Talk:Braided river

Untitled

Why is this listed for speedy? It seems encyclopedic to me. --User:AlbertHerring ^{Io son l'orecchio e tu la bocca: parla!} 17:28, 19 October 2006 (UTC)

Keep. I did not create this article, but I contributed an image to it, so I hesitate to remove the speedy deletion template. The article is a reasonably good treatment of a legitimate topic. It is certainly not nonsense. Tagging it with the speedy deletion template is a plain act of vandalism on the part of User:24.92.201.3. Note that User:24.92.201.3 not only tagged the article for speedy deletion, but also added the "hangon" tag contesting the deletion. -- Cuppysfriend 17:45, 19 October 2006 (UTC)

First image

The first image looks to me more like an anastamose pattern than a braided one - I'm removing it (feel free to complain about my actions); it would probably be worthwhile creating an anastamose river article. Awickert (talk) 17:54, 16 April 2009 (UTC)

Ah, there's some info on Anabranch, though it needs clean-up. Awickert (talk) 18:03, 16 April 2009 (UTC)

Definition in Formation section

In the Formation section of the article, it is said: "Braided rivers, as distinct from meandering rivers, occur when a threshold level of sediment load or slope is reached whilst a steep gradient is also maintained." I wonder how accurate this sentence is. When I look at many of the images of braided rivers at the bottom of this article, I do not see "steep gradients". I can appreciate that an abundance of sediment is required, but steep gradients? Just asking, Attic Salt (talk) 13:33, 8 October 2017 (UTC)

Contradictions

This article as written has very misleading sections, and explicitly contradicts itself in several places. For instance, in intro "Braided streams occur in rivers with low slope"; in formation section: "Conditions associated with braided channel formation include: ... a steep channel gradient". In intro: "Braided channels are also typical of environments that dramatically decrease channel depth"; in Formation: "a stream with highly erodible banks will form wide, shallow channels". The final sentence of the intro appears to be entirely nonsense.

"Formation" appears to be good material, but the lede needs totally rewriting. I don't have time right now, so have attached the appropriate warnings... DanHobley (talk) 13:43, 17 January 2019 (UTC)

Similar systems of rivers can form in several different environments; the term "braided river" is, in essence, a catch-all for systems that involve multiple channels, and thus the confusion. Icarosaurvus (talk) 00:35, 21 January 2019 (UTC)

@DanHobley: I agree with Icarosaurvus that there is no contradiction, and I see no evidence of factual inaccuracy; hence, I am removing the maintenance tags that say there is a contradiction and/or factual inaccuracy. If you disagree, feel free to put the tag back, but please provide a reliable source here to show that information in the article is somehow inaccurate. --David Tornheim (talk) 08:50, 22 April 2019 (UTC)

Both - thanks for the input! I'm going to restore the tags, pending a deeper dive. Reference-wise, take a look at the cited ref [1] already in the lede (which I note is primary, but we've all been there with this kind of article, right?):

At a very low slope and sediment load, the channels remained straight... a meandering-thalweg channel formed at slopes greater than 0.002... At slopes greater than 0.016, a braided channel formed.

0.016 is not a "low slope", and clearly in this context "braided channels" is the highest slope category. The current text is actively misrepresenting its own sources.

My second text example above is a bit more subtle - and is going to resist simple citation. The claim about braided rivers being "typical" of environments with downstream deconfinement and decreased flow velocity is misleading on two fronts. Firstly, there are very many delta (and to a lesser extent, fan) environments in which braided rivers do not exist - they are found on (small, steep) Gilbert deltas, but not of larger, lower gradient delta systems (Mississippi, Fly River, Mekong, etc.). The statement is broad enough to be actively misleading. Secondly, and possibly more importantly, this statement suggests that the deconfinement is the key element in creating the braided river. This is not true. If it were true, it would be possible to find examples of fans or deltas where the river type changes from e.g. meandering upstream of the debouche to braided downstream, on the fan. This does not happen, as the lack of confinement in this case is not genetically linked to the braiding. However, here, the onus is on the original author to defend the information, as their claim is not cited either. I'm going to it for now.

@Icarosaurvus: I take your point about forming in different environments. We should be clearer about that here. But my issue with the lede as-is is that it suggests they are characteristic of environments in which they are very much exceptions if they do exist.DanHobley (talk) 12:46, 22 May 2019 (UTC)

ETA: there is a lot of misinformation lurking out there, it appears - which is part of the problem. On the subject of slopes, this (http://worldlandforms.com/landforms/braided-river/) is in active conflict with this (http://www.seddepseq.co.uk/DEPOSITIONAL_ENV/Fluvial/Braided/braided.htm) and this (http://www.alevelgeography.com/braided-channels/). The latter two are correct in light of the modern primary literature. (Also pinging @David Tornheim: as I appreciate it's been a while) DanHobley (talk) 12:56, 22 May 2019 (UTC)

I ended up rewriting the lede. I believe the web sources are OK, but less than ideal. They could be replaced with the more technical but primary literature resources lower down, or with textbook detail - but I don't have the time to go on a proper hunt through textbooks atm... DanHobley (talk) 13:26, 22 May 2019 (UTC)