Waller Creek Sub-basin

1
Waller Creek Sub-basin

• HMS

2
Review

• Original project idea scrapped
• Difficult to find adequate GIS data
• No measured flow data to validate model results
• Selected new study area

3
New Area
4
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

5
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

6
Data

• TIN developed by Esteban Azagra
• One-meter DEM (courtesy of Becky)
• Vegetation
• Vegetation Removed
• Dr. Barretts rainfall and runoff data at outlet

7
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?

8
Story Begins

• It all started with Esteban Azagras TIN
• Converted TIN to a grid
• Projected grid from State Plane to UTM
• Overlayed grid onto a DOQQ for position
  verification

9
Conversion

• TIN

• GRID (DEM)

10
Projected Grid

• Arc-Info

11
Projected Grid

• Code

12
Overlayed Grid onto DOQQ
13
Story Progresses

• Fun with HEC-geoHMS
• Familiar with HEC-geoHMS
• Processed terrain data
• Analyzed final result

14
Familiar with HEC-geoHMS
15
Familiar with HEC-geoHMS
16
HEC-geoHMS In Action!

• Fill Sinks

• Flow Direction

17
HEC-geoHMS In Action!

• Flow Accumulation

• Watershed Delineation

18
HEC-geoHMS In Action!

• End Result Streams!
• Cool, but bad!
• Why?
• Streams are not behaving
• No way to modify!

19
Uh Oh! What now?
20
Pre-Pro In Action!

• Drew in sewer system

• Burned into grid

21
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

22
Enter LIDAR!

• Vegetated

• Vegetation Removed

23
Processing Both Grids in Pre-pro

• LIDAR Flow Direction

• TIN Flow Direction

24
TIN Product
25
LIDAR Product
26
Comparison of Watersheds
27
Comparison of Streams
28
Creation of HMS Schematic

• TIN GIS Model

• TIN Schematic

29
Creation of HMS Schematic

• LIDAR GIS Model

• LIDAR Schematic

30
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

31
Intro to HMS

• 3 Parts

32
Basin Model

• Chose SCS for loss and transform methods
• Chose no baseflow
• Chose lag method for reach routing
• Parameters by Hand (and Arcview)

33
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

34
Hydrologic Parameters

• Sub-basin attributes
• Notice SLOPES!!
• Those darned buildings!!!

35
Hydrologic Parameters By Hand (and Arcview)

• Reach Attributes
• Chose lag transform
• Easy

36
Meteorologic Model and Control Specifications

• User Specified Hyetograph
• From 000 to 2355 10/18/99
• 5 minute increments

37
RESULTS!!!

• After all of this hard work I am ready to reap
  what I have sowed

38
Comparison to measured data
39
Looks good

• But Im off by a factor of 10
• Units problem?
• Variability in rainfall?
• Another problem?
• ???

40
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

41
Questions?