Download - 1 CEE 795 Water Resources Modeling and GIS Session #1 (some material from Dr. David Maidment, University of Texas) January 18, 2006 Learning Objectives:

1

CEE 795Water Resources Modeling and GIS

Session #1(some material from Dr. David Maidment, University of Texas)

January 18, 2006Learning Objectives:• Outline the various types of models that can be integrated with GIS• Describe the geospatial database of hydrologic features • Outline the Arc Hydro data model• Demonstrate the use of curved earth and a flat map projections

Handouts: Assignments:Get SCR login accounts

2

Water Resources Modeling and GIS: Session 1

• Water Resource Models and GIS

• Geospatial database of hydrologic features

• Arc Hydro data model

• Curved earth and a flat map

3

GIS and Hydraulic Models

• HEC Geo-RAS• Used for Pre and Post

processing of data from HEC-River Analysis System (RAS)

• Open Channel flow model

4

GIS and Hydrologic Models• Automated

Geospatial Watershed AssessmentTool (AGWA)

1992 NALC Hillshade DEM STATSGO

ForestOak WoodlandsMesquite WoodlandsGrasslandsDesertscrubRiparianAgricultureUrbanWaterBarren / Clouds

Land CoverForestOak WoodlandsMesquite WoodlandsGrasslandsDesertscrubRiparianAgricultureUrbanWaterBarren / Clouds

Land Cover

0 5 10 km0 5 10 km

NN

5

GIS and Water Distribution Models

• Haestad WaterGEMS

6






7

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

8

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:

10

Themes or Data Layers

Vector data: point, line or polygon features

11

Kissimmee watershed, Florida

Themes

12

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

14http://srtm.usgs.gov/srtmimagegallery/index.html

Santa Barbara, California

15

How do we combine these data?

Digital ElevationModels

Watersheds Streams Waterbodies

16

An integrated raster-vector

database

17

Data Model Based on Behavior

“Follow a drop of water from where it falls on the land, to the stream, and all the way to the ocean.”

R.M. Hirsch, USGS

18

Integrating Data Inventory using a Behavioral Model

Relationships betweenobjects linked by tracing pathof water movement

19






20

Arc Hydro: GIS for Water ResourcesPublished by ESRI Press

The Arc Hydro data model andapplication tools are in the publicdomain

21

Arc Hydro — Hydrography

22

Arc Hydro — Hydrology

23

Flow

Time

Time Series

Hydrography

Hydro Network

Channel System

Drainage System

Arc Hydro Components

24

Hydrologic Information System

Analysis, Modeling, Decision Making

Arc Hydro Geodatabase

25

Nexrad Radar Rainfall Map

26

Nexrad Map to Flood Map in Model Builder

FLOODPLAIN MAP

Flood map as output

Nexrad map as input

Model for flood flow

Model for flood

depth

HMS

27






28

Origin of Geographic Coordinates

(0,0)Equator

Prime Meridian

29

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

30

Latitude and Longitude in North America

90 W120 W 60 W

30 N

0 N

60 N

Austin: (30°N, 98°W)

Logan:(42°N, 112°W)

Map Projection

Curved EarthGeographic coordinates: ,

(Latitude & Longitude)

Flat Map Cartesian coordinates: x,y

(Easting & Northing)

32

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)

33

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

Download - 1 CEE 795 Water Resources Modeling and GIS Session #1 (some material from Dr. David Maidment, University of Texas) January 18, 2006 Learning Objectives:

Top Related