Final Project

1

• Final Project
• I. Calibration
• Drawdown Prediction
• Particle Tracking
• Presentation of Results

2
Schedule Week of April 14 No lectures. Work
on Parts I IIof Final Project April 22, 24
Particle tracking and Profile Models (PS6). Work
on Part III of Final Project. April 24 30 min
in-class, closed book quiz. April 28, May 1
Group presentations of final project. May 6, May
8 Grid design/parameter selection final
thoughts. PS6 due on May 6.
3
Calibration Sensitivity Analysis
4
Calibration Targets
associated error
calibration value
???0.80 m
20.24 m
Target with smaller associated error.
Target with relatively large associated error.
5
Examples of Sources of Error

• Surveying errors
• Errors in measuring water levels
• Interpolation error
• Transient effects
• Scaling effects
• Unaccounted heterogeneities

6
Calibration parameters are uncertain
parameters whose values are adjusted during model
calibration.
Typical calibration parameters include hydraulic
conductivity and recharge rate.
7

• Sensitivity analysis is used
• In automated calibration (inverse modeling)
• (Sensitivity coefficients
• ?sum of squared residuals/?parameter
• or ?h/?parameter)
• As an uncertainty analysis after calibration

8
Automated calibration using inverse modeling
Codes MODFLOWP used in MODFLOW2000 GV
Calibration PEST UCODE
Available in GWV
9
Island Recharge Problem- Forward Problem
L
y
2L
ocean
well
Parameters known with certainty R 0.00305
ft/d K 100 ft/day
Solve for head
x
ocean
10
Island Recharge Problem Inverse Problem
L
y
2L
ocean
Head in well 120 feet
well
Uncertain parameters R 0.00305 ft/d K 100 ft/day
x
ocean