Baseflow vs. infiltration of groundwater into natural channel

[MapEngr]

I am under the impression that baseflow in a natural channel is a function of infiltration of groundwater into the channel. However, I am reading a report where baseflow and groundwater infiltration were modeled two seperate ways. The report assumes a constant baseflow value obtained from flow monitoring data recorded during dry days whereas groundwater infiltration only occurs during significant or prolonged rainfall events.

I have been able to come up with reason as to why the report modeled baseflow and groundwater infiltration seperately, however, I do not want to influence anyone with my train of thought. With that, can anyone explain to my why they think the report did it this way?

 

[RWF7437]

"With that, can anyone explain to my why they think the report did it this way? "

You said you were able to come up with a reason. What was it?

I can easily imagine that a perennial stream could have flow year around if it is fed by springs, snowmelt or some similar sources. These would NOT be considered "groundwater" because they flow over the surface of the earth. So, it might make good sense to model them separately because the flow rates and arrival times at the stream are likely to be quite different. Whether ir not you would do so might depend on the data you have available and the purpose of the report you are preparing.

 

[civilperson]

If the hydraulic elevation of ground water is higher than the stream elevation the two models are not applicable. When the ground water elevation is below the stream, one of the two models described will apply.