Need help coming up with ideas (bachelor's thesis)

[pingaan]

TL;DR Summary: Need help coming up with ideas to present a current thesis in terms of qualitative and quantitative ideas.

Hey!

I have a problem. I have picked up on a project for which I am planning on doing my bachelor's thesis on. The guy behind the project is not a physicist, per se, as he is a professor at the geographical department at this university.
I, on the other hand, am a physics student and therefore I will of course take my degree in physics.

I have been away from the physics department for more than a year, taking subjects in geography and biophysics to broaden my aspect. This, however, has somewhat blanken my mind a bit (in terms of physics) and I'm out of ideas, meaning I am in dire need of help to come up with some.

The project in short is focused on the water level in a mire/bog and how the nearby vegetation is affecting it. I have tons of collected data to work with and will take some more myself as the weather changes on a daily and seasonal basis.

The two quantitative things I can think of are:
#1. The home-made instrument used to measure the water level, which basically measures the water level by measuring the difference in pressure going from air to water.
#2. The gradient which will appear as the water level gradually changes from high to lower as I get from the centre of the mire/bog to the outskirts.

I am planning on taking a course in fluiddynamics at the end of next semester, which I'm guessing would be helpful, but I feel it may a bit too late to apply new stuff that late.

Any help is appreciated. Any qualitative and quantitative suggestions, please. There are no dumb suggestions!
Please help me out.

 

[sophiecentaur]

@pingaan it's not clear to me what you actually want here. You say that you have plenty of numerical evidence but you are prepared to gather some more. Do you want to plan some useful extra experiments? Do you want to find a meaningful model? Or do you just want to analyse the data with no particular end in mind?

TL;DR Summary: Need help coming up with ideas to present a current thesis in terms of qualitative and quantitative ideas.

The project in short is focused on the water level in a mire/bog

I'd suggest you should be thinking in terms of 'water levels' (plural) at various points in the bog. The water will be flowing through the bog at rates which depend on the depth of its 'hard bottom' from the surface as well as the level of the general water table (again, this will vary all over the area). As the input stream flow is increased, the flow will increase.

It may be worth thinking of a simple model in two dimensions (a deep slot with an In and an Out). As you are familiar with Physics you may see the makings of thought experiment based on an electrical analog with a ladder of Capacitors, coupled by series Resistors and fed from a Voltage Source. (Easy to simulate but you would ned to supply meaningful values and quantities.) The volts on the capacitors will be progressively lower towards the output end (with a resistor to another maintained voltage source). Through the year, the vegetation density would correspond to the equivalent series resistor values and the level of the input and output streams a would correspond to the supply and drain volts.

You need to come back to us with some more detail and, perhaps a response to the limited number of ideas I have written above.
You need some serious searching about ground water flow - and there must be a load of that out there. If it's for a Batchelor's Thesis then it wouldn't be a lifetime's work so you have to aim at as simple a model as you can get away with.

I found this, amongst a lot of other stuff.

It strikes me that, as a Physicist, you could appear to be a good geographer and, as a geographer, you could appear to be a good physicist. It could work in your favour (or not??).

 

[ezfzx]

This sounds interesting, but (speaking only for myself) I'm not clear on the goal. You want to see the affect of nearby vegetation on the water level of the bog. But that is a big wide open problem statement, that probably needs to be refined a LOT.

When you say "water level", do you mean depth? Density? Concentration? Toxicity? And when you say "affect", do you mean changing any of those things? Are you looking for how much of the bog is water vs. not-water?

For something like a thesis or a dissertation, you need precise definitions of what you've got, what question you're asking, what you think is going on (your hypothesis), exactly how you plan on testing your hypothesis, your interpretation of your results, and any objective speculation.

sophiecentaur gave some good suggestions, like collecting data at multiple locations, and testing the water from an electrical perspective.

From a fluid dynamic perspective, there are tools that can measure "mass flow rate" ... effectively measuring the density of a fluid as it circulates through the system. If you're looking for algae or other biologicals, there are tools that can visually scan samples for specific spectrums. (Pure water wouldn't be green, for example.) Things in water change the heat capacity, thermal conductivity and buoyancy of the liquid. (Think: Galileo's thermoscope for example.)

I think it's also important to distinguish between your emphasis on the situation you're examining and the invented tools you're creating to do the examining. One of the biggest problems with writing a research paper is something we call "scope-creep" ... where you begin looking at one thing, and get side-tracked with other tangential interesting things. Then, a project that should have taken a few months ends up taking a few years instead. Find and maintain a tight focus on your goal, and stay focused.

Something else to keep in mind: If this is for a bachelor level project, you can think of it as "Part One", and then use your master's thesis, or doctoral dissertation as "Part Two" and "Part Three" ... a continuation and elaboration on the same research. After that, you write a book, cure cancer with bog science, become famous, get a Nobel prize, etc.

 

[Baluncore]

I think you will need to model the latitude dependent energy flows, sunlight, reflection from the water surface, evaporation, and thermal mass.

Hydrosere is the magic word that has not yet appeared in this thread.
https://en.wikipedia.org/wiki/Hydrosere

 

[pingaan]

First of all, thank you for all your input and advice!

@sophiecentaur: Yes, there has been data collected with even intervals throughout the past 12 years or so, so I have tons of data to work with. However, the actual measure taking is not super advanced and does not correlate to varying weather, hence my presence during and after rainfall to collect data is required.
The idea is to build a model which shows how the water levels are affected by the vegetation in every possible aspect, I suppose. One important fact that carelessly got lost in translation is that it's not a general matter of vegetation, but specifically trees. The increased evaporation, the absorption of the root system, how the flow is affected etc. It would be a great thing to develop such a model which could be used for other bogs as well.

It is indeed plural, not a single water level I will look for.
The electro analog sounds interesting! It's been ages since I last took a subject in electromagnetism. While I do see that it already is quite elaborated, do you think you can elaborate it a bit more? Perhaps add a doodle? =)
In Sweden, we actually have data recorder by some of the government branches on every possible geographical thing - including ground water. This will come in handy!

The thesis you linked seems to be of a lot of help as well. Thank you!

@ezfzx Yes, I see what you mean. This experiment could sprout of in any direction, but my the part I'm studying in this case is clear. It generates from what the professor (my supervisor) has hypothesised, which is that due to longer periods of drought the seeds from surrounding trees manages to grow rootsystems large enough to survive once the water returns. I mentioned above to Sophie that I previously said it was concerning vegetation, while it's actually only concerning trees and their spreading. By water levels I mean depth, but while sticking the instruments in the ground one could collect values for concentration and pH as well, although I think that's been rather unchanged the past decade (if I'm not mistaken).

@Baluncore By thermal mass, you mean the heat capacity of the water?
Thanks for the hydrosere concept. This is new to me.

 

[osilmag]

First of all, thank you for all your input and advice!

@sophiecentaur: Yes, there has been data collected with even intervals throughout the past 12 years or so, so I have tons of data to work with. However, the actual measure taking is not super advanced and does not correlate to varying weather, hence my presence during and after rainfall to collect data is required.
The idea is to build a model which shows how the water levels are affected by the vegetation in every possible aspect, I suppose. One important fact that carelessly got lost in translation is that it's not a general matter of vegetation, but specifically trees. The increased evaporation, the absorption of the root system, how the flow is affected etc. It would be a great thing to develop such a model which could be used for other bogs as well.

It is indeed plural, not a single water level I will look for.
The electro analog sounds interesting! It's been ages since I last took a subject in electromagnetism. While I do see that it already is quite elaborated, do you think you can elaborate it a bit more? Perhaps add a doodle? =)
In Sweden, we actually have data recorder by some of the government branches on every possible geographical thing - including ground water. This will come in handy!

The thesis you linked seems to be of a lot of help as well. Thank you!

@ezfzx Yes, I see what you mean. This experiment could sprout of in any direction, but my the part I'm studying in this case is clear. It generates from what the professor (my supervisor) has hypothesised, which is that due to longer periods of drought the seeds from surrounding trees manages to grow rootsystems large enough to survive once the water returns. I mentioned above to Sophie that I previously said it was concerning vegetation, while it's actually only concerning trees and their spreading. By water levels I mean depth, but while sticking the instruments in the ground one could collect values for concentration and pH as well, although I think that's been rather unchanged the past decade (if I'm not mistaken).

@Baluncore By thermal mass, you mean the heat capacity of the water?
Thanks for the hydrosere concept. This is new to me.

I don't how deep you need to go, however you can find ICs out there that will measure pressure and water levels. The water leveler would probably require trying different resistors in the water to have conduction to the transistor.
https://www.electricaltechnology.org/2019/04/water-level-indicator-circuit.html