property is geometric associated with a reference system
• may have various relationships to other features
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Application of GIS in hydrology and water resource management
geometry
graphical description(per feature class)
attributive data
OID
e.g. ESRI‘s ArcView Shape-Format:
• geometry: Shape-File (*.shp)
• attributive data: DBase-File (*.dbf)
• „link“ or „index“ file (*.shx)
• graphical description: Project-File (*.apr)
How to store and manage this information?Approach 1: separated storing of geometry, graphical description and attributive data
Still one of the most often used format for data exchange
in GIS!
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Application of GIS in hydrology and water resource management
How to store ands manage this information?Approach 2: storing geometry and the graphical description for each feature separated from the attributive data geometry + graphical description
attributive data
OID
e.g. Autodesk‘s AutoCAD-Map:
• geometry + graphical description: DWG or DXF-File
• atributive data: Database-File
Most GIS support the direct import of CAD data
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Application of GIS in hydrology and water resource management
How to store ands manage this information?Approach 3: storing geometry and attributive data together, but separated from the graphical description
geometry + attributive data
graphical descriptionfeature
class
e.g. ESRI‘s ArcGIS (Personal Geodatabase, real database systems like Oracle, Informix, DB2)
• geometry + atributive data: Database-File (MS-Access, Oracle)
• graphical description: Map-File (*.mxd)
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Application of GIS in hydrology and water resource managementData Modeling in UML (Unified Modeling Language)
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Application of GIS in hydrology and water resource management
Features versus objects• Only attributes, no operations• Mapping on „flat“ database
tables structure like Personal Geodatabases– No inheritance– No complex objects, i.e. no
nested tables
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Application of GIS in hydrology and water resource management
The model and its implementation
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Application of GIS in hydrology and water resource management
Process Modeling
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Application of GIS in hydrology and water resource management
Dimensions
2D:
without any height information, only latitude/longitude or Northing/Easting
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Application of GIS in hydrology and water resource management
2D+1D:
position and contour lines two independent layers
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Application of GIS in hydrology and water resource management
2.5D:
position with heights as attributive data
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Application of GIS in hydrology and water resource management
3D surface:
to each position one height is associated
(sometimes also called 2.5 surfaces, don‘t get confused!)
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Application of GIS in hydrology and water resource management
3D wire frame / volume:
to each position more than one height can be associated
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Application of GIS in hydrology and water resource management
4th dimension: time
2+1+1D
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Application of GIS in hydrology and water resource management
time in ArcGIS
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Application of GIS in hydrology and water resource management
TopologyStructure of objects independent of their geometry. Using continuous transformation, topologic properties remain unchanged
“rubber sheet” transformation
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Application of GIS in hydrology and water resource management
Characteristics of the space in GIS
• 3D Euclidean space. Geometric primitives: points (zero-dimensional), lines (one-dimensional), areas (two-dimensional) and volumes (three-dimensional)
• the space is a metric space, (distance function)
• the space is a topological space
• interior and boundary are invariant under topological mappings
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Application of GIS in hydrology and water resource management
Problems not using topology• lines between adjacent polygons must be digitized and stored twice (slivers and gaps)• there is no neighborhood information• islands are impossible except as purely graphical constructions• there is no easy way to check if the boundary is correct and complete (dead-ends, weird polygons)
slivers
gaps
dead ends
weird polygons
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Application of GIS in hydrology and water resource management
Vector Data Structures & Topology
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Application of GIS in hydrology and water resource management
Geographical Objects (Simple Features)
object
coordinates
P1 x1,y1,x2,y2,x3,y3,…,x1,y1
P2 x1,y1,x9,y9,x8,y8,…x1,y1
…
Area-Object by area-object exist explicitly!
Topology only exist implicitly!
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Application of GIS in hydrology and water resource management
Interoperability
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Application of GIS in hydrology and water resource management
Exterior
Area (with holes)Line / Polyline
Simple Features – Geometry Definition
0, 1 and 2 - dimensional geometry
Single objects
Groups of similar objects
Object (Feature)
Definitions for
Point
BorderInterior
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Application of GIS in hydrology and water resource management
Simple Features – Geometry Definition
• only straight connection of points (no curved arcs)
Pecularities of simple feature geometries:
• no topology
Examples for not allowed objects (not simple)
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Application of GIS in hydrology and water resource management
Topological Structure
Area-object by area-object and topology exist explicitly!
arc Fromnode
Tonode
Left Right
1 1 2 0 P12 2 3 0 P1… … … … …7 7 8 P2 P1… … … … …10 1 13 P2 0
node X y
1 X1 Y1
2 X2 y2
3 x3 y3
… … …
area arc
P1 1,2,3,4,5,6,7,8,9
P2 10,11,12,13,14,7,8,9
… …
node-arc-area (NAA) representation
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Application of GIS in hydrology and water resource management
Topology has historically been viewed as a spatial data structure used primarily to ensure that the associated data forms a consistent and clean topological fabric. With advances in object-oriented GIS development, an alternative view of topology has evolved. The geodatabase supports an approach to modeling geography that integrates the behavior of different feature types and supports different types of key relationships. In this context, topology is a collection of rules and relationships that, coupled with a set of editing tools and techniques, enables the geodatabase to more accurately model geometric relationships found in the world.
Topology in ArcGIS
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Application of GIS in hydrology and water resource management
…
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Application of GIS in hydrology and water resource management
…
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Application of GIS in hydrology and water resource management
Maintaining data consistency & topology
• some GIS maintain consistency geometrically, i.e. by coinciding coordinates
• maintaining explicitly stored topology is very time consuming
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Application of GIS in hydrology and water resource management
Data exchange• de-facto-standards like Shape-Format or DXF (only geometry) based on simple features• no real standard for topology• no real standard for symbology• Metadata very important• OGC (Open Geospatial Consortium: initaitives on specification for interoperability
– Simple feature specification– WMS and WFS specification– Symbology encoding– Geo Processing
• tools for data transformation like FME (Feature Manipulation Engine) from Safe software
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Application of GIS in hydrology and water resource management
Summary• data models and their implementation should
represent spatial phenomena completely and support efficient analysis
• grids for continuous fields (and discrete fields)• discrete primitives for objects (and discrete
fields)• vector-GIS organize geographic objects in
feature classes• GIS are more or less still 2D and 3D surfaces• simple feature is the standard for data
exchange• Topology helps maintaining consistent data
sets• with WebServices data exchange problems will
become less important