Monsoons
are back along with lightning
By
K.R. Abhayasinghe
The second intermonsoon season during October and November
follows the south west monsoon season in Sri Lanka and under certain
conditions may even continue till mid-December.
During this
intermonsoon season, we experience various weather conditions. Wind
and temperature enhance the development of the cloud type called
cumulonimbus and sometimes "anvil cloud"- so called because
of its similarity to the blacksmith's anvil.
These clouds
produce lightning, tornadoes and hailstorms. The cumulonimbus clouds
develop between the altitudes 500 and 12 km under atmospheric conditions
with strong upward movement of air associated with convection.
The lower part
of a cumulonimbus cloud mostly consists of water particles and drops
but the region above 5 km has mainly super-cooled water drops and
ice. Since rain starts with falling ice particles, we may sometimes
experience rain with ice (hailstorms). Fortunately, we are living
in a tropical country where the low level temperatures are much
above freezing temperature and the ice tends to melt before reaching
earth, saving property from damage.
A lightning
flash, after travelling about half a kilometre from the clouds selects
the closest conducting path to come to earth before being neutralized.
Therefore, the tallest objects are the best supporters of a lightning
flash on its way to ground. In a natural environment, tall trees
are lightning-attracters. Otherwise, conducting (metal) structures
or objects (like communication towers, telephone and power supply
lines and TV antenna) will attract lightning flashes. In the absence
of such objects, buildings are vulnerable to direct hits by thunderbolts.
During bad
weather conditions with thunderstorms, lightning surges may reach
the inside of a building in a number of ways.
*Direct hit
:
Single, considerably
tall buildings are vulnerable to lightning flashes. Once lightning
strikes a building, the current will pass through its conductive
materials (reinforced iron in concrete columns and slabs, wiring,
electrical circuit metal structures etc.) on its way to the ground
if no safe way is provided for the purpose.
*Side flash:
A part or whole
current of a lightning flash, which has hit a telephone or powerline
or a TV antenna, may travel to a building via the electrical (metal)
connection between the point of striking and the building. Depending
on a number of parameters, a part of a lightning flash reaching
a tall object (tree, tower) close by may spark to the conducting
parts (concrete sun shade, concrete chimney roof or aluminium sheet)
of a building even without any electrical connection.
*Step voltage:
The voltage
difference between the feet resulting in a current spreading from
a point of a lightning strike on the ground.
*Contact potential:
A shock occurs
when there is contact with an object like a tree, building or conducting
wire that acts as a part of a conductor of a lightning current.
Lightning is
a natural phenomenon and, therefore, it is difficult to stop. But
hazards caused by lightning could be reduced with precautionary
measures, to pass the high current surge of a direct or indirect
lightning current to earth safely. Some of them are:
*Install good
earths for the electric circuit of buildings.
A lightning
flash conducted through a power supply circuit may be as hazardous
as a direct lightning strike. In buildings powered by the main power
supply lines without the earth wire, this may be very serious.
* Use power
surge diverters
Supply lines
of power and communication can be interrupted by a power diverter
which is capable of directing high currents - intruding into a building
along supply cables as a result of a lightning flash-to the ground
without allowing it to come into the interior of the building circuit.
* Installing
lightning conductors/arresters
The direct
hit of a lightning flash on a building is the most dangerous where
lightning hazards are concerned. Solitary and tall buildings are
the most vulnerable to lightning. The lightning rod, lightning arrester
or conductor is the widely used device for the protection of buildings.
* In environments
with thunderstorms,
- Electrical
instruments should be disconnected from the main power supply.
- Television
antennas should be disconnected from television sets and connected
to properly installed earth rod. If this is not possible the antenna
socket should be placed close to the earth outside the house.
- As far as
possible, avoid handling/touching electrical instruments like refrigerators,
electric iron metal frames, TVs and radios.
- Find shelter
in a safe place in the open. If the time interval between lightning
flash and thunder becomes less than 15 seconds, move quickly to
a protected location as there is immediate danger of a lightning
strike nearby.
- Try to avoid
being in open areas like paddy fields, tea estates or play grounds.
Avoid working in open air, holding metal tools like mammoties, knives
and iron rods. lf this cannot be avoided, crouch down, singly, with
feet together. Footwear or a layer of any non-absorbing material,
such as a plastic sheet, offers some protection against ground currents.
- Do not seek
shelter under or near isolated tall trees and in high grounds. If
the vicinity of a tree cannot be avoided, seek a position just beyond
the spread of the foliage.
- Avoid touching
or standing close to tall metal structures, wire fences and metal
clothes lines.
- Limit the
use of telephones when a thunderstorm is overhead.
The writer is a Deputy Director,
Department of Meteorology
Rain
or sun, home for them is where their wheelchairs or carts take them
Their wheels of life
By Ruwanthi Herat Gunaratne and Esther Williams
The man on the wheel chair was there last morning. He was
there late last night and this
morning too. In fact he has been on that pavement every time we
passed that way in the past few months, in rain or sun. His shoulder-length
grey hair is unkempt, a sign of what his life has become.
Didn't
he have a home to go to, a family? Apparently not, for Linton is
a cynic who has lost faith in every aspect of the social system.
His life centres around his wheelchair.
To some extent,
this is due to his amputated lower limb. At the prime age of 32,
Linton came down with a bad case of diabetes which led to gangrene.
This physical condition forced him to quit his job at the Model
Farm.
His employers
donated a tricycle-style wheelchair (self-operated) which keeps
him mobile to a certain extent. His mobile home is parked on one
side or the other of a by-lane, depending on the weather. Rain will
see him under the big old "Mara" tree round the corner
while sunshine sees him under the shady mango tree.
Homeless:
Hemapala with his two children
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Linton
doesn't beg. But his presence evokes much sympathy from passersby
who from time to time give him food packets. He goes to the Town
Hall to wash each day and during the weekends he visits his brother
in Narahenpita and takes the opportunity to bathe and freshen up.
Some time back
he was accused of drug peddling and was taken in by the police.
Having been found innocent, he is back on the road with no one to
call his own.
Fifty- six
-year-old K. Dianis of Matara is just around the corner. A polio
victim, he is a cobbler and worked many years ago in Maradana. Owing
to his disability, he chose to be out on the streets rather than
trouble his relatives.
Like Linton,
Dianis was given a wheelchair. The calliper and money he was promised
never
materialised. A devout Buddhist, Dianis goes to the temple once
a week. Will his prayers ever be answered, we wonder. "Is there
any place that you can think of, that I can go to?" he asks.
What would
you do if you lived in a cart and a storm comes up? All your possessions
and offspring have to be crowded in one small space. That is the
daily ritual at the Hemapala household.
Two carts,
one crammed with little toys, saucepans and other knick-knacks which
you and I would call junk, while the other provides bedding for
a family of four make up their home. The latter has no comfortable
mattress, just a hard cardboard to line it. A grid woven from nylon
cord is attached to the cart. "When it rains, I simply use
the grid as a frame and cover the cart with polythene," smiles
Hemapala.
His son Pradeep,
aged six, attends a nearby school after which his main chore is
to look after his baby sister, one-year-old Niluka. Every weekend
consists of a trip to Thimbirigasyaya to wash and bathe. But why
not try to earn a bit of money and provide the children with a roof
over their heads? "That's what we did initially. We paid Rs.
1000 a month for two rented rooms. But the rent kept rising, and
we just couldn't manage," Hemapala says.
Hemapala baby-sits
while his wife is out in the mornings working - cleaning a furniture
shop. She is paid Rs 1,000 a month. Once she gets home, Hemapala
sets off, collecting discarded cardboard boxes from supermarkets
and grocery stores, which he sells to vendors in Pettah.
Their daily
earnings are enough to live on but not adequate to obtain housing.
"But people around are so helpful. They give all kinds of goods
and toys for the children. Yet, we are unable to utilize them as
we have no space. Now we have got a room a little away from here
at Rs. 300 per month to store our stuff." He lives in hope.
But housing is still ages away.
What about
medical attention? "That is really nothing to worry about.
We are able to go to the General Hospital whenever a crisis pops
up. The little one was quite sick the past few days and I think
that it was due to the weather. But it blew over."
These people
are not beggars. They are part of our society who lack the basic
need of a roof over their heads.
There may be
solutions for elders like Linton and Dianis, (see box) but as for
Hemapala and family, the Social Service Department has no answer.
"It is a complex problem. Land has to be acquired and built
upon. If there was a disabled person amongst them we could have
helped. Someone has to intervene positively," an official said.
Available
options
What options do the homeless have?
Where can they seek help? The Department of Social Services is quick
to point out that there are facilities available for disabled and
elderly citizens. "There are 154 homes for the disabled and
151 of these are run by Non- Governmental Organisations (NGOs),"
an official said.
The procedure to get into these homes is simple enough. Each of
the eight provinces has its own Social Service Officers. Any one
wishing to obtain help needs to contact an officer from his/her
province. And once the details have been documented he is then referred
to the Director of the Province. If the relevant criteria is met
he/she is placed in a home as soon as possible. Easier said than
done though.
"Not everyone likes to enter a home which has strict rules
and regulations. And most are unwilling to abide by them. Some feel
that by checking into one they've signed an agreement to give up
their freedom. We try to change this attitude, but it can be difficult
at times," the official explained.
Helpage Sri Lanka also provides financial support to 158 elders
homes and 100 day care centres for the aged around the country.
K. D. Dharmawardene, the Publicity Officer of Helpage agrees with
the Social Services Department that those seeking help feel that
freedom is limited.
Their main focus is to encourage the elderly to live with their
families and only in the worst cases do they advise that the elders
should go into homes.
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