ENGINEERING
HYDROLOGY
1 |
Introduction to
Hydrology &
Weather Basics
Water is vital to life and development in all parts of the world. In
Third World countries where the agricultural sector plays a key role
1.1 | Introduction to
Hydrology
Hydrology
INTENDED LEARNING OUTCOMES
• Define Hydrology and understand
its application in engineering
• Differentiate Hydrology from
Hydraulics
in their economic growth, the management of water resources is
an item of high priority in their developmental activities. The basic
inputs in the evaluation of water resources are from hydrological
parameters and the subject of hydrology forms the core in the
evaluation and development of water resources. In the civil
engineering curriculum, this subject occupies an important
position.
What is hydrology?
• Hydrology means the science of water. It is the science that
deals with the occurrence, circulation and distribution of water of
the earth and earths atmosphere.
• Scientific Hydrology the study which is concerned with the
academic aspects.
• Engineering or Applied Hydrology a study concerned
with engineering applications. In a general sense
engineering hydrology deals with (i) estimation of water
resources, (ii) the study of processes such as precipitation,
runoff, evapotranspiration and their interaction and (iii) the
study of problems such as fl oods and droughts, and
strategies to combat them.
Hydrology in
engineering
Hydrology finds its greatest application in the design and
operation of water-resources engineering projects, such as
those for (i) irrigation, (ii) water supply, (iii) flood control, (iv)
water power, and (v) navigation. In all these projects
hydrological investigations for the proper assessment of the
following factors are necessary:
1. The capacity of storage structures such as reservoirs.
2. The magnitude of flood flows to enable safe disposal of the
excess flow.
3. The minimum flow and quantity of flow available at various
seasons.
4. The interaction of the flood wave and hydraulic structures,
such as levees, reservoirs, barrages and bridges.
The hydrological study of a project should necessarily precede
structural and other detailed design studies. It involves the
collection of relevant data and analysis of the data by applying
the principles and theories of hydrology to seek solutions to
practical problems
Hydraulics
• HYDRAULICS is defi ned as the study of the mechanical
behavior of water in physical systems. In engineering terms,
hydraulics is the analysis of how surface, and/or subsurface
fl ows move from one point to the next. Hydraulic analysis is
used to evaluate fl ow in rivers, streams, storm drain networks,
water aqueducts, waterlines, sewers, etc.