1 CEE 795 Water Resources Modeling and GIS Session #1 (some material from Dr. David Maidment, University of Texas) January 18, 2006 Learning 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 Assessment Tool (AGWA)

5 GIS and Water Distribution Models Haestad WaterGEMS

6 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

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 based on Inventory of data layers

Spatial Data: Vector format Point Point - a pair of x and y coordinates (x 1,y 1 ) Line Line - a sequence of points Polygon Polygon - 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 Point Line Polygon VectorRaster Raster data are described by a cell grid, one value per cell Zone of cells

14 Santa Barbara, California

15 How do we combine these data? Digital Elevation Models 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 between objects linked by tracing path of water movement

19 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

20 Arc Hydro: GIS for Water Resources Published by ESRI Press The Arc Hydro data model and application tools are in the public domain

21 Arc Hydro — Hydrography

22 Arc Hydro — Hydrology

23 Flow Time Time Series HydrographyHydro 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 FLO ODP LAIN MAP Flood map as output Nexrad map as input Model for flood flow Model for flood depth HMS

27 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

28 Origin of Geographic Coordinates (0,0) Equator Prime Meridian

29 Latitude and Longitude Longitude line (Meridian) N S WE Range: 180ºW - 0º - 180ºE Latitude line (Parallel) N S WE Range: 90ºS - 0º - 90ºN (0ºN, 0ºE) Equator, Prime Meridian

30 Latitude and Longitude in North America 90 W 120 W 60 W 30 N 0 N 60 N Austin: (30°N, 98°W) Logan: (42°N, 112°W)

Map Projection Curved Earth Geographic coordinates: , (Latitude & Longitude) Flat Map Cartesian coordinates: x,y (Easting & Northing)

32 Earth to Globe to Map Representative Fraction Globe distance Earth distance = Map Scale: Map Projection: Scale Factor Map distance Globe distance = (e.g. 1:24,000) (e.g )

33 Coordinate Systems (  o, o ) (x o,y o ) X Y Origin A planar coordinate system is defined by a pair of orthogonal (x,y) axes drawn through an origin