Distributed Modeling in Hydrology using Digital Data and Geographic Information Systems

Goals

• To teach the principles of GIS and use of ArcView for spatial information display and analysis.
• To show how spatial hydrologic modeling can be done by developing a digital representation of the environment in the GIS then adding functions simulating hydrologic processes.
• To learn how land surface information, most significantly digital elevation model (DEM) data, is represented and used in GIS.
• To learn how hydrologic attributes and model parameters can be derived from digital elevation model (DEM) data.

Lecture 1. Introduction and use of ArcView

• Overview
• GIS data structures
• Raster, vector
• Geodesy, projections and coordinate systems
• Use of ArcView
• Installation and use of extensions
• Polyline theme (Stream reaches)
• Point theme (rainfall data)
• Grid theme (elevation data)
• Tables
• Charts
• Layouts
• Coordinate transformation and projection
• Map Algebra

Lecture 2. Watershed and stream network delineation

• Grid Digital Elevation Models
• Eight direction pour point model (D8)
• Contributing area
• Pits and pit removal
• Simple channel network delineation by contributing area or support area threshold
• Channel network geomorphology
• Drainage density
• Horton's laws
• Stream drops
• Slope-area properties
• Hack's law
• Advanced channel network delineation
• Grid network order pruning
• Curvature based methods
• Slope area plot and stream order analysis

Lecture 3. DEM Based Hydrologic Modeling

• Slope, Contributing Area and Specific Catchment Area
• Multiple flow directions and the D¥ method
• TOPMODEL Wetness Index
• Semi-distributed hydrologic modeling with TOPNET

Lecture 4. Computer Modeling/GIS Linkages

• Concepts
• Hydrologic Response - The Unit Hydrograph
• The time area diagram
• Geomorphologic Unit Hydrographs
• The "width" function
• GIS application ideas
• Distance to outlet from each grid cell
• Distance to outlet from each point on a channel
• Distance to outlet from each point on contributing area
• Combination of distance with dispersion to get travel time distribution
• Cascade model at each grid cell
• Cascade model of watersheds
• Computer application
• FORTRAN model for distance to outlet. Using qgio.f to work with ASCII DEM grid files.
• C gridio application programmers interface functions to directly work with ESRI binary grid files
• Avenue scripting.

Exercises

Handouts

These materials may be used for study, research, and education, but please credit the authors and the Utah Water Research Laboratory, Utah State University. All commercial rights reserved. Copyright 2000 Utah State University.