Wayanad
Land Slide and Lifeline Structures
The
landslide disaster in Wayanad along the western slopes of the Western Ghats
brings one issue of civil structural design – Lifeline Structures.
If
a natural disaster strikes an area, agencies entrusted effective disaster
response would know what are the available lifelines including mobile phone
towers, power lines, and bridges. Why are they called lifelines? For this the
readers may wish to take a sharp look at the “rescue” of a person struggling to
keep afloat in water.
The
rope winding down from the “rescuer’s” waist to the floatation device, the red
thing clutched by “struggling swimmer” (I know she doesn’t look either like
struggling at all or clutching; maybe she has struggled out!) carries the
agency of the lifeline, and is called, you guessed it, lifeline. With this contraption
in place, the rescuer knows that the person being saved is not sinking, and her
head is above the waterline. This is the lifeline, and the meaning is evident –
you do not allow an event to become a full-fledged disaster by being prepared
for it.
Did
the landslide area have any of these lifelines? I do not want to answer these
in stark terms, but it does appear that there was at least one deficient
lifeline – a bridge. From an article in Frontline
(September 6th), I learn that “[T]he sole bridge that connected the
village to nearby Chooralmala and the rest of the world was destroyed in the
landslide...”
Out
of my own interest I have read upon lifeline structures, initiated into it by a
clause in the Indian Standard IS 875 (Part 3) on wind loads. It is
too technical a matter – so technical that I could not explain it to my post-graduate
students at their level of comprehension – that I would stop elaborating
further. Wind load calculation is a probabilistic endeavour, and those who
compiled the code referred above stopped explaining it beyond what is required
for efficient design (though there is an explanation on probability orientation), that is, going into efficient design. Lifeline design should
also be treated on the philosophy of having the necessary infrastructure in
place to enable maximum rescue efforts under a scenario (plotline, say).
The
first priority is to save lives, of humans and cattle. To save lives, you need
to communicate to people in the affected area – hence, operating mobile towers
with multiple antennae of various connectivity providers. Then, you need
dependable power supply and hence transmission line towers. Next comes reaching
the people as bad as the situation maybe expected to be (hence probability) and
also to give the rescuers as clear a path to disaster location as possible –
hence, bridges. Note the plural.
Yes,
we can, given the budgetary constraints, and have to assign a low probability
to two bridges collapsing simultaneously. We cannot – emphasize, cannot – leave any community in a
vulnerable area dependant on a “sole bridge”, like it was done at the landslide
location, per the newspaper article (referred above).
The
disaster prone areas have been mapped by the national disaster response agency,
I am sure. Yet, they had not located the need for a lifeline structure, an extra
bridge, for the communities along the ecologically sensitive western face of
the Western Ghats slopes. The reason could be that road building ministry did
not have the resources (money) for this “luxury” item!
Western
Ghats is not the Himalayas, perhaps more prone to earthquakes and landslides.
If you are asking for two routes to Gangotri, Yamunothri, Kedarnath, Badrinath
etc., I can understand the need for a double look before going for an
additional connectivity – the cost would be prohibitive.
Yet,
foundation
stone has been laid in December 2016 for a minimum 10m wide National Highway with
long bridges and tunnels; and a railway line too. I am sure
that the planned expansion has been vetted for its environmental (neoclassical
economics) and ecological (Sustainable Development Goal) imprints. This is for
the future, catering to the expected demand-supply.
No
matter how federal a Union government is, its actions will always be tuned to
resonate with the requirements of the dominant constituent of the governing
coalition. This is par for the natural course of politics and governance, but could
not be for natural disasters.
The
most effective pathway is for the State Government of Kerala to locate its own
resources and not go to the Union Government with a begging bowl in hand. That
is the most effective lifeline.
Every
swimming pool must have its own lifeguard.
Think
national but live local.
Raghuram
Ekambaram
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