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Post by JohnV on Feb 20, 2020 9:48:34 GMT
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.... You always have to look at the "opinion of the scientific community" with a certain degree of sceptisism There is a tendency for some foremost scientists to make a view known tying that view to their own self importance. If they are prominent in the hierarchy then many other scientists will follow the party line finding it better for their careers not to buck those at the top. Many times in the past the "opinion of the scientific community" has proved to be very wrong and the recognition of that fact has been delayed sometimes for many decades because those proponents of a different theory have been labelled as crackpots. I am not saying they are wrong, what I am saying is that they may be wrong and other views should always be listened to as, in spite of sometimes overwhelming evidence .... they may be right. At the moment other views are being shouted down and not considered because they don't fit with what the activists and the media are supporting
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Post by Jim on Feb 20, 2020 10:12:39 GMT
Exactly so, but probably wasted effort posting it. There's none so blind.... You always have to look at the "opinion of the scientific community" with a certain degree of sceptisism There is a tendency for some foremost scientists to make a view known tying that view to their own self importance. If they are prominent in the hierarchy then many other scientists will follow the party line finding it better for their careers not to buck those at the top. Many times in the past the "opinion of the scientific community" has proved to be very wrong and the recognition of that fact has been delayed sometimes for many decades because those proponents of a different theory have been labelled as crackpots. I am not saying they are wrong, what I am saying is that they may be wrong and other views should always be listened to as, in spite of sometimes overwhelming evidence .... they may be right. At the moment other views are being shouted down and not considered because they don't fit with what the activists and the media are supporting There comes a point where the facts are ascertained though, as we get more information and better measurements we can be nearer the truth, sometimes it's just a fact, not up for discussion, not an opinion. 2+2=4 but if a scientist or an expert says it some just will not believe it.
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Post by Deleted on Feb 20, 2020 10:15:40 GMT
Taking this thread as a perfect example ... opinions are always many and varied, I find it difficult to know which is right.
I used to read the technical electrical threads on CWDF with some amusement ... a subject which is based on laws of physics ... electricians of great experience, people with degrees in the subject, and d.i.y. ers of many years standing ... all having blazing rows on a subject that they all feel they know inside out.
I have to say for my part, simple logic suggests dredging is essential to maintain navigation ... is on canals so must be on rivers, to maintain 'capacity' and to ensure smooth flow.
The guttering analogy, and photos John put up reinforce that idea.
Rog
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Post by Deleted on Feb 20, 2020 10:24:00 GMT
You always have to look at the "opinion of the scientific community" with a certain degree of sceptisism There is a tendency for some foremost scientists to make a view known tying that view to their own self importance. If they are prominent in the hierarchy then many other scientists will follow the party line finding it better for their careers not to buck those at the top. Many times in the past the "opinion of the scientific community" has proved to be very wrong and the recognition of that fact has been delayed sometimes for many decades because those proponents of a different theory have been labelled as crackpots. I am not saying they are wrong, what I am saying is that they may be wrong and other views should always be listened to as, in spite of sometimes overwhelming evidence .... they may be right. At the moment other views are being shouted down and not considered because they don't fit with what the activists and the media are supporting There comes a point where the facts are ascertained though, as we get more information and better measurements we can be nearer the truth, sometimes it's just a fact, not up for discussion, not an opinion. 2+2=4 but if a scientist or an expert says it some just will not believe it. Like the the MMR vaccine scandal ? Rog
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Post by TonyDunkley on Feb 20, 2020 10:48:34 GMT
Taking this thread as a perfect example ... opinions are always many and varied, I find it difficult to know which is right. I used to read the technical electrical threads on CWDF with some amusement ... a subject which is based on laws of physics ... electricians of great experience, people with degrees in the subject, and d.i.y. ers of many years standing ... all having blazing rows on a subject that they all feel they know inside out. I have to say for my part, simple logic suggests dredging is essential to maintain navigation ... is on canals so must be on rivers, to maintain 'capacity' and to ensure smooth flow. The guttering analogy, and photos John put up reinforce that idea. Rog It's also essential to maintain a clear channel of sufficient X-sectional area to allow floodwater to pass along it as freely and quickly as possible. To resort to a much overused idiom - it ain't rocket science ! A deeper container will hold more water, without spilling any, than a shallower one will, . . . and that same water will drain away more quickly through a bigger gap or hole than it will through a smaller one.
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Post by bodger on Feb 20, 2020 10:51:35 GMT
1) 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 ! 2) 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 ! 1) I fully agree that most of the flood defence walls are ineffective, but in many/most cases that is not necessarily related to a lack of dredging.
2) an over-simplistic analysis .... which is what I have come to expect from you. nuff sed.
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Post by bodger on Feb 20, 2020 10:54:37 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 that was my intent - irony is wasted on you.
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Post by JohnV on Feb 20, 2020 11:02:24 GMT
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 that was my intent - irony is wasted on you. twat
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Post by Deleted on Feb 20, 2020 11:09:02 GMT
Near my home is a culvert under a dip in the road ... like a U shaped road. In times of heavy rain the storm ditch running through the culvert fills up and the ditch becomes a torrent. There used to be a team of guys visiting this, and many other culverts, and also clearing out the gutters and storm drains on a regular basis. Then economies were made as necessary at the time, and this work along with grass cutting seemed to 'drop off'. Suddenly in periods of heavy rain, the road flooded quite badly in the dip (2012). Since then they now routinely clear the culvert, and the road doesn't flood. Of course, the water is still around, but it rushes off on its way to ... who knows ... perhaps flood somewhere else There is no doubt dredging will work ... but whether it just moves the problem I don't know. Rog
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Post by bodger on Feb 20, 2020 11:15:38 GMT
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. saturated ground has the same effect as frozen ground.
for practical purposes (farming, and construction on farmland) there is a factor known as the soil moisture deficit ratio which is an indication of whether (and to what degree) the soils can absorb rainfall. When constructing pipelines across agricultural land there was (is?) an agreement with the NFU that entry will not be made onto fields where there is no significant deficit, because that means that any rain that falls will not soak in and any construction work will create a quagmire. The deficit has now been zero for several months and even with a break in the rain (which seems highly unlikely) it will remain at zero for several more months.
I defy anyone to provide data to suggest that we are not suffering from the most serious rainfall events ever recorded. Climate change deniers are assholes. It is clear that all the historical data used to establish the severity of 10 year events and 100 year events are now worthless in this respect. The problem is that there are now no figures available to engineers to allow them to predict rainfall events. We don't even know if what we are experiencing now is the new norm, or if it may become much worse. As an example of what is possible, I worked in the Burmese rain forest where daily rainfall of 30cm during the wet season was not unexpected and events of 60cm and even 90cm were not unheard of. The latter were very localised but often created massive landslips on heavily forested hillsides.
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Post by bodger on Feb 20, 2020 11:17:09 GMT
Near my home is a culvert under a dip in the road ... like a U shaped road. In times of heavy rain the storm ditch running through the culvert fills up and the ditch becomes a torrent. There used to be a team of guys visiting this, and many other culverts, and also clearing out the gutters and storm drains on a regular basis. Then economies were made as necessary at the time, and this work along with grass cutting seemed to 'drop off'. Suddenly in periods of heavy rain, the road flooded quite badly in the dip (2012). Since then they now routinely clear the culvert, and the road doesn't flood. Of course, the water is still around, but it rushes off on its way to ... who knows ... perhaps flood somewhere else
There is no doubt dredging will work ... but whether it just moves the problem I don't know.Rog wise words
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Post by bodger on Feb 20, 2020 11:18:04 GMT
that was my intent - irony is wasted on you. twat is that the best you can do?
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Post by JohnV on Feb 20, 2020 11:22:04 GMT
You always have to look at the "opinion of the scientific community" with a certain degree of sceptisism There is a tendency for some foremost scientists to make a view known tying that view to their own self importance. If they are prominent in the hierarchy then many other scientists will follow the party line finding it better for their careers not to buck those at the top. Many times in the past the "opinion of the scientific community" has proved to be very wrong and the recognition of that fact has been delayed sometimes for many decades because those proponents of a different theory have been labelled as crackpots. I am not saying they are wrong, what I am saying is that they may be wrong and other views should always be listened to as, in spite of sometimes overwhelming evidence .... they may be right. At the moment other views are being shouted down and not considered because they don't fit with what the activists and the media are supporting sometimes it's just a fact, not up for discussion, not an opinion. 2+2=4 but if a scientist or an expert says it some just will not believe it. a (possibly slightly paraphrased) quote from Dr Bronowski "Doubt is important, there has been more evil inflicted on the human race by people who knew they were right than any other cause"
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Post by JohnV on Feb 20, 2020 11:26:12 GMT
is that the best you can do? you were the one making a ludicrous statement and snide comments to support your point of view so "twat" will do very nicely
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Post by JohnV on Feb 20, 2020 11:41:11 GMT
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.
I defy anyone to provide data to suggest that we are not suffering from the most serious rainfall events ever recorded.
notalotofpeopleknowthat.wordpress.com/2015/12/30/the-decade-when-it-rained-and-rained-and-rained/
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