1. Hydrologic modeling of Waller Creek
Prepared by: Mustafa AKCAY

2. TABLE OF CONTENTS  BACKGROUND  WORKING WITH HEC-Prepro  RUNNING HMS
 CALIBRATION OF HMS PARAMETERS
 RESULTS
 CONCLUTION

3. BACKGROUND HYDROLOGIC SYSTEM MODEL
HSM is an approximation of the actual system in which inputs and outputs are measurable hydrologic variables and system operator is described by a set of equations linking the inputs and outputs.
Input Output
I(t) Q(t)
Q(t)= I(t)
Operator,

4. Hydrologic Model Classification
Hydrologic Models
Physical Models  Abstract Models
Input Output
HMS (Hydrologic Modeling System) Deterministic  Stochastic
Output is not a fixed
Input F(infiltration,transform,routing) Output value but instead
described as a
Precipitation, i Stream flow,Q probability distr.
System
f(ran.,space,time)

5. RUNNING HEC-Prepro
Dem  Digital Elevation
RF3  Stream Network

6. BURNING IN  FILLING STREAM GRIDS FLOW DIRECTION  FLOW ACCUMULATION
Rising the land surface cells that are of stream to delinate streams from DEM.
Filling the pits that are probably to cause wrong flow directions
Defing threshold or minimum drainage area
Darker the color of individual grid,the more grid cells drain into that cell.

7. GAGES--OUTLETS--LINKS SUB-WATER DELINEATION VECTORIZATION
Shape file with points representing gages that will be imported into ArcView.
Adding outlets to change the places of gages that are off the river and pointing the joints
Delineation of watershed according to gages,outlets,links
Vectorization for easyness of using and storing data compared with grid base analysis.

8. RUNNING HMS RUNNING HMS Transfer of Hydrologic Attributes to Schematic  Creating the HMS Components
HMS schematic is conceptual model that captures the connectivity between the different elements of the hydrologic system
Opening a new HMS project and importing the basin file , and then adding a background map .

9. Location of USGS Stations ,38th street and 23rd street, and their annual peak values for corresponding rainfall.

10. Stream flow vs Precipitation

11. Best-lines for runoff-rainfall data

14.  Application of Rational Method
Assumptions:
Computed peak rate of runoff at the outlet point is a function of the average rainfall rate during the time of concentration.
Time of concentration: Time from most remote part of the drainage area to the out flow point.
Constant rainfall intensity.

15. Most critical flow between Q1(HMS)=173cfs Q1(Measured)=289cfs 40% accuracy Q2(HMS)=295cfs Q2(Measured)=717cfs % accuracy

16. Most Critical Flow Between 1965-1972 Q1(HMS)=366
Most Critical Flow Between Q1(HMS)=366.9cfs Q1(Measured)= % accuracy Q2(HMS)=633cfs Q2(Measured)= % accuracy

17. Most Critical Flow Between Q1(HMS)=614cfs Q1(Measured)=521cfs 15% accuracy Q2(HMS)=1059cfs Q2(Measured)=1386cfs 30% accuracy

18. RESULTS
According to data I obtained, by the definition of stochastic model;
the runoff will fall in 140%, 60%, 30% neighborhood of runoff you obtained from HMS between , , respectively.
For runoff from ?

19. CONCLUSION
Using SCS Method for Infiltration may increase the precision of the model.
Lots of uncertainty affecting the output so it is difficult to make modeling with high accuracy
Don’t even think of a modeling of a basin by just one rainfall gage station!

20. Appreciations
Esteban AZAGRA
Jona F.JONSDOTTIR