# Engineering Hydrology Questions and Answers – Hydraulic Method of Flood Routing

This set of Engineering Hydrology Multiple Choice Questions & Answers (MCQs) focuses on “Hydraulic Method of Flood Routing”.

1. Which of the following does not describe the St. Venant equations used in hydraulic flood routing?
a) Simultaneous
b) Quasi-linear
c) Second order
d) Hyperbolic

Explanation: The St. Venant equations comprise of two partial differential equations which are used in hydraulic flood routing. They are simultaneous, quasi-linear and hyperbolic first order differential equations.

2. What type of method is applied to solve the St. Venant equation in hydraulic routing?
a) Analytical
b) Empirical
c) Numerical
d) Semi-empirical

Explanation: The general analytical solution cannot be found for the St. Venant equations. High speed digital computers with advanced programming languages are used to solve the equations through numerical methods.

3. How many categories of numerical methods are there to solve St. Venant equations?
a) 2
b) 3
c) 4
d) 5

Explanation: The different numerical techniques that are used to find the solution of the St. Venant equations are broadly categorized into two types – approximate numerical methods and complete numerical methods.

4. The Muskingum method is an example of approximate numerical method.
a) True
b) False

Explanation: Approximate numerical methods use only the continuity equation or a very simplified version of equation of motion. Hydrologic routing methods like Muskingum equation are examples of this method.

5. Which of the following is not a complete numerical method for analyzing St. Venant equations?
a) Direct method
b) Variable separable method
c) Method of characteristics
d) Finite element method

Explanation: Complete numerical methods are the main techniques used in hydraulic routing. They are mainly classified into three types – direct method, method of characteristics and finite element method.

6. The direct method of complete numerical analysis in[s further divided into which of the following?
a) Explicit and implicit
b) Homogeneous and non-homogeneous
c) Exact and non-exact
d) Linear and non-linear

Explanation: The direct method and method of characteristics in complete numerical analysis are further classified into two categories on the basis of how the variables are extracted. These methods are explicit and implicit methods.

7. In which method are the partial differential equations of St. Venant converted to ordinary differential equations?
a) Approximate method
b) Direct method
c) Finite element method
d) Method of characteristics

Explanation: The St. Venant equations are converted to their ordinary characteristic form before solving it using finite difference in the method of characteristics. Whereas in the direct method, the partial derivatives are directly replaced by the finite differences and solved.

8. Which of the following is a characteristic of the inflow and outflow hydrograph of a linear channel?
a) Both peak lag and attenuation
b) Only peak attenuation
c) Neither peak lag nor attenuation
d) Only peak lag

Explanation: A linear channel is a hypothetical channel for which the time taken to pass a given discharge is constant. There is only translation of the inflow hydrograph without any attenuation.

Sanfoundry Global Education & Learning Series – Engineering Hydrology.