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Post by Deleted on Feb 19, 2020 19:53:45 GMT
It is important in all this to acknowledge that individual beliefs or opinions around the causes of global warming are in fact completely irrelevant. When the end of the world comes Armageddon outa here. All the super rich people are going back to Mars soon. What a lot of humans do not understand is that it is them who are the alien species. They accidentally landed here years ago in a flying saucer and were so much more clever than animals they invented things like dinosaurs because the only way to get back to Mars safely was by enslaving all the other diluted humans by offering them money so they can have more comforts but even more importantly provide cash to help build good rockets. No flying saucer tech down here sadly and no interstellar Comms. the original humans suffered high reproduction rates including, sadly, with non aliens which leads to a diluted species, and a lot of idiots. All of history is a cleverly organised scam to get money off people to make rockets to get back to Mars. It's actually quite simple, and deliberate warming of the environment will agitate the non original humans enough to make them have a go at each other while the original ones get their shit together to go back to Mars. Then big bang #2 happens. The end. Are you in any way related to L. Ron Hubbard?
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Post by Deleted on Feb 19, 2020 19:55:21 GMT
Not that I am aware of but there is a family history of subscribing to loony fridge beliefs to be fair.
I don't follow anyone myself I just make it up as I go along.
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Post by Deleted on Feb 19, 2020 19:59:02 GMT
I just make it up as I go along. No shit?
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Post by Deleted on Feb 19, 2020 20:04:25 GMT
Once a day quite regular.
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Post by bodger on Feb 19, 2020 20:04:52 GMT
Drilling some holes at an angle across the edge of the earth's crust followed by lining with concrete might be worth looking at. brilliant!!
(be careful - you may be nominated for a Nobel Prize}.
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Post by bodger on Feb 19, 2020 20:05:40 GMT
Once a day quite regular. after breakfast, or after a brisk walk?
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Post by peterboat on Feb 19, 2020 20:05:42 GMT
In its Fifth Assessment Report, the Intergovernmental Panel on Climate Change, a group of 1,300 independent scientific experts from countries all over the world under the auspices of the United Nations, concluded there's a more than 95 percent probability that human activities over the past 50 years have warmed our planet.
and
But several lines of evidence show that current global warming cannot be explained by changes in energy from the Sun:
- Since 1750, the average amount of energy coming from the Sun either remained constant or increased slightly.
- If the warming were caused by a more active Sun, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead, they have observed a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. That's because greenhouse gases are trapping heat in the lower atmosphere.
- Climate models that include solar irradiance changes can’t reproduce the observed temperature trend over the past century or more without including a rise in greenhouse gases.
I am firmly in the we are in the do dah camp and its our fault for releasing all that CO2 and other obnoxious global warming gases into the atmosphere!! I am firmly in the scientists corner that say large changes need to happen if we are to have a chance. The other thing though is Tony and Steve are right and dredging will help and in some cases will eliminate flooding completely, ask John how bad the river Hull is, I have seen it a 60 foot wide river with a very small channel in it! Its in a right mess a harbour so far up the river is blocked with mud from the fields of North/East Yorkshire , it wants dredging and putting back on the fields where it came from. Same with the Dod and the Rother where I am, the Rother was once navigable up to the mill for deep drafted barges, not anymore now anything drawing more than a couple of feet hits the bottom!
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Post by Deleted on Feb 19, 2020 20:08:00 GMT
Once a day quite regular. after breakfast, or after a brisk walk? Too much information.
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Post by JohnV on Feb 19, 2020 20:34:16 GMT
Ah, computer design modeling. What a load of crap. The fact is, eight miles of the Somerset levels were dredged a few years back, and the successful results have proven the need for regular dredging. Here's a rather simple computer modeling design for you So your computer modelling is limited to treating a river as a static container, such that if you remove the silt at the bottom the water will no longer spill over the rim?
That is nursery school logic. Your analysis is not 'a rather simple computer model', it's simplistic nonsense.
If dredging is undertaken in order to allow water to replace the silt, then why not just dig big holes all over the flood plain and let them fill with water?
The river flow regime is largely governed by the gradient of the water surface. Dredging silt from the bottom of the river does not increase the gradient - it may increase the effective cross sectional area of the river, but without adequate gradient not much changes. Lowering the water level downstream does increase the gradient, but if the water is not being discharged from the lowest point it won't happen. As I said earlier, in the case of the Somerset Levels, the water level at the lowest point is governed by the sea (tide) level.
as has been said we are not talking about the Somerset Levels .... we are talking about navigable rivers. The river Hull has plenty of gradient, what it lacks is a width of channel unrestricted by large reed beds and a depth of channel capable of providing a sufficient unrestricted flow down to the sea at Low tide. and as the height of tide is of the order of 8 metres there is plenty of fall. What is lacking is the flow rate to clear flood levels ( that are several metres above the normal tidal range) quickly enough during the ebb and low tide period and that underlined statement is definitely simplistic crap school boy logic ? most of your post lacks any form of logic it is purely argumentative for the sake of it
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Post by Deleted on Feb 19, 2020 20:49:14 GMT
So your computer modelling is limited to treating a river as a static container, such that if you remove the silt at the bottom the water will no longer spill over the rim?
That is nursery school logic. Your analysis is not 'a rather simple computer model', it's simplistic nonsense.
If dredging is undertaken in order to allow water to replace the silt, then why not just dig big holes all over the flood plain and let them fill with water?
The river flow regime is largely governed by the gradient of the water surface. Dredging silt from the bottom of the river does not increase the gradient - it may increase the effective cross sectional area of the river, but without adequate gradient not much changes. Lowering the water level downstream does increase the gradient, but if the water is not being discharged from the lowest point it won't happen. As I said earlier, in the case of the Somerset Levels, the water level at the lowest point is governed by the sea (tide) level.
as has been said we are not talking about the Somerset Levels .... we are talking about navigable rivers. The river Hull has plenty of gradient, what it lacks is a width of channel unrestricted by large reed beds and a depth of channel capable of providing a sufficient unrestricted flow down to the sea at Low tide. and as the height of tide is of the order of 8 metres there is plenty of fall. What is lacking is the flow rate to clear flood levels ( that are several metres above the normal tidal range) quickly enough during the ebb and low tide period and that underlined statement is definitely simplistic crap school boy logic ? most of your post lacks any form of logic it is purely argumentative for the sake of it We are not short on fall, short on depth though.... The River Nene is the tenth-longest river in the United Kingdom. From its source at Arbury Hill to Northampton, the river falls a total of 300 feet (91 m) in 17 miles (27 km).[1] For the remainder of its course, the Nene falls less than 200 feet (61 m).[6] It has a catchment area of 631 square miles (1,630 km2) and a mean flow of 328 cubic feet per second (9.3 m3/s).[7] The final 88 miles (142 km) from Northampton to the Wash is navigable
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Post by TonyDunkley on Feb 20, 2020 8:01:42 GMT
This thread is not about the Somerset Levels ! The whole point behind opening the topic is the effect on flooding that many years of very little or no dredging have had, and are now having, on our navigable rivers and river navigations. Had you taken the trouble to read what I actually said in the second post I made on page 1 of this thread you would have realized that my mention of the Somerset Levels was only in response to to a question from Dogless asking - "what can be done ?". I merely cited the effectiveness of public pressure on the EA and the Government in getting what the locals believed to be much needed and overdue dredging done, . . I did NOT claim to have any personal experience or knowledge of flooding, or the means of alleviating it, on the Somerset Levels. As for your questioning of what I specifically know with regard to the usefulness of the EA and C&RT [as maintainers of navigations], and any - "specialist training, knowledge and experience" that I have, . . how about what I've learned from a total of 64 years of boating of one form or another, with 49 of those years (my last commercial boating work ended in July 2013) on UK inland waterways operating a range of cargo carrying commercial vessels from narrowboats carrying around 50 tons on a pair up to 500 ton capacity barges, river and canal tugs, crane-barges, and various other forms of maintenance, dredging, and specialized AIL and contracting craft ? You may question the extent of my - "specialist training, knowledge and experience", but when UK Boatmaster's Licences became mandatory in 2007, I was one of the handful of people to whom the MCA issued an unrestricted UK Boatmaster's Licence under what is generally known as 'grandfather rights'. Is that good enough for you ? so, as I suspected, you have no specific training or knowledge of flood prevention engineering, just the experience of observing and navigating flood events, which is not particularly relevant.
You suggested that my experience of constructing flood defence works was not very relevant, which would of course have been true because constructors are generally disinterested in the whys and wherefores of the design process .............. but as noted above that was not a correct description of my involvement.
Your experience is marginally relevant, mine is totally pertinent.
It often appears that your agenda is driven by a disdain for the competence of the authorities, unfortunately this inevitably leads to a biassed viewpoint that is not based on engineering principles.
Your arrogant dismissal of the value of many years of first hand observation of the beneficial effects of well planned, targeted, and regular dredging on river flows speaks volumes ! I'm very much of a mind to treat the above response with the contempt it deserves by ignoring it completely. It may, however, appear persuasive and logical to others who share your very apparent lack of knowledge and practical experience of how properly dredged navigable rivers can transport flood water away far more rapidly than neglected rivers with areas of natural shoaling restricting the flow volume, so it is perhaps worth devoting a little time and effort in attempting to correct the misconceptions you, and the like-minded theory merchants at the EA are passing off as sound river engineering principles. The unthinking faith you share with the EA in the effectiveness of flood defences alone stands utterly discredited. Without the accompaniment of a routine dredging program targeted at known siltation points along any river, flood defence walls alone simply turn what would otherwise have been a progressive slow flooding event into a delayed but eventually far more rapid deluge of a much greater volume of water. As a stand alone measure, flood defences DO NOT work ! A simple analogy which shouldn't be beyond anyone'e comprehension is what happens as a result of ill-maintained and partially blocked guttering on buildings during heavy rainfall. Guttering obstructed or partially blocked not only has it's water holding capacity reduced by the crud that accumulates in such places, but that same crud also gets in the way of the free flow of water from the roof flowing freely and quickly along the guttering to the vertical drainpipes, . . . and then the guttering overflows, . . in much the same way as undredged rivers frequently overtop recently constructed flood defences !
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Post by peterboat on Feb 20, 2020 8:38:46 GMT
So your computer modelling is limited to treating a river as a static container, such that if you remove the silt at the bottom the water will no longer spill over the rim?
That is nursery school logic. Your analysis is not 'a rather simple computer model', it's simplistic nonsense.
If dredging is undertaken in order to allow water to replace the silt, then why not just dig big holes all over the flood plain and let them fill with water?
The river flow regime is largely governed by the gradient of the water surface. Dredging silt from the bottom of the river does not increase the gradient - it may increase the effective cross sectional area of the river, but without adequate gradient not much changes. Lowering the water level downstream does increase the gradient, but if the water is not being discharged from the lowest point it won't happen. As I said earlier, in the case of the Somerset Levels, the water level at the lowest point is governed by the sea (tide) level.
as has been said we are not talking about the Somerset Levels .... we are talking about navigable rivers. The river Hull has plenty of gradient, what it lacks is a width of channel unrestricted by large reed beds and a depth of channel capable of providing a sufficient unrestricted flow down to the sea at Low tide. and as the height of tide is of the order of 8 metres there is plenty of fall. What is lacking is the flow rate to clear flood levels ( that are several metres above the normal tidal range) quickly enough during the ebb and low tide period and that underlined statement is definitely simplistic crap school boy logic ? most of your post lacks any form of logic it is purely argumentative for the sake of it I mentioned your river earlier John its a perfik example of not what to do!! remember that harbour we passed solid mud due to no dredging, worse all that valuable mud came off fields all the way along its length, no wonder the country is flooding all the time the fields are losing depth and becoming lakes!!
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Post by Deleted on Feb 20, 2020 9:25:17 GMT
Some of the flooding might be related to unusually high rainfall figures. Dredging would help in theory but if there is more rain falling down then it's going to make rivers flood more.
Plus of course loads of new roads over recent years and hardstanding associated with housing and industrial developments probably makes the run off faster.
I was looking at some info on the great flood in 1947 on the Thames and apparently one of the things which made it worse was frozen ground preventing water soaking in.
At least we don't have that at the moment but according to the figures there is generally more actual rain coming down.
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Post by Jim on Feb 20, 2020 9:27:38 GMT
Bullshit. You only see what suits your own ignorance. Try NASA. Well I did come across this NASA page on climate this morning. The first sentences say it all really. climate.nasa.gov/causes/Unless the majority of scientists are lying, our production of greenhouse gases is making things worse regardless of natural events. Exactly so, but probably wasted effort posting it. There's none so blind....
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Post by Jim on Feb 20, 2020 9:30:43 GMT
I just make it up as I go along. No shit? Lots!
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