Sir,

This is in response to the letter by Geologist Mrinmoy Chakraborty (SOM dated Aug.11, 2019) defending the views of the Geological Survey of India (GSI) published in SOM dated Apr.25. I write this to bring to light a few facts that go to show that Chakraborty has hastened to defend the warnings given by GSI a bit too early and to furnish some clarifications regarding the extreme events that wreaked havoc in Kodagu this August and perceptions arising out of them.

The series of landslides that devastated Kodagu in 2018 occurred mostly during the period 15th, 16th and 17th August. Some intriguing data on rainfall pertaining to this period tells the story. This data is from the rain gauge at Kudigana, a place near the border of the catchment of Harangi, which witnessed the worst kind of disasters in 2018.

Record rainfall

Till 6th August, the station had recorded about 5,500 mm of rain, and then on rainfall on the successive days read (in mm): 81, 250, 269, 90, 115, 121, 262, 295, 320, 461 (16th), 394, 197, 164, 95, the total for the fortnight amounting to 3,114 mm (Mysuru’s annual rainfall is 780 mm). Probably the 5-day extreme rainfall recorded then at Kudigana (1,686 mm) is the highest ever recorded in the rain gauging history of Kodagu (which extends for over 120 years now), the earlier highest being 1,462 mm in 1964 pertaining to the station of Bhagamandala.

On the other hand, the records at Kudigana for this year read thus: Total rainfall up to 1st August – 2,041 mm; then on – 30, 0, 16, 136, 183, 254, 312, 276, 298, 158, 90, 46, 35, 100 (15th), during the next 14 days – this is the period when the floods ravaged the district. The extremes here are just about 75% of last year’s and the total for season up to 20th Aug. is not even half of last year’s (nearly 4,090 and 8,614 mm respectively).

Once in 10-12 years

The highest one-day rainfall recorded this year has been reported from Bhagamandala, places around which contribute to flow in Cauvery and stands at 400 mm. The seven-day extreme for this year here has been 1,142 mm. Strangely, these values have return periods of 12 years and 10 years respectively.

This means, the type of flood-causing rain that fell this year occurs, according to data available, nearly once in 10-12 years. Even the flood magnitudes in the four rivers of the basin that were reported this year have return periods of 15 – 20 years.

On the other hand, the rainfall of 2018 that caused havoc in areas around Madikeri and in the catchment of Harangi shows a return period of over 50 years! This is the reason why even though Kodagu experienced severe floods this August, only just a couple of incidents of severe landslides have occurred.

Technical data

Very often, blockage of roads due to mud falls from tall and nearly vertical cuttings (Plate 1), many times triggered by uprooting of trees and washing away of the valley side road formations, are also termed as landslides, while the landslides of 2018 were removal of unimaginably large portions of hills, mostly in the valleys.

A large number of the over 150 landslides that occurred then got initiated far away from the highways and inhabitations (Plate 2), in total contrast to the common belief that tampering with nature and cutting land indiscreetly is the root-cause of landslides.

Many of these slides carried tens of thousands of cubic meters (like 200 m x 100 m x 2 m) of earth submerging hundreds of hectares of land downstream in mud (Plate 3 and 4). However, even earth falls of volume of a few hundred cubic meters (20 m x 10 m x 2 m) block roads and cause damage to houses — only one landslide of the former nature has been reported this year. It is not strange that extremes not quantified by measurements are blown out of proportion, painted colourfully and projected as catastrophes in this era of rampant use of mass and social media.

Predictions fail

Dr. H.S.M. Prakash, Director General of GSI, is reported to have explained (SOM, 25th April) thus: “There are indications of excessive downpour happening in five phases just like last year …”; “likewise, three to four more similar downpours are likely to be experienced… The rainfall in August is likely to result in floods”. Yes, one spell of rainfall has resulted in floods. But what about the rest? It is a common experience that any astrologer, once approached, would point out a number of cases in which his predictions have gone perfectly right, hiding others! The fact is that rainfall in Kodagu this year has been very poor except for that one spell — even after that week of deluge, the total seasonal rainfall for the year remains 25-40% lower than the normal (except in small pockets of Virajpet), while the last year it was about 25-50% higher than the normal.

Strong low pressure

It is claimed by Chakraborty (SOM, 11th Aug.) that the predictions for this year have been those based on “evidences”. Dr. Prakash had explained: “There is a possibility of heavy rain being caused due to volcanic eruptions in Hawaii and Mauritius. And, as if an indication, it has already started raining in Kodagu (in April)”.

It is utterly sad that an agency with a legacy of 200 years has fished out evidences for the floods in August, in the excessive rainfall of April! It is well established that the pre-monsoon rains of April and May are a phenomenon occurring due to local convections, while the monsoon rains in Kodagu are due to the global circulation, aided by strong low pressures in North/ Central India and the local orography (high rising mountains) of the Sahyadris.

It is now popularly known that the excessive rainfall of the ten days of August this year has been due to a strong low pressure that developed in the Odisha coast, and experts from GSI claim it to be due to excessive heat of magma in Mauritius!!

Better to err on safer side

Being half correct about events not known of is one hundred perfect in Statistics — probably the messengers, the people at the helm of affairs, believe that it is better to err on the safer side than on the other. Sweeping and arbitrary long-range predictions are not only unwarranted, but are also dangerous.

Rather, there shall be healthy introspection and debate on why even extreme events of smaller magnitude have been resulting in excessive damages in recent days. Further, very little of the Hydrology of this region has been understood, much remains to be done. It is hoped that the agencies concerned take a more pragmatic and purposeful look at the recent events and use them to learn about the region.

– Yadupathi Putty, Mysuru, 3.9.2019

You can also mail us your views, opinions, and stories to voice@starofmysore.com

source: http://www.starofmysore.com / Star of Mysore / Home> Voice of the Reader / September 16th, 2019

Provides sensor-based online real-time data on storage level to officials in New Delhi

Madikeri/Mysuru:

Telemetric Water Gauge has been installed at Krishna Raja Sagar (KRS) Dam in Mandya district and also at Harangi Dam in Kodagu for sensor-based real-time data on the storage level, inflow and outflow of the reservoirs.

The installation comes weeks after an Internal Committee of Cauvery Water Management Authority (CWMA) visited the two Dams in the first week of June this year. The team, after studying the water levels and reporting mechanisms, had decided to set up Online Monitoring System for all the reservoirs in Cauvery Basin through Telemetry-based Real-time Data Acquisition and Transmission.

The facility transmits data to CWMA Office in New Delhi and the authorities who decide on the water release as mandated by Supreme Court need not wait for the data from the Dams. They can easily access the data through the Telemetry Transmission system.

No room for errors: All these years, the authority sitting in New Delhi had to obtain data from each reservoir every day to determine the storage levels, inflow and outflow. This system was prone to errors as the people manning the Dams take physical measurements. Now with the new system, errors are eliminated and accurate real-time data can be accessed, making the decision-making process easy and accurate.

The Union Government has constituted the CWMA and and Cauvery Water Regulation Committee (CWRC) as directed by the Supreme Court and an Internal Committee comprising Irrigation experts from the Cauvery Basin States of Karnataka, Tamil Nadu, Kerala and Puducherry has been formed.

Real-time data acquisition

During their visit, the CWMA team discussed real-time data acquisition and transmission, installation of water-level sensors, flow rate sensors at all canals / outlets taking off from all the eight Reservoirs coming under Cauvery Basin and technical issues such as capacity enhancement of Dams, safety of Dams, prevention of leakages, modernisation of canals for prevention of seepage, etc.

The new advanced telemetry system has been installed based on the directions from CWRC. Sources said that such a system has been installed at Reservoirs including Hemavathy, Harangi, Kabini and KRS in Karnataka and in Banasura Dam at Kerala and Lower Bhavani, Amaravathi and Mettur dams in Tamil Nadu.

On mobiles

Speaking to Star of Mysore this morning, Vasudev, Assistant Executive Engineer of Cauvery Neeravari Nigam Limited (CNNL) that manages KRS and Harangi, said that the Telemetric Water Gauge gives live data to CWMA and CWRC authorities and they can access the data at any given point of time on their mobile phones.

The system transmits live data from the Dams and an exclusive cell has been set up at CWMA Office in New Delhi to receive the data and send them real-time through mobile phones. “With this system, now no one can bluff the CWMA by constantly claiming more water, hiding the real storage level data at the Dams. Even the CNNL authorities can access the data,” he said.

The data will measure minute details about number of canals and their location, water levels inside the canals, their turbulence, number of sluice gates, size of gates and the amount of water discharged from the crest gates. It also records spill- over water.

source: http://www.starofmysore.com / Star of Mysore / Home> News / July 26th, 2019

Siddapura:

Concerned at the increasing instances of elephant-human conflict, the Forest Department, for the first time in Kodagu, has put radio collars on elephants to study their migration patterns.

The Department has decided to put radio collars on selected elephants so that their migration patterns can be studied. An analysis of their movements will help in avoiding human-elephant conflict that results in deaths of humans and damage to crops, said Department officials.

Accordingly, over six elephants that usually enter coffee estates and fields have been radio-collared in places including Virajpet, Madikeri, Kushalnagar, Maldare, Ammathi & Pollibetta. These areas have witnessed increased elephant attacks in the recent past.

The collars were fitted on the wild pachyderms with the help of tamed elephants including Bhima, Abhimanyu and Krishna. Last time, over four collars were fitted on the elephants and the Department staff was able to successfully track the elephant movements and prevented them from entering the human habitats.

Department officials said that radio collars could further strengthen the elephant corridor management strategy. It could also become an early warning system for villagers in order to avoid conflict with elephants as the collars could provide real-time information. Radio-collaring of animals is a tried and tested method of studying free-ranging wild animals that has been in practice for several decades. It is primarily used for tracking the movement and activity patterns of the tagged animal, with the signals being sent to a handheld device or to a computer via a satellite.

It is often the only method that is available for studying the movement and activity patterns of a secretive species like the tiger or a wide-ranging species like the elephant. Information obtained from the use of radio telemetry is of high scientific and conservation value. The GPS-enabled radio collars will provide updates in real-time about the location of a herd and help track them within the State as well as during migration. A tool embedded in the collar will send signals 24X7.

“Once we receive signals on the presence of the elephant herd near human habitation, the ground-level Rapid Response Team of the Dept. will be alerted on their mobile phones so that they can rush to the place and launch an operation to drive elephants back into the woods,” said District Forest Officer Maria Kristhu Raj.

The kumkis (tamed elephants) will infiltrate the herd and scatter the elephants. When the female leader is isolated, the experts perched on the nearest kumki will shoot her with a dart loaded with a tranquillising drug called xylazine. The dosage will be decided according to the size and strength of the matriarch. “After being hit, the elephant will walk like it is intoxicated for 10 minutes and then it will fall asleep. So, our men have a window of about 40 minutes to put the radio collar on the elephant,” he explained.

“In the 40 minutes the animal was under sedation, the team fixed the radio collar and activated it. Soon, veterinarians injected a drug to revive it. The entire operation was over in 50 minutes and the animal started heading back into the forests,” the DFO added.

source: http://www.starofmysore.com / Star of Mysore / Home> News / May 14th, 2019