INTRODUCTION
Man
has always faced weather and climate vagaries and problems
related to droughts. However,
the recent problems of inadequate water quality, which effectively reduced the
available resources, increased the severity of water deficits. Drought-related disasters
have been more devastating than other natural hazards
(earthquakes, volcanoes,
etc), as far as deaths, suffering and economical damages
are concerned. Apart
from destructive direct effects, drought events have been
followed by secondary, indirect
calamities, such as famine, epidemics, fire, etc. Despite the progress in
science and technology,
man is still vulnerable to extreme drought events. The losses
increase due to the
continuing development of costly infrastracture, rise in
population density, and
decrease of the buffering capacities (deforestation,
urbanization, drainage wetlands, etc).
Understanding droughts, their occurrences, mechanisms, characteristics and regularities
is of great importance for the design and management of
water resources systems.
MEANING OF DROUGHT
A
drought is a natural disaster of
below-average precipitation in a given region, resulting in prolonged shortages
in the water supply, whether atmospheric, surface water
or ground water.
A drought can last for months or years, or may be declared after as few as 15
days. It can have a substantial impact on the ecosystem
and agriculture
of the affected region and harm to the local economy.
Annual dry seasons in the tropics significantly increase the chances of a drought
developing and subsequent bush fires. Periods of heat can significantly worsen
drought conditions by hastening evaporation of water vapour.
CAUSES OF DROUGHT
1.
Land and water temperatures cause drought. As overall
temperatures increase more water evaporates and severe weather conditions
increase. Landscapes and crops need more water to survive and overall the
demand for water increases. This is why it is so important to consider changes
in ET when discussing water savings. You might be using more
water or less water depending on weather conditions.
2.
Air circulation and weather patterns also cause
drought. Key events like El Nino
or La Nina help contribute to drought in areas. All the water we ever had we
have today and it is stored in the air or on land. Weather patterns move the
water in the air around. This is constantly changing.
3.
Soil moisture levels also contribute to drought. When
soil moisture is depleted there is less evaporation of water to create clouds.
Surface temperatures rise, more water is needed and less is available which contributes
to a more severe drought.
4.
Drought can also be a supply and demand of water
issue. When a region is growing rapidly the demand for water can exceed the
supply. When weather conditions, temperatures or air patterns push a region
toward a drought the demand for water by people can offset or worsen the
situation depending on how the region reacts. Excessive irrigation is an
excellent of people contributing to a drought.
5.
If the timing of water doesn’t match the agricultural
season you may have too much water when you don’t need it and too little when
you do need it. Proper storage and collection of water is key to counter
balancing this cycle and clearly in the scope of human management.
EFFECT OF DROUGHT TO
THE ECONOMIC DEVELOPMENT OF NIGERIA
Generally speaking, drought has a vast effect on mass
starvation, famine and cessation of economic activity especially in areas where
rain fell agriculture is the main stay of the rural economy. Forced human migration
and environmental refugees, deadly conflicts over the use of dwindling natural
resources, food insecurity and starvation, destruction of critical habitats and
loss of biological diversity, socio-economic instability, poverty and climatic
variability through reduced carbon sequestration potential are common knowledge
of the causes of drought.
Several research have been conducted on the effect of drought
and they have come to terms that drought especially in Africa and with
particular reference to Nigeria assert that several challenges such as the
widespread poverty, the fact that Nigeria’s economy depend on climate-sensitive
sectors mainly rain fed agriculture, poor infrastructure, heavy disease
burdens, high dependence on and unsustainable exploitation of natural
resources, and conflicts are major reasons why drought often harm the Northern
region of Nigeria.
Other forms of effect of drought was identified in the work
of Jibrin such as low or no crop yields resulting in low food security index;
mass famine; death of livestock; low groundwater levels resulting in dry wells
(which needed to be dug deeper and deeper to obtain water for drinking); drying
of lakes and dams; loss of biodiversity and impoverishment of ecosystem; acute
shortage of water for domestic use and for livestock; decline in GDP; migration
into urban areas; separation of families; and increased indebtedness. Other identified
categories of drought effect includes; on agriculture and food security, on
water availability, on biodiversity, and energy availability.
AREAS WHERE DROUGHT IS
PREDOMINANT IN NIGERIA
National Emergency Management Agency
(NEMA) has placed eleven states in the northern part of the country under red
alert following reports of possible adverse weather conditions in the areas.
The
affected states include Sokoto, Katsina, Zamfara, Kebbi, Jigawa and Kano in the
North-West and Borno, Yobe, Gombe, Bauchi and Adamawa States in the
North-Eastern part of the country.
The Director General of the agency, AVM Mohammed Audu-Bida
(rtd) disclosed this at the weekend after a quarterly meeting of the zonal
coordinators of NEMA in Abuja.
The NEMA boss said 11 states in the Northern part of the
country have been sent early warning letters, detailing local government areas
that may be affected and the population of the people in the areas.
Mohammed Audu-Bida listed the states to be affected to
include Sokoto, Katsina, zamfara, kebbi, Jigawa and Kano in the North-West and
Borno, Yobe, Gombe, Bauchi and Adamawa States in the North-Eastern part of the
country.
Audu-Bida said the drought warning alert by the agency became
necessary as a precautionary measure that would guide the states to make
adequate planning including sensitization of farmers, contingency stockpiling
and networking with focal institutions for effective mitigation on likely
negative consequences of the climate condition.
The NEMA boss regretted that few states took the advice of
the agency early in the year when it (NEMA) sent the last early warning to
governors on likely flooding before the commencement of the rainy season that
was heavy and erratic in various part of the country. He said consequences of
inaction badly affected cities and town in coastal areas with the floods
rendering over 150,000 Nigerians homeless and properties worth millions of
Naira lost.
Audu-Bida said the agency apart from relying on relevant
institution like NIMET in whether forecasting, it is equipped with latest
remote sensing technology to forecast climatic changes and detect disaster
prone spots. The state-of-the- arts equipments that use satellite technology
include Geographic Information System (GIS) Laboratory and Corspas-SarSat in
the Mission Control Centre (MCC) at the agency Headquarters in Abuja.
The agency which recently increased its zonal office in the
country to seven with creation of Abuja Office to cater for neighbouring states
of Kogi, Niger and Kwara has increased monthly subvention to the zones just as
it givens zonal coordinators executive powers and independence to initiate
programmes and respond promptly to emergency situations in their zones towards
disaster risk reduction.
METHODS
OF CONTROLLING DROUGHT IN NIGERA
1. Assess your priorities. Survey your
landscape: What areas or individual plants do you want most to save? Give top
priority to irrigating established trees and shrubs; they’re virtually
irreplaceable. Consider perennials a second priority.
2. Identify root zones. The roots
of various plants grow to different depths; the trick is to apply just enough
water to moisten the roots. Most tree roots are located in the top 2 feet of
soil. The dripline of a tree or shrub, which runs around the perimeter of the
canopy, outlines much of the root zone. Focus water there.
3. Try a root irrigator. The
hose-end device has a needlelike shaft that injects water into the ground,
irrigating roots directly so no water is lost to evaporation. Check garden
centers for root irrigators like the one from Hound Dog Products (about $20;
800/694-6863). Insert the shaft 6 to 12 inches or deeper into the soil around
trees and shrubs. After watering in one spot along the dripline, move the
irrigator to another spot until you complete one round-trip.
4. Check soil moisture. Dig
down 1 foot with a trowel or spade and feel a handful of soil. An even easier
way to test moisture is to use a sampling tube to “read” the soil. When you
push the metal tube into the ground and twist it back out, it extracts a
12-inch or longer core, showing in cross section how wet or dry the soil
actually is. If the top 2 inches of the soil sample are dry, it’s time to
water. Sampling tubes are available from [XREF
“http://www.forestry-suppliers.com” “Forestry Suppliers”] (from $40;
800/647-5368).
5. Irrigate slowly. Slow
soaking limits runoff and encourages plants to develop deep root systems that
are better able to tolerate drought. The heavier your soil, the more important
slow soaking is in preventing runoff. Using an oscillating sprinkler to water
large areas helps reduce runoff. But if you see puddling, turn the water off
for an hour, then start again. To minimize evaporation, irrigate in the early
morning or evening.
6. Build watering basins. Mound soil
berms around young trees and shrubs such as roses to concentrate water on the
root zones. Fill the basin with a slow-running hose so water soaks in.
7. Use soaker hoses. These porous
hoses ooze water along their length. Run them among flowers and shrubs or along
hedges or rows of vegetables. Coil them under the driplines of large trees; a
good average length is 50 or 100 feet.
8. Apply mulch. Drought or
not, spreading a layer of mulch over the soil around plants is simply good
gardening. Mulch reduces evaporation, insulates roots from extreme temperature
changes, and helps prevent weeds, which steal water needed by desirable plants.
Spread a 3-inch layer of organic mulch such as compost or shredded bark around
trees and shrubs; for flowers and vegetables, apply 1 to 2 inches. Gravel and
other mineral mulches are also effective.
9. odify lawn care. If
local restrictions allow lawn irrigation, there are some things you can do to
reduce the amount of water you apply. Set your mower to cut at the high end of
the recommended range: 1 1/2 inches for bent grass; 2 inches for bluegrass and
perennial ryegrass; 3 inches for tall fescue. Taller grass shades the soil,
reducing evaporation. In early June, fertilize with 1 pound of nitrogen per
1,000 square feet of turf to strengthen grass before it becomes stressed. In
July, cut back to a 1/2 inch of water every week; under this regime, lawns turn
the color of straw and go semidormant through summer but bounce back after the
weather cools.
10. Be water-wise with pots. Use glazed
terra-cotta or plastic ones, which hold water better. For extra insulation,
nest smaller pots inside larger ones, or bury pots up to their rims in the
ground.
11. Harvest rain. Even in
summer months, some rain usually falls on the Northwest, and roofs catch a lot
of it. Channel runoff into a rain barrel, then use it to water container plants
PICTURES TO SHOW THE AREA IN NIGERIA EFFECTED
BY BROUGHT
REGULATORY
AGENCIES
Federal Environmental Protection Agency (FEPA) –
defunct
Forestry Research Institute of Nigeria (FRIN)
National Biosafety Management Agency (NBMA)
National Environmental Standards and Regulations
Enforcement Agency (NESREA) National Oil Spill Detection and Response Agency
(NOSDRA)
Abuja Environmental Protection Board (AEPB)
REFERENCE
Baloutsos,
G. (1993). Characteristics of Meteorological
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Scientific Topics, 4(2), Geotechnical Chambre of Greece.
Blumenstock,
G. (1942). Drought in the Nigeria
analyzed by means of the theory
of probability, Technical
Bulletin. Department of Agriculture.
Campbell,
D. (1968). Droughts,
Causes, Effects, Solutions. F. W. Cheshire, Melbourne, Australia.
Correia,
F. (1987). Engineering risk in regional drought
studies, in L. Duckstein and E. Plate (eds), Engineering
Reliability and Risk in
Water Resources, Martinus Nijhoff, Dordrecht.
Keddy, P.A. (2007), Plants and Vegetation: Origins, Processes,
Consequences, Cambridge, UK.:
Cambridge University Press, ISBN 978-0521864800
Nyong AF, Adesina, Elasha BO (2007) The Value of Indegenous Knowledge in Climate change Mitigation and Adaptation
Strategies in the African Sahel.
Mitigation and Adaptation
Strategies for Global Change 12: 787-797.
Loukas A,
Vasiliades L (2004) Probabilistic analysis of drought spatiotemporal
characteristics in Thessaly region,
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