Satellites Reveal Cause of Uttarakhand Flood That Devastated Hydroelectric Dams | Hacker News Reader

Satellites Reveal Cause of Uttarakhand Flood That Devastated Hydroelectric Dams

scientificamerican.com

150 pointsystad47 comments

> The disaster draws attention to the controversial hydropower projects

Why is this the subheading of the article? All the speculation regarding the actual flood is a glacier breaking away and falling 2km on valley floor triggering landslides and sudden water release. So, why choose to focus on something which many initially incorrectly identified as the reason for destruction.

I am not saying we should not focus on this and the highway construction happening there, as there actually are some valid concerns about them; but seems like a poor thing conflating these two.

Also, most of these new dams in the upper reaches are not the massive water holding barrages that cause ecological destruction. Most of them hold little or no water. They are constructed on the route of a river to funnel water through a tunnel to the turbines that is used to generate power.

Further in the article it explains that communities often form around the remote dams, bringing people closer to the rivers, and increasing the body count when something like this happens.

But that has nothing to do with the dam itself. That should be regulated by the state authorities. Living close to rivers in such fragile places is not a good idea.

Back in 2013, roughly the same place witnessed ~6000 deaths in floods. https://en.wikipedia.org/wiki/2013_North_India_floods

Based solely on my observations traveling in the area, the topography is so extreme (very steep cliffs not far from the river banks) that there is little option but to live near the river.

I'm sure there are more and less safe places on the river bank, but there aren't many places a safe distance from the river that aren't also thousands of feet up in elevation.

The biggest reason why most people prefer to live near the rivers in this region is water. A lot of the villages up in the mountains do not have running water and you have to hike a few kilometers down the valley to get water from hand-pumps and small streams. That was the case when I last visited my grandparent's village in Uttarakhand. Even my hometown which is one of the largest towns in the region has water problems. It gets worse the higher you go in the Himalayas.

Landslides are also a major factor as the mountains are extremely fragile. I've witnessed several such small landslides during my trips that often block the small mountain roads. They are very common.

There is pretty much no usable agricultural land and most villages rely on money from people working outside the region or small scale cattle domestication. Upper Himalayas is a rough terrain and so not many people live there. Living closer to the rivers is much better. Even better is living closer to the major roads that often are closer to the rivers.

Things are slowly and steadily improving these days. The regulations are also being more strictly enforced. Though I'm quite concerned that many similar disasters will happen in the future due to climate change. :/

The article makes the assertion that communities often form around remote dams, and perhaps this is true for dams in the desert or dams on the plains, but maps and photos of this region reveal that the rivers here are deeply incised among steep mountains, there's essentially no arable land, and villages have been clinging to cliffs just above the rivers for as long as humans have settled here. There's simply nowhere else for them to live, and they've lived there long before any dams.

The people who died in this disaster died because a surge of water and mud and debris rushed down the river valley from high up in the mountains. You can't arrest a debris flow [1], you either have to hope it doesn't happen, or engineer at great cost that it doesn't happen, or you pre-emptively relocate to a place where you won't be caught in it. These are hard choices, but the nature of the problem is simple, and traces back to topography..

[1] You can arrest a debris flow with a very large embankment of your own, preferably if there's no lake behind it; water is not compressible, so a debris flow into a reservoir will always risk overtopping the dam with a frighteningly large wave. But, putting dry dams in a narrow river valley is much more complex than dams behind which water can collect.

[1] is correct but the process drastically reduces the energy and peak flow rates. Assuming the dam survives it makes a large difference for people down stream.

Visually it’s hard to notice but even just 1 foot matters in a flood.

Big oil has been funding anti - nuclear and anti - hydro efforts for years.

The truth is that far more people die from pollution from fossil fuels than have ever died from nuclear or hydro.

That is rather self fulfilling, though. We produce and use significantly more fossil fuels than we have nuclear or hydro power.

If the whole world was run by hydro and nuclear, and fossil fuels were relegated to somewhere between non-existent or hyper-regulated, it wouldn't be a stretch to imagine the reverse as well.

It’s compared on a deaths per unit of energy produced basis. Kind of like how we compare stats per capita between countries of different sizes.

https://youtu.be/Jzfpyo-q-RM

Edit: Further reading if you prefer it to videos. https://sites.google.com/view/sources-nuclear-death-toll/

I believe those figures are per-capita as well.

> Big oil has been funding anti - nuclear and anti - hydro efforts for years.

You gotta stay updated with the latest current affairs. Big oil is no longer big. They have moved to electric and tourist

I spent 2 years on a motorbike all over Northern Vietnam / Cambodia / Laos. The number of hydro dams being built by these countries (and China) in the region along the Mekong is insane.

They already feel the effects from this... in the summer the rivers dry up to the point that you're driving a motorbike across dry lake beds and in the winter (aka: rainy season) there is massive landslides and the dams break and wash away villages.

From what I can tell, it is less about blaming the dam and more about the thirst for power and complete disregard for how we go about getting it. It is a complete eco disaster.

I've spent 12 months of last 10 years (~1 month/year) at same region, on motorbike, too. I could confirm your observations.

BTW, 95% of these dams are Chinese one and exports electricity to China, not to be used by locals. China build hospitals and some roads for this, which is good, but all these projects doesn't have any ecological expertise in it. And China DOESN'T CARE of course.

It is new colonialism, really.

> China build hospitals and some roads for this, which is good, but all these projects doesn't have any ecological expertise in it. And China DOESN'T CARE of course.

But isn't the honesty refreshing? They don't come with guns or bibles or any notion of superiority. Just preying on the weak willed. I call that good business.

You're getting downvoted, for good reason. You're wrong on at least one point. "Any notion of superiority".

One thing I witnessed first hand in Laos is that China is building a very long road south. As they come in and build dams and the roads, the construction workers also move their families into the region. They buy up land from locals and then they bring a whole new set of expectations, including driving prices up.

The notion of superiority is what is driving all of this. "We are better than you, we will build you a dam, buy up all your land, give you some of the electricity and take the rest for ourselves."

I don't give two left feet and a chicken for downvotes/upvotes. What matters is discussion. At least to me.

On the point of "notion of superiority" I will admit the phrasing is incorrect. Every group thinks they are better than those not in their group from your local book club to whole nation states.

Just a quick follow up... saw this article in the local VN paper today... it is a massive eco disaster.

https://tuoitrenews.vn/news/international/20210212/mekong-ri...

This is hardly above the nebulous drivel of the articles that popped up during the week of the flood, just dressed up with a professional veneer. It manages to sneak in a clickbait headline, and despite the promise, you don't get to find out the cause, just three contributing theories. Also, did you know dams are bad?

The terrain in these Himalayan states is rough. Steep river valleys, no flat land, and towns clinging to cliffsides. They're vulnerable to floods every day. If anything, dams alter the risk profile dramatically, increasing the impact of the rarest of floods but greatly reducing their frequency. And, they generate soot-free, low-carbon electricity from these rivers that are hardly ecological havens: they're the upper tributaries of some of the most polluted rivers on the planet.

Altering the natural environment is always a trade-off we should examine and justify. But in this instance, they add up. Without the dams, an identical flood would've resulted in at least as many casualties, and that will continue to be the case until you build even bigger dams whose reservoirs provide more cushion against freak floods, melt, and landslides, and/or until you banish people from their homes in towns that dot these deep gorges at a great socioeconomic cost.

The environmental risks are an inseparable part of the region. You can't wish the possibility of all landslides away, the glaciers can misbehave as long as they exist (and we want them to exist), and the topography and the settlement patterns will remain vulnerable to floods. Only abandonment, damming, or relocating the towns to flattened ridgelines stand a chance to improve outcomes for its people, and all of these come at high cost and involve major trade-offs.

> hardly ecological havens

Ecologically the harshest environments are also the most vulnerable to small changes. Plants and insects at the edges of survivability only need what we might consider a minor change to push them to extinction. Slow, low, small growth is often boring and ignored by us. Individual mountains often have unique ecologies and species because they are “islands”. And sometimes the harshest environments are the most biologically pristine because there are not many humans around (farming is probably our most ecologically destructive activity).

I don’t know anything particular about the Himalayas, but I am just asking you take care before jumping to conclusions.

I used to like reading newspapers from across the spectrum. They had information and facts leavened with reasoned opinions, balanced perspectives. Reading the news media these days is no different than reading some rando on Twitter. Tragic it has come to do this.

The NY Times had a truly abominable series of articles on these all focusing on the "negligence" of the current government on building dams. Take this one for dated 2/8: "Before Himalayan Flood, India Ignored Warnings of Development Risks" [1]

Somewhere at the end:

"Exactly what caused the latest flooding was not clear as of Monday night, with the Indian government saying a team of experts would visit the site to investigate. Ranjeet Rath, the head of India’s geological survey, said initial information suggested a “glacial calving at highest altitude.” Calving is the breaking of ice chunks from a glacier’s edge."

Dams had absolutely nothing to do with this tragedy. Some folks on Twitter are claiming that Dams might have reduced casualties downstream by modulating the flow but every single article seems to have an anti-dam agenda. I too hate the aesthetic of dams because they are monolithic and massive and alter the landscape. There is something primal within us which clamors for unaltered nature. I also don't like the eyesore of the gas-fired power plant a two miles away from where I live. But I don't try to warp every tragedy and lay it at the feet of the power plant to further my aesthetic biases.

[1] https://www.nytimes.com/2021/02/08/world/asia/india-flood-ig...

NYT might be a paragon of journalism for American issues but it is hardly a good source for news about countries like China or India.

I have been following their international coverage for some time and what they have mastered is the art of misleading through omission. Whether that is intended or just by virtue of hiring journalists and op-ed writers from the same echo chamber, that I don't know. It is smart in a way actually, as they rarely write outright lies. What they will do instead is just cover the points of one side, keep doing it through several articles and someone following NYT will have a very different idea of an event.

I am not sure how NYT is gauged inside China as I can't read their social media but I am surprised NYT is treated like sacrosanct by Indians with their critical articles of the establishment being widely shared there. Just look at the coverage of the farmer protests in NYT, Guardian etc.

So when these same platforms complain about Facebook eating their lunch and allowing fake news, I have no sympathy for them as their holier than thou attitude for their own content is just off putting.

I broadly agree with what you are saying. Most of the journalists covering India have an left-bias or are from the opposite ideological/religious spectrum. Modi has won the last two general elections with an overwhelming majority and regularly gets approval ratings highest of any world leader but NYT has not done a single positive article on him. Guess 1.3B Indians wrong and NYT right. If that is not blinkered colonialist superiority complex, I don't know what is.

You are getting downvoted by the wide HN audience, I guess the NYT has fans on HN ;)

I broadly agree with both of you on the nature of coverage in mainstream Western [1] generalist publications about topics on India and China (but also Southeast Asia and Africa, to a point). In my observation, a lot of the coverage on those parts of the world is hollow and lacks sophisticated contextualization along a variety of local and global concerns. If local concerns are noted, it's either an echo of popular Western concern, or some jarring evocation of culture shock and poverty porn.

Notable exceptions include the BBC, who take better care to explain local concerns in greater depth, although they do so in a characteristically terse style that doesn't play well among the New York Times or The Atlantic crowd.

[1] Western here is a byword for US, UK, CA, AU, NZ in the Anglosphere, but also some of the similarly leaning publications in Europe publishing in English.

The Feb 07 flood in India [1] was first thought to be a burst glacial lake but:

> Other reports have suggested that satellite images imply that a landslide may have triggered the events... In satellite images, a 0.5 mi (0.80 km) scar is visible on the slopes of the Nanda Ghunti, a peak on the southwestern rim of the Nanda Devi sanctuary, a wall of mountains surrounding the Nanda Devi massif.

[1] https://en.wikipedia.org/wiki/2021_Uttarakhand_flood#Cause

I was under the impression that while the exact time of a landslide is hard to predict, it is relatively easy to predict that an area of land might suffer landslides. (ie. by looking at the angle of every layer of rock and looking for any that are near their critical slippage angle)

Surely that is checked for all land surrounding any hydro project, and the land stabilized with piles or grout before the hydro project starts?

It appears that the side of a 6000m (20000 ft) mountain collapsed.

Clearly this has happened many times through the geological history of the Himalaya - which is arguably the most extreme and dynamic mountain range on the planet - but on human timescales this is an extreme outlier event, so very hard to plan for.

I live 50km away from this place. And people live near river because it's easier to take water from the river. Rivers are violent during the summer and monsoon season, other times they are furious but not that violent and you can easily throw a bucket and get the water you need.

Slowly borewell came and people started using that while still occasionally going to river when there's too much rush at borewell. Government didn't help to dig multiple ones but these days almost no one goes to river anymore - we get the water from a creek which is supplied to our home using pipelines and now electricity, cable TV, and internet is available even in the remotest village in Himalayas except a few ofc.

Why people are stuck living at such places? Mostly due to sense of community. My own grandparents got rich through trade in commodities which these land produced and were given opportunity to move elsewhere but the reason they didn't move is because they did not want to lose their village community.

These days it also has changed, now people don't really care about each other even in villages and most teenegers leave the village for studies and most of them never come back.

Since e-commerce websites and internet came to these villages, people have become more individualistic. Earlier you could have easily asked for monetary help from any member of village and they'd have given it to you easily but not now it seems everyone the community is lost even tho the standards of living are far better with supplied water, toilets in every home, government offering essentials to poor people in village.

Most people even stopped agriculture in Himalayas because labor is hard to find now. Most labor will go to plains where large continuous tracts of land provide better output and more wages/quality of life and mobility. As a result my grandparents 50 acres of land is now a waste. We grow nothing on them. Given it a few generations and these villages will no longer exist.

The buried lede: A landslide blocked a river and water backed up.

It's a generally poorly written article, with a lot of speculation and short on facts.

I particularly dislike the way it starts "Sunday, an flood..." Which Sunday? What date?

Scientific American went straight downhill in the last few years, particularly devoting itself a great deal to social issues that have nothing to do with it.

The moment I observe an article overzealously relying on direct quotes and anecdotes of everyone the 'reporter' was able to get their hands on, it's tab close time.

Like the news articles that have done nothing but gather random tweets from people? Journalism has become a joke of itself

If you are going to use quotation marks, it should be a direct quotation, not an ungrammatical paraphrase.

It's also talking about the most recent Sunday, so perfectly sensible, though I agree it is not the best form for the statement.

Maybe. The landslide is clear but the mechanism by which the landslide may have caused the flood is unclear. A team of geologists is hiking to the area to investigate more closely.

The real buried lede is that no one is sure of the actual cause.

Does anyone else find it strange that the headline focuses entirely on the damage to dams and not, say, the people or homes or communities destroyed?

But he also explains that the friction of an avalanche creates a lot of heat, which could have melted much of the ice tumbling down the mountainside.

Hm. It takes 334,000 J to melt a kilogram of ice. At least; that's just the energy to go from solid to water. It takes a vertical drop of about 35Km to get that much energy. Check me on this, please.

That's for ice at 0°C too. I make it a 34km drop for 1kg of ice to gain that much energy. Are we missing something?

I wonder if that author was misquoted. He has a PhD in glacier hydrology.[1] He has to know there just isn't enough potential energy in falling ice to melt it rapidly.

[1] https://udayton.edu/directory/artssciences/geology/haritashy...

Could well be. Maybe it's about it falling to lower altitudes with higher temperatures, and the friction of the avalanche warms it a bit and breaks it up so it can melt quickly in the warmer air.

At the Bondo landslide in Switzerland 2017 (https://www.bbc.com/news/world-europe-41036851), a lot of water came from glacier ice melted from tumbling down.

Not seeing that in the article. That looks like a combined avalanche and mudslide.

It's normal for sliding ice to melt under pressure at the surface, lubricating movement. That's how ice skating works.

this article is trash and does not reveal anything. it's as if two different people wrote the article and the headline.

I never forget 16 June 2013.

https://www.downtoearth.org.in/coverage/natural-disasters/he...

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