HEC-HMS

Hydrologic Modeling on Lower Colorado Basin

Ki-Weon Seo

Study Area-Lower Colorado Basin

Real data

- Nov/01/2000 ~ Nov/06/2000 (Hourly data)

- 4 Precipitation gages (1) Town lake near Longhorn dam (2) Buckners creek near muldoon (3) Colorado river above LaGrange (4) Colorado river at Wharton

Real data

- 3 Discharge gages (1) Onion creek at US Hwy 183 (2) Colorado river above LaGrange (3) Colorado river at Wharton

- Source Town lake near Longhorn dam

Working with Project

Basin Model

Basin Model

1. Loss Rate - Initial and Constant - SCS Curve Number 2. Transform - Snyder’s Unit Hydrograph 3. Base flow - No base flow 4. Routing - Lag and Muskingum

Basin Model

Basin Model

Meteorologic Model

1. Precipitation - Nov/01/2000 ~ Nov/06/2000

2. Evaportranspiration - No evaportranspiration

Meteorologic Model

Discharge

Result

- Initial and Constant Loss Rate (1) Calibrating Muskingum k and x (2) Calibrating Initial and Constant Loss rate

- SCS Curve Number (1) Calibrating SCS CN.

Initial and Constant(without calibration)

Initial and Constant(without calibration)

Initial and Constant(with calibration)

Initial and Constant(with calibration)

SCS CN(with calibration)

SCS CN(with calibration)

Calibrating at Wharton

Optimization Schematic

Calibrating at WhartonObjective function value

Calibrating at Wharton

Simulated and observed hydrographs

Calibrating at Wharton

Scatter graph of simulated and observed hydrographs

Calibrating at Wharton

Residual graph of simulated and observed hydrographs

Calibrating at LaGrange

Optimization Schematic

Calibrating at LaGrangeObjective function value

Calibrating at LaGrange

Simulated and observed hydrographs

Calibrating at LaGrange

Scatter graph of simulated and observed hydrographs

Calibrating at LaGrange

Residual graph of simulated and observed hydrographs

Discussion

. SCS CN method is recommended

. We need more data for Muskingum

. Calibration at each subbasin will improve the results

acknowledgment

• Sarah Stone• Chris Riley