What is the relationship between impact factor and journal ranking
This is a particularly difficult question for interdisciplinary research, because different fields have radically different citation customs and publication time-tables, which leads to the same impact factor meaning very different things. Impact factor also has numerous other problems.

Moreover, absolute ranking of a journal is in many cases less important than reaching the audience that you want to talk to, particularly in interdisciplinary research and especially if you want to reach an application community.

Rather than focusing on impact factor, I would recommend using the following method to determine how to rank journals as possible publication targets: 


Pick half a dozen researchers who you highly respect and want to be the audience for this paper.
Look at the journals that they publish in.  The more frequently a journal appears, the better it is as a target for this audience.


This can also help you distinguish between targets for broad and narrow papers.  For example, you might have a methodology paper that speaks to a very particular sub-discipline.  A journal specifically for that sub-discipline may have a much lower impact factor, but may be a much better place to place the paper and it may actually end up having much higher impact and citations than if it is in a "better" venue where it is mostly read by people for whom it is irrelevant.