The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
GRADUALLY
VARIED FLOW
Introduction
Gradually varied flow refers to flows where the flow parameters vary along
the length of the flow plane gradually. Assumptions include
Steady conditions
Nonuniform flow
Slope is relatively small
Velocity distributi
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
SEDIMENT YIELD
AND DEPOSITION
Sediment yield
Sediment yield refers to that part of the gross erosion that is transported. Gross
erosion is the total amount of material eroded.
Method of estimation
Sediment Sampling  Sediment sampling method requires th
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Governing Equations of Motion
Description of flow
Lagrangian description of motion : The motion of an individual particle of
fluid in time is observed and described by its position s(t), v(t) and a(t). In
this approach, the same mass of fluid is followed
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
OPEN CHANNEL
FLOWS
Introduction
Definition  Open channel flow refers to flows in which the surface of flow is at atmospheric pressure.
Types of open channels
Natural or artificial, by origin
Prismatic or nonprismatic, by geometry (Prismatic channels h
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
SEDIMENT
TRANSPORT
Introduction
Sediment classification  Sediment load is classified as bed load and suspended
load depending on the mode of transport. It can also be classified as wash load
and bed material load.
Bed Load  that part of the sediment lo
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
(ii) From the given data, mean and standard deviations are
= 13,788 m3/s;
= 3937 m3/s
For Gumbel distribution,
0.5772
;
1.2825
Substituting and solving,
3.257 x10 4 ; 12,016
y ( x ) ln( ln(1
(iii)
Tr
(years)
y
x (m3/s)
1
)
Tr
1.01
1.5
10
50
100
200
5
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
CIVL 3510: Tutorial no. 3: Analysis of rainfall data and runoff
1. The average rainfall for the water year (April March) 1991/1992 for the following raingauge
stations in Hong Kong island were as follows:
Station No.
5
7
11
24
128
140
147
Name of station
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
The z values corresponding to return periods 25, 50 and 100 should be 1.76, 2.06 and 2.33
(from statistical tables) instead of 1.76, 2.6 and 3.33. Therefore the corresponding answers
should be 1482, 1606 and 1720 respectively.
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Fluid Mechanics
Hong Kong University of Science and Technology
Given by
Zhaoyin Wang
Visiting Professor of HKUST and Professo of Tsinghua
University
Vice President of WASER
Vice President of IAHR
About the course Civl 2500
Chapter 1 Prof. Muhamed Guidoui
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Fluid Mechanics
Hong Kong University of Science and Technology
Given by
Zhaoyin Wang
Visiting Professor of HKUST and Professor of Tsinghua
University
Vice President of WASER
Vice President of IAHR
About the course Civl 2500
Chapter 1 Prof. Muhamed Guidoui
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
FLOW THROUGH
SATURATED POROUS
MEDIA
OCCURRENCE OF GROUND WATER
Ground water is stored in aquifers which are ground water
reservoirs in water bearing formations. They may be
confined or unconfined. A confined aquifer holds water
under pressure between two
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
HYDRAULIC
MACHINERY
Introduction
Hydraulic machines can be broadly classified
into two types; namely, Pumps and Turbines.
Pumps convert mechanical energy into fluid
energy thereby increasing the energy of the
fluid (increase of pressure). Turbines conver
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Hydraulics of
alluvial channels
Introduction
Sediments Gravel, Sand, Silt, Debris
Sources of sediments  Mountain catchments, Withered sedimentary
rocks, Construction sites
Modes of transport  By suspension, By moving along the bed layer
Places of de
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
UNIT HYDROGRAPH METHODS
SOME DEFINITIONS
Unit hydrograph
A unit hydrograph is a discharge hydrograph resulting from one unit of direct
runoff (1 mm or 1 cm or 1 inch) generated uniformly over the catchment area
at a uniform rate during a specified period
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Probability and statistics in
Hydrology
Introduction
Statistical concepts are used in Hydrology when it is desired to estimate the likelihood of
occurrence or nonoccurrence of an event of a certain magnitude. The basic procedure
involves the following s
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
Flood Routing
Introduction
Channel storage can be significant in large rivers.
When a flood wave propagates downstream, the effect of channel
storage should be taken into consideration in the computation of the
downstream hydrograph from an upstream hyd
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
HYDRAULIC
MACHINERY
Introduction
Hydraulic machines can be broadly classified
into two types; namely, Pumps and Turbines.
Pumps convert mechanical energy into fluid
energy thereby increasing the energy of the
fluid (increase of pressure). Turbines conver
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
PIPE NETWORKS
Introduction
In many conveyance systems, several pipes are connected together to
form a network of pipes.
The network may have loops as well as open ends. The
determination of the head losses in each branch of such a system is
more difficu
The Hong Kong University of Science and Technology
Hydraulics
CIVL 2510

Fall 2014
OPEN CHANNEL
FLOWS
Introduction
Definition  Open channel flow refers to flows in which the surface of flow is at atmospheric pressure.
Types of open channels
Natural or artificial, by origin
Prismatic or nonprismatic, by geometry (Prismatic channels h