What is ravine.ppt

CONSERVATION OF

GULLIES AND RAVINES

GROUP MEMBERS

AJAY PRATAP SINGH(64)

ABHISHEK KUMAR SRIVASTAVA(65)

RITU SINGH(66)

CONTENT

Introduction

Causative factors

Process of formation

Gully

A gully is a landform created by

running water, eroding sharply

into soil, typically on ahillside. Gullies

resemble large ditches or

small valleys, but are metres to tens of

metres in depth and width.

RAVINE

A very small valley.

Product of streamcutting erosion.

Typically classified as larger in

scale than gullies, although smaller than

valleys

CAUSATIVE FACTORS

Natural Factors.

Man-made Factors.

1) Constant Rainfall:

Monthly distribution.

Rainfall Intensity & Run-off.

Rapid Snowmelts.

2) Prolonged inundation and impact of back water during high floods.

Improper land use.Forest and grass fires.Overgrazing.Mining.Road construction.Livestock and vehicle trails.Destructive logging.

Ravine formation is the

cumulative results of:

Indiscriminative destruction of

forests or vegetation.

Unplanned cultivation.

Destructive grazing and

Severe water erosion.

Formation of RavineSplash Erosion

Sheet Erosion

Rill Erosion

Gully Erosion

Ravine

Ravine and Gully types

U and V shaped Ravines:

1) It can classified based on the shape of

their cross-section.

2) Both U and V shaped Ravines may be

found in same channels.

U AND V SHAPE RAVINES

Ravines spread – 3.67 million hectares along the river and tributaries.

It spreading at the Rate of about 0.5% annually.

Serious ravine intrusions.Beas in PunjabChambal in Madhya Pradesh.Kalisind, Banas, Morel andGambhir in Rajasthan.Yamuna in Uttar Pradesh.Mahi, Sabarwati, Narmada and Tapti in

Gujarat.

State Ravine area(lakh ha)

UP 12.30

MP 6.83

Bihar 6.50

Rajasthan 4.52

Gujarat 4.00

Pune and Haryana 1.20

West Bengal 1.04

Tamil Nadu 0.62

Maharastra 0.20

Total 37.00

Types of Control Measures

Mechanical

Biological

Mechanical Measures

1)Check Dam

Bolder check dam

Loose stone check dam

Log&Pole check dam

Gabion Structures

Wire woven baskets filled with stones

Adoptable: High slope & Heavy rainfall areas

Constructed across small stream to conserve stream flows with practically no submergence beyond stream course

The height of such structure is around 0.5m & normally used in the streams with width of about 10 to 15m

Contd…

Percolation Tanks

Embankments across natural depressions

It is permanent method

Control Storm Water Flow

Temporary Underground Water Storage

Infiltration of Water into Surrounding Soil

Storing Water for Re-use

Nala Bunds

Earthen embankments across nala

It is permanent method

Biological Measures

Strip Planting

Growing of different crops on alternate strips of

ground that usually follow the contour of the

land

To minimize erosion

2)COVER CROP

Any annual,biennial or perenial plant grown as monoculture or polyculture.

To improve soil fertility,soil quality and water infiltration.

3)Afforestation

Planting the trees along the edges of the feilds,the wastelands and the steepy slopes to prevent erosion.

Research center for Ravine

The Central Soil & water conservation research and training institute,Research Center.(CSWCRTIR)

It has carried out research at last 25 years investigations to control of gullies and reclamation of Ravines,Especially onthe banksof Mahi river in Gujarat.

References

M.P.SINGH,D N TIWARI(1996) Agroforestry &Wasteland.

www.thisland.illinois.edu/60ways/images/

http://www.thehindu.com/todays-paper/tp-national/tp-newdelhi/destruction-of-ravines-poses-threat-to-indian-wolf/article2804572.ece

www.wikkipedia.org

Thank You