Monday, July 04, 2005

The following Posting is reproduced from: www.sethunews.blogspot.com


2005, July 5, sethunews exclusive

Research Papers challenging Tuticorin Port Trust's observations on Tsunami, Cyclones and Sedimentation issues related with SSCP and Palk Bay

Links:

1. Indomer-Alkyon’s tsunami simulation model reveals the contrary! It reveals that Sethu Canal will be dangerous to both Indian and Sri Lankan Coastlines instead!! in
http://www.asiantribune.com/show_article.php?id=2475


2. http://lareef.blogspot.com/2005/04/sethusamudaram-in-time-of-tsunami.html

(This article 'Will to Disaster' was subsequently published in 'The Economic and Political Weekly' dated 25 June 2005 ) - www.epw.org.in


Both these articles are available in this blog also.


Titles:

1. Sethusamudram Shipping Canal would destroy the coastline stability of Sri Lanka and India. - Posted on June 10, 2005

2. The Will to Disaster - Posted on May 13, 2005


Additional Sources available in this blog that refute TPT's answers still further:


1. Is ignorance Bliss? - Posted on May 25, 2005

2. Movie in 3 dimension, depicting inundation by tsunami waves on the shores of South India and Sri Lanka - Posted on May 18, 2005

3. Animation Movie on the pattern of interaction of the December 26th Tsunami waves with Palk Bay - Posted on May 14, 2005

4. December 26th Tsunami GIF and QT movies on a 3d platform - Posted on May 13, 2005



....................................................................................................................................................................


Tuticorin Port Trust's Response to Prime Minister's Office's note (dated March 8, 2005) of reservation on SSCP

courtesy: www.sethusamudram.gov.in



Answers given to Prime Minister’s Office by the Tuticorin Port Trust (probably in late April – early May) and most likely to be responsible for gaining a clearance from it, has been released in the official website of Sethusamudram Project (www.sethusamudram.gov.in) on 30 June 2005.

(This response is most likely from Dr.P.Chandramohan of Indomer Hydraulics Pvt.Ltd., Chennai. It is noteworthy to remember here that he was an NIO scientist till 1997. In 1998 he had started his company ‘Indomer’.) (His company’s website: www.indomer.com )


It is also likely, that Prof.Victor Rajamanickam, who currently heads the Department of Disaster Management at SASTRA Engineering College, Tanjore (and who had been the head of of the Department of Earth Sciences, Tamil University, Tanjore till 2003 – when he left for SASTRA) would have contributed to this text; but it is felt, that, it is Dr.Chandramohan, who is its author)


This resonse was made public on June 30, 2005, that is 2 days before the inauguration of the SSCP at Madurai.

– www.sethunews.blogspot.com



Following is the full text of TPT's answers as published in its website


…………………………………………………………………………………………..

PMO Note

1. Subsequent to the Tsunami calamity, certain urgent technical issues have arisen regarding the SSCP which have been noted with alarm in responsible sections of the scientific community of the country



Tuticorin Port Trust Observations

PMO Note is the summary of an article titled " Pre- and Post Tsunami – Is the Sethusamudram Shipping Canal Project Technically feasible ? " which appeared in the Economic and Political weekly dated January -22, 2005.

The article is contributed by Dr. R. Ramesh, M.B., B.S., who is a medical professional. His expertise in the complex phenomenon of Tsunami and its impact is debatable. His readings on the subject of tsunami and the project region are limited as evident from the references cited by him.

There have not been any observations made by any scientist on the basis of scientific evidence except for some statements in the media attributed to Dr. Ted Murty, NRI Scientist about the need for reorientation of the channel entrance in the Bay of Bengal. This is dealt with separately.



PMO Note

2. The Tsunami waves which were generated on December 26, 2004 by an earthquake of 9 Richter magnitude off the west coast of north Sumatra traveled westwards and eastwards. The eastern wave was blocked by the Thai, Malaysian and Indonesian landmasses. A portion of the undissipated energy of this eastern wave was transferred to the western wave front traveling towards Sri Lanka and the Indian east Coast.

Tuticorin Port Trust Observations

Yes.

This is also supported by animation models generated in India and also outside.




PMO Note

3. Before touching Sri Lanka, the tsunami was traveling westward. When it struck Sri Lanka and the east coast of India, a clock wise wind was created with the Palk Bay as it hub. Had the Sethusamudram Shipping Canal been operational at the time of this tsunami, the currents in the Palk Bay and the associated turbulence would have damaged the canal considerably and would have caused a wide disposal of the dredged material placed at sea.

Tuticorin Port Trust Observations

A slide from an animation model by M/s. Indomer Coastal Hydraulic (P) Ltd., Chennai in association with M/s. Alkyon Hydraulic Consultancy and Research by the Netherlands is enclosed (slide 1) . This clearly establishes that Palk Bay and Palk strait were comparatively free from the turbulence caused by the Tsunami in the Bay of Bengal and Indian Ocean. This slide is also supported by the animation model of the National Institute of Advanced Industrial Science and Technology , Japan (Slide 2)

In the case of tsunami, significant damages have been and will be seen only along the near shore beach areas because of resistance of near shore structures against the Tsunami passage. The very location of the Sethusamudram channel far away from the Indian or Sri Lankan coast pre-empts this possibility.

Scientists have also expressed the view that the channel situated in mid sea can not show any resistance displayed by near shore structures except for the possibility of bed scouring which may have the impact of increasing the depth of the channel as witnessed in Chennai Port.

Tuticorin Port, situated in the Gulf of Mannar and very close to the project region, did not experience any significant change in the bathymetry due to tsunami's impact.

If a clockwise swirl had indeed been created in the region with the Palk Bay as its hub ( as stated in the note but not supported by the animation models), such clockwise swirl would have taken the dredged materials placed at sea, proposed to be dumped in depths of about 20-30 M in the Bay of Bengal away from Palk Strait. A quantity of around 34.5 million M3 of dredged materials is proposed to be dumped in an area of about 25 Sq.KM, which will raise the sea-bed by an average of 1.4 M only. The clockwise swirl would have carried this deep into the Bay of Bengal, redistributing it over a very wide area making the impact of such redistribution, even if it would have taken place, insignificant in view of the wide area over which it would be redistributed and greater depths available North and Northeast of the proposed dumping location in Bay of Bengal

Therefore, there is no scientific basis for the apprehension that the shipping channel , if it were in place during tsunami, would have been damaged by the currents and / or associated turbulence. `Wide dispersal of the dredged materials placed at sea' would have had insignificant effect.



PMO Note

4. The SSCP is an off shore shipping canal project in the Palk Bay. It aims to shorten the distance navigated by ships sailing form the west coast and bound for ports on the east coast by avoiding circum-navigation of Sri Lanka. On the completion of the SSCP, ships would navigate through the Gulf of Mannar and Palk Bay and enter the Bay of Bengal directly

Tuticorin Port Trust Observations

Yes.



PMO Note

5. The total length of the canal in the Palk Bay is 152.2 Km. This is divided into three legs – the Southern leg in the Adam's Bridge area which is 20 KM, the northern leg in the Palk Strait area which is 54.2 Km and the central portion which is 78 Km in length. Dredging would have to be done in the southern and northern legs to dredge the shallow sea bed of the Palk Bay and Adam's Bridge to a depth of 12 metres in order to make navigation possible. The central leg does not require dredging as it lies the adequate depth of 12 metres.

Tuticorin Port Trust Observations

The statistics furnished in the Note are based on the Techno-Economic Feasibility Report prepared by the National Environmental Engineering Research Institute, Nagpur in July 2004. The Detailed Project Report since submitted to the Ministry of Shipping, RT & H, has suggested some minor changes in the channel alignment on navigational considerations. The length of the proposed channel now is 167.57 Km , with the southern leg at Adam's Bridge area having a length of 34.92 Km, the northern leg in Palk strait 54.33 Km, and the intervening stretches of Palk Bay, not requiring any dredging, having a length of 78.32 Km




PMO Note

6. This is the first effort by the India to dredge a navigation channel, which is located 30-40 Kms off shore. It is also the longest sea bed dredging project undertaken by India.

Tuticorin Port Trust Observations

Yes.



PMO Note

7. The problems that will be faced by SSCP are expected to be

(i) problems due to sedimentation

(ii) problems due to tropical cyclonic disturbances and

(iii) issues related to dumping of the dredged materials

Tuticorin Port Trust Observations

Significant issues relating to the SSCP, which has a major dredging component, are :-

i.Sedimentation in the Channel which will determine the stability of the channel and maintenance dredging.

ii.Identification of dumping locations for dredged materials disposal with the objectives of -

a)minimising environmental impact to manageable levels and

b)ensuring that the dumped spoils do not re-enter the dredged channel.

Though the National environmental Engineering Research Institute had scientifically identified the dumping areas supported by modelling studies, further modelling studies were carried out by Tuticorin Port Trust during September 2004 – January 2005 with involvement of Alkyon Hydraulic Consultancy and Research bv the Netherlands for validation and verification of NEERI's findings, and for optimisation of distance to dumping locations. While validating NEERI's findings the studies have indicated the possibility of opitimising the lead distance. However, considering the environmental sensitivity of the project region, it has been decided to retain the dumping locations suggested by NEERI.



PMO Note

8. In order to tackle these problems, detailed information and knowledge needs to be gathered regarding sedimentation and cyclone disturbances in the Palk Bay

Tuticorin Port Trust Observations

Tuticorin Port Trust has carried out detailed wave modeling studies, tide and current circulation modeling studies, nautical studies and sedimentation modeling studies inter-alia analysing in-depth the sedimentation regime along the entire channel length.

As regards tropical cyclonic disturbances, " information on the normal wave conditions is required for further studies on sedimentation and erosion and to establish the limiting conditions for navigation through the channel. Information on the extreme wave conditions is required for the design of various structures, like groynes and bank protection," (Report of Indomer Coastal Hydraulics (P) Ltd., Chennai on Hydradynamic modeling and ship Maneuvering studies for the SSCP). Wave modeling studies of international standards, involving an internationally acclaimed organisation, have been carried out to meet these requirements.

The following findings of the modeling studies are relevant vis-a-vis sedimentation in the channel in Palk Bay / Palk Strait which the Note primarily deals with-

"Based on the computed sediment transports, it can be concluded that the incoming sediment volume (23,100 m3 ) is of the same order of magnitude as the transported sediment along the channel (32,500 m3). This would imply the following -

•At the shallow zone of Palk Strait, the channel depth will remain constant at CD (-) 12m (the incoming sediment volume from long shore transport approximately equals the outgoing sediment volume due to transports parallel to the ship channel). This implies that no maintenance dredging is required along this channel section (at Palk Strait).

•East and west of shallow zone, however, the transported sediment volume will deposit due to reduced sediment transport capacities. The deposited sediment volume equals to 32,500 m3/y."

The relevance of the findings is two-fold:

(i) Detailed field investigations/ modelling studies have been carried out in the project region.

(ii) There will be very little sedimentation in the channel in Palk Strait, compared to other approach channels in the country.

The general philosophy followed worldwide in designing an off shore structure is that predictions about the ocean environment have to be made first, ideally based on the history of the environment for 'hundreds of years of data' (A.K.Malhotra – "Ocean Science and Technology" p 32, 1980)". "In actual fact, the data for a particular location usually cover a much shorter period and, therefore, are a poor basis for predicting the future from the oceanographer – statistician's point of view. Despite this, valid operating and design values can be obtained by one of several methods" (A.K.Malhotra). This is normally done through predictive modelling, as carried out by Tuticorin Port for SSCP.

The issues relating to cyclonical disturbances are discussed in Section 12.



PMO Note

9. Palk Bay is one of the major permanent sediment sinks of India. In a study entitled " Littoral Drift Sources and Sinks along the Indian Coastal by Chandramohan and others in 2001, the sea depth reduction due to sedimentation in the Palk Bay has been estimated to be 1 cm per year Marine and riverine sources contribute to these sediments. In a publication entitled " Rapid Land Building Activity along Vedaranyam Coast and its Possible Implications" brought out by Ramasamy and others in 1998, the sediment building activities due to sea currents in the Vedanarayanam-Jaffna peninsular stretch of Palk Bay has been estimated to be 29 metres per year. Similarly in another study on the Sethusamudram Canal published by Rajamanickem in 2004, the sedimentation rate has been estimated to be 24 cms per year in the Manamelkudi area of Palk Bay

Tuticorin Port Trust Observations

The Note refers to findings reproduced in some research papers which are based on micro-regional studies or application of mathematical formulae.

The study of Rajamanickam has been mentioned. Rajamanickam says in his paper – "Sethusamudram Canal: The life line of Tamilnadu" (National Seminar on Ecological balance and Sethusamudram Canal, 1-3rd October, 2004, Department of Oceanography and Coastal Area Studies, Alagappa University), that "it is interesting to see that the maritime surveys conducted between 1960 and 1986 reveal the change of contour to the tune of 6m shallowness in the Palk Strait. That shows that around 24 cm per year is being silted off in the Strait." The Note only quotes this part of his observation but fails to add that he has actively supported the construction of the navigation channel to remedy his natural phenomenon. In his paper, Rajamanickam visualizes "the merger of this two (spit from Thalaimannar side in Sri Lanka and spit from Manalmelkudi in India) within the next 50 years. Once these spits join, the Palk Strait will become into two lagoon of the north and south. The flushing of waters from Gulf of Mannar to Bay of Bengal will be stopped". He has further opined -"Because of such ocean circulation, Tamil Nadu is getting monsoonal rainfall. The day siltation initiated, one must have observed the drifting of cyclones and low depressions to Nellore and Orissa.

Slowly the quantum of rainfall in Tamil Nadu and the order of cyclones in delta region have been in the decreasing order. If the flushing is completely stopped, the monsoonal winds and ocean circulations may not be directed through this Strait. If such action takes place, Tamil Nadu may not get proper rainfall and subsequently the granary of rice, the Cauvery deltas will become a desert by the turn of this century.

The moment, Sethusamudram Canal is brought in force, that Canal may become the draining canal first for all the silts dumped along the coast of Palk in the past. There is every possibility to retrieve back the clear water and comparatively deeper shelf in many areas. Such increase of depth and clarity of water may enable the delicious fish varieties to get more populated and fishermen in this region can do the fishing right in front of the hamlets as in the case of 19th century. The per capita income of the fishing community of nearly 40,000 people may go up many times. The delta region may get good rainfall and may plan to go for cultivation without the dependence of Mettur water. In the beginning, the Sethusamudram Canal may face frequent dredging due to the sliding of the silts dumped earlier. In few years this will be settled. The fear complex developed among the fishing community is baseless. Instead of loosing their fishing and trawling, they will get more catch due to the International navigation as in the case of Panama.

Therefore, scientific evidence is being cited against the project when the scientist who has produced such evidence goes on to say in the same research paper that the scientific evidence leads him to believe that an environmental and ecological disaster is waiting to happen unless the Sethusamudram Ship Channel is urgently created to provide a draining canal for the silt in Palk Bay/Palk Strait.

For a dredging project involving creation of a navigation channel, sedimentation in the project setting and in the channel as a result of sedimentation regime in the area need to be studied. In the case of SSCP,, sedimentation transport rate along the channel and long shore sediment transport across the channel need estimation for computation of annual maintenance dredging requirements. Such estimation has been done in the past (earlier studies) through modelling and radio-active tracer analysis. Tuticorin Port Trust has carried out sedimentation modelling in the project area involving a world-renowned organisation which has clearly established that sedimentation transport rate along and across the channel is insignificant.



PMO Note

10. Those findings indicate that there are specific regions in Palk Bay where the annual sea depth deduction is 25-75 times higher than the average value proposed by Chandramohan etc. for the entire Bay. The two legs of the SSCP where dredging is required happen to cross two such micro regions with high sedimentation rates.

Tuticorin Port Trust Observations

The legs of the SSCP where dredging will take place pass through two micro regions with high sedimentation rates – Adam's Bridge and Palk Strait. This prompted Tuticorin Port Trust to commission further modeling studies to verify and validate NEERI's findings. The modeling studies have led to reliable estimation of sediment transportation rate along and across the channel in these regions.



PMO Note

11. The Environmental Impact Assessment (EIA) for Sethusamudram Shipping Canal Project carried out by the National Environmental Engineering Research Institute (NEERI) has not taken into account the sediment contribution from the rivers flowing into Palk Bay. This study does not pinpoint the sediment source for about 99.4 % of the total sedimentation volume.

Tuticorin Port Trust Observations

While undertaking the EIA Study NEERI have generated primary data in addition to relying upon secondary data. Primary data has also been used by them for validation of Secondary data. They had also carried out mathematical/ simulation studies. Tuticorin Port Trust, in its endeavour to verify and validate NEERI's findings, had commissioned further modelling/ simulation studies.

P.Chandramohan et al (Littoral drifts sources and sinks along the Indian Coast, Current Science, Vol.81, No.3, 10 August 2001) in their study had estimated 0.3 x 1010 m3 sediment deposition in Palk Bay region, in an area of 117 km x 105 km over a period of 51 years. M/s.Indomer Coastal Hydraulics (P) Ltd. (of which Dr.P.Chandramohan is the Managing Director) have estimated sediment deposit of 32, 500 m3/y in Palk Strait part of SSCP, which will have a length of 54 kms. A comparison of the estimates is shown below:

1.Sedimentation capacity in the channel,

proportionate to estimate to

Chandramohan et at .

54x0.3x1010 = 77,569 m3

117x105x51



2.Sedimentation computed by

TPT modelling study

Along the channel-

Incoming sediment volume =23,100 m3 Outgoing sediment volume =32,500 m3

Across the channel-

Deposited sediment volume =32,500 m3 --------------------------

Total =88,100m3

==================

Therefore, the findings from the modelling studies compare favourably with results of research studies available for the area. The imputation that the studies do not pin-point the sediment source for about 99.4% of the total sedimentation volume appears to be based on the following

(i)Total sediment load computed:

58.8 x 106m3

by Chandramohan et al for entire Palk Bay

(117 x105 sq.km.)



(ii)Less net annual sediment transport :

0.2657 x 106m3

Computed by NEERI for Adam's Bridge area

(which has a length of 17 kms)



(iii) Less estimation made by Sanil Kumar et al for net littoral sediment

transportation:

0.095 x 106 m3 into Palk Bay from Nagapattinam coast.

Unaccounted, according to the Note

58.4393 x 106m3

The primary source of the sediments deposited on the beaches is the weathering of the land; the sediments are then transported through rivers to the ocean' (Chandramohan et al, 2001). It is also estimated that 'The quantities of materials contributed by head land erosion and aeolian transport are both less than 2 per cent of river transport' (Chandramohan et al, 2001).

Therefore, when the sedimentation due to littoral drift from the north (Nagapattinam) estimated by Sanil Kumar et al (2002) and the total sedimentation load for Palk Bay region computed by Chandramohan et al (2001 – Sanil Kumar was also part of this research group) are accepted as valid, the source of the difference is very clear-sediment contribution from the rivers. This is supported by the following excerpts- `Vaigai, Vaishali and Valryar rivers are the major sediment sources entering the palk bay region'. (Malik, T.C., Indian Journal of Marine Science, 1983-12,203-208). `Large amounts of sediments from the pediments are removed constantly by rainfall and carried by minor rivers and dumped into the Palk bay'.(Loveson et al, Sea Level Variation and its impact on Coastal Environment, ed Rajamanickam, 1990, PP159-178).

The studies carried out by the Project authorities are for the purpose of delineating the project setting in order to identify the environmental consequences of the proposed project, assess their impact, evaluate the environmental viability of the project and devise an Environmental Management Plan to minimise the environmental impacts. The findings of these studies are substantiated and supported by research studies of the region in which the project is situated.




PMO Note

12. Out of the 61 cyclones that have crossed the Tamilnadu coast in the period 1891-1995, 6 have directly crossed the Palk Bay. The Met Department considers the coastal stretch between Nagapattinam and Pamban as a high risk zone for tropical cyclones. A study entitled " Identification of Costs Vulnerable for Severe Tropical Cyclones – Statistical Evaluation" published in 2004 has named this coastal stretch as the most vulnerable to severe tropical cyclones among the many coastal regions of the Bay of Bengal. Studies on the pattern of movement of sediments during the cyclonic storms are not available at present. However, it is known that these storms have a tendency to transport sediments into Palk Bay from the Nagapattinam coast and from Gulf of Mannar

Tuticorin Port Trust Observations

'The most damaging oceanographic episode that coastal residents can face is a cyclone with a combination of wind, waves, surge and rain' (Antonio Mascarenhas, Current Science, Vol.86, No.3, 10 February 2004). An important prerequisite for sustainable development, therefore, is resilience towards natural hazards and elimination of disasters.

In terms of landfall, among the severe cyclones over a century, according to Mascarenhas, '55 crossed the coast of Tamilnadu, 69 hit Andhra Pradesh, 58 affected Orissa, 33 struck West Bengal.' Impacts of tropical cyclones have been and continue to be the most disruptive recurring events for the east coast of India. From available records, Mascarenhas concludes -

(i) Andhra Coast is the most vulnerable to several tropical cyclones. About 32% of the cyclones forming in the Bay of Bengal make landfall along this coastal state every year.

(ii) Orissa follows with 27%, Tamilnadu with 26% and West Bengal with 15%.

(iii) The Andhra Coast has been subjected to storms, with a highly significant increase in the mean frequency of severe storms incident on Andhra Coast after 1975 as compared to earlier periods.

(iv) Orissa is affected by the highest frequency of severe cyclones in October and November every year, with the highest probability (56%) of at least one cyclone crossing the coast and 1% probability of four cyclones crossing Orissa every year.

(v) In terms of storm surges, the West Bengal coast is highly vulnerable to attack by storm surges with heights ranging from 2-12m.

The coast of Orissa has witnessed maximum surge heights of 7 m. The Andhra Pradesh and Tamilnadu Coasts are vulnerable where observed surge heights are in the range of 1 to 6 m.

(vi) Andhra and Orissa are the most vulnerable to coastal inundations.

To summarise his findings,

(a) In terms of incidence of severe tropical cyclones, Andhra and Orissa are more vulnerable than the Tamilnadu coast.

(b) In terms of storm surges, West Bengal and Orissa coasts are highly vulnerable, while the Tamilnadu Coast is vulnerable.

(c) Andhra and Orissa are the most vulnerable to coastal inundations.

Therefore, absolute figures relating to Tamilnadu Coast need to be compared with the rest of the east coast. The statistics furnished in para 11 of the Note that `against the incidence of 61 cyclones on the Tamilnadu coast during the period 1891-1995, only 6 had directly crossed the Palk Bay' is also relevant in this context as in simple arithmetical language it conveys that the Palk Bay is less vulnerable to incidence of cyclones than the rest of the Tamilnadu Coast. The Sethusamudram Ship Canal Project was originally conceived by the British as early as in 1860 with the objective of providing sheltered passage to merchant and navy ships, sparing them from the vagaries of nature and to provide safe anchorage during the tropical cyclones normally encountered off the Tamilnadu Coast during the North East monsoon (October – December).

The Note cites the incidence of cyclones in the project area as the reason for reviewing the need for the project when the major ports of Visakhapatnam, Paradip and Haldia are situated in coastal areas more vulnerable to such incidence. So is Kakinada where a major port facility is coming up.

PMO Note

13. There are two previous records of tsunami destruction in this area. The first record is of an earthquake, which originated at the Car Nicobar islands on December 31, 1881. It had generated a tsunami in the Bay of Bengal that had been felt at Pamban. The second record is of August 27, 1883 when the Karkathova volcano of Indonesia erupted and created a tsunami that reached Nagapattinam.

Tuticorin Port Trust Observations

The experience of 26 December, 2004 showed that Palk Bay faced less turbulence caused by the tsunami than in Bay of Bengal and Indian Ocean.

'Tsunami is basically a transient and pressure wave due to compression of fluid by the energy released during the process of earthquake or subducting movement of tectonic plates of earth. This can be surmised as the reverse process of water hammer in the pipe flow. In case of tsunami, the damages can be seen only along the near shore beach areas because of resistance of near shore structures against the Tsunami passage, whereas Sethusamudram Shipping Canal can not show such resistance except for bed scouring (Dr.B.Nagendra Kumar, Scientist, NIOT). He also says that redistribution of bed sediments in Palk Bay due to turbulence, if any, generated by the loss of tsunami wave energy, was a possibility and adds - 'if shipping channel had been present, these sediments would also have been redistributed along the channel as a part of instantaneous process; however, the subsequent over passage of tsunami at the Adam's Bridge and onslaught of higher tsunami energy must have generated high flushing flows along the shipping channel driving these redistributed sediments into Gulf of Mannar for next stage of redistribution at high speeds.'

The implications of these expert views are two fold -

(i) Only near shore areas and near shore structure are damaged by the tsunami wave energy

ii) The worst case scenario is that had the canal been in place on 26 December, 2004, it would have experienced bed scouring.

'The Hindu' of 27-02-2005 reports that Seismologist Arun Bapat has scotched rumours about another large temblor or tsunami. According to him, "Another earthquake of such a magnitude and another tsunami is next to impossible for the next 70- 100 years." The probability of occurrence of tsunami similar to that of 26-12-2004 may not be significant in the time scale of historical events. It is a moot point to consider whether the probability of occurrence of a rare event such as tsunami should affect development projects which normally have a life span of upto 50 years. In the DPR for SSCP an economic life of 30 years is taken into consideration for financial analysis.

" The significance of a net work of canals and drains, in addition to tidal creaks, within the low lands of East Godavari District need to be noted. Such inter-linked drainage systems have alleviated the impacts of storms by receiving, accommodating and returning surge waters back into the sea" (Antonio Mascarenhas, 'Oceanographic validity of buffer zones for the east cost of India: A hydro-meteorological perspective,' Current Science, Vol. 86, 3, 10 February, 2004). On 26.12.2004 and also the succeeding days, it was reported that the River Cooum in Chennai accommodated the excess water from Marine incursions caused by the tsunami. By the same scientific evidence, the SSCP should prove to be a boon in the event of surges caused by severe cyclone and tsunami. The observation made by Rajamanickam (see para 9) that SSCP is urgently needed to provide a draining canal for Palk Bay is also relevant in this context.



PMO Note

14. Finally, specific dump sites for dredged materials have been identified only for 8.5 to 9.5 per cent of the total dredged spoil. The exact dumping sites for 90.5 to 91.5 percent of the dredged material are not known. Similarly, information about the nature of the dredged spoil is also lacking. This information is available only for about 38.5 -10.6 per cent of the total dredged spoil.

Tuticorin Port Trust Observations

Specific dumping sites have been identified and delineated in NEERI's EIA Report in Bay of Bengal, and in the Gulf of Mannar, for dumping of dredged materials from Palk strait and Adam's Bridge respectively, contrary to what is stated in the paragraph. NEERI had also conducted modelling studies for predicting dispersal of deposited materials in the Gulf of Mannar. Tuticorin Port Trust has conducted further studies which have not only validated NEERI's proposals, but also suggested possible relocation of the dumping site in Gulf of Mannar nearer the dredging location, which has not been accepted by Tuticorin Port Trust in view of ecological sensitivity of the region. The option of reclamation of about 750 ha. of land in Dhanuskhodi island, lost during the 1964 cyclone, at an additional cost of Rs.100 cr. app. is retained. The paragraph alludes to the estimated quantity of about 7 million.m3 required for reclamation of this area only, when it states that specific dump sites have been identified only for 8.5 to 9.5 % of the total dredged spoil

Information about the nature of the dredged spoil has been furnished in NEERI's Report both for Adam's Bridge area and Palk Strait. Data from earlier reports, sub-bottom profiling and borehole data generated by NEERI etc. provided the basis of such information Tuticorin Port Trust has carried out, through the NIOT, more detailed and sophisticated sub-bottom profiling of the project area, vibro-coring in 44 locations and boreholes to further refine the project proposal.


PMO Note

15. Thus, there are huge gaps in the current status of knowledge about the sedimentation regimes existing in the various micro regions of Palk Bay. Knowledge about the effects of tsunamis and cyclones on the dredged material and on the SSCP is also incomplete. The Environmental Impact Assessment and the Technical Feasibility Report prepared by NEERI have ignored these aspects. Yet, the SSCP authority has applied for a no objection certificate from the Ministry of Environment & Forest and the Tamil Nadu Pollution Control Board.

Tuticorin Port Trust Observations

(i) Sedimentation regime in Palk Bay/Palk Strait has been studied through field studies and modelling studies as adequate and relevant for the project setting and for reliable estimation of maintenance dredging requirements.

(ii) Tsunami and tropical cyclones impact the coast through changes induced by them in wave regime, currents and winds. Modelling studies have produced more than adequate data to examine the impact of extreme conditions on the project, especially on the stability of the channel, net sedimentation, navigability and downtime etc.

(iii) All necessary studies as per international requirements have been carried out by the project authorities to ascertain the environmental viability and technical feasibility of the project.




PMO Note

16. Going ahead with the construction of this mega project without collecting information on the above aspects could lead to major economic, technical and human problems in future that could border on a disaster. It is, therefore, advisable that he project authority for the SSCP should first look into these specific aspects and give their detailed comments thereon. If the project authority feels that these aspects have been adequately taken care of, they should provide convincing and substantial evidence to that effect that will withstand the scrutiny of the scientific community at large.




Tuticorin Port Trust Observations

(i) Sedimentation regime in Palk Bay/Palk Strait has been studied through field studies and modelling studies as adequate and relevant for the project setting and for reliable estimation of maintenance dredging requirements.

(ii) Tsunami and tropical cyclones impact the coast through changes induced by them in wave regime, currents and winds. Modelling studies have produced more than adequate data to examine the impact of extreme conditions on the project, especially on the stability of the channel, net sedimentation, navigability and downtime etc.

(iii) All necessary studies as per international requirements have been carried out by the project authorities to ascertain the environmental viability and technical feasibility of the project.


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