This document provides an overview of hydrology and the hydrologic cycle. It begins with an introduction to water as a natural resource and the role of hydrology in understanding water systems. It then defines hydrology as the science dealing with the occurrence, circulation, and distribution of water on Earth. The main components of the hydrologic cycle are described as evaporation, transpiration, precipitation, and runoff. The document discusses different forms of precipitation including rain, snow, hail, sleet, and drizzle. It also covers terms related to rainfall such as intensity, daily rainfall, mean annual rainfall, isohyets, and catchment area. Measurement of rainfall using non-recording and recording rain gauges is briefly explained

1. Subject: Water Resource Management (3340604)
Topic: Hydrology
Guided by : Amit K Vahoniya
Fatema K Lanewala

2. TOPIC: HYDROLOGY
Sr. No. Enrollment no. Name
1 166300306514 Damor Shailesh B.
2 166300306008 Baria Bhavesh M.
3 166300306024 Charel Vipul J.
4 166300306046 Garasiya Prakash M.
5 166300306082 Pargi Amit N.
6 156300306502 Bhabhor Nikunj S.

3. Index
1) Introduction
2) Hydrology
3) Hydrologic cycle
4) Process of hydrologic cycle
5) Forms of precipitation
6) Types of precipitation
7) Terms related with rainfall
8) Measurement of rainfall
9) Conclusion

4. Introduction
Water is one of our most important natural resources.
Without it, there would be no life on earth. The lifestyle we have
become accustomed to depends heavily upon having plenty of
cheap, clean water available as well as an inexpensive, safe way to
dispose of it after use.
The supply of water available for our use is limited by
nature. Although there is plenty of water on earth, it is not always
in the right place, at the right time and in the right quality. Adding
to the problem is the increasing evidence that chemical wastes
improperly discarded yesterday are showing up in our water
supplies today.

5. Today, we face record consumption, uncertain supplies,
and growing demands for protection from flooding and pollution.
The health and economic effects of a shortage of clean water are
matters of great concern. Hydrology has evolved as a science in
response to the need to understand the complex water systems of
the earth and help solve water problems. Hydrologists play a vital
role in finding solutions to water problems, and interesting and
challenging careers are available to those who choose to study
hydrology.

6. Hydrology
Hydrology is the science which deals with the occurrence ,
circulation and distribution of water upon, over and beneath the earth
surface. It is the science concerned with the transportation of water
vapor through the air , the precipitation occurring on the ground as
rainfall or snowfall and the flow of water over the ground surface and
through the underground strata of the earth .

7. The Hydrologic cycle
Hydrologic Cycle is also called Water Cycle. It deals with the
origin and distribution of water on the globe.
Complex pathways include passage of water from gaseous
stage in the atmosphere to oceans, lakes, rivers etc.
The hydrologic cycle is the system which describes the
distribution and movement of water between the earth and its
atmosphere.
The model involves the continual circulation of water between
the oceans, the atmosphere, vegetation and land

8. Hydrologic cycle

9. Hydrologic cycle

10. Hydrological cycle includes the following processes:
1. Evaporation and transpiration
2. Precipitation
3. Runoff
Processes of hydrologic cycle

11. Evaporation and transpiration :
Evaporation occurs when water changes from liquid
state to gaseous state.
Evaporation occurs on water surfaces like lakes, seas
etc. Evaporated moisture is lifted into atmosphere. But, some
vapor always exists in the atmosphere.
1. Evaporation:-

13. Transpiration:-
Transpiration is the biological process that occurs mostly in
the day.
Water inside plants is transferred to the atmosphere as water
vapor. Only a small portion of water is retained by the plants

15. Precipitation
Precipitation may be
defined as the fall of
moisture from the
atmosphere to the earth
surface in any from .

16. Precipitation is the process that occurs when water particles
fall from the atmosphere and reach the ground.
Precipitated water may fall into water bodies or on land. It
can then go to streams or penetrate into the soil.

17. Runoff is a flow from a drainage basin in surface streams.
It generally consists of the flow that is unaffected by
artificial diversions or storages
Runoff
The rainwater flows, either over the ground into rivers and
back to the ocean, or…infiltrates downwards through the soil and
rocks where it is returned to the oceans Through groundwater flow
There are three types of runoff
1. Surface runoff
2. Sub-surface runoff or interflow
3. Ground water flow or base flow

19. Surface runoff is the flow of water that occurs when excess
stormwater, meltwater, or other sources flows over the Earth's surface.
This might occur because soil is saturated to full capacity, because
rain arrives more quickly than soil can absorb it, or because
impervious areas (roofs and pavement) send their runoff to .
Surface runoff
Surface runoff is water, from rain, snowmelt, or other sources,
that flows over the land Surface , and is a major component of the
water cycle. Runoff that occurs on Surface before reaching a channel
is also called overland flow. Urbanization increases Surface runoff.

21. Sub-surface runoff or interflow
In the water cycle, when precipitation falls on the earth's
land, some of the water flows on the surface forming streams and
rivers. The remaining water, through infiltration, penetrates the soil
traveling underground, hydrating the vadose zone soil, recharging
aquifers, with the excess flowing in subsurface of runoff

22. Ground water flow or base flow
Base flow is the groundwater contribution to
stream flow. This is accomplished as groundwater intercepts a
stream channel and initiates ground- water discharge into the
stream from points of higher to lower elevation in the water
table. Streams that receive large portions of
their flow from groundwater Base flow tend to have.

24. Forms of precipitation
Forms of
precipitation
1). liquid
2). solid

25. Examples:-
1) Rain
2) Snow
3) Hail
4) Sleet
5) Drizzle
6) glaze

26. Rain
Rain is the
most common
type of
precipitation in
our atmosphere.
Rain is when
liquid droplets
fall to the
surface of the
Earth.

27. Snow
Snow is the
second most
common
precipitation in
the North East.
Snow forms
when water vapor
turns directly into
ice without ever
passing through a
liquid state. This
happens as water
condenses around
an ice crystal.

28. Hail
Hail is created when
moisture and wind are together.
Inside the cumulonimbus clouds
ice crystals form, and begin to
fall towards the surface of Earth.
When this starts to happen wind
gusts start to pick up the ice
crystals pushing them up high
into the clouds. As they start to
fall down again they continue to
grow in size. A wind gust might
catch the hail stone again which
will push it back up into the
cloud.

29. Sleet
Sleet consists of
transparent, globular,
solid grains of ice
formed by the
freezing of raindrops
or freezing of largely
melted ice crystals
falling through a layer
of sub freezing air
near the earth’s
surface.

30. Drizzle
Mist is a bunch of small droplets of water which are in the
air. This occurs with cold air when it is above a warm surface, for
example water
Fog and mist are very similar, the only difference is their
visibility.
If you cannot see 1 kilometer or less you know you're
dealing with fog
You can see visuals through mist and it is more haze
looking than a thicker substance

31. Drizzle

32. Glaze
Glaze is the ice coating, generally clear and smooth,
formed on exposed surfaces by the freezing of super cooled
water deposited by rain or drizzle.

33. Types of precipitation
There are five types of precipitation:-
1) Convective precipitation
2) Orographic precipitation
3) Cyclonic precipitation
4) Frontal precipitation
5) Precipitation due to turbulent ascent

34. Convective precipitation
Convectional precipitation results from the heating of the earth's
surface that causes air to rise rapidly. As the air rises, it cools and
moisture condenses into clouds and precipitation .

35. Orographic precipitation
It results when warm moist air of the ocean is forced to rise
by large mountains. As the air rises it cools, moisture in the air
condenses and clouds and precipitation result on the windward
side of the mountain while the leeward side receives very little.
This is common in British Columbia.

36. Cyclonic precipitation
Frontal precipitation results when the leading edge( front) of a
warm air mass meets a cool air mass. The warmer air mass is forced
up over the cool air. As it rises the warm air cools, moisture in the air
condenses, clouds and precipitation result.

37. Frontal precipitation
Frontal precipitation is caused by frontal systems
surrounding extratropical cyclones or lows, which form when
warm and often tropical air meets cooler air. Frontal
precipitation typically falls out of nimbostratus clouds. ...
Warm fronts occur where the warm air pushes out a
previously lodged cold air mass.

39. Precipitation due to turbulent ascent:-
Air mass is forced to rise up due to greater friction of earth
surface after its travel over ocean. The air mass rises up because
of increased turbulence and friction. when it ultimately
condenses and precipitation occurs.
Winter rainfall in Madras state is mainly due to this process.

40. Terms related with rainfall:-
There are five types of rainfall
1. Intensity of rainfall:
The intensity of rainfall is a measure of the amount of rain
that falls over time. The intensity of rain is measured in the
height of the water layer covering the ground in a period of time.
It means that if the rain stays where it falls, it would form a layer
of a certain height.
2. Daily rain fall
The Western end of the Axis of Monsoon is normally over
Rajasthan, however, currently it has shifted Southwards so the
Axis of Monsoon trough at mean sea level passes through Deesa,
Ujjain, Center of Well Marked Low Pressure area,

41. 3.Mean annual rainfall
Annual rainfall is the sum of daily rainfall, that can be
calculated from raingauge records. Here, while
calculating average annual rainfall one must take the length of
period into account. One cannot simply average the 10 years of
data to state the average rainfall. It has to be 30-35 years.
4.Isohyet:
A line on a map connecting places having equal
rainfall. line on A map connecting points having equal
amounts of precipitation during a given time period or for a
particular storm. isohyet is in the lower 50% of commonly
used words in the Collins dictionary.

42. 5.Catchment area
A catchment is an area where water is collected by the
natural landscape. Imagine cupping your hands in a downpour
of rain and collecting water in them. Your hands have become
a catchment.

43. Measurement of Rainfall
There are two main types of rain gages which are used to
measure the precipitation. These are:
1.Non recording rain gages
2. Recording rain gages

44. Non recording rain gauges
It is a rain gage which does not provide the distribution of
amount of precipitation in a day. It simply gives the amount of
precipitation after 24 hours (daily precipitation).

45. Recording rain gauges
These rain gauges are also called integrating rain gauges
since they record cumulative rainfall. In addition to the total
amount of rainfall at a station, it gives the times of onset and
cessation of rains thereby gives the duration of rainfall events
Types of recording Rain gauges
There are three main types of recording rain gauges:
1. Float type rain gages
2. Tipping bucket type rain gages
3. Weighing type rain gages

46. 1. Tipping bucket gauges
A tipping bucket rain gauge is used for measurement of
rainfall. It measures the rainfall with a least count of 1 mm and
gives out one electrical pulse for every millimeter of rainfall

47. 2. Weighing type gauges
It consists of a storage bin, which is weighed to record the mass.
It weighs rain or snow which falls into a bucket, set on a platform with
a spring or lever balance. The increasing weight of the bucket and its
contents are recorded on a chart. The record shows accumulation of
precipitation.

48. 3. Float recording gauges
The rise of float with increasing catch of rainfall is recorded.
Some gauges must be emptied manually while others are emptied
automatically using self starting siphons. In most gauges oil or
mercury is the float and is placed in the receiver, but in some cases the
receiver rests on a bath of oil or mercury and the float measures the
rise of oil or mercury displaced by the increasing weight of the
receiver as the rainfall catch freezes. Float may get damaged by
rainfall catch freezer

50. Thank you