Archive for the ‘Disaster Management’ Category

They are marine eels, not sea snakes

December 12, 2017

Reports that swarms of what were initially mistakenly identified as venomous sea snakes had got caught in fishing nets in the east coast, had many puzzled and others worried with rumours spreading of an impending tsunami. But scientists have categorically said they are not sea snakes but a species of marine eel.

The hundreds of eels that caught in fishing nets. Pix by Adiran

These creatures had got caught in areas including Batticaloa, Kalladi and Nawalady. They were reported as having slender bodies with the largest specimen being about four feet long.

The National Aquatic Resources Research and Development Agency (NARA) has identified the sea creatures as a species of snake eels. NARA’s Marine Biology Division Head Dr. Sisira Haputantri said that snake eels like fish have gills, a dorsal and anal fins, although not clearly visible like in the case of fish. However, they do not have scales and a tail fin but have tapering tails ending in a point. This gives the species the appearance of a snake.

Explaining further Dr. Haputantri said the species is scientifically categorised into genus Callechelys belonging to the family Ophichthidae. The name itself gives the hint of a snake with the term “Ophichthidae” originating from Greek ophis (“serpent”) and ichthys (“fish”). Some snake eels have coloured spots or stripes to mimic the appearance of venomous sea snakes to deter predators. These eels cannot be consumed as food and have no economic value, according to NARA.

Snake eels live mainly in sandy reefs burrowing in sandy or muddy bottoms waiting to catch their prey of crustaceans and small fish.

According to NARA the snake eels caught in the east may have been washed ashore as a result of conditions in the Bay of Bengal.

This is not the first time such an incident had been reported. Riayas Ahmed, a senior lecturer attached to the Eastern University said a similar infestation of eels was reported in 2012 during this same period of the year.

Marine Biologist Arjan Rajasuriya said that some oceanic fish species show spawning aggregations that could lead to them getting caught. However he said more research needed to be done to find out the reason behind this rare phenomenon.

Meanwhile, snake expert Dr.Anslem de Silva said it is easy to identify sea snakes as they have a rudder-like tail useful in swimming as opposed to the pointed tapering tails that eels have. He said 15 species of sea snakes have been recorded from Sri Lanka, all of them highly venomous. This includes the beaked sea snake (Enhydrina schistose) commony called ‘Walakkadiya’ in Sinhala. It is regarded as one of the most venomous sea snake in the world.

Veteran diver and marine naturalist, Dr.Malik Fernando said divers occasionally encounter sea snakes and they are common in areas like the Gulf of Mannar. “Sea snakes are stunningly beautiful. They swim underwater hunting for their prey in reef crevices – many eat eels. I have seen them off Negombo. They show no fear of divers. And we have to dodge them when they come our way,” Dr.Fernando added.

Dr.Fernando who is also a medical doctor pointed out that snake antivenom available in Sri Lanka is not effective against sea snakes and warned not to meddle with them if one spots them on a beach or while diving.

Published on SundayTimes on http://www.sundaytimes.lk/171210/news/they-are-marine-eels-not-sea-snakes-272310.html

Batticaloa fishermen with their unusual catch

Living with landslides: Community-based programme teaches combat techniques

July 31, 2017

As landslide deaths become increasingly regular in Sri Lanka during heavy rains, a community-based science programme offers a life-saving mechanism. Getting to know about an imminent landslide even a second earlier could make a big difference, but often the early signs are ignored. To address this issue, an ambitious programme was launched last year.

Nature often gives early landslide warnings such as changes in the landscape, cracks on walls and difficulty in closing or opening doors or windows. (read the box story).  Drawing people’s attention to such early warnings is one of the aims of the Community-Based Landslide Early Warning Project (CBLEW). It teaches people in a landslide-prone community to monitor early signs and prepare an initial response.

A house in Biyagama affected by a landslide. Pic by Lal S. Kumara

The National Building Research Organization (NBRO), the premier institution responsible for dealing with landslide prevention, has identified several risk zones.

NBRO Geologist Darshani Rajapakse said the CBLEW project had been introduced to about 100 villages in Badulla, Nuwara Eliya and Kegalle.
The first step of the programme is to educate the communities on early signs of a landslide and how to respond when disaster occurs. The villages are then taught how to use simple equipment such as a rain gauge, a basic but useful device that can save lives.

According to scientists, 75mm rain for 24 hours in a landslide-prone area should put the people on ‘alert’ while 100mm rain upgrades the risk level to a ‘Warning’. A rainfall of 150mm for 24 hours means it is time for ‘evacuation’ for safety.

The third stage of the programme trains the villagers to map the danger zone, identify safe areas to run in case of a disaster and plan safe passage for evacuation. The last stage of the project involves the setting up of a monitoring committee consisting of active participants chosen from the community.

Ms. Rajapakse said the communities were also taught how to use extensometers which monitor earth movements. She said the NBRO had plans to set up automated extensometers in risk areas where cracks had been sighted. If any major movement of the earth is detected, relevant people are notified through a text message.

According to NBRO studies, 20 percent of Sri Lanka’s land or 13,000 square km in 13 districts is landslide prone, with the Badulla, Nuwara Eliya, Matale, Kandy, Kegalle, Ratnapura and Kalutara districts being the top seven districts on the danger list. Areas with isolated mountains and earth mounds in the Monaragala, Kurunegala, Gampaha, Galle, Matara and Hambanthota districs have also been identified as danger zones. The NBRO said it wanted to implement the CBLEW project in all the areas identified as danger zones.

Published on 28.05.2017 on SundayTimes http://www.sundaytimes.lk/170528/news/living-with-landslides-community-based-programme-teaches-combat-techniques-242728.html

Early warnings of a landslide

  • Changes occur in your landscape such as patterns of storm-water drainage on slopes (especially the places where runoff water converges), land movements, small slides, flows, or progressively leaning trees.
  • Doors or windows stick or jam for the first time.
  • New cracks appear in plaster, tile, brick, or foundations.
  • Outside walls, walks, or stairs begin pulling away from the building.
  • Slowly developing, widening cracks appear on the ground or on paved areas such as streets or driveways.
  • Underground utility lines break.
  • Bulging ground appears at the base of a slope.
  • Water breaks through the ground surface in new locations.
  • Fences, retaining walls, utility poles, or trees tilt or move.
  • A faint rumbling sound that increases in volume is noticeable as the landslide nears.
  • The ground slopes downward in one direction and may begin shifting in that direction under your feet.
  • Unusual sounds, such as trees cracking or boulders knocking together, might indicate moving debris
  • Collapsed pavement, mud, fallen rocks, and other indications of possible debris flow can be seen when driving (embankments along roadsides are particularly susceptible to landslides).

Source: http://www.weather.com

Drones – a handy tool in trained, trusted hands

January 29, 2017

A drone being prepared for a habitat mapping operation.

When police seized a drone that recorded the Hambantota port protests last week, it renewed the debate on whether to welcome this ‘new kid on the block’ or to ‘rope him tightly’.

While few view drones as a menace, their applications in different fields can open up new opportunities that had not been previously thought of. Professionals in different fields welcome this new kid on the block while recognizing the need to ‘discipline’ it.

Dr Eric Wickremanayake, a conservation scientist of the World Wildlife Fund, points out that drones can be used in protected areas to map habitat, monitor traffic, and track illegal activities.

A drone is an unmanned aerial vehicle (UAV) that can be remotely operated and transmits video and images. Infrared sensors can be used for different applications.Drones have been used over decades specially for military applications, but now they are used for commercial, scientific, recreational, agricultural, and other purposes.

Dr Wickremanayake said mapping habitat is essential for wildlife park management and previously it was done using satellite imagery. But satellite imagery is expensive, difficult to process and can’t be obtained immediately. “But now we can send a drone on a pre-programmed grid, photograph the terrain and using specific software, prepare the map.”

Dr Wickremanayake is the chairperson of Environmental Foundation Limited and also conservation scientist of WWF. He is assisting conservation work in Nepal.

“We got down drones also with the aim of tracking poachers, but found that habitat mapping is a better application,” he said.

Drones can be used to track Sri Lanka’s illegal cultivations of ganja for example.

In Africa, drones have been used in anti-poaching operations, but this is a difficult proposition in Sri Lanka, he said, especially because of closed canopy forests.

“However, opportunities to use drones in conservation are enormous. For example, we may use drones to control traffic in parks. Take Yala, for example, where adrone can easily detect areas that has problematic congestion and take action,” Dr Wickremanayake suggests.

Drones can be used to address the conflict between humans and elephants.

The Sri Lanka Wildlife Conservation Society under guidance of Ravi Corea in Wasgamuwa has begun research on how drones can be used in the conflict. WCSG research scientist Chandima Fernando said he noted elephants can be deterred by drones, but that the drawback is elephants raid farms at night, when operating a drone is a challenge.

Dr Wickremanayake suggests that a network of pre-programmed drones be set up on the perimeter of villages. These can then be automatically activated in response to infra-sounds made by elephants. The drones can then help scare the elephants. “It is, of course, a futuristic project, but technology is available and it is a matter for an engineer to piece them together to present a practical solution” Dr Wickremanayake said.

Fernando also worked closely with a research team in New Zealand’s Auckland University using drones for conservation and even locate injured elephants.

In 2014, there was an attempt to introduce drones to wildlife applications. This was done by Tropical Ecosystem Research Network together with the University of Singapore. They mapped sections of protected areas such as the Horton Plains, Udawalawe, and Lunugamwehera.

These experts say the Wildlife Department should explore the use of drones in their work. They also accept drones need to be operated based on rules and regulations. Fernando said that in New Zealand, permission is needed to operate drones.

Drone- ' new kid on block' - can also be used for conservation and many other applications

Drone- ‘ new kid on block’ that can be used for many different applications

Drone can be used effectively in responding to natural disasters, as well. “During the floods, we used drones to find out paths of the floodwater. Dronescould be used in rescue missions. They can be particularly used for precision agriculture, or what is called smart farming,” points out Manju Gunawardana, a research scientist who studies use of drones in agriculture.

Gunawardana and the team last year introduced a way to spray weedkillers in farmlands by first identifying where it is needed.

“What is happening now is spraying agrochemicals evenly across a field irrespective of need. The use of drones can cut down agrochemical use,” Gunawardana said.

The International Water Management Institute, too, has been experimenting with drones for a number of applications in Sri Lanka. The data management unit’s Salman Siddiqui told the Sunday Times that the institute studied how drones can be used to give farmers early warning of problems. “Using infrared sensors we can identify stress in a plant 10 days before the effects are visible to the eye. It could be water shortage, lack of fertilizer, or due to a pest attack,” he said.

The institute also assisted the survey department to map Badulla town, which is prone to landslides. Drones have been used to map location of wells suspected to be linked to chronic kidney disease.

Sri Lanka should be ready to use drones for various purposes with proper regulation, experts agree.

Published on SundayTimes on 22.01.2017 http://www.sundaytimes.lk/170122/news/drones-a-handy-tool-in-trained-trusted-hands-225710.html

Tsunami alarm network makes island feel safe than sorry

January 1, 2017

Prof. Samantha Hettiarachchi

Sri Lanka will never be fully protected from a tsunami, but at least people can feel  safer than in 2004, when 36,000 Sri Lankans who perished had not been warned even though they had a two-hour window to reach higher ground.

This week, on December 26, 2004, Sri Lanka along with many other Asian nations, was hit by a tsunami that killed more than 200,000 people. The mammoth wave was generated by an undersea earthquake off Sumatra Island and it took two hours to reach the southern and eastern shores of Sri Lanka.

“Unlike in the past, Sri Lanka is now equipped to issue an early warning in a short period of time,” assures Anusha Warnasuriya, the deputy director of forecasting at the Department of Meteorology. It is responsible for issuing tsunami warnings. An accurate forecast can be made with the assistance of the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS), she said.

By 2004, other oceanic regions already had a tsunami warning system. But the Indian ocean region did not have such a mechanism. So the Indian Ocean Tsunami Warning System was agreed to at a United Nations conference in January 2005. The Indian Ocean Tsunami Warning and Mitigation System became operational in late June 2006 with the leadership of UNESCO’s Intergovernmental Oceanographic Commission (IOC).

A Sri Lankan expert made a major contribution to the warning system.

Moratuwa University Department of Civil Engineering Professor Samantha Hettiarachchi was elected vice chairman of the IOTWMS in 2015 and in October 2016 appointed acting chairman.

“This warning system consists of several seismographic stations relaying information and Deep-ocean Assessment and Reporting of Tsunami buoys that are capable of sensing an upcoming tsunami wave. By also assessing rises in sea-level recorded by the tidal wave gauges, the computer simulation models in regional tsunami service providers can predict of a tsunami,” Prof Hettiarachchi explained.

Currently India, Indonesia and Australia serve as regional TSPs and when an earthquake occurs, the central agency of each country receives an alert. “TSPs issue warnings only to designated bodies and not to other agencies or the public. In Sri Lanka, the met department and the Disaster Management Centre receives information about a tsunami. The met department is the official designated body to receive and disseminate information in consultation with the Disaster Management Centre,” Prof Hettiarachchi elaborated.

The met department’s Warnasuriya said alerts are received from all three TSPs. “Assessing all these warning issued by IOTWMS, our director general in consultation with other stakeholders take a quick decision to issue a warning according to the risk level. The rest of the ground level work such as evacuations are then mainly taken care of by the Disaster Management Centre,” she said. Since 2005, the met department has been tasked with being the central agency to receive tsunami alerts.

Sri Lanka is separated  into 13 coastal forecast zones and sirens have been setup at highly vulnerable places. Tsunami-related evacuation drills had been done on March 29, 2005, September 17, 2007, and April 11, 2012.

“Education, awareness, preparedness, early warning, and response at the country level is essential. Evacuation plans, too, need to be clear. Regular drills are important,” Prof Hettiarachchi advises.

He points out that Sri Lanka is definitely safer against a tsunami threat than in 2004. But due to the nature of the tsunami threat Sri Lanka can never be completely safe, so the island must remain vigilant, he added. Sri Lanka had been slow to conduct national vulnerability studies, but it is an exercise that can help to save lives and property, Prof Hettiarchchi recommended.

He also points out need to protect natural coastal ecosystems such as mangroves, coral reefs and sand dunes to help minimise potential damage from tsunami and other ocean waves.

Published on SundayTimes on 01.01.2017 http://www.sundaytimes.lk/170101/news/tsunami-alarm-network-makes-island-feel-safe-than-sorry-222503.html

Multiple tools used to warn of tsunami

All mobile phone users can be alerted by text messages in the event of a tsunami, a disaster management official says. This is in addition to a warning towers in coastal areas. 

“Now we have setup 77 tsunami warning towers covering the most vulnerable coastal areas of Sri Lanka. There is also one on Delft islands and these can be remotely activated to issue a warning with a siren and message in all  three [main] languages,” said Pradeep Kodippili, the deputy director of the Disaster Management Centre. “But tsunami towers are only one mode of disseminating information to the public.’’

The centre said it has set up a network linking all the key government agencies and assigned pre-defined tasks to be able to act quickly. “We have our own radio frequencies to communicate with all the key agencies and also have the ability to issue an SMS similar to the ones issued by the President to all mobile users,’’ Kodippili said.

“The centre also has a vehicle equipped with communications channels and other necessities, so even if our building is damaged, we are in a position to coordinate management of a disaster,’’ he added.

Any person can register with the centre’s alert system by dialling #117 and by following the instructions. An app called ‘Disaster Early Warning Network – DEWN’ can also be downloaded.