What is ravine.ppt

1. CONSERVATION OF GULLIES AND RAVINES

2. GROUP MEMBERS AJAY PRATAP SINGH(64) ABHISHEK KUMAR SRIVASTAVA(65) RITU SINGH(66)

3. CONTENT Introduction Causative factors Process of formation

4. Gully A  gully  is a  landform  created by running  water ,  eroding  sharply into  soil , typically on a hillside . Gullies resemble large  ditches  or small  valleys , but are metres to tens of metres in depth and width.

5. Ravine A very small valley. Product of streamcutting erosion. Typically classified as larger in scale than gullies, although smaller than valleys

6. Causative Factors Natural Factors. Man-made Factors.

7. Natural Factors Constant Rainfall: Monthly distribution. Rainfall Intensity & Run-off. Rapid Snowmelts. 2) Prolonged inundation and impact of back water during high floods.

8. Improper land use. Forest and grass fires. Overgrazing. Mining. Road construction. Livestock and vehicle trails. Destructive logging . Man- Made Factors

9. How Ravine or gullies are Formed? Ravine formation is the cumulative results of: Indiscriminative destruction of forests or vegetation. Unplanned cultivation. Destructive grazing and Severe water erosion .

10. Formation of Ravine Splash Erosion Sheet Erosion Rill Erosion Gully Erosion Ravine

11. Ravine and Gully types U and V shaped Ravines: It can classified based on the shape of their cross-section. Both U and V shaped Ravines may be found in same channels.

12. U AND V SHAPE RAVINES

13. Ravines Zones in India 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 Punjab Chambal in Madhya Pradesh. Kalisind , Banas , Morel and Gambhir in Rajasthan. Yamuna in Uttar Pradesh. Mahi , Sabarwati , Narmada and Tapti in Gujarat.

14. 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

15. Types of Control Measures Mechanical Biological

16. Mechanical Measures 1)Check Dam Bolder check dam Loose stone check dam Log&Pole check dam

17. 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 …

18. Contd … Percolation Tanks Embankments across natural depressions It is permanent method

19. Percolation tank uses: Control Storm Water Flow Temporary Underground Water Storage Infiltration of Water into Surrounding Soil Storing Water for Re-use

20. Nala Bunds Earthen embankments across nala It is permanent method

21. Biological Measures Strip Planting Growing of different crops on alternate strips of ground that usually follow the contour of the land To minimize erosion

22. 2)COVER CROP Any annual,biennial or perenial plant grown as monoculture or polyculture. To improve soil fertility,soil quality and water infiltration.

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

24. 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.

25. 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

26. Thank You