Surface Water Hydrology

1. ELEMENTS OF SURFACE HYDROLOGY
By,
Mr. Akshay D. Raut

2. CONTENTS
• What is Surface Water Hydrology?
• Hydrological Cycle
• Overland Flow
• Rivers
• Lakes
• Sediment Transport & Deposition
• Water Measurement
• Flood Events

3. WHAT IS SURFACE WATER HYDROLOGY?
• Surface Water Hydrology is a field that encompasses all
surface waters of the globe.
• It includes water in the rivers, lakes, oceans, overland flow,
watershed, etc.
• It does not include Atmospheric and Ground waters.
• The surface water is important for transportation, irrigation ,
water supply, hydropower, etc.

5. HYDROLOGICAL CYCLE

6. PRECIPITATION CANOPY INTERCEPTION
SNOWMELT RUNOFF
INFILTRATION SUBSURFACE FLOW
EVAPORATION CONDENSATION
SUBLIMATION DEPOSITION
ADVECTION TRANSPIRATION
PERCOLATION PLATE TECTONICS
HYDROLOGICAL CYCLE : PROCESSES

7. OVERLAND FLOW
• Rain falls onto vegetation, and then to the ground.
Interception is lost in the vegetation
Throughfall makes it to the ground
Stemflow runs down the vegetation
• Water reaching the ground can:
Accumulate in depressions
Soak into the ground (infiltration)
Flow across the surface as overland flow

8. RUNOFF GENERATION
• Runoff generation involves the movement of water thought
soil pores and macropores
• Types of Runoff Generation
1) Hortonian Overland Flow
2) Saturated Overland Flow

10. SUBSURFACE STORM FLOW
• It is a runoff producing mechanism operating in most upland
terrains.
• Part of the storm rainfall that flows below the land surface for
a certain distance before eventually reaching the surface
channel.
• Consist of both slower matrix flow and faster macropore
flow.

12. RIVERS
• Components of River

13. RIVER MORPHOLOGY

14. • Ephemeral River: Whenever snow melts quickly or there is an exceptionally heavy rain, it
can result in an ephemeral river.
• Episodic River: Episodic rivers are formed from run-off channels and found in areas with
very dry climate.
• Exotic River: Any river that flows through a very dry region is called an exotic river.
• Intermittent River: These rivers are known for their seasonal flow in wet periods.
• Mature River: A mature river is not very steep and has a slow flow when compared to
youthful rivers
• Old Rivers: Old rivers have a low gradient and they depend on floodplains.
• Periodic River: Periodic rivers have dry spells throughout the year, they usually flow best
right after a heavy rain.
• Permanent Rivers: Permanent rivers are those which have water all year around
• Youthful Rivers: With a steep gradient and only a few tributaries, youthful rivers flow
quickly.
TYPES OF RIVERS

15. LAKES
• A body of fresh or saline water surrounded by land.
• Types of lakes
Cirque Lake Pluvial Lake Kettle Lake

16. SEDIMENT TRANSPORT AND DEPOSITION
• This refers to soil carried by water and then deposited in low energy
environments.
• The heavy sediments (sands) fall out along the river banks, forming levees
• Finer materials (clays and silts) fall out in flood plains
• A delta forms where the sediment chokes the main channel often in braided
rivers.

17. WATER MEASUREMENT
• Rational Formula
Q = C i A
Where,
o Q is the peak runoff rate,
o C is the runoff coefficient,
Urban areas (C= 0.9)
Industrial areas (C= 0.8)
Residential areas ( C= 0.6)
Forested areas ( C= 0.1)
o i is the rainfall intensity/ hr
o A is the watershed area in acres

18. RIVER DISCHARGE
• Discharge is the flow of water
• Measured in units of cubic feet per minute
• Formula for finding the river discharge
Q= VA
Where,
Q is the river discharge
V is the river velocity
A is the area

19. FLOOD EVENTS

20. FLOOD EVENTS
• 100- year flood:
Flood that is exceeded on average once every 100 years, the
probability in 1 year is 1/100 = 1%
• 10- year flood:
probability of flood is 10%
• Mean annual flood:
Exceeded once every two year, probability = 50%

21. Thank you for watching my presentation !!
Please consider trying some of the ways to save water !!
Our life and the beautiful mother Earth depends on it !!