1. DROUGHT AND FLOOD Prepared by M. U. Kale Assistant professor Deptt
DROUGHT AND FLOOD Prepared by M .U. Kale Assistant professor Deptt. Irrigation & Drainage Engineering Dr. P.D.K.V. Akola

2. Drought
According to IMD, if seasonal rainfall is less than 75% then there is drought situation.
the scarcity of water in the surface or sub-surface water resources like river, reservoir and groundwater is called drought.

3. Types of drought Meteorological drought:
It occurs when seasonal rainfall is less than 75%.
Hydrological drought:
It indicates the scarcity of water in surface or subsurface water.
Agricultural drought:
It occurs when rainfall and soil moisture are inadequate to meet the crop water requirement for healthy growth and maturity.

4. Socio-economic drought:
Socio-economic effect of meteorological, hydrological and agricultural drought in supply and demand is known as socio-economic drought.
Moderate drought – between 26% to 50%
Sever drought – more than 50%

5. Causes of drought Onset of monsoon Soil physical characteristics
Crop varietal characteristics
Duration of water stress period and crop stage
Intensity of water stress.

6. Management of drought
The recommended practices may be broadly grouped as:
Crop management practices
Water management practices

7. A. Crop management practices
Selection of appropriate crop
Intercropping
Planting densities
Weed management
Integrated nutrient management

8. B. Water management practices
Integrated management of water resources development
Development of new resources
Optimal utilization of new developed water resources
Preserving the resources
Runoff collection and recycling

9. Strategies for drought protection, mitigation or relief include:
Dams - many dams and their associated reservoirs supply additional water in times of drought.
Cloud seeding - a form of intentional weather modification to induce rainfall.
Desalination - of sea water for irrigation or consumption.
Drought monitoring - Continuous observation of rainfall levels and comparisons with current usage levels can help prevent man-made drought.

10. Land use - Carefully planned crop rotation can help to minimize erosion and allow farmers to plant less water-dependent crops in drier years.
Outdoor water-use restriction - Regulating the use of sprinklers, hoses or buckets on outdoor plants, filling pools, and other water-intensive home maintenance tasks.
Rainwater harvesting - Collection and storage of rainwater from roofs or other suitable catchments.
Recycled water - Former wastewater (sewage) that has been treated and purified for reuse.
Transvasement - Building canals or redirecting rivers as massive attempts at irrigation in drought-prone areas.

11. flood
Overflows of river inudating vast areas of agricultural land leads to submergence of crop

12. Causes of flood River in spate Snow melt Storm surges
Short intense storm causing flash flood
Cyclone and heavy rainfall

13. Damages: Damages Irrigation system Breakages of tanks and embankments
Drainage system altered
Effect on living habitat

14. Management of flood Watershed management Natural detention of basins
Safe disposal of surplus runoff
Timely warning system flood proofing
Contingency planning
land management ('keeping people away from floods')
Water management (storage operation);
Structural protection (dykes) ('keeping floods away from people');

15. Flood management can aim at:
Reduced risk of floods,
Reduced vulnerability to floods improved preparedness,
Streamlined emergency management once a flood damage has occurred,
Improved knowledge (about cause-effect relationships, driving forces and management options).

16. Thank you!