GIS in Water Resources: Lecture 1
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Transcript of GIS in Water Resources: Lecture 1
GIS in Water Resources: Lecture 1
• In-class and distance learning• Geospatial database of hydrologic features • GIS and HIS• Curved earth and a flat map
Six Basic Course Elements
• Lectures– Powerpoint slides– Video streaming
• Readings– “Arc Hydro: GIS in Water
Resources” and other materials
• Homework– Computer exercises– Hand exercises
• Term Project– Oral presentation– HTML report
• Class Interaction– Email– Discussion
• Examinations– Midterm, final
Our ClassroomDr David Tarboton
Students at Utah State University
Dr David Maidment Students at UT Austin
Dr Ayse Irmak Students at University of Nebraska - Lincoln
University Without Walls
Traditional Classroom CommunityInside and OutsideThe Classroom
Learning Styles
• Instructor-Centered Presentation
• Community-Centered Presentation
Student
Instructor
We learn from the instructors and each other
GIS in Water Resources: Lecture 1
• In-class and distance learning• Geospatial database of hydrologic features • GIS and HIS• Curved earth and a flat map
Geographic Data Model
• Conceptual Model – a set of concepts that describe a subject and allow reasoning about it
• Mathematical Model – a conceptual model expressed in symbols and equations
• Data Model – a conceptual model expressed in a data structure (e.g. ascii files, Excel tables, …..)
• Geographic Data Model – a conceptual model for describing and reasoning about the world expressed in a GIS database
Data Model Data Model based on based on Inventory of Inventory of data layersdata layers
Spatial Data: Vector format
PointPoint - a pair of x and y coordinates(x1,y1)
LineLine - a sequence of points
PolygonPolygon - a closed set of lines
Node
vertex
Vector data are defined spatially:
Themes or Data Layers
Vector data: point, line or polygon features
Kissimmee watershed, Florida
Themes
Attributes of a Selected Feature
Raster and Vector Data
PointPoint
LineLine
PolygonPolygon
VectorVector RasterRaster
Raster data are described by a cell grid, one value per cell
Zone of cells
http://srtm.usgs.gov/srtmimagegallery/index.html
Santa Barbara, California
How do we combine these data?
Digital ElevationModels
Watersheds Streams Waterbodies
An integrated raster-vector
database
Point Water Observations Time Series
A point location in space A series of values in time
Linking Geographic Information Systems and Water Resources
GIS WaterResources
Water Information in Space and Time
GIS in Water Resources: Lecture 1
• In-class and distance learning• Geospatial database of hydrologic features • GIS and HIS• Curved earth and a flat map
Ocean Sciences
What is CUAHSI?
• CUAHSI – Consortium of Universities for the Advancement of Hydrologic Science, Inc
• Formed in 2001 as a legal entity
• Program office in Washington (5 staff)
• NSF supports CUAHSI to develop infrastructure and services to advance hydrologic science in US universities
Earth Sciences
AtmosphericSciences
UCAR
CUAHSI
Unidata
HISNational Science Foundation
Geosciences Directorate
CUAHSI Member Institutions
122 Universities as of August 2009
Hydrologic Information System Goals
• Data Access – providing better access to a large volume of high quality hydrologic data;
• Hydrologic Observatories – storing and synthesizing hydrologic data for a region;
• Hydrologic Science – providing a stronger hydrologic information infrastructure;
• Hydrologic Education – bringing more hydrologic data into the classroom.
Rainfall & SnowWater quantity
and quality
Remote sensing
Water Data
Modeling Meteorology
Soil water
Data are Published in Many Formats
Services-Oriented Architecture
A services oriented architecture is a concept ‐that applies to large, distributed information systems that have many owners, are complex and heterogeneous, and have considerable legacies from the way their various components have developed in the past (Josuttis, 2007).
HTML as a Web LanguageText and Picturesin Web Browser
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" /><title>Vermont EPSCoR</title><link rel="stylesheet" href="epscor.css" type="text/css" media="all" /><!-- <script type='text/javascript' language='javascript‘ src='Presets.inc.php'>--></head>
HyperText Markup Language
WaterML as a Web LanguageDischarge of the San Marcos River at Luling, TX June 28 - July 18, 2002
USGS Streamflow data in WaterML
WaterML is constructed as a Web Services Definition Language using WWW standards
CUAHSI Water Data Services
35 services15,000 variables1.75 million sites8.33 million series342 million data
Texas Water Data Services
10 services7,010 variables15,870 sites645,566 series23,272,357records
A Theme Layer
Synthesis over all data sources of observations of a particular variable e.g. Salinity
Arc Hydro: GIS for Water Resources
• Arc Hydro– An ArcGIS data model
for water resources– Arc Hydro toolset for
implementation– Framework for linking
hydrologic simulation models
The Arc Hydro data model andapplication tools are in the publicdomain
Arc Hydro — HydrographyThe blue lines on mapsThe blue lines on maps
Arc Hydro — HydrologyThe movement of water through the hydrologic systemThe movement of water through the hydrologic system
Integrating Data Inventory using a Behavioral Model
Relationships betweenobjects linked by tracing pathof water movement
Flow
Time
Time Series
Hydrography
Hydro Network
Channel System
Drainage System
Arc Hydro Components
Hydrologic Information System
Analysis, Modeling, Decision Making
Arc Hydro Geodatabase
A synthesis of geospatial and temporal data supporting hydrologic analysis and modeling
GIS in Water Resources: Lecture 1
• In-class and distance learning• Geospatial database of hydrologic features • GIS and HIS• Curved earth and a flat map
Origin of Geographic Coordinates
(0,0)Equator
Prime Meridian
Latitude and Longitude
Longitude line (Meridian)N
S
W E
Range: 180ºW - 0º - 180ºE
Latitude line (Parallel)N
S
W E
Range: 90ºS - 0º - 90ºN(0ºN, 0ºE)
Equator, Prime Meridian
Latitude and Longitude in North America
90 W120 W 60 W
30 N
0 N
60 NAustin:
Logan:
Lincoln:
(30°18' 22" N, 97°45' 3" W)
(41°44' 24" N, 111°50' 9" W)
40 50 59 96 45 0
(40°50' 59" N, 96°45' 0" W)
Map Projection
Curved EarthGeographic coordinates: ,
(Latitude & Longitude)
Flat Map Cartesian coordinates: x,y
(Easting & Northing)
Earth to Globe to Map
Representative Fraction
Globe distanceEarth distance
=
Map Scale: Map Projection:
Scale Factor
Map distanceGlobe distance =
(e.g. 1:24,000) (e.g. 0.9996)
Coordinate Systems
(o,o)(xo,yo)
X
Y
Origin
A planar coordinate system is defined by a pairof orthogonal (x,y) axes drawn through an origin
Summary (1)
• GIS in Water Resources is about empowerment through use of information technology – helping you to understand the world around you and to investigate problems of interest to you
• This is an “open class” in every sense where we learn from one another as well as from the instructors
Summary (2)
• GIS offers a structured information model for working with geospatial data that describe the “water environment” (watersheds, streams, lakes, land use, ….)
• Water resources also needs observations and modeling to describe “the water” (discharge, water quality, water level, precipitation)
Summary (3)
• Geography “brings things together” through georeferencing on the earth’s surface
• Understanding geolocation on the earth and working with geospatial coordinate systems is fundamental to this field