Bangladesh, the Poster Child

Thank you for this.
It seems obvious that deltas will always beat sea level. Otherwise they would not exist. You explain it with the degree of detail which is often missing.

Yes, people brainwashed by “rising ocean due to melting polar ice” tend to look over the ocean, forgetting that real danger comes at their back — rising rivers and lakes with more rains, more flash flood, as global cooling sets in. Thus, they are often caught unprepared.

Very interesting! Another lie bites the dust, or in this case the mud.
Questions for all the bright minds around here:
What is the mass of the Himalayas?
What is their average height?
How much energy did it take to lift them that high?
How long did that take at current tectonic energy levels?
What is the height loss due to erosion in that time? (16km thickness spread over the delta equates to what spread over the erosion area? And presumably in millions of years, huge volumes of sediment have been washed out to sea.)
The conventional ideas on mountain building see to me to be comparable to a car crash test film where instead of being slomo the film is time lapse. So when the car hits the wall, it stops. No crumpling because there is no kinetic energy to cause it. The same seems to go for mountain building taking millions of years. They would have eroded faster than they were being lifted, so they should not in fact be there. But they are. Does anyone have ideas for a believable mechanism?

Update to my last comment.
The link for The dynamic response of reef islands to sea-level rise has an error. Here are alternative links:
http://dx.doi.org/10.1016/j.gloplacha.2010.05.003
http://www.citeulike.org/user/kaiserm/article/7258183
http://www.sciencetimes.com.cn/upload/blog/file/2010/6/2010661255519341.pdf
http://www.nipccreport.org/articles/2010/aug/18aug2010a5.html

The misinformation from people like Al Gore and the lunatic fanatics from the UN
continues to make headlines.
They are recycling the already debunked scares and introducing new ones.
With the CO2 scare and and the peak oil scare in the background billions of dollars are wasted on useless alternative energy concepts and their latest plan now making headlines is their plan to feed 1 billion people with insects.
All in the name of the environment.
http://blog.foreignpolicy.com/posts/2010/08/06/un_policy_paper_encourages_farming_insects_for_food
This is becoming a very dark ideology and we better stop it before they make use of their recently acquired powers to control the Internet.

I guess the situation in New Orleans is similar, in that fixed concrete levees have prevented flooding for many years and hence the city has “sunk” relative to the local environment of the delta.
OT: I just heard a New York based economist on RT saying the climate change will no doubt this year increase the incidence of natural disasters such as earth quakes. And this was shortly after a general whinge about the ignorance found on many blogs. Makes you weep.

Hi there! Nice article!
I have earlier written the article “Bangladesh, how can we help”:
http://hidethedecline.eu/pages/posts/bangladesh-how-can-we-help-137.php
K.R. Frank

Patrick Davis says:
January 3, 2011 at 12:29 am
Interesting. However, I wonder how long it’ll be before alarmists and politcians attribute the flooding in Queensland, Australia to rising sea levels/rainfall as a result of man-made Co2 induced global warming?

They partly blamed the recent drought in Queensland on co2 warming:
http://www.climatechange.qld.gov.au/climatechange/climatechangeinqueensland.html
Now Queensland suffers biblical floods:
http://www.bbc.co.uk/news/world-asia-pacific-12102126
It’s all natural variability according to the findings of a team of CSIRO researchers led by Dr Wenju Cai.
http://carbon-based-ghg.blogspot.com/2010/11/southeast-queensland-drought-likely.html

B. Quartero writes well
————–
I think that your right the Bangladesh thing might be s little overblown. But I also get the idea that this a bit of a straw man.
B. does explain that the delta does respond to sea level rise.
AND
We expect that any appreciable sea level rise is not seen now or in the near future but will be seen on a 100 year time scale.
SO
Is the rate of sediment build up fast enough to compensate. It looks as if the delta will gain 100mm in sediment while losing 500-1000mm in depth. Looks kind of negative to me with the shore line moving inland.
Also if the weird weather we are having lately becomes permanent (a 20 year old prediction proving correct perhaps) it could get serious for Bangladesh. We know it suffers badly from storm surges.

LazyTeenager says:
January 3, 2011 at 6:02 am
Also if the weird weather we are having lately becomes permanent (a 20 year old prediction proving correct perhaps) it could get serious for Bangladesh. We know it suffers badly from storm surges.
It’s my view the world has always had what you call weird weather. It’s only now in the age of instant communication and 24 hour (bad better still disaster) news channels that we have become aware of it. Like everything like this sometimes there is more sometimes less. Previous generations relied on living memory. Even in the 70s and 80s nations like China and Russia were able to keep natural disasters secret. China only opening up in 2005
http://english.people.com.cn/200509/13/eng20050913_208168.html
Living memory is just that memory of the oldest person you know. For instance this is from the Anglo Saxon Chronicle:-
A.D. 1115. This year was the King Henry on the Nativity in
Normandy. And whilst he was there, he contrived that all the
head men in Normandy did homage and fealty to his son William,
whom he had by his queen. And after this, in the month of July,
he returned to this land. This year was the winter so severe,
with snow and with frost, that no man who was then living ever
remembered one more severe; in consequence of which there was
great destruction of cattle. During this year the Pope Paschalis
sent the pall into this land to Ralph, Archbishop of Canterbury;
and he received it with great worship at his archiepiscopal stall
in Canterbury. It was brought hither from Rome by Abbot Anselm,
who was the nephew of Archbishop Anselm, and the Abbot John of
Peterborough.
Now it is a racing certainty that there was equally bad snow prior to that just no one could remember it. So you look a bit further back in the Anglo Saxon chronicle and guess what
A.D. 1046. This year went Earl Sweyne into Wales; and Griffin,
king of the northern men with him; and hostages were delivered to
him. As he returned homeward, he ordered the Abbess of
Leominster to be fetched him; and he had her as long as he list,
after which he let her go home. In this same year was outlawed
Osgod Clapa, the master of horse, before midwinter. And in the
same year, after Candlemas, came the strong winter, with frost
and with snow, and with all kinds of bad weather; so that there
was no man then alive who could remember so severe a winter as
this was, both through loss of men and through loss of cattle;
yea, fowls and fishes through much cold and hunger perished.
More snow worse than anyone could remember, amazing.
I would posit that your prediction from 20 years ago isn’t worth the paper it was written on.
By the way I would recommend reading the Anglo Saxon Chronicle which is a fascinating look into history.

Patrick Davis says:
January 3, 2011 at 12:29 am
Interesting. However, I wonder how long it’ll be before alarmists and politicians attribute the flooding in Queensland, Australia to rising sea levels/rainfall as a result of man-made Co2 induced global warming?
__________________________________
The BBC are already trying just that, any weather event is simply a propaganda tool for the BBC to use. Fortunately the Australian commentator actually told the truth to the BBC anchor, it is a natural cyclic post drought event and nothing more. You can imagine that this particular guest will not be receiving another BBC invite any time before the next millennium. The BBC researchers will be looking for anyone regardless of qualifications who will be more ‘on message’ next time.

I gotta say “People living in deltas should learn to swim” is a flippant comment that seems pretty insensitive to the thousands of people who have died in Bangladesh flooding. That’s like telling the okies in the 30s they need to learn how to farm with less water.
I agree that blaming AGW for Bangladesh’s woes is foolish, but the Bangladeshis should be educated and allowed to make their own choices, not mocked. In a way, many Bangladeshis have made the same decision that New Orleanians have. I wonder which group of people is counting on the largess of others in times of trouble more.

@Gilbert K. Arnold says: January 3, 2011 at 4:15 am
Yeah, did all that and confirm that it is both interesting and enjoyable.
But I can also confirm, from my observations, that shroudwaving pays a lot better. If you do it without blushing, you can even win a Nobel prize (Gore, Pachauri, Obama…)

Triton says, “A growing delta is not in balance, it is growing.”
Most people have trouble with a concept called ‘dynamic equilibrium’. Think of a balloon with a small hole in it, leaking air out. You can keep it the same size by blowing in just enough air to balance the air leaking out. Similarly, ‘balance’ in a delta might mean steady growth (not accelerating or decelerating). Yes, it’s a little loose technically, but it is a useful way to describe steady growth – in balance. What words would you rather use?

Triton
January 3, 2011 at 7:34 am
You must be a lefty as your criticism is idiotic. All you guys do, when confronted with facts, is to distract and confuse, by screaming for reference for the obvious, and twisting about the meaning of what is written so that you can denigrate it. But what you really are doing is denigrating your own misinterpretation. Not being able to understand what the author wrote, makes you look mighty foolish.
BTW, the behavior of deltas as explained here is an accurate assessment of what has been understood by REAL scientist for decades. And just so you know, estuary ecology (including the physical character of deltas) was one of my two main areas of study, before I got disgusted by all of the Marxist nonsense that was being crammed down my throat.
Pal Reviewed papers does not make science. Duplicatable experiments makes science.

Triton,
Jan3 2011, 7:34
I wrote: in balance with sea level. This means that deltas don’t sink , unless they are starved of sediment, in which case the delta will not be there for very long or would never have been there in the first place. They also don’t get much higer than sea level. It is a vertical or topographic balance. They do built out, again “up to sea level” , not much higher.
Some parts of deltas are periodically starved of sediment and thus sink, or are flooded for prolonged periods. Those areas become prefered deposition centres once rivers break out of there natural levees during spring floods, then prefer to flow to the lowest points, eventually dumping their sediment in those lows. Over time this amounts to some form of balance. But yes, deltas build out and are not in balance geographically. The avulsion process, when rivers change course, is also highly erosional and modifying topography. If you prefer to approach nature that way indeed very few things are in balance.
If you want to read more about Deltas I am sure you can find your way to a fine collection of decent text books.

Triton & Hoser
re: balance
Triton is correct that Quaternero’s original sentence is awkward. ,“[Deltas] will always be in balance with sea level but almost by definition increase in size, if rivers are allowed to follow their course.”
To my mind, a balanced delta would be one that oscillated around an average land area. i.e. sometimes the sea would eat away some of the delta, sometimes the rivers would deposit more new land. However, the whole point of a delta is that it’s growing, creating horizontal land out of vertical land (mountains). I still support Quaternero’s point that as sea levels rise, deltas will switch from generation of horizontal land to generation of vertical land. When an equilibrium is reached however, it’s back to the generation of square footage.

What does this portend for New Orleans? From what I understand, the land under the city is sinking, and since the city, being below sea level, is protected with levies the river is not allowed to deposit silt. Consequently, the situation in New Orleans will get worse and worse.

Ken Harvey says:
January 3, 2011 at 9:38 am
“I notice that somewhat to the south west of Bangladesh the Assam tea crop is being decimated by global warming.”
Assam is north east of Bangladesh. And in the linked article we learn that rainfall has decreased by 20%, and that last years crop was damaged by to much rain, both presumably due to CAGW.

I dont even need to read this post to know what the answer is, its high school level geology. As an environmental engineer who specialises in hydraulics, including sediment transport it obvious that the delta would be a constantly evolving, expanding and rising area of land and will not be affected by small rates of sea level rise. Why anyone would say otherwise is beyond me, they probably just got a digital elevation model for the earth and raising the sea by 0.5m to see where would flood, ignorant of the constant changing surface of the earth, or the large errors such a DEM would contain. But thats Al Gore IPCC Greenpeace science for you…
The only risk to the Delta is engineered flood schemes like large canalised channels which would instead move the sediment out to sea, disturbing the natural processes of sediment accumulation.
Then there is the issue of planning, if an area is going undersea or is prone to flooding – dont let people build there, or if they do, make sure the building floor levels are above the flooding and they have a stash of backup food etc… or tell them “live there at your own risk, we wont help you”. I am often shocked at the poor planning of even councils in the western world that let people build in ephemeral lakes, functional flood plain, below perched canals / levies / leats or even over a river valley blocking the rivers flow path and reducing its capacity!
Man is normally to blame when there is tidal or fluvial inundation, but its not due to co2 emissions, its normally as simple as a poor decision to build there, or the 10,000 ha of forest upstream has been stripped leaving bare-fields instead (trees are very good at reducing run-off from land as they massively increase evapotranspiration and store a lot of rainfall on their leaves and in the leaf litter and buffer out peaks in rainfall).

I guess I’m pretty sensitive in general, though I’ve rarely been called politically correct in RL. I just think that if Anthony jumps on the alarmists for their exploding people ad, that that kind of sets the tone.
I think that telling people who are suffering from a natural disaster to learn how to swim is inappropriate, yea though it be a repetitive disaster in nature.
To me, it’s the equivalent of telling Katrina victims – “Learn how to swim!”
Mexicans dying in the drug war “Learn how to defend yourself.”
Californians laboring under the tax yoke “Figure out how to live with less money!”
etc.

Not withstanding this natural phenomenon, Bangladesh has for more than 80 years been messing up the natural watercourses of the country, now nature is catching up. As the Poster Child Bangladesh has a dubious history…
Bangladesh (was East Pakistan) had for years manipulated their geography (with soviet assistance) using widespread flood control, re-routing natural drainage, building large scale irrigation schemes, land recovery projects, and damming rivers for hydroelectric schemes, etc, etc.
() changed to
http://www.mowr.gov.bd/about_bwdb.htm and re-edited in the last year to remove most references to the soviet assistance.
Bangladesh also has an unsustainable population growth when the high population density is considered.
https://www.cia.gov/library/publications/the-world-factbook/geos/bg.html

Great to see a well explained article. I have previously lamented the loss of physical geography from the education system. It astounds me that simple principles like “fast rivers erode, slow rivers deposit” have been so easily forgotten. Just a few questions and observations. What role does vegetation (mangroves etc) play in moderating levels of sediments and temporary island construction? Most photos of the Sunderbans show mangroves. Does it enhance deposition and reduce erosion during flood events? Consolidation of sediments is understood in engineering foundation design including the use of preloading to accellerate consolidation. Does the height of deposition similarly have a limit?
The other half of the equation is the reality that people have always settled near to water for a number of reasons including security of water supply, trade and transportation and not coincidently, deep alluvial soils are great for agriculture. So it is no coincidence that flood plains make attractive areas of settlements. It is just unfortunate (for the inhabitants) that they happen to FLOOD ocassionally – or in the case of Bangladesh, seasonally with the monsoons.
The current floods in Australia are not unusual on a historical scale and largely a result of the current La Nina phase. Some of the flooding is actually LESS severe that it would otherwise be due to the existance of man made dams that moderate peak flood levels. River gauges on the Burnett River that flooded Bundaberg actually show flood peaks of 10000 cumecs upstream of the (enviromentally unpopular) Paradise Dam but no less than 4000 cumecs below the dam showing the benefits of temporary flood storage. This significantly reduced the scale of the floods and no doubt the quantum of “climate change ;-)” refugees.
It is also unsurprising that areas of western Queensland currently flooding are actually described as “large areas of fine-textured alluvial plains associated with the main tributaries of the Condamine River system”. In other words, nothing unprecedented here, just nature doing what it does.

Joshua, MKelly,Stumpy, Anna v
I wrote: “people living in deltas (in general) should learn how to swim”. This is ment to be entirely pre-emptive. It also includes people in the Mississippi delta, the Nile Delta, the Rhine delta etc. . It is the simplest way of avoiding completely unnecessary drowning due to entirely predictable and seasonal events and to recognize the dangers of your environment. I would be surprised if more than 25% of the people in Bangladesh can actually swim. I suspect that none of the female half and less than half of the male population can actually swim. It also would also surprise me if swimming lessons are part of the school curriculum in New Orleans, while I know it is part of the school curriculum in the Netherlands, for a good reason. If someone wants to regard this comment as flippant, that is their prerogative. I was actually quite serious about this, including having boats. Inhabitants of the Mekong delta prefer to live on boats. The danger lurks when dealing with such an immense delta as Bangladesh, where flooding occurs hundreds of miles away from the coast line, in a flood plain that can be reasonably well protected by natural levees for dozens of years and then suddenly floods when a levee breaks. The most effective option is to build settlements on man-made elevated “highs” rather than to dam or control the run-off. Fixing the enormous rivers and their sediment load according to human design is a monumental task, likely to fail in the long run. The population growth rate in Bangladesh however guarantees that only the elite will be able to secure the highs, leaving a large percentage to fend for themselves on the least favorable lows. I really don’t know what else to advise. The points about the Vesuvius are indeed quite analogous. Fertile soils will always attract people, never mind the dangers. Naples will eventually become the next Pompeii, but my advice to them would be similar: have a boat to get out of there, highways will be plugged when it matters.
Swimming however detracts from the main argument. Although Stumpy believes thata this is “high school geology”, I believe that insufficient geology is actually taught at high schools, or else Al Gore would have realized his complete ignorance. Anna v said itwell: try to convince them..