1. Engineering Hydrology

2. 1. Basic Hydrology Concept
Introduction
Water is vital for all living organisms on Earth.
For centuries, people have been investigating where water comes from and where it goes, why some of it is salty and some is fresh, why sometimes there is not enough and sometimes too much.
Hydrology is formed by two Greek words: "hydro" and "logos" meaning "water" and "science".

3. What is Hydrology?
It is a science of water.
It is the science that deals with the occurrence, distribution and movement of water on the earth and earth’s atmosphere.
A good understanding of the hydrologic process is important for the assessment of the water resources, their management and conservation on global and regional scales.

4. In general sense engineering hydrology deals with
Estimation of water resources
The study of processes such as precipitation, evapotranspiration, runoff, infiltration and their interaction.

5. Hydrologic Cycle
Water exists on the earth in all its three states, viz. liquid, solid, gaseous and in various degrees of motion.

6. Hydrologic cycle….
The earth’s water circulatory system is called as Hydrologic cycle.
Hydrologic cycle is the process of transfer of moisture from the atmosphere to the earth in the form of precipitation, conveyance of precipitated water by streams and rivers to ocean and lakes & evaporation of water back to the atmosphere.

8. Hydrologic cycle consists follow. processes ….
Evaporation from water bodies
Water vapor moves upwards
Cloud formation
Condensation
Precipitation
Interception
Transpiration
Infiltration
Runoff–stream flow
Deep percolation
Ground water flow

9. Hydrologic cycle….
The water that is stored in a oceans & lakes can
evaporate and become a gas.
As the water rises through the atmosphere, it
cools, condenses and becomes clouds.
When the water gets heavy enough it can fall to
the ground in the form different types of
precipitation.
If the ground is saturated, the water that has
fallen can become runoff and flow directly into
streams, rivers, or lakes.

10. If the ground is not saturated, the water will
Hydrologic cycle….
If the ground is not saturated, the water will
infiltrate the ground and move into the zone of
aeration or the zone of saturation.
The interface or boundary between these two
zones is called the water table.
The roots of plants can reach into the zone of
saturation soak up the water, and the water
can then re-enter the atmosphere through the
process of transpiration.

11. Importance of Hydrologic cycle….
The hydrologic cycle has importance influence in a variety of fields agriculture, forestry, geography, economics, sociology, and political scene.
Engineering application of the knowledge are found in the design and operation of the projects dealing with water supply, hydropower, irrigation & drainage, flood control, navigation, coastal work, various hydraulic structure works, salinity control and recreational use of water.

12. Hydrologic Equation
The Hydrologic cycle may be expressed by following simplified equation –
PRECIPITATION=EVAPORATION+RUN-OFF
P = E + R

13. Application in Engineering
Hydrology finds its greatest application in the design and operation of water resources engineering projects -
The capacity of storage structures such as reservoir.
The minimum flow and quantity of flow available at various seasons.
The interaction of the flood wave and hydraulic structures, such as levees, reservoirs, barrages and bridges.

14. THE END