The massive Nepal earthquake of 7.9 intensity (Richter scale) on April 25, 2015 with epicenter 77 km north-west of Kathmandu in Nepal is a major noteworthy event in the Himalayas which also has warnings for what is in store for future. The earthquake left a major trail of destruction affecting over 20 districts of Nepal, of which 8 million live in 11 severely affected districts. Besides, it affected areas of India (Bihar, UP, W Bengal, Sikkim, Assam), Bangladesh, Tibet. The earthquake has now been given the official name of Gorkha Earthquake.
The intensity of this earthquake is generally comparable with the 2005 earthquake in Kashmir which killed over 86,000 in Pakistan and India. This is the largest earthquake in Nepal since the Bihar-Nepal earthquake of 1934. The 1934 earthquake was 8.3 magnitude and centered near Mount Everest, more than 10,000 people were killed.
India Meteorology Department, provides a list of 85 aftershocks till May 4, 2015 after the earthquake of April 25, 2015. The list is given in Annexure 1.
Impacts in Nepal
- According to Nepal Government, 7557 people have died, 14536 are injured, 10718 government buildings are totally destroyed and 14741 government buildings are partially affected. 191058 private buildings are destroyed and 175162 are damaged. Total affected population is 2 649 4504. The figures continue to rise.
- Kathmandu valley a meter up at the cost of Mount Everest! According to scientists from the European Space Agency, post earthquake, the Kathmandu Valley area of about 120 km by 50 km has risen by up to a meter. A 24 hour GPS survey confirmed that indeed the valley altitude is up 80 cm from 1338 m to 1338.8 m after the earthquake (Kathmandu is now 80cm taller The Times of India, May 7, 2015). The Mount Everest has sunk by one inch and areas north have settled below their original height probably because the land below loosened up, as built up strain was released. That possibly triggered the base camp avalanche that killed 22 people.
- The Hindu reported that the Kathmandu valley is more vulnerable to damage as underneath the valley is a 300 m deep layer of black clay, the remnants of a prehistoric lake, which amplifies the damage caused by severe earthquakes.
- Prof Michael P Searle (Oxford University) said in an interview in The Hindu (May 7, 2015 title: “South Asia suffers more during quakes due to poor infrastructure) that during the quake, the fault appears to have ruptured eastwards for nearly 120 km. The damage was worse in the region in the regions of the quake, in the Gorkha-Lamjung region, the Burhi Gandaki valley and Ganesh Himal. Kathmandu was badly hit because it is built on old lake sediments that are highly susceptible to shaking. As the Himalayas rise, the rivers will cut back by headwall erosion. Some large rivers like Arun (a tributary of Kosi) have cut a long way north beyond the main Himalayan axis. But course of the rivers take longer to change and is not immediately visible. The active thrust fault dips about 5-10 degrees to the north of the Himalayan front. The earthquake depth, about 15 km below the Gorkha region was on this rupture. The maximum amount of slip along the fault that ruptured may have been 4-5 m but the fault did not break to the surface.
A peculiarity of this Nepal Earthquake is that almost all the aftershocks and most of the damage has been caused in areas to the EAST of the epicenter of the earthquake, very little to the west. I have been wondering how can this be explained and asking a number of persons, but have yet to find a satisfactory reply. As noted by David Petley in his blog on April 26, 2015, “In the case of the Nepal Earthquake the rupture appears to have propagated mostly towards the east of the epicentre, not to the west. So the epicentre itself is at the west end of the earthquake affected zone. This is clear from the USGS shakemap.”
Noteworthy positives The earthquake response has thrown up some positives too. The effort of the common people in the immediate impact zone has been praiseworthy at many places. The prompt response of Indian government, including air-force, NDRF and others has been acknowledged by the Nepal government. Indian state governments have also been providing useful help to the affected people and others. Indian and international media have been trying their best to give a true picture of the situation.
THE QUAKE EXPOSED MANY FAILURES In the aftermath of the earthquake, a number of failures of India’s response system were exposed.
- Dysfunctional NDMA The National Disaster Management Authority has been dysfunctional for many months, since all the members (except one) of the NDMA resigned in June 2014 after Modi government took over. It was only in January 2015 that three of the eight new members were appointed. In the meantime, the annual drill of the disaster management this year was cancelled. This does not sound great for India’s premier disaster management institute. A former member of the NDMA and senior official of NDRF confirmed this situation to this author.
- Quake Monitoring Network in Coma: The Hindustan Times reported, “The country’s network of “ground-motion” detectors, the backbone of quake monitoring, has not been working for nearly eight months now due to a bureaucratic bottleneck, putting millions of lives at risk.” Ground or strong-motion detectors — also called accelerographs — are critical as they serve as the basis for India’s earthquake early-warning system, but they were found to be lying idle in the aftermath of the Nepal India’s network of 300 strong-motion sensors, installed at critical points across 14 states, cover high-risk seismic zones V and IV as well as some heavily populated cities in zone III. These imported devices, which measure movement generated during a quake and also help identify areas that could be vulnerable, cost Rs 10 crore to install and about Rs 1 crore a year to maintain. In Sept 2014, the government moved the project out of IIT-Roorkee after it decided to carve out a separate seismological organisation from the India meteorological department. Funding was cut off in September 2014, without an alternative arrangement in place. When this author asked very senior official of government of India about this, he confirmed that yes, there has been problem in transition to Geological Society of India, but hoped that the instruments were recording the readings and that the readings in any case will be useful at a latter date.
- India has fewer GPS stations than Nepal The Indian Express reported that Nepal has a network of 300-400 GPS instruments spread over the entire fault line, while India does not have more than 25-30 that are permanently deployed. These instruments help monitor the tectonic movements. A top earthquake expert, Roger Bilham of Colorado University (US) said that Nepal in fact is better prepared than India to withstand strong earthquakes since it has started taking remedial measures several years back.
- Lack of actionable landslide maps during disaster While our government and various agencies talk about this prowess of Remote Sensing images providing information, what was required in the immediate aftermath of the earthquake was quick information from this source about the possible sites where earthquake had led to landslides so that rescue and relief action can be taken up. This was particularly important when communication and transport was completely disrupted in the remote areas. However, we did not see any useful actionable inputs in this regard from India’s (or for that matter from other countries) remote sensing agencies.
- No Post Disaster reporting One of the key way to learn lessons for future from disasters is to have comprehensive reporting about what happened at the disaster and who played what role. Unfortunately we have no such comprehensive report about even the Uttarakhand disaster of June 2013 that killed between 6500 and 30 000 people as per different estimates. NDRF director General and a former member of NDMA who were with me at a Lok Sabha TV discussion after the April 25 earthquake agreed we need such reports
It is good to see that Union Ministry of Earth Sciences have decided to put in place a topological model for India to understand earthquakes better . The government is also going to set up 10 seismic stations each in Nepal and Myanmar. Dr Shailesh Nayak, Secretary, Union Ministry of Earth Sciences hopes that this will help understand physics of earthquake, first step in move towards predicting earthquakes. There are over 66 active faults in India, the Himalayan belt is dissected by 15 major active faults. India currently has 84 seismic stations, and has placed orders to increase this number to 130.
DAMAGED HYDROPOWER PROJECTS Experts have been warning about the danger of building large dams in the seismically unstable Himalayas, where the collapse of large infrastructure can magnify devastation in mountains. Such role of the projects in Uttarakhand flood disaster in June 2013 was confirmed by the Expert Body (chaired by Dr Ravi Chopra) appointed by the Union Ministry of Environment and Forests (MoEF) following the Supreme Court order of Aug 2013 and also as per the affidavit of the MoEF in the Supreme Court in December 2014.
Deaths, damages at Rasuwagadi HEP The huge earthquake caused serious damage to the 111 MW Rasuwagadhi Hydropower station, which a Chinese company started to build two years ago, 67 kilometers west of the quake’s epicenter in Rasuwa district of Central Development Region. The China Three Gorges Company & media reported that two Chinese & four Nepalese workers were killed in the quake and several were seriously injured. On April 28, a child and 24 other people were airlifted by helicopter to nearby Jilung County in China’s Tibet Autonomous Region, according to the quake relief headquarters in Jilung. The dam itself has suffered serious damages. The Rasuwagadhi Dam was being built on the upper Trishuli River in a very remote corner of Nepal near the Tibetan border. The dam’s reservoir is to stretch back 25 km, holding back 1500 million cubic metres of water (these figures are The Ecologist article by Michael Buckley, if anyone has contrary figures, pl let us know with reference). Writer Michael Buckley asks in his article in The Ecologist: “Rasuwagadhi Dam was described as severely damaged by the quake. And that brings up a nightmare scenario. What if that dam were up and running, with a huge reservoir sitting behind it? … It would be a Fukushima moment – earthquake followed by tsunami.”
Workers stuck at Upper Tamakoshi HEP In a news report that appeared eight days after the earthquake, Ganesh Neupane, chief of the environment division of the Upper Tamakoshi Hydropower Company Limited, said some 200 Chinese technicians and engineers as well as 70 Nepalese workers are stranded in the powerhouse station at the hydropower project site after a massive landslide caused by the earthquake blocked the 11-kilometer-long Lamabagar-Gongar stretch of the road connecting the region. The 456 MW Project of Nepal Electricity Authority is located at Lamabagar VDC, Dolakha District, Janakpur Zone, Central Development Region. The workers are stuck but safe at the Upper Tamakoshi hydropower project in Lamabagar Area in Dolakha district, where reports suggest that more than 90 per cent of houses in rural areas have been destroyed. The stranded workers are from China’s Sinohydro Corporation Limited, the contractor of civil construction work for the Upper Tamakoshi Hydropower Company Limited in charge of the project.
Kulekheni Dam Our colleague Ratan Bhandari reported on May 4, 2015 that Nepal’s only storage dam, the Kulekhani Reservoir dam has cracked by the earthquake. According to Nagarik daily (Nepali) the water level in the 114 m high Kulekhani dam is being reduced by three meters. Nepal Electricity Authority is doing micro study of the dam. According to the senior officer of NEA, the dam is cracked in various part from north to south.
Other affected hydro projects As per latest news in Nepal media, the earthquake of April 25 and series of aftershocks have damaged around 14 hydropower plants across the country, resulting to loss of 150 MW of electricity, see the details below. The total capacity of the 16 projects listed below comes to 280.1 MW. Some of the projects are in operation, in case of some others, full information is not available.
Hydropower Projects of Independent Power Producers damaged by the earthquake
|Upper Bhotekoshi||45||Penstock burst due to rock fall from nearby cliff; power house & generators submerged due to penstock burst; rock slide continues, no access to project; pylons washed by landslide in August 2014 & project was shut down for 5 months then.|
|Sunkoshi Khola||2.5||PH wall has fallen inside PH room, landslide at penstock alignment and landslide at headwork areas, no access to project|
|Indrawati III||7.5||Significant damage; in operation|
|Chaku Khola||3||Not in operation; details not known|
|Baramchi Khola||4.2||Penstock pipe burst; no access to power plant but in operation|
|Middle Chaku||1.8||Not in operation, no details, no access|
|Sipring Khola||9.65||Ext joint burst, landslide at penstock alignment, not in operation|
|Ankhu Khola I||8.4||Substation, PH fully damaged by landslide; 11 poles damaged; not in operation|
|Mailung Khola||5||Significant damage in headworks, penstock pipe & PH; not in operation, no access|
|Bhairab Kunda||3||Tunnel leakage, penstock burst; switchyard & Tr lines damaged; PH safe; not in op|
Total: 90.05 MW
Hydropower Nepal Electricity Authority damaged by the earthquake
|Trishuli||24||Cracks in the crest in the balancing pond; colony damaged; Not in operation|
|Devighat||14||A cascade project with Trishuli; cannot operate until Trishuli resumes|
|Sunkoshi||10.05||Severe multiple leakages in a stretch of 200 m of the 3 km canal; repair of damages due to Aug 2014 landslide incomplete; again damaged, staff staying in tents; not in operation|
|Kulekhani||60||Cracks in the crest of the dams, but in operation; the cracks are above the current water level; it might create problem when the water level goes up during monsoon|
|Chilime||22||Damage in Tr line|
|Upper Trishuli 3A (under construction)||60||Severe damage in the construction works after landslides from both sides not only killed four employees but also buried heavy equipment; damage in the audit tunnels and a suspension bridge; 3 km access road washed away by landslides|
Total: 190.05 MW
Grand Total: 280.1 MW
The condition of two more existing hydropower stations is not known, said Nepal authorities. Hydroworld, an industry trade magazine, reported that the 144-megawatt Kaligandaki hydroelectric power station and 22.1-megawatt Chilime hydropower plant “may have been affected according to news reports from the area.” Kaligandaki on the Gandaki River is about 187 miles west of Kathmandu near Mirmi in the district of Syangja District. Chilime Project on the Bhotekoshi river is in the district of Rasuwa, which is 83 miles north of Kathmandu. In Aug 2014, Nepal’s deadliest landslide in a decade caused destruction that knocked out 10% of its power generation capacity.
LANDSLIDES On the day of the earthquake on April 25, 2015, Earthquake Without Frontiers warned about the possibility of landslides compounding the dangers from the earthquake: “The Mw 7.9 Nepal earthquake on 25 April 2015 appears to have occurred on a shallowly north-dipping thrust fault beneath the Himalayas of central Nepal. The steep topography and high relief in the area of the epicentre, and the high intensity of shaking that was felt, mean that thousands of landslides are likely to have been triggered by the earthquake. Based on past experience of earthquakes in steep mountainous terrain, like the 2005 Kashmir and 2008 Wenchuan earthquakes, some of these landslides will be large enough to create temporary dams across rivers in the area. The lakes created by these dams are particularly hazardous because they can drain without warning, usually within a few days of filling up, due to collapse of the unstable dam material.” Mapping the landslides will require satellite imagery taken after the earthquake, but unfortunately there are not sufficient inputs available in this respect, including from India’s National Remote Sensing Centre, which can be useful in time for rescue and emergency relief action.
A preliminary map of landslide locations given below is taken from Earthquake Without Frontiers, from an article published on May 5, 2015, with title Nepal earthquake: update on landslide hazard. In Annexure 2 we have listed List of confirmed or potential valley-blocking landslides, sourced from this article. Some key messages of this article are (all observations based on available cloud free satellite imagery):
- “Major or disruptive landsliding is limited to a zone that runs east-west, approx. parallel to the transition between the Lesser and High Himalaya. This zone includes parts of the districts of Gorkha, Dhading, Nuwakot, Rasuwa, Sindhupalchok, Dolakha, Ramechhap, and Khavre.
- We observe several large valley-blocking landslides. Most observed landslides comprise comparatively small rockfalls and debris avalanches that have a significant local impact and loss of life.
- The need to plan measures to mitigate landslide deaths and disruption in the forthcoming monsoon season must remain a priority. Many more damaging landslides may occur in the 2015 monsoon, likely to start in late June, than would be expected if a major earthquake had not occurred.
- We have identified several large valley-blocking landslides (landslide dams) on the basis of satellite imagery. We stress that further valley-blocking landslides may still be found as additional imagery becomes available”
In absence of remote sensing images, EWF has prepared susceptibility maps, (The first map was produced by Dr Tom Robinson of the University of Canterbury, New Zealand): “Susceptibility in these models is determined by the intensity of the shaking (derived from the USGS ShakeMap estimates, http://earthquake.usgs.gov/earthquakes/eventpage/us20002926#impact_shakemap), the steepness of the topography, the position of a given location on a hillside (because shaking tends to be greater at the tops of ridges than in neighbouring valleys), and the aspect (the direction in which the hillside faces).” The model gives some ominous indications: “The map shows that high landslide susceptibility values – and thus the greatest chance of landsliding – occur in the high Himalayas to the north of the epicentre and Kathmandu. This includes the major river valleys of central Nepal, including the Kali Gandaki, Marsyandi, and Trisuli Rivers, as well as parts of the Sun Kosi River catchment. These areas also have high relief between valley floors and ridge crests, meaning that landslides there are potentially large enough to block the valleys.” David Petley wrote in his first blog on this event on the day of the earthquake: “Kathmandu in particular is vulnerable, with poor quality buildings and soils that are prone to liquefaction,”
The EWF also provides some explanation for the major damages in Kathmandu valley: “Kathmandu itself seems to have experienced much greater intensities of VIII or IX – probably because seismic waves were amplified by the soft sediment fill within the valley.”
Narrating the possibilities of landslides post earthquake, Petley writes, “The most seriously affected area from the earthquake is mountainous and remote, but there are substantial numbers of people living in the valleys and on the hillsides… This is highly landslide-prone territory, and the impact of the earthquake in these regions is going to be dreadful. Some effort is already being made to analyse the likely landslide effects, although at this stage such efforts are tentative… the analysis is really interesting and helpful. It shows that to the north of Kathmandu, the very remote areas are likely to have been severely affected by landslides – but as yet there is no information from up there of course. And interestingly the hills to the south of Kathmandu are also badly impacted by landslides triggered by the Nepal earthquake – indeed the landslide picture might be as bad there as to the north. This is significant for two reasons – first, there are lots of people living in this area; and second, the roads that link Kathmandu to the outside world have to cross these hills… The monsoon is going to be a real problem this year.”
Langtang: “possibly the greatest single landslide tragedy of the earthquake”: As per David Petley blog on May 2, 2015 and other sources, there may have been two large rock/ice avalanches, one affecting Langtang and the other, a few days later, destroying Ghotabela in the immediate lower level below Langtang. It is feared that some 300 people may have been buried in Langtang landslide in Rasuwa district in Trishuli river valley. According to Mountain Hydrology, “Langtang village was located below a very steep ridge and above the ridge there is a glacier towards the north-west and large snow field right above the village. There has been a lot of snow fall this year and at the moment of the earthquake there were considerable amounts of snow at higher altitudes. From a preliminary investigation we think it is most likely that either a snow avalanche from directly north of Langtang village or a debris/ice avalanche from the north-west has caused this disaster.”
Petley wrote: “It is hard to believe that these will be many survivors from this. It appears that this may have been a rock/ice avalanche, but information is still scarce.” In his earlier blog on April 29, 2015 on Nepal Earthquake, Petley described this disaster, quoting eye witness account of Robbie Barnett from Austin Lord, posted on the Modern Tibet Facebook page as: “the site of the largest single catastrophe, as the entirety of village was completely buried by an avalanche that came from thousands of feet above on the southern slopes of Langtang Lirung and Langtang II. Smaller settlements on the outskirts of Langtang, such as Chyamki, Thangsyap, and Mundu were also buried. It is impossible to determine exactly how many people died there, but the estimate is perhaps over 300 people in total. The handful of survivors, roughly twelve locals and two foreigners, walked down to Ghodatabela below after spending the night of the 25th in a cave – thus there is no one at Langtang itself. This avalanche is perhaps 2-3 kilometers wide… Langtang is probably one of the greatest single tragedies of this earthquake.”
For a BBC video of the Langtang landslide, see: https://www.youtube.com/watch?v=9BEDRlFImD8 and for more information on this, see the David Petley blog on May 5, 2015: http://blogs.agu.org/landslideblog/2015/05/05/the-langtang-ice-and-rock-avalanche-in-the-gorkha-earthquake/.
Ghodatabela According to David Petley blog, not far from the quake’s epicenter, 250 people were feared missing after a mudslide and avalanche on Tuesday, April 28, 2015 at Ghodatabela village. Heavy snow had been falling near the village Ghodatabela, and the ground may have been loosened by the quake.
Tatopani stretch of Arniko Highway Kantipur has reported massive landslide along the Tatopani stretch of the Arniko Highway connecting Kathmandu to Tibet caused by Sunday’s aftershock measuring 6.9 on the Richter scale: “It is suspected that scores of people, including some foreigners, visiting Tatopani and around 25 vehicles were buried in landslides triggered by Saturday’s massive earthquake. According to witnesses, scores of people were buried at Miteripul, Chaku, Jhyalebhir, Nayapur, Daklang Paharo and Jhirpu. “Ten to fifteen people working at caterings and restaurants in Khasa were buried by landslide at Chaku,” said Shyam Shrestha, who witnessed the tragedy. Some buses, private vehicles and motorcycles were also buried in the area.” Sixteen dead-bodies have been recovered so far.
Lapark village, Gorkha district Bill Haneberg said about the possibility of landlide at this village in a comment on David Petley blog on April 28, 2015: “Laprak, a village of about 2000 people located 12 km north of the epicenter, is on a landslide that has been moving episodically during wet periods since it was reactivated in 1999 (http://eeg.geoscienceworld.org/content/17/1/23.abstract). Early reports and aerial photos suggest almost complete destruction, but it is unclear if it was a result of shaking, sliding, or some combination of the two.” There is no information about the situation at this village, though.
Other landslides These are just some landslides on which information is available. There are possibilities of many more now and more likely in coming monsoon months. ICIMOD has provides some indications & maps of river blocking landslides like: Site of potential landslide blocking a stream in Ward No. 5, Samagaun VDC, Gorkha district of Nepal, Avalanche blocking upper reaches of Budi Gandaki in Ward No. 5 and 8 of Samagaun VDC, Gorkha district, among others. Indian Express reported that on April 28 afternoon, six persons were killed and 10 injured when a landslide buried a bus between Mungling and Narayanghat.
BIGGER HIMALYAN EARTHQUAKES ARE DUE
The BIG ONE is still to come Even as the April 25 Earthquake was the biggest to hit the central Himalayan region since 1934, scientists say this was not the big one that they had been fearing would strike the area. In the Himalayan region the Indian plate is known to be pushing north and northwestwards, getting below the Eurasian plate, which is the reason for most earthquakes in the area. “We know there is a huge amount of accumulated strain in this area. It is due for a major earthquake, perhaps a series of earthquakes, bigger than 8 on the Richter scale. That is the kind of energy that is estimated to be accumulated there. This was certainly not one of those earthquakes that is probably imminent. In terms of energy release, I would say this would not have released even four or five per cent of the energy that is estimated to be stored there,” said Harsh K Gupta, former director of the Hyderabad-based National Geophysical Research Institute and a former member of the National Disaster Management Authority.
Prof Sankar Kumar Nath of IIT Kharagpur said, “This earthquake would only be classified as medium in terms of energy released. The 2500-km stretch from the Hindukush region to the end of Arunachal Pradesh, is capable of generating much bigger earthquakes, even nine on Richter scale. The trouble is that in terms of energy release, which is what causes the damage, it would take 40 to 50 earthquakes of magnitude 7.9 to avoid an earthquake of magnitude 9”. Since they cannot be predicted or prevented, an expert said, the key to avoiding large-scale devastation from earthquakes is, therefore, precaution and planning. 
Let us divide the Himalayans into four segments and try to understand the quake history and see future vulnerabilities. The whole of the Himalayas is prone to earthquake of 8 or above as is clear from the history, see below.
Western Himalaya In this region broadly from Kashmir to Yamunotri, several major quakes have happened. The 2005 quake of 7.6 magnitude in PoK and India killed 86000 people. Earlier the Kangra earthquake of 1905 (8.0) killed 19000 people. Some geologists believe that this region is prone to much higher magnitude quakes.
West Central Himalaya In this region between Yamunotri to Pokhara, some of the major recent earthquakes have been Uttarakashi (1991 – 6.6) and Chamoli (1999 – 6.8) earthquakes. However, seismologists have been warning that this region can experience a major earthquake of above 8 intensity anytime.
East Central Himalaya In this region between Pokhara and Sikkim, after the 1934 earthquake of 8.3 that killed estimated 10700 people, the April 25 2015 earthquake of 7.9 is of comparable magnitude.
North East India In terms of magnitude, North East Region is vulnerable to highest magnitude earthquake since India’s biggest earthquakes in past have happened here in Shillong (1897 of 8.7 intensity, the highest recorded in the region) and Arunachal – China Border (1950 – 8.5), both 8.5 or above. The latest earthquake to affect NorthEast India happened in Sikkim in Sept 2011, but that had magnitude 6.9, so it is not likely to have released much of the North East’s underground stress. As Sanjoy Hazarika wrote in Indian Express, every city in the North East India, from Aizwal to Agartala, from Gangtok to Guwahati, from Itanagar to Imphal, from Shillong to Silchar is prone to huge damages in the event of a big quake that is due here. To illustrate, as per an assessment by GeoHazards International of California in Mizoram made public only in April 2015, in the event of a magnitude 7 quake, the damage would include: collapse of 13000 buildings, 1000 landslides, 25000 fatalities and major damage to utilities and infrastructure. In this region, not only the government doing nothing to address these hazards, they are increasing by imposing massive agenda of large dams and hydropower projects on the region without doing any credible impact assessment or participatory process. He says there is “the conviction among governments and corporates that development means “big”. Thus, huge dams have come up on the Teesta in West Bengal, reducing the roaring river of literature and history to a placid, sickly pond. How safe are these dams in terms of quakes and cloudbursts? Could an independent audit be essayed after the recent disaster in Nepal?” We hope the government will respond to these questions rather than going for more projects.
Dams are unsafe in earthquake prone regions It is clear from above how the hydropower projects were damaged during the earthquake and they in turn can be cause for deaths and damages. Post earthquake, hydro industry website noted that the future of Nepal’s hydropower development will inevitably now demand significantly greater attention to structural integrity in the face of seismic events. As Martin Wieland, Chairman of the ICOLD Committee on Seismic Aspects of Dam Design, concluded in his 2012 paper that dams are not inherently safe against earthquakes.
The Zipingpu Dam in Sichuan Province in China has been implicated in the disastrous quake of 2008 that killed over 85,000 people and left millions homeless: the dam was just 4 miles from the epi-centre of the 7.9-magnitude quake. The quake cracked Zipingpu Dam and caused damage to 60 other smaller dams in the region. Dam personnel and miliary rushed to empty water from scores of dam reservoirs, causing considerable flooding downstream.
CASCADING DISASTERS Japan is known to have gained expertise in dealing with earthquakes. However, what happened in that country on March 11, 2011, started with a magnitude 9.0 earthquake, compounded first by Tsunami and than by melting of three nuclear reactions, the after effects of that disaster are still being experienced not only by Japan, but even by the nuclear industry across the world. This was a case of cascading disasters.
India is prone to such cascading disasters in several ways. Nepal experienced some such events after the April 25 earthquake. One instance of this was the landslides that killed large number of people, these landslides were second order disaster after the earthquake. Another such instance would be if a major dam or hydropower project, while still full of water, were to get damaged after the earthquake or a landslide. David Petley and EWF have indicated a third possibility when a landslide post earthquake were to create a dam on river, which would than be a bomb for the downstream areas when it inevitably bursts.
Geologists and environmentalists have said if a Nepal-like earthquake strikes any of the Himalayan states including North East India and Bhutan, there will be a large scale destruction and death owing to compounding of disasters due to hydropower projects. Dr SP Sati from the department of Geology, HNB Garhwal University, Srinagar, said about Uttarakhand hydro, “Barring Tehri Dam, which is rock and mud-filled structure, most of the hydropower dams in Uttarakhand are made up of reinforced concrete cement. The ability of these dams to withstand high-intensity tremors is highly questionable. They could collapse and lead to a large scale death and destruction downstream.” Tehri dam is also yet to be tested, considering the large number of landslides that have already occurred in its catchments.
Climate Change compounds the problem The possibility of compounding or cascading disasters is further compounded by two additional reasons. First is the climate change. As it was apparent in Uttarakhand flood disaster of June 2013, while the unseasonal rainfall was the primary reason, the Kedarnath shrine and downstream Mandakini & Alaknanda & Ganga River faced bigger floods due to the glacier lake outburst flood. The third compounding factor in that case was the massive silt dumped on the riverbed by the under construction hydropower projects.
This factor of under construction and operating hydropower projects adding several layers (e.g. deforestation, blasting, tunneling, minding, muck dumping, damming, to name only a few) to the cascade of disasters is something that is not even acknowledged, leave aside assessed or factored in decision making process.
In conclusion It is high time we wake up to these clear dangers staring at us. However, the Union Ministry of Environment & Forests (MoEF) is busy diluting environmental governance in India. Just a day before the April 25 earthquake, the Expert Appraisal Committee on River Valley Projects was sitting to consider the massive 6000 MW Pancheshwar Dam on Mahakali river on Nepal-Uttarakhand border. SANDRP, MATU, Toxics Alliance, Himal Prakriti, Dr Bharat Jhunjhunwala and a number of other groups & individuals have written to the EAC why this project should not be given even first stage (Terms of Reference) clearance. But the way Indian Prime Minister Mr Narendra Modi and Nepal Government signed the agreement when Indian PM visited Nepal last year, it seems difficult to believe that wiser counsel will prevail. In fact current government is pushing more hydropower projects in Uttarakhand, some like massive Lakhwar Dam on Yamuna without so much as Environment Impact Assessment and public consultations.
When I had an opportunity to meet a Union Government Secretary & past and current senior officials of the Disaster Management apparatus at the Doordarshan News program to discuss the aftermath of the Earthquake and I raised all these issues, they said yes, there are environment impact assessment that is supposed to look into such issues! Such faith in this EIAs that are proved to be such unreliable documents is touching! But the stakes here are so high, we need to react much more strongly.
Himanshu Thakkar SANDRP (email@example.com)
Post Script: As I finished writing this, I have been thinking of the earthquake victims, particularly those of the Nepal, praying for the survivors. Nepal society and economy will take long to recover, but one hopes they are able to recover as soon as possible. The apprehensions that are expressions here are for future, so that we learn right lessons to reduce the damage in future (there is obviously very little chance of a major earthquake in the same region soon). Nepal economy’s mainstay, tourism, agriculture, horticulture can recover pretty rapidly with right help. Let us all pray they achieve such recovery.
RELIMINARY LOCATIONS OF EARTHQUAKES
DURING THE APRIL 25 – MAY 4, 2015 NEPAL
|25/04/2015||09:17:01||28.3°N||87.3°E||05||5.8||CHINA – NEPAL BORDER REGION|
|27/04/2015||12:35:49||26.7°N||88.1°E||10||5.1||NEPAL – INDIA (W BENGAL)BORDER|
List of confirmed or potential valley-blocking landslides
- Therapati, in the south of the Langtang National Park, in the Melamchi catchment. There is no evidence of a lake forming, but the valley at this time of year does not appear to have an active channel. The valley drains into the Trisuli River. If this interpretation is correct, this blockage may be a concern during melt / rainfall.
- Satellite images suggest multiple large valley blocking landslides in the main stem of the Trisuli, between Resuo (Nepal) and north to Jilong Community (Tibet). Some of these have already been identified by ICIMOD. This area presents concern.
- Video footage from the Upper Bhote Koshi suggests several reaches of rivers with abnormal standing water, notably immediately south of Chaku – most probably from extensive rockslides which appear to have removed extensive sections of the Arniko Highway, making this impassable. Flow downstream from these sites continues, so these blockages are unlikely to be high risk.
- Satellite images and news reports describe large post-seismic landslides in the 20 km north of Chaku to the Tibet – Nepal border at Kodari. In addition, satellite imagery indicates extensive rockfalls and channelized failures on this stretch of road.
- Satellite images north of the Tibet – Nepal border at Nyalam show extensive areas of landsliding and avalanching. Rockslides have in places crossed the road and have reached the river, but none have generated lakes that are visible in the presently available imagery in the river network.
- Near Poki: a 1 km long rockslide (identified also by ICIMOD), appears to have blocked a valley, but has now been breached by the river. This area presents concern, but reports and imagery suggest that water is now flowing across this dam.
- Langtang: extensive landslides, rock avalanches and possible glacier snout collapses appear to have traversed the valley floor, and are likely to inhibit flow during melt.
 https://twitter.com/NEoCOfficial/status/595450804170985473, official status at 10 am on May 5, 2015
 Introduction from the blog itself: “Dave Petley is the Pro-Vice-Chancellor (Research and Enterprise) at the University of East Anglia in the United Kingdom. His blog provides a commentary on landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.”
 http://www.cctv-america.com/2015/05/02/chinese-workers-stranded-at-nepal-hydropower-station-return-home, http://www.thethirdpole.net/chinese-dam-workers-stranded-after-nepal-quake, http://www.theecologist.org/News/news_analysis/2855302/in_nepals_next_big_quake_hydropower_dams_threaten_catastrophe.html
 http://ewf.nerc.ac.uk/2015/04/25/nepal-earthquake-likely-areas-of-landsliding/, interesting to note that the Tata Institute of Social Sciences and Bihar State Disaster Management Authority are the two Indian partners listed on EWF website.
 For details about the earthquakes mentioned in this section, see: http://www.imd.gov.in/section/seismo/static/signif.pdf