Tamil Nadu considers region receiving less than mm rainfall as drought affected, while Karnataka considers regions receiving rainfall less than 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. Besides rainfall, various other climatic and soil factors have also been used for drought classification. Studies at CAZRI categorised drought based on moisture stress during crop growing season using the following criteria: Impact of drought depends on the phonological state of crop growth.
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 A 2 moderate and A 1 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.
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. 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.
Historical rainfall data of the country suggests that the monsoon rainfall recorded in the country during drought year of was the lowest. Severe drought years that occurred over the past years are shown in Table 5. Administrative districts frequently affected by drought are given in Table 5.
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. Plants can adapt to drought conditions in two ways: 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. 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. 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 mm are the most prone.
Irrigation Commission had identified 67 districts as drought prone. These comprise taluks located in 8 states, covering an area of Subsequently, National Commission on Agriculture MoA 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: Some states used other criteria also. Tamil Nadu identified taluks in which rainfall was less than 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: Karnataka considered those areas as drought areas which received less than mm rainfall during kharif and less than 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: 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. It is the earliest area development programme launched by the Central Government in 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. 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.
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 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 had attributed the unsatisfactory performance of the programmes to the following major factors: Inadequate allocations to the programme and programme expenditures thinly spread overlarge problem areas. Programme implemented through government agencies with least or no participation of local people. 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 and were made applicable with effect from 1.
Famine breaks out people face untold miseries and hardships. The cruelty of the angry rain-god, as most of the people in rural areas are prone to believe, makes them suffer from disease and starvation. Poverty and squalor become their inseparable companions. Sometimes, their tales of sadness and sorrow grow beyond proportion when they find that sowing the seeds for growing Rabi crops becomes impossible due to drought condition.
This results in famine conditions. Industry suffers a setback due to the scarcity of raw materials produced by agriculture. Already there is a substantial shortfall in industrial production.
This combined with the demand of increased wages by the workers, puts the industrialists on the horns of a dilemma and some industries face closure. To tackle the problem of drought in our country, the following solutions are suggested. Its effects and solution Essay on Environmental Pollution:
Drought is a condition of no rains when the standing crops, mostly rain-fed, gets dried up and is destroyed. The causes of drought includes the followings.
Essay on Drought: Definition, Causes, Regions and Other Details! The most common cause for drought is failure of rains. The tanks, wells and similar underground water reserves remain unchanged. As a result there is not enough water available through hand pumps, wells and other traditional sources.
Free drought papers, essays, and research papers. Consequences of the Drought in the Central Valley - On the heart (center) of California is a flat area with miles and miles of . Drought means the acute dryness resulting from the failure of rain. When drought occurs, a dry of alarm sweeps over the country. Related Articles: Essay on Drought.
Essay on drought - Quality researches at competitive costs available here will make your education into delight put out a little time and money to get the report you could not even dream about Entrust your papers to the most talented writers. Free Essay: Effects on Drought Drought has long been recognized as one of the most insidious causes of human misery. It has today the unfortunate distinction.