2. Contents
1.Introduction
2.Types of Droughts
3.Occurrence of Droughts in The World
4.Droughts and Indian Scenario
5.Historical Droughts in India
6.Causes of Droughts
7.Impacts of Droughts
8.Various Indicators for Assessment of Droughts
9.Drought Relief
10.Institutional Response to droughts
11.Mitigation of Droughts
12.Conclusions
3. Introduction
Definition of Drought
Common accepted definition is:
• A temporary reduction in water or moisture
availability significantly below the normal or expected
level for a specified period
• A period of dry weather of sufficient length and
severity to cause at least partial crop failure
• Actual moisture supply at a given place consistently
falls short of the climatically expected moisture
supply
4. Introduction
• It is temporary aberration in aridity which is
permanent feature of climate … National Institute
of Disaster Management, India
• It is often referred to as a "creeping phenomenon"
and its impacts vary from region to region…..
National Drought Mitigation center, USA
Droughts according to apex research institutes
5. Types of Droughts
Droughts Meteorological
Droughts
Significant decrease from normal
precipitation over an area
Hydrological Droughts
Depletion of surface water and fall
in water tables
Agricultural Droughts
Soil moisture and rainfall is
inadequate to support crops
6. Meteorological
Droughts
Moderate
Droughts
Rainfall deficiency over 20% of
area is between 26% and 50%
Severe
Droughts
Rainfall deficiency over 20%
of area is > 50%
Areas
affected
Drought prone
areas
Those areas that experience
meteorological drought in 20% of years
Chronic Drought
prone areas
Those areas that experience
meteorological drought > 40% of years
Types of Droughts
Classification of Areas affected
7. Occurrence of Droughts in the world
Pattern of intensity of
drought globally
Pattern of global frequency of
droughts in duration of 2000-2008
8. Rainfall distribution
Droughts and Indian Scenario
• 33 % area receives rainfall < 750mm -chronically drought prone
• 35 % area receive rainfall = 750-1125 mm- drought prone
• Total 68 % area of the country prone to drought
Seasonal Spells Rainfall (%)
Pre-Monsoon(March-May) 10.4 %
SouthWest Monsoon(Jun-Sept) 73.3%
NorthEast Monsoon(Oct-Dec) 13.3%
Winter Rains (January-Feb) 3.0 %
Country’s Vulnerability to Drought
9. Droughts and Indian Scenario
Drought map according to IMD
(Indian Meteorological Department)
Pattern of drought occurrence
(year 2012)
10. Historical droughts in India
S. N. Year Affected area People
affected
1 1966 Bihar and Orissa 50 million
2 1969 Rajasthan, Gujarat, TN, UP, AP, Haryana, Karnataka, and
MP
15 million
3 1970 Bihar and Rajasthan 17.2 million
4 1972 Rajasthan, Himachal and Uttar Pradesh 50 million
5 1979 Eastern Rajasthan, HP, Punjab and UP 200 million
6 1982 Rajasthan, Himachal Pradesh and Punjab 100 million
7 1983 TN, West Bengal, Kerala, Rajasthan, Karnataka, Bihar
and Orissa
100 million
8 1987 Entire North, West and Eastern India 300 million
9 2000 Rajasthan, Gujarat, Orissa, Andhra and MP Over 100 million
10 2002 Rajasthan, Karnataka, AP and TN Over 300 million
11. Causes of droughts
1. Natural Causes:
I. Prevalence of High air pressure system over particular geographical
area
II. High level of Sunlights = bright sunlight causes the drying of water
vapour present in atmosphere
III. Wind carrying continental air mass rather then oceanic air mass =
continental air mass is drier than oceanic air mass, which triggers
rainfall seldom
IV. Absence of obstruction in the way of water vapour carrying clouds =
Presence of obstruction can facilitate cooling of water vapour, hence
condensing the same.
12. 1. Natural Causes:
V. Absence of humidity to help condense the water vapour =
humidity helps converting vapour to water drops
VI. Erratic distribution of Monsoon = Alteration in the pattern of
monsoon distribution causes the uneven rainfall over a
particular geographical area
VII.Disruption in the pattern of trade winds and oceanic currents
= Trade winds and oceanic wind affect the pattern of
monsoon globally
VIII.Occurrence of El-Nino
Causes of droughts
13. 2. Human activities:
I. Global warming = It will lead to disruption of water cycle over a large
geographical area at global scale.
II. Deforestation = reduction of the forest cover causes the drier area
which can not attract the water vapour to condense.
III. Excessive irrigation over a particular area = Excessive irrigation can
leads to water logging which can be attributed to salination of ground.
Hence reduction in crop yield will take place.
IV. Soil erosion = It reduces the water holding capacity of the ground
which will lead the futility of ground.
V. Absence of rain water harvesting = Inexistence of rain water harvesting
will lead to water shortage in the time of need.
Causes of droughts
14. Impacts of droughts
A.Direct Impact
A. Reduced agricultural production
B. Depleted water level
C. Higher mortality rate for humans and wildlife
D. Damage to livestock
B. Indirect Impact
A. Reduced income for farmers
B. Increased unemployment
C. Increased rate of inflation
D. Decreased purchase capacity
Impacts of droughts
15. Impacts of droughts
1. Economic Impacts
1. Reduced GDP and GNP
2. Reduced purchase power parity
3. Reduced Exports
4. Reduced forex reserves
5. Decreased value of currency
6. Increased inflation rate
2. Environmental Impacts
1. Reduced ground water level
2. Reduced forest cover
3. Disruption in ecosystem
4. Loss of biodiversity
3. Social Impacts
1. Migration of rural population
2. Disruption in socio-economic condition of families
3. Malnutrition due to starvation
16. Various indicators for assessment of drought
1. Meteorological drought indicators
Rainfall deciles
Monthly aggregated data of precipitation (rain and snow) are compared
with average values extracted from long term observations. The
method uses precipitation deciles, which are created with ranked
observed precipitation.
Standardized Precipitation Index (SPI)
The SPI calculation is done with monthly precipitation, which is fitted to
a two parameter gamma probability distribution. This distribution is
then transformed into a normal distribution. Because of the normalized
distribution, wetter and drier climates can be represented and
compared in the same way.
17. 1. Meteorological drought indicators (Continued...)
Cumulative Precipitation Anomaly (CPA)
The Cumulative Precipitation Anomaly (CPA) measures the shortage of
precipitation compared to the long-term mean. The timescale of this
method is not fixed and can vary from monthly to annual precipitation. A
disadvantage of the CPA is that the mean precipitation is often not the
same as the median.
Effective Drought Index (EDI)
A method to calculate drought on a daily time scale is the Effective
Drought Index (EDI). It was developed to calculate daily water
accumulation with a weighting function of time passage.
Rainfall Anomaly Index (RAI)
The RAI is calculated on weekly, monthly or annual time scale. The choice
of time scale is done based on the distribution of precipitation
Various indicators for assessment of drought
18. Various indicators for assessment of drought
2. Soil moisture drought indicators
Palmer drought severity index
The Palmer Drought Severity Index (PDSI) was developed by Palmer
(1965) to provide a index based on drought severity, that allowed the
comparison of droughts with different time and spatial scales. The PDSI
takes into account precipitation, evapotranspiration, and soil moisture,
although it is still classified by many authors as a meteorological
drought indicator.
Palmer Z-index
The Palmer Moisture Anomaly Z-index (Z-index) is used for the
calculation of soil moisture droughts. The soil moisture anomaly for the
current month is calculated as the Z-index. The Z-index is derived from
the calculation of the PDSI. Thus, the Z-index suffers from the same
advantages and disadvantages as the PDSI.
19. Various indicators for assessment of drought
2. Soil moisture drought indicators (Continued…)
Soil Moisture Deficit Index (SMDI)
The Soil Moisture Deficit Index (SMDI) has recently been developed by
Narasimhan & Srinivasan (2005).They developed a drought index, which
could detect short-term dry conditions, has no dependency on the
season, and which has no reference to a climate region. The SMDI is
used for the calculation of agricultural droughts and is used on a weekly
time scale.
Crop Moisture Index (CMI)
The Crop Moisture Index (CMI) was developed by Palmer (1968) as a
meteorological-driven drought indicator. The CMI monitors short-term
soil moisture changes in observed or simulated data, and is classified as a
soil moisture drought indicator
20. Various indicators for assessment of drought
3. Hydrological drought indicators
Surface Water Supply Index (SWSI)
It was developed to deal with accumulation of snow, and the delayed
runoff caused by this process. The SWSI is suitable for the calculation of
hydrological droughts. It incorporates climatologic and hydrological
characteristics into a single index value, which has the same
classification as the Palmer indices.
Groundwater Resource Index
For the calculation of groundwater droughts, the Groundwater Resource
Index (GRI) can be used. The GRI is based on a normal distribution of the
simulated groundwater storage in at a site.
Base Flow Index (BFI)
The Base Flow Index (BFI) was proposed for a low flow study in the
United Kingdom and is calculated on a daily time step. The BFI has not
been used in drought analysis on a global scale.
21. Drought Relief
Multi-sectoral and multi-dimensional relief and response are to be given at
the onset of droughts.
1. Contingency crop planning
Dissemination of information to farmers
Suggestion of cropping to farmers region wise and season wise
Advocate crop diversity
Provision of Agro –advisory agency which can render advise to
farmers at no benefit and cost
2. Support to farmers
Agriculture Input Support
Energy Support
Extension support
Tax free Credits to farmers
Incentives for production of allied products such as animal
husbandry and milk production etc.
22. Drought Relief
3. Relief employment
1. NREGS (National Rural Employments Guarantee Scheme)
2. Local Area Development Programs (MP-LAD and MLA-LAD funds)
3. Relief employment by District disaster management committee
4. Water resources managements
Provision of water for basic need of human
Provision of water for basic need of Cattle
Reservoir management
Repair of existing water supply systems
Special measures for drinking water
Construction of temporary water pipe line
Mobilization of water from local reservoir with help of local
transport system such as bullock carts etc
23. 5. Food security
Provision of food
Providing nutritional food with help of ICDS (Integrated Child
Development Schemes)
Mid Day meal Programs
Cattle camps and fodder supply
Transferring equivalent cash to the beneficiary to help buying grains
with help of DBT (Direct Benefit Transfer) scheme
Low cost grain supply with help of PDS (Public distribution system)
6. Gratuitous Assistance
Tax waivers and concessions
Reduction of interest rate for affected people
Drought Relief
24. Institutional Response to droughts
1. Central Government
Ministry of Agriculture is responsible for response of union govt
Drought management division of the department of agriculture looks
for relief measures
Calamity Relief Fund (CRF) and National Calamity Contingency Fund
(NCCF) is used
IMD (Indian Meteorological Department) and NIDM (National Institute
of Disaster management) coordinates for Technical inputs
National Crisis management Committee holds decision over policy
decision
2. State Government
Department of Disaster management is responsible for state govt
decisions and their execution
Relief commissioner issues directions and instructions
District administration coordinates with Gram Panchayats and NGO to
reach grass root level
25. Mitigation of droughts
Mitigation means the action taken before or at the onset of disaster to
reduce the adverse impacts of the same.
National Rainfed Area Authority (NRAA) was set up to look for
drought mitigation in long term basis. NRAA issues knowledge inputs
for systemic upgradation and management of country’s dry land and
rainfed agriculture.
Watershed development in India
Integrated watershed management program ==== Low cost and locally
available technology for water conservation, soil moisture
conservation, biomass production, increase land productivity and
pasture development.
Drought –Prone Areas Program (DPAP) and desert development
program (DDP) = meant to drought proofing and combating
desertification in arid and semi arid areas.
26. Implementation of mitigation measures :
Water harvesting and conservation
Artificial recharge of ground water
Contour bunding, Contour trenching, Contour cultivation
Bench terracing,
Graded bunding
Gully plugging
Check dams (Nalla Bunding Construction),Anicut, inject wells
Gabion structure
Traditional methods (Rural)
Dug well recharge
Tanka/Kund/Kundis/Bavadi/Khadin
Spring water harvesting
Traditional methods (urban)
Rooftops drain
Paved unpaved area drains
Mitigation of Droughts
27. Implementation of mitigation measures :
Innovative Irrigation methodology
Drip and sprinkler irrigation system
Prevention of evaporation loss of the reservoir
Integrating small reservoir and major reservoir
Integrating basin planning
Afforestation
Crop insurance
Community participation in drought mitigation
Mitigation of Droughts
28. Conclusions
1. Drought is Creeping phenomena which imposes adverse impact on
each nook and corner of the socio-economic fabric of the society.
2. India has large arid and semi arid area which comes under drought.
3. Researchers have developed various indicators to assess the impact
of droughts.
4. In India, we have established institutional frame work to combat
drought
5. Institutional frame work consists central and federal structure of the
organizations. i.e. National Disaster Response Center
6. However, a struggle was faced while implementing the mitigation
measures.
7. A need was felt to motivate research into policy formulation as well
as technical aspects to strengthen the capacity building to combat
natural calamity like droughts