tcoulthard / caesar-lisflood

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Some doubts about formulation and input values #8

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago
Dear Professor Coulthard.

I apologize for bothering you with my doubts.
I've been running CAESAR in watershed mode and after some tests I am with 
several doubts.
I enumerated that to be more organized.

Today I saw that there is a new CAESAR version and according to the changes 
information, version 1.2o is better to reach model. So, can I suppose that 
version 6.2m is better to Catchment model? Is that correct?

These are my doubts

1. At File Tab.

In the field generate time series output – Save file every X min, this X min 
- is the time step of the output file or is the interval of that CAESAR will 
save the .txt file in my computer?
Eg: I am using daily data, in this field I should inform 1440 min? Or Is the 
output time step always the same of the rainfall data file time step?

2. At Sediment Tab
To run the model in catchment model is it necessary inform sediment data?
If yes, there is a way to input this data as .asc like DEM, to make some type 
of spatialisation of sediment? I notice that there is the Grain data file input 
field in file tab, but I not found a file example.

2.1. If I have just three (3) types of superficial sediment, (eg: clay to 
sand), in the grain size I should put zero in the other 6 fields?
I try to made this but CAESAR didn’t generate Q.
Our watershed had a lot of colluvial deposits (debris flow deposits), with 
boulders. It is CAESAR capable to modelling this situation or capable to input 
some kind of cross stratigraphy that occurs sometimes even in fine sediments at 
floodplain?

2.2. Our watershed have a deep soil (~15m) and some reaches are cascade, that 
means that a lot of boulders, pebble and cobble. Because of this I am not sure 
about this active layer. Is there a paper that I can read to understand this 
active layer? 

3. When I run the model, in the field time (left of interations) always appear 
5.xxxxxx. It started normally and then stabilizes at 5.xxxxx, varying only the 
numbers after the dot. Is that a problem on my input rainfall data?

4. I read in a paper, maybe in Hancock (2012) or Hancock and Coulthard (2012) 
that CAESAR needs, as other hydrological models, a time of self adjustment, and 
the data must be not considered, specially Q and Qss.  CAESAR also works with 
events? What occur in this case? Is it possible to work with events in 
watershed model or short time series (1 year of 10 min data) or its better 
simulated events only in reach model?

5. There is relationship between Max # interations and Max run duration ?
If I am running since 1942 daily data, Is that correct put in Max run durations 
(69 years*365*24) = 604440hs.
In fact, I would like to use half data to calibrate and half to simulate. So, 
the ideal number is 302220 hs? And the interation number will be the same?

In the same tab, the max time step in this case will be 1444*60= 86400s?

If I don`t orientate my watershed exactly West-East, the model will not run 
correctly?

These first tests I made with a 10m DEM resolution and daily data. My watershed 
had only 16km².

I also have a doubt about the formulation. There is a threshold equation that 
allows CAESAR simulated surface (runoff) and subsurface flow. This equation use 
K (hydraulic conductivity). How CASESAR estimated it if there is no field to 
inform? There is a Pedotransfer function?

Dear professor, I am really sorry to boring you with these elementary 
questions. Thank you a lot for your time and sorry for my not so good english

Original issue reported on code.google.com by roberto....@gmail.com on 25 May 2012 at 3:53

GoogleCodeExporter commented 9 years ago
Hi Roberto,
Could you copy & paste up your questions on the discussion board please? I'm 
getting 5 or 6 queries a day and I need to start answering them generally 
rather than individually or I get asked the same questions!!
Thanks,
Tom

https://groups.google.com/forum/?fromgroups#!forum/caesar-lisflood

Original comment by Tom.Coul...@gmail.com on 25 May 2012 at 7:42

GoogleCodeExporter commented 9 years ago

Original comment by Tom.Coul...@gmail.com on 29 May 2012 at 11:18