Mubeena Iram and Muhammad Nazim
Drought is at variance from other natural catastrophes in
its gradualness of onset and its commonly lengthy duration. Drought is a hazard
that requires many months to emerge and that may persist for many months or
years thereafter. This type of threat is known as a “creeping hazard” (Coppola,
2007).
It is difficult to provide a precise and universally
accepted definition of drought due to its varying characteristics, impacts,
across the different regions of the world, such as rainfall pattern, human
response and resilience and diverse academic perspectives. In general, drought
is an insidious natural hazard that results from a departure of precipitation
from expected or normal that, when extended over a season or longer period of
time, is insufficient to meet the demands of human, plant and animal activities
( A Primer for parliamentarians, NDMD).
In the literature, drought has been classified into four
categories in terms of impact:
Meteorological Drought
Meteorological drought is defined as the deficiency of
precipitation from expected or normal levels over an extended period of time.
Meteorological drought usually precedes other kinds of drought. Meteorological
drought is said to occur when the seasonal rainfall received over an area is
less than 25% of its long term average value. It’s further classified as a
moderate drought if the rainfall deficit is 26-50% and severe drought when the
deficit exceeds 50% of the normal.
Under any circumstances, meteorological measurements are
the first indicators of drought.
Agricultural Drought
Agricultural drought, usually triggered by meteorological
and hydrological droughts, occurs when soil moisture and rainfall are
inadequate during the crop growing season causing extreme crop stress and
wilting. Plant water demand depends on prevailing weather conditions,
biological characteristics of the specific plant, and its stage of growth and
the physical and biological properties of the soil. Agriculture is usually the
first economic sector to be affected by drought (Institute of Food and
Agricultural Sciences, 1998).
Hydrological Drought
Hydrological drought refers to deficiencies in surface
and subsurface water supplies. It is measured as stream flow, and as lake,
reservoir and ground water levels. There is a time lag between lack of rain and
less water in streams, rivers, lakes and reservoirs, so hydrological
measurements are not the earliest indicators of drought. When precipitation is
reduced or deficient over an extended period of time, this shortage will be
reflected in declining surface and subsurface water levels (Institute of Food
and Agricultural Sciences, 1998).
Socioeconomic Drought
Socioeconomic drought is what happens when physical water
shortage starts to affect people, individually and collectively. Or, in more
abstract terms, most socioeconomic definitions of drought associate it with the
supply and demand of an economic good (Institute of Food and Agricultural
Sciences, 1998).
Impacts of Drought
Drought produces wide ranging impacts that span many
sectors of the country. Drought has both direct and indirect impacts. With the
increased intensity or extended duration of drought prevalence, a significant
fall in food production is noticed. The drought not only affects the food
production at the farm level but also the national economy and the overall food
security as well. Other direct impacts includes: depleted water levels, deficit
in ground water recharge, land degradation, and damage to wildlife and fish
habits. When direct impacts have multiplier effects through the economy and
society, they are referred to as indirect impacts. These include a reduction in
agricultural production that may result in reduced income for farmers and
agribusiness, increased prices for food and timber, unemployment, reduced
purchasing capacity and demand for consumption, default on agricultural loans,
rural unrest, and reduction in agricultural employment leading to migration and
drought relief programs.
The impacts of drought are classified as economic,
environmental, and social.
Economic Impacts
Economic impacts refer to production losses in
agriculture and related sectors, especially forestry and fisheries, because
these sectors rely on surface and subsurface water supplies. It causes a loss
of income and purchasing power, particularly among farmers and rural population
dependent on agriculture. All industries dependent upon the primary sector for
their raw materials would suffer losses due to reduced supply or increased
prices. Drought thus has a multiplier effect throughout the economy, which has
a dampening impact on employment, flow of credit and tax collections. If the
drought is countrywide, macroeconomic indicators at the national level are
adversely impacted. (Dept. of Agriculture and cooperation, 2009)
Environmental impacts
Environmental impacts, such as lower water levels in
reservoirs, lakes and ponds as well as reduced flows from springs and streams
would reduce the availability of feed and drinking water and adversely affect
fish and wildlife habitat. It may also cause loss of forest cover, migration of
wildlife and their greater mortality due to increased contact with agricultural
producers as animals seek food from farms and producers are less tolerant of
the intrusion. A prolonged drought may also result in increased stress among
endangered species and cause loss of biodiversity.
Reduced stream flow and loss of wetlands may cause
changes in the levels of salinity. Increased groundwater depletion, land
subsidence, and reduced recharge may damage aquifers and adversely affect the
quality of water (e.g., salt concentration, increased water temperature,
acidity, dissolved oxygen, turbidity). The degradation of landscape quality,
including increased soil erosion, may lead to a more permanent loss of
biological productivity of the landscape (Dept. of Agriculture and cooperation,
2009).
Social impacts
Social impacts arise from lack of income causing out
migration of the population from the drought-affected areas. People in India
seek to cope with drought in several ways which affect their sense of
well-being: they withdraw their children from schools, postpone daughters’
marriages, and sell their assets such as land or cattle. In addition to
economic hardships, it causes a loss of social status and dignity, which people
find hard to accept. Inadequate food intake may lead to malnutrition, and in some
extreme cases, cause starvation. Access and use of scarce water resources
generate situations of conflict, which could be socially very disruptive.
Inequities in the distribution of drought impacts and relief may exacerbate
these social tensions further. (Dept. of Agriculture and cooperation, 2009)
About
the Author:
Mubeena Iram is a MPhil research Student in Environmental
science and Engineering at GC University, Faisalabad. She finds her interests
in climate change scenarios.
Muhammad Nazim, Assistant Agronomist in the office Director Agriculture
(Extension) Division Bahawalpur.
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