Complete one constituent transport

[nmizukami]

Implementation of constituent transport routines.

• allow to transport one constituent

#153 #167

[nmizukami]

Hi @ekluzek, Here is the draft on constituent transport within mizuRoute. If possible, I would be looking for coding design guidance so make it easy to implement more constituents the same time. Now hold one constituent (for now targeting DOC)

[nmizukami]

Some of changes to be done in future PR:

For an array like array(0:1), 0 means previous time step and 1 means current time step. Replacing with magic numbers with the parameters is good idea and will be done in another PR since this type of array is all over the codes.

For printing out the detailed reach routing information in log file, it would be better to use a function like this (may not need comment) in all the routing routines verbose = print_reach_states(reach_id)

[nmizukami]

Thanks Erik (@ekluzek) for the comments. I went through almost all the comments, and would like you to take a quick look, but not sure about what to do with a few things (so has not changed yet)

1. mass balance tolerance
2. comments on subroutines e.g., write_tracer_state etc. (but please see my replies)

history output variable names are hard coded in meta_rflx in popMeta.f90. I changed variable names related to tracer localDOC-> localSolute, routedDOC -> soluteFlux, DOCmass-> soluteMass