HMG-IITM Investigating the effect of calibration objective function on a flood forecasting system Cicily Kurian 1 , K.P. Sudheer 1,2 , Debabrata Sahoo 3 19 January 2018 Hydrologic Modeling Group Department of Civil Engineering, Indian Institute of Technology Madras 1 Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 2 Agricultural and Biological Engineering, Purdue University, West Lafayette, USA 3 Water Resources, Woolpert, Columbia, SC, USA
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HMG-IITM
Investigating the effect of calibration objective function on a flood
forecasting system
Cicily Kurian1, K.P. Sudheer1,2, Debabrata Sahoo3
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras
1 Department of Civil Engineering, Indian Institute of Technology Madras, Chennai
2 Agricultural and Biological Engineering, Purdue University, West Lafayette, USA
3Water Resources, Woolpert, Columbia, SC, USA
HMG-IITM
Introduction Disasters - a natural or human
caused phenomenon causingdisruption to the functioning of acommunity
Flood – the most common naturaldisaster causes huge loss oflives, and damage to livelihoodsystems and public utilitiessystems and public utilities
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 2
What is the Solution ?
Understanding the level of risk and selection of appropriate flood control
measures
Accurate and reliable flood forecasting serves the purpose
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Flood Forecasting Using Hydrological Models
Flood forecasting models - generally achieved by applying
Various hydrological models
Hybrid models - combines the strength of different modelling
aspects in hydrology
A flood forecasting model aims to capture A flood forecasting model aims to capture
The Peak Discharge
Time of peak
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 3
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Calibration and Selection of Objective Function Calibration- A process to find the optimal parameter set
Calibration can be done using various objective functions
Each objective function able to capture only a certain amount of
information
Understanding the effect of objective functions on the model and its Understanding the effect of objective functions on the model and its
parameters might help us to improve the model performance
To study the effect of objective functions on model calibration of a
flood forecasting model
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 4
Objective of the Study
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Developing a flood forecasting system
A hybrid model – Combines a physically based model with a data
driven model
HEC-HMS Setup and calibration
Meteorological data
Topographic data
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Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 5
Runoff estimation
Training & testing
ANN
Runoff estimation
Runoff at current time step
Pt-6
Pt-5
Pt-4
Pt-3
Pt-2
Qet-2
Qet-1
Qet
Observed rainfall
Runoff fromHEC-HMS
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Objective Functions considered
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 6
Combinations Used Nash Sutcliffe Efficiency
Modified Peak Difference
Nash Sutcliffe Efficiency and Modified Peak Difference
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Study Area – Mills Avenue Watershed
Greenville county - South
Carolina – USA
Area – 6.85 Km²
Length of river – 3.3 Km
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Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 7
Annual avg rainfall -1260 mm
Mean annual temp - 16.4ºC
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Nash Sutcliffe Efficiency
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Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 8
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Modified Peak Difference
19 January 2018
Hydrologic Modeling Group
Department of Civil Engineering, Indian Institute of Technology Madras 9