Waller Creek Sub-basin
description
Transcript of Waller Creek Sub-basin
Waller Creek Sub-basin
HMS
Review
• Original project idea scrapped• Difficult to find adequate GIS data
• No measured flow data to validate model results
• Selected new study area
New Area
Area Characteristics
• Located on UT campus at 24th and San Jacinto
• Dr. Barrett has a monitoring point at basin outlet
• Very urban and hydrologically restricted
Goals
• Create terrain model in Arcview
• Process terrain model with HEC-geoHMS
• Create working hydrologic model in HEC-HMS
• Calibrate model and evaluate results with measured rainfall and runoff data
Data
• TIN developed by Esteban Azagra
• One-meter DEM (courtesy of Becky)• Vegetation
• Vegetation Removed
• Dr. Barrett’s rainfall and runoff data at outlet
Interesting Questions
• Which data source is best suited for this application?
• How can we use HEC-geoHMS?
• How can we create a hydrologic model of a restricted basin in a meaningful way?
• How will this model interact with other models created in the area?
Story Begins
• It all started with Esteban Azagra’s TIN• Converted TIN to a grid
• Projected grid from State Plane to UTM
• Overlayed grid onto a DOQQ for position verification
Conversion
• TIN • GRID (DEM)
Projected Grid
• Arc-Info
Projected Grid
• Code
Overlayed Grid onto DOQQ
Story Progresses
• Fun with HEC-geoHMS• Familiar with HEC-geoHMS
• Processed terrain data
• Analyzed final result
Familiar with HEC-geoHMS
Familiar with HEC-geoHMS
HEC-geoHMS In Action!
• Fill Sinks • Flow Direction
HEC-geoHMS In Action!
• Flow Accumulation • Watershed Delineation
HEC-geoHMS In Action!
• End Result: Streams!
• Cool, but bad!
• Why?
• Streams are not behaving
• No way to modify!
Uh – Oh! What now?
Pre-Pro In Action!
• Drew in sewer system • Burned into grid
The Plot Thickens!
• Becky provides one-meter DEM of study area (E00 Files)
• E00 files no longer a mystery to me • Import 71
• Becky solves vegetation problems
Enter LIDAR!
• Vegetated • Vegetation Removed
Processing Both Grids in Pre-pro• LIDAR Flow Direction • TIN Flow Direction
TIN Product
LIDAR Product
Comparison of Watersheds
Comparison of Streams
Creation of HMS Schematic
• TIN GIS Model • TIN Schematic
Creation of HMS Schematic
• LIDAR GIS Model • LIDAR Schematic
The Winner Is:
• LIDAR for HMS • Too cumbersome to do both (out of time)
• LIDAR looks better
• Checked soil types via SSURGO
• Developed curve numbers
• Input hydrologic attributes
• Ran model
Intro to HMS
• 3 Parts
Basin Model
• Chose SCS for loss and transform methods
• Chose no baseflow
• Chose lag method for reach routing
• Parameters by Hand (and Arcview)
Getting Soiled With SSURGO
• All for this?• Soil type is Ur (urban)
• Either C or D
• Land use is urban
• Curve numbers are either 94 (C) or 95 (D)
• I went with 95
Hydrologic Parameters
• Sub-basin attributes• Notice SLOPES!!
• Those darned buildings!!!
Hydrologic Parameters By Hand (and Arcview)
• Reach Attributes
• Chose lag transform• Easy
Meteorologic Model and Control Specifications
• User Specified Hyetograph
• From 0:00 to 23:55 10/18/99
• 5 minute increments
RESULTS!!!
• After all of this hard work: I am ready to reap what I have sowed
Comparison to measured data:
Looks good …
• But I’m off by a factor of 10• Units problem?
• Variability in rainfall?
• Another problem?
• ???
I Would Like To:
• Calibrate this model (determine problem)
• Try to use HEC-geoHMS in combination with Pre-pro (burn sewers, process with geoHMS)
• Figure out how to make Pre-pro transfer hydrologic attributes
• Study how this model fits into models already completed
Questions?