drought indian case studies

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DROUGHT

Drought Indian case studies

Indian case studies

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What is drought? Drought is an extended period of months or years when a region notes a deficiency in its water supply whether surface or underground water. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region. Although droughts can persist for several years, even a short, intense drought can cause significant damage and harm the local economy.

Many plant species, such as cacti, have adaptations such as reduced leaf area and waxy cuticles to enhance their ability to tolerate drought. Some others survive dry periods as buried seeds. Semi-permanent drought produces arid biomes such as deserts and grasslands. Most arid ecosystems have inherently low productivity.

We can feel the dryness in your throat. The land is barren and covered in thin dust. cracks appear in the earth. This is drought, when water is so scarce that the existence of life becomes threatened. How do humans effects from drought?

INTRODUCTION


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C l a s s i f i c a t i on

Physical aspects also used to classify drought. They clubbed into three major groups:

MetrologicalAgriculture Hydrological


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C a u s e s o f d r o u g h t s 1. Less rainfall:

2. High Air pressure: When there is high air pressure, air falls instead of rising. With the air pressing down in a high pressure zone, no currents of water vapor are carried upward. As a result, no condensation occurs, and little rain falls to earth.

3. Low air pressure: Low-pressure systems see more cloudy, stormy weather. Usually, however, we experience both high- and low-pressure systems.

4. Monsoon role: Usually, summer winds known as monsoons carry water vapor north from the Indian Ocean inland, providing desperately needed rain.

Sometimes, however, instead of blowing from north to south, they blow east to west. When that happens, the vapor doesn’t leave the Indian Ocean and many people suffer from the resulting droughts.

5. Water Vapor role: Droughts occur because water vapor is not brought by air currents to the right areas at the right times. Water that evaporates from the oceans is brought inland by wind to regions where it is needed. However, sometimes those winds are not strong enough.

Drought


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6. Moisture: In some states, moisture is carried up from the ocean by blowing winds. This moisture is then pushed by other winds until it reaches the location. However, if the winds don’t blow at the right time, in the right direction, or with enough force, the moisture falls in other areas and suffers from drought.

7. Mountains region wind: Mountains can prevent wind from blowing moisture to needed regions. As air is moving past a mountain range, it is forced to rise in order to pass over the peaks. However, as the air rises, it becomes colder and the vapor condenses into rain or snow.

When the air mass finally makes it over the mountain, it has lost much of its vapor. This is another reason why many deserts are found on the side of a mountain facing away from the ocean. This phenomenon is known as the rain shadow effect.

8. Rainfall pressure: Generally, rainfall is related to the amount of water vapor in the atmosphere, combined with the upward forcing of the air mass containing that water vapor. If either of these are reduced, the result is a drought.

Drought


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9. Global warming: Human activity can directly trigger exacerbating factors such as over farming, excessive irrigation, deforestation, and erosion adversely impact the ability of the land to capture and hold water.

10. Decline in groundwater : India has seen a sharp decline in groundwater levels, leading to a fall in supply, saline water encroachment and the drying of springs and shallow aquifers. Around 50% of the total irrigated area in the country is now dependent on groundwater, and 60% of irrigated food production depends on irrigation from groundwater wells.

11. Depletion of forest : The rapid depletion of forest cover is also seen as one of the reasons for water stress and drought. India has a forest cover of 76 million hectares, or 23% of its total geographical area – much lower than the prescribed global norm of 33%.

12. Rainwater harvesting : Combined with these and a host of other factors – poor irrigation systems, pressure from the increasing industrial use of water is the appalling indifference displayed towards rainwater harvesting. Little has been done over the years to drought-proof the country, when community based rainwater harvesting measures could easily accomplish this feat.

Drought


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14. Rainwater harvesting : Combined with these and a host of other factors – poor irrigation systems, pressure from the increasing industrial use of water is the appalling indifference displayed towards rainwater harvesting. Little has been done over the years to drought-proof the country, when community based rainwater harvesting measures could easily accomplish this feat.


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Common causes in I n d i a Meteorology · Inadequate monsoon rainfall. · High temperature & evaporation, wind speed. · Unseasoned rains & fog / snowfall.

Water Resources · Inadequate water availability, high water loss in storage & distribution,

utilities. · Over exploitation of surface & ground water.

Agriculture- Crop Yield · Shift in agricultural practices(low to moderate water demand crops to high

crops). · Crop damage due to rain & snow / pest.

Population · High greater rate of human & animals. · Location of high water consuming milestones at semi arid / arid regions.


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Droughts in India Drought in India has resulted in tens of millions of deaths over the course of the 18th, 19th, and 20th centuries. Indian agriculture is heavily dependent on the climate of India: a favorable southwest summer monsoon is critical in securing water for irrigating Indian crops. In some parts of India, the failure of the monsoons result in water shortages, resulting in below-average crop yields. This is particularly true of major drought-prone regions such as southern and eastern Maharashtra, Karnataka, Haryana , Gujarat, and Rajasthan. In the past, droughts have periodically led to major Indian famines, including the Bengal famine of 1770, in which up to one third of the population in affected areas died; the 1876–1877 famine, in which over five million people died; and the 1899 famine, in which over 4.5 million died.



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Percentage of Drought Affected Districts- 2015-16


1979 1982 1983 1987 20130

200000

400000

600000

800000

1000000

1200000

1400000

1600000

Area Affected in India by Drought

Area Affected in (Km sq.)


1979 1982 1983 1987 20130

50000000

100000000

150000000

200000000

250000000

300000000

People affected in India by Drought

People affected



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Group Members

(115075) (115076)


Education

drought indian case studies