Flood routing

Question 1

what is flood routing?

Answer 1

mathematical procedure to predcit the changing magnitude, speed and shape of a flood wave as a function of time at one or more points along a river

Question 2

why do we do flood routing?

Answer 2

1) flood prediction/ forecasting: safety
2) civil structure design and risk analysis

Question 3

Regression method/ Non-storage routing

Answer 3

water stages can be related using historical measurements
travel time of flood can be estimated
does not take into account the lateral inflow

Question 4

Hydrological routing

Answer 4

uses the continuity principle to describe the process of flood wave propagation
conceptually modelled
important concept is the introduction of ‘storage’

Question 5

Principle of continuity

Answer 5

difference between total flow in volume and flow out volume is the storage

Question 6

Prism storage

Answer 6

inflow > outflow
water stored when there is no flood wave disturbance

Question 7

Wedge storage

Answer 7

outflow > inflow
water stored when flood waves are introduced

Question 8

Reservoir routing

Answer 8

impact of inflow storage can be ignored (large open surface)
outflow indirectly and uniquely related to stage H
storage directly related to stage H

Question 9

River routing - musking method

Answer 9

consists of two parts; prism and wedge storage
uses two linear functions to represent the two storage parts