An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field m - PowerPoint PPT Presentation

About This Presentation
Title:

An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field m

Description:

An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field m – PowerPoint PPT presentation

Number of Views:68
Avg rating:3.0/5.0
Slides: 15
Provided by: Wen123
Category:

less

Transcript and Presenter's Notes

Title: An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field m


1
An integrated approach to flood hazard assessment
on alluvial fans using numerical modeling, field
mapping, and remote sensing
In addition to providing better hazard
information to the public, revising the
floodplain maps could have a major economic
impact on the rapidly growing Southwest.
ScienceDaily, Oct. 1, 2005
2
(No Transcript)
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
2 dimensional continuity equation for unsteady
flow
However, their model uses steady flow b/c, 1)
direct constraints on flood duration are
unavailable, 2) no specified hydrograph shape
Time dependent variable removed, continuity
equation for steady flow
This simplifies the analysis b/c now 1) only peak
flood stage needs to be specified, 2) each flood
stage has unique inundation.
Mannings Equation
Continuity equation combined with flow equation
that relates discharge to flow depth in each pixel
Assuming uniform roughness cancels n out of Eq.
3, and using square pixels cancels out delta x
and delta y
9
Equations 2 and 3 are solved for the whole grid
simultaneously using Newtons Method
Eq. 2 rearranged to find the residual vector,
which goes to zero when the exact solution is
found
Iteratively estimates the vectors of flow depth
for the entire grid
Eq 5 is solved implicitly using the
Alternating-Direction-Implicit (ADI) technique
which converges to the exact solution (h) from
any starting point.
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com