LauraClem 0 Report post Posted August 31, 2012 Dear All, I have recently completed a linked ISIS TUFLOW model. There were instability issues at the 1d/2d link that caused the model to repeatedly crash mid-run. I resolved this by assigning a value of 0.25 in the 'a' attribute for the 2d_bc_IsisLink file. The manual explains that this attribute is used to add FLC values to all HX cels along the HX line. I understand that it specifies additional energy losses between 1d and 2d. However, can anybody tell me when it is most appropriate to use this, and what an appropriate value would be? I look forward to any pointers.. Kind regards, LC Quote Share this post Link to post Share on other sites
adamgeorgesinclair 0 Report post Posted August 31, 2012 Hi Laura, My understanding is that this attribute could be used to represent anything on the river banks between the 1D and the 2D that would reduce the volume of water flowing out of channel and onto the floodplain. I would use it where vegetation is very dense on the channel banks or perhaps there is a fence that would represent a blockage to water flowing onto the 2D floodplain. Its perhaps not hugely useful in a relatively large model, however it may be applicable to small scale modelling. Not sure of what values you would be best using but perhaps a value based on the % blockage you expect to have between the channel banks on the floodplain? I may of course be very wrong about all of this, so i would welcome anybody with a greater understanding to correct me! Adam Quote Share this post Link to post Share on other sites
katebradbrook 0 Report post Posted September 11, 2012 Hi Laura, I would add to Adam's post that if the sinuousity of your river was high, you may expect greater shear and turbulence at the river/overbank interface and this would be another reason to increase the losses here... Kate Quote Share this post Link to post Share on other sites
