| Message/Author |
|
|
 Tom posted on Wednesday, August 17, 2005 - 03:21 pm
|
|
|
Hello
I'm developing a new lateral erosion routine for CAESAR at the moment, and am wondering if anyone wants to help develop/test it?
Tom |
|
|
| Peter_Cole
posted on Monday, August 29, 2005 - 10:44 pm
|
|
|
| Tom, this would probably be very helpful to me, but I am still a wee way off getting my DEM down to size. Lateral erosion is pretty much where my study is 'at', so any improvements here are welcome. |
|
|
| Tom posted on Tuesday, August 30, 2005 - 08:46 pm
|
|
|
OK Peter, its still very much in development - the erosion works fine, its the deposition on the inside of the bend thats the problem! I'll keep you posted,
Tom |
|
|
|
|
Accurate deposition would be really important as the Motueka River is (apparently) very low in sediment load, so small amounts of actual sediment can be relatively important.
Thanks. |
|
|
| Tom posted on Friday, September 02, 2005 - 10:35 am
|
|
|
Getting the model do deposit on the inside of bends - or where there are such flow conditions is rather hard. This is one of the difficulties with the CA approach. Because we have simplified the flow equations to make them run much much faster, we loose terms for momentum that could be used to calulated cross stream flow - and thus where lateral deposition should occur. At present, with the lateral erosion scheme I'm working on this is driven by the radius of curvature.
I can determine the tightness of inside and outside bends - and then interpolate between them- which gives a cross stream 'gradient' which is proportional to the tightness of the bend. But there are two key problems with this at present. 1. Its based on curvature not the actual flow contitions - so we are driving lat erosion with the symptoms rather than the causes. 2. How do we parameterise this rather abstract gradient? We need to determine how much sediment is routed downstream compared to how much is routed cross!
Just some of the ideas I'm working on at present..
Tom |
|
|
| Tom posted on Thursday, September 29, 2005 - 09:27 am
|
|
|
THis refers to the ESP&L article in press - where we (me & Marco) write up the methodology for lateral erosion..
Started trying to use only manhattan neighbors when summing wet and dry cells, as was getting excessive quantities of dry cells when dealing with single thread diagonal cells - which was skewing results.
Thoughts Marco? |
|
|
| Tom posted on Wednesday, January 04, 2006 - 05:28 pm
|
|
|
Version 5.1 is now on the website. Includes lateral erosion and can run in reach and catchment mode at the same time. More details in the header of the source file.
Thanks,
Tom |
|
|
| Back to top |
