Selection of Hydrologic Model
The model selection depends on available data, site conditions, gauged or ungauged
catchment, and size of the watershed (HEC 2010).
General Applicability and Limitations
The significant advantages of this software are the wide selection of different
hydrologic models suitable for different environmental conditions. Further, it
includes options in the calibration of the chosen models against measured precipitation and runoff data. The limitation of the model is that continuous simulations
cannot be performed, so the modeling is limited to single events.
Hydraulic Model-HEC RAS
HEC-RAS is a hydraulic model developed by the U.S. Army Corps of Engineers
Hydrologic Engineering Center. The software is capable of performing
one-dimensional (1-D) steady- and unsteady-flow simulations and also has graphical
user interface data storage and separate hydraulic analysis components (HEC 2010).
Data Requirements
The data required for flow simulation in HEC-RAs are geometric details and the
relative surface roughness of the analyzed flow channel, over banks, flow data, and
data about hydraulic structures such as levees or weirs, and bridges. The base of any
geometric model in HEC-RAS is the river system schematic.
Applications and Limitations of HEC-RAS
In this study, HEC-RAS is used for the determination of floodplains based on
unsteady-flow simulations of flood hydrographs with statistical return periods of
2, 5, 10, 50, and 100 years. The software is selected primarily for its wide application
in the stable and practical flow model. The model is easy to use and provides
complete practical documentation (Hu and Walton 2008). Its suitability in different
condition and its application have been widely examined (HEC 2010).
In major cities, flooding is one of the most dangerous phenomena, one that cause
loss of human life and their properties to a large extent. The major cities are centers
of economic activities with vital infrastructure that needs to be protected 24 Â 7. In
most of the cities, damage to vital infrastructure not only has a bearing for the state
and the country but could even have global implications. Major cities in India have
48
S. Natarajan and N. Radhakrishnan
The model selection depends on available data, site conditions, gauged or ungauged
catchment, and size of the watershed (HEC 2010).
General Applicability and Limitations
The significant advantages of this software are the wide selection of different
hydrologic models suitable for different environmental conditions. Further, it
includes options in the calibration of the chosen models against measured precipitation and runoff data. The limitation of the model is that continuous simulations
cannot be performed, so the modeling is limited to single events.
Hydraulic Model-HEC RAS
HEC-RAS is a hydraulic model developed by the U.S. Army Corps of Engineers
Hydrologic Engineering Center. The software is capable of performing
one-dimensional (1-D) steady- and unsteady-flow simulations and also has graphical
user interface data storage and separate hydraulic analysis components (HEC 2010).
Data Requirements
The data required for flow simulation in HEC-RAs are geometric details and the
relative surface roughness of the analyzed flow channel, over banks, flow data, and
data about hydraulic structures such as levees or weirs, and bridges. The base of any
geometric model in HEC-RAS is the river system schematic.
Applications and Limitations of HEC-RAS
In this study, HEC-RAS is used for the determination of floodplains based on
unsteady-flow simulations of flood hydrographs with statistical return periods of
2, 5, 10, 50, and 100 years. The software is selected primarily for its wide application
in the stable and practical flow model. The model is easy to use and provides
complete practical documentation (Hu and Walton 2008). Its suitability in different
condition and its application have been widely examined (HEC 2010).
In major cities, flooding is one of the most dangerous phenomena, one that cause
loss of human life and their properties to a large extent. The major cities are centers
of economic activities with vital infrastructure that needs to be protected 24 Â 7. In
most of the cities, damage to vital infrastructure not only has a bearing for the state
and the country but could even have global implications. Major cities in India have
48
S. Natarajan and N. Radhakrishnan