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Here is a compilation of essays on ‘Drought’ for class 6, 7, 8, 9 and 10. Find paragraphs, long and short essays on ‘Drought’ especially written for school students.
Essay on Drought
Essay Contents:
- Essay on the Introduction to Drought
- Essay on the Definition of Drought
- Essay on the Classification of Drought
- Essay on the Criteria of Drought
- Essay on the Impact of Drought
- Essay on the Periodicity of Drought
- Essay on Plant Adaptations to Drought
- Essay on the Drought Prone Areas
- Essay on the Drought Prone Areas Programme (DPAP)
Essay # 1. Introduction to Drought:
Since time immemorial, mankind has lived under the threat of natural disasters. Amongst various hazards of nature, drought is the most disastrous. In the past, India had been a frequent victim of disastrous droughts, which resulted in famine deaths of large members of human and livestock.
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Drought, thus, is a precursor of famine and undoubtedly man’s worst natural enemy. Technological developments and natural efforts are in progress to ameliorate the impacts of drought and being about sustainability to agricultural productivity in the country.
Low rainfall or failure of monsoon rains is a recurring feature in India. This has been responsible for droughts and famines. The word drought, generally, denotes scarcity of water in a region.
Though, aridity and drought are due to insufficient water, aridity is a permanent climatic feature and is the culmination of a number of long term processes. However, drought is a temporary condition that occurs for a short period due to deficient precipitation for vegetation, river flow, water supply and human consumption. Drought is due to anomaly in atmospheric circulation.
Drought is a climatic anomaly, characterised by deficit supply of moisture resulting either from subnormal rainfall, uneven distribution, higher water need or a combination all the factors. Droughts lead to problems like widespread crop failure, unreplenished groundwater resources, depletion in lakes/reservoirs, shortage of drinking water, reduced fodder availability etc.
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Essay # 2. Definition of Drought:
There is no universally accepted definition of drought:
Early workers defined drought as prolonged period without rainfall. According to Ramdas (1960), drought is a situation when the actual seasonal rainfall is deficient by more than twice the mean deviation. American Meteorological Society defined drought as a period of abnormally dry weather, sufficiently prolonged for lack of water to cause a severe hydrological imbalance in the area affected.
In general, drought means different things to different people. To a meteorologist it is the absence of rain while to the agriculturist it is the deficiency of soil moisture in the crop root zone to support optimum crop growth and productivity.
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To the hydrologist it is the lowering of water levels in lakes, reservoirs etc. while for the city management it may mean the shortage of drinking water availability. Thus, it is unrealistic to expect a universal definition of drought for all fields of activity.
Prolonged deficiency of soil moisture adversely affect crop growth indicating incidence of agriculture drought. It is the result of imbalance between soil moisture and evapotranspiration needs of an area over a fairly long period as to cause damage to standing crops and to reduce the yields.
Essay # 3. Classification of Drought:
Drought can be classified based on duration and nature of users. In both the classifications, demarcation between the two is not well defined and many a time overlapping of the cause and effect of one on the other is seen.
Droughts are classified into eight kinds:
(i) Permanent Drought:
This is characteristic of the desert climate where sparse vegetation growing is adapted to drought and agriculture is possible only by irrigation during entire crop season.
(ii) Seasonal Drought:
This is found in climates with well-defined rainy and dry seasons. Most of the arid and semiarid zones fall in this category. Duration of the crop varieties and planting dates should be such that the growing season should fall within rainy season.
(iii) Contingent Drought:
This involves an abnormal failure of rainfall. It may occur almost anywhere especially in most parts of humid or sub-humid climates. It is usually brief, irregular and generally affects only a small area.
(iv) Invisible Drought:
This can occur even when there is frequent rain in an area. When rainfall is inadequate to meet the evapotranspiration losses, the result is borderline water deficiency in soil resulting in less than optimum yield. This occurs usually in humid regions. Droughts are also classified based on their relevance to the users.
(v) Meteorological Drought:
In India, the definition for meteorological drought adopted by IMD is a situation when the deficiency of rainfall at a meteorological sub-division level is 25 per cent or more of the long- term average (LTA) of that subdivision for a given period. Drought is considered moderate; if the deficiency is between 26 and 50 per cent and severe if it is more than 50 per cent.
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In our country, a year is considered to be a drought year in case the area affected by moderate and severe drought, either individually or together, is 20 to 40 per cent of the total area of the country and seasonal rainfall deficiency during southwest monsoon season for the country as a whole is at least 10 per cent or more. When the spatial coverage of drought is more than 40 per cent, it will be called as all India severe drought year (IMD Technical Circular No 2/2007).
(vi) Atmospheric Drought:
It is due to low air humidity, frequently accompanied by hot dry winds. It may occur even under conditions of adequate available soil moisture. Plants growing under favourable soil moisture regime are usually susceptible to atmospheric drought.
(vii) Hydrological Drought:
Meteorological drought, when prolonged, results in hydrological drought with depletion of surface water and consequent drying of reservoirs, tanks etc. This is based on water balance and how it affects irrigation as a whole for bringing crops to maturity.
(viii) Agricultural Drought:
It is the result of soil moisture stress due to imbalance between available soil moisture and evapotranspiration of a crop. It is usually gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil moisture stress. This situation arises as a consequence of scant precipitation or its uneven distribution both in space and time. It is also usually referred as soil drought.
When soil moisture and rainfall are inadequate during crop growing season to support healthy crop growth to maturity, which situation causes extreme crop stress and wilting is called agricultural drought. It is defined as a period of four consecutive weeks (of severe meteorological drought) with a rainfall deficiency of more than 50 per cent of the long-term average (LTA) or with a weekly rainfall of 5 cm or less during the period from mid-May to mid-October (kharif) when 80 per cent of the country’s total crop is planted, or six such consecutive weeks during the rest of the year.
Essay # 4. Criteria of Drought:
In India various states and official commission have adapted different criteria for classifying droughts.
Irrigation Commission, while adopting the IMD classification of Meteorological drought based on departure of annual rainfall from normal, considered those regions which experienced drought in 20 per cent of years as drought areas and those area which experienced drought in more than 40 per cent of the years as chronic drought areas.
National Commission on Agriculture (1976) considered agricultural drought as an occasion when at least four consecutive weeks receive rainfall half of the normal (normal rainfall being 5 mm or more) during the crop season (mid-May to mid-October) or six such weeks during other period.
The criteria adopted in different states also vary depending on the rainfall and crops grown in the region. Tamil Nadu considers region receiving less than 900 mm rainfall as drought affected, while Karnataka considers regions receiving rainfall less than 400 mm during kharif and less than 30 per cent during crop season and 20 per cent deficiency of rainfall during crucial stages of crop growth as drought affected areas.
Rajasthan on the other hand considers a year as scarcity year when the productivity decrease by 50 per cent compared to a good crop year. Many of the states also follow the “Annawary” system wherein the crop conditions are assessed through visual estimates.
The criterion followed is:
Production above 75 per cent of normal: No drought.
Production 50 to 75 per cent of normal: Moderate drought.
Production 25 to 50 per cent of normal: Severe drought.
Production less than 25 per cent normal: Disastrous drought.
Besides rainfall, various other climatic and soil factors have also been used for drought classification. These include the aridity index (la) anomaly and ratio of actual to potential evapotranspiration (AE/PE).
Studies at CAZRI categorised drought based on moisture stress during crop growing season using the following criteria:
Drought Free Period:
When cumulative AE curve is above cumulative PE/2 curve.
Moderate Drought Period:
When cumulative AE curve lies between cumulative PE/2 and PE/4 curves.
Severe Drought Period:
When cumulative AE curve is below cumulative PE/4 curve.
Impact of drought depends on the phonological state of crop growth. Hence, a novel method of classification of agricultural droughts was attempted at CAZRI, considering the values of AE/ PE during different phenophases of crop growth as indicated in Table 5.4.
Depending upon the values of AE/PE during different phenophase, drought code varies as S1 V3, R2, S0V1, R1 etc.
This is a generalised classification without specification of any crop. At this state, crop factor can be introduced and drought code in three syllables can be unified into a single drought code (A) applicable to one particular crop for a specific region. Based on this criteria, the above two situations mentioned come under classification of A2 (moderate) and A1 (mild) respectively.
Apart from climatological parameters, physical parameters like canopy-air temperature differences have also been used for assessing stress degree days (SDD) to indicate the impact of drought. The SDD have been found to correlate well with yield fluctuations as a result of moisture stress. Also spectral ratios of infrared to red reflectance obtained from radiometers (satellite or ground based) can be used to monitor agricultural effects of drought based on observed rate of change of absorbed radiation expressed as a fraction of maximum rate.
Essay # 5. Impact of Droughts:
One of the sectors where immediate impact of drought is felt is agriculture. With increased intensity or extended duration of drought prevalence, a significant fall in food production is often noticed. Drought results in crop losses of different magnitude depending on their geographic-incidence, intensity and duration. Drought not only affects food production at farm level but also national economy and overall food security as well.
Besides shortage of food and drinking water, impact of drought is also felt due to:
a. Deficit groundwater recharge.
b. Non availability of quality seed.
c. Reduced draught power for agricultural operations due to distress sale of cattle.
d. Land degradation.
e. Fall in investment capacity of farmers for further investment in agriculture.
Essay # 6. Periodicity of Drought:
Drought prone areas in the country, classified on annual rainfall departure, fall either in arid, semiarid and dry sub-humid regions where droughts occur frequently.
Periodicity of drought in different meteorological subdivisions is given in Table 5.5:
Historical rainfall data of the country suggests that the monsoon rainfall recorded in the country during drought year of 1918 was the lowest.
Severe drought years that occurred over the past 200 years (1801-2000) are shown in Table 5.6:
Administrative districts frequently affected by drought are given in Table 5.7:
Essay # 7. Plant Adaptations to Drought:
Plants can grow and survive in dry habitat by escaping drought and drought resistance.
Escaping Drought:
Many short duration desert plants (ephemerals) germinate with rains and mature in five to six weeks. They have no mechanism to overcome soil moisture stress and are not drought resistant. In cultivated crops, early maturity before soil moisture stress is the main adaptation to drought in dry regions.
Drought Resistance:
Plants can adapt to drought conditions in two ways: avoiding stress and tolerating stress. Stress avoidance is the ability to maintain favourable water balance and turgidity even when subjected to drought thereby avoiding stress and its consequences. Favourable water balance can be achieved either through conserving water by restricting transportation (water savers) or by accelerating water uptake (water spenders).
The mechanisms for conserving water are regulating stomatal opening, increased photosynthetic efficiency, low rates of cuticular respiration, decreasing transpiration by lipid deposition on leaves, reducing leaf area, stomatal frequency and location and presence of awns. Water uptake can be accelerated by efficient root system, high root to top ratio, differential osmotic potential of plants and change of water spenders to water savers.
Drought Tolerance:
Plants can tolerate drought either by mitigating the actual stress or by showing high degree of tolerance to stress. Mitigating the stress by resistance to dehydration and by preventing leaf collapse permit the plants to maintain a high internal water potential inspite of drought conditions.
Tolerating the stress by resistance to metabolic strain (starvation acid protein loss) and plastic strain (increased resistance to stress due to exposure to sublethal stress for long period) can increase the plant ability to resist and survive under conditions of soil moisture stress.
Essay # 8. Drought Prone Areas:
Out of the total geographical area of India, almost one-sixth area with 12 per cent of the population is drought prone; the areas that receive an annual rainfall up to 600 mm are the most prone. Irrigation Commission (1972) had identified 67 districts as drought prone.
These comprise 326 taluks located in 8 states, covering an area of 49.73 M ha. Subsequently, National Commission on Agriculture (MoA 1976) identified a few more drought prone areas with slightly different criteria. Later, based on detailed studies, 74 districts of the country have been identified as drought prone.
In the past, one or more of the following four criteria were used to identify drought prone areas:
(1) Meteorological data.
(2) Revenue remission.
(3) Frequency of famine or scarcity.
(4) Availability of irrigation facilities.
Some states used other criteria also. Tamil Nadu identified 311 taluks in which rainfall was less than 900 mm or less than 35 per cent of the cultivable area irrigated as drought area. Rajasthan considered an area to be drought prone when the ratio of good crop year to scarcity year was 2: 1 or when not less than 50 per cent of the village of the area were affected by drought.
Karnataka considered those areas as drought areas which received less than 400 mm rainfall during kharif and less than 150 mm during rabi with a variability of more than 30 per cent during each season and rainfall deficiency of more than 20 per cent at the critical stages of crop growth. Thornthwaite used water balance approach for evaluating drought and proposed the aridity index.
The Irrigation Commission relied, on only two criteria: meteorological data and available irrigation facilities and demarked the areas as drought or chronic drought zones. Drought zones are areas with 25 per cent probability of rainfall departure from the normal. Chronic drought zones are areas with 40 per cent probability of rainfall departure or more than – 40 per cent from the normal.
Essay # 9. Drought Prone Areas Programme (DPAP):
It is the earliest area development programme launched by the Central Government in 1973- 74 to tackle the special problems faced by those fragile areas, which are constantly affected by severe drought conditions. These areas are characterised by large human and cattle populations which are continuously putting heavy pressure on the already degraded natural resources for food, fodder and fuel.
Basic objective of the programme is to minimise the adverse effects of drought on production of crops and livestock and productivity .of land, water and human resources, leading to drought proofing of affected areas.
The programme aims at promoting overall economic development and improving the socio-economic condition of resource poor and disadvantaged sections inhabiting the programme areas through creation, widening and equitable distribution of resource base and increased employment opportunities.
The objectives of the programme are being addressed, in general, by taking up development works through watershed approach for land development, water resource development and afforestation/pasture development.
Recent impact studies sponsored by the ministry have revealed that with the implementation of watershed projects under Drought Prone Areas Programme, overall productivity of land and water table have increased and there has been a significant impact in checking soil erosion by water and wind. The programme has also helped in overall economic development in the project areas.
Major problems are continuous depletion of vegetative cover, increase in soil erosion and fall in groundwater levels due to continuous exploitation without any effort to recharge the underground aquifers.
Though the programme had a positive impact in terms of creating durable public assets, its overall impact in effectively containing the adverse effects of drought was not found to be very encouraging. In addition, many of the states had also been demanding inclusion of additional areas under the programme.
With a view to identifying the infirmities in the programme and also for considering the case for inclusion of additional areas under the programme, a high level technical committee under the chairmanship of Prof CH Hanumantha Rao, Ex-Member Planning Commission was constituted in April 1993 to critically review the contents, methodology and implementation processes of all area development programmes and suggest suitable measures for improvement.
The Committee in its report submitted in April 1994 had attributed the unsatisfactory performance of the programmes to the following major factors:
1. Implementation of programme activities over vast areas in a sectoral and dispersed manner.
2. Inadequate allocations to the programme and programme expenditures thinly spread overlarge problem areas.
3. Programme implemented through government agencies with least or no participation of local people.
4. Taking up of a vast array of activities, which were neither properly integrated nor necessarily related to objectives of the programme.
Based on recommendations of the Hanumantha Rao Committee, comprehensive guidelines for watershed development, commonly applicable to Drought Prone Areas Programme, Desert Development Programme and Integrated Wastelands Development Programme were issued in October 1994 and were made applicable with effect from 1.4.1995. Subsequently, based on the feedback received from states, project implementation agencies and others concerned, guidelines were revised in September 2001.
Relevant definition of agricultural drought appears to be a period of dryness during the crop season, sufficiently prolonged to adversely effect the yield. The extent of yield loss depends on the crop growth stage and the degree of stress. It does not begin when the rain ceases, but actually commences only when the plant roots are not able to obtain the soil moisture rapidly enough to replace evapotranspiration losses.
Important causes for agricultural drought are:
a. Inadequate precipitation.
b. Erratic distribution.
c. Long dry spells in the monsoon.
d. Late onset of monsoon.
e. Early withdrawal of monsoon.
In India, seasonal rainfall (monsoon rains) over Indian subcontinent is a global phenomena associated with large scale hemispherical movement of air masses. As such, identification of major atmospheric phenomenon that influences the monsoons over Indian subcontinent is essential in drought management research.
Two such relationships are:
(i) Sea surface temperature anomaly around the Indian subcontinent in relation to atmospheric circulation.
(ii) Large scale pressure oscillation in atmosphere over southern Pacific Ocean.
The El Nino event is one such phenomenon, which has profound influence on the monsoon activity over Indian subcontinent, The Southern Oscillation Index (SOI) is one important parameter in the predictive sixteen parameters model used by IMD for long range forecasting purposes.
As per IMD studies, all the drought years are El Nino years where as all the El Nino years are not drought years indicating thereby that various other factors also equally influence the monsoon over the Indian subcontinent.
In this context, the winter circulation over the subcontinent, extended period of occurrence of western disturbances (late in the season), strengthening of heat low over N-W India in summer and shifts in zonal cells over India are some of the important parameters that influence monsoon system over the country.