Author Topic: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire  (Read 4593 times)

Offline aricooperdavis

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #50 on: October 09, 2020, 10:48:21 pm »
I think the API includes rainfall records from weather stations, rather than radar data, which could be interpolated for sites in-between.

I could be wrong as I haven't actually tried the radar service yet, but there is documentation for how to fetch rainfall radar tiles using datapoint on the Met Office website, so unless this is no longer or not yet supported it should be doable?

Offline Tim Pickering

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #51 on: October 09, 2020, 10:53:22 pm »
Tim Pickering - showcaves being normally resurgences, their water is often collected from a very wide area, where differing rainfall over the catchment may result in variations in observed levels & timings. Some of that water will come directly through large conduits, so providing rapid & often muddy influxes, others through tiny passages, some may cause flooded chambers to overspill, thus forcing cleaner water through the system & sometimes that overflow may be overwhelmed (or become blocked) & rise to another passage that takes it off in a different direction (plus all the variables in ground / saturation conditions mentioned already)...

I've noticed times when the inlets are responsive but the streamway level remains relatively unchanged or the streamway at the far end of the show cave may be higher than normal but it hasn't affected the level nearest the entrance. I will at some point have a wander around and note down all the sinks and resurgences in the vicinity, and hopefully get down some of the pots. Absolutely fascinating stuff! I've given up using the river stage as an indication of whether we'll be running tours.


Offline mikem

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #52 on: October 09, 2020, 11:14:48 pm »
River level is only a good indicator for water flowing through vadose (open) passage, whilst most resurgences are phreatic.

I could be wrong as I haven't actually tried the radar service yet, but there is documentation for how to fetch rainfall radar tiles using datapoint on the Met Office website, so unless this is no longer or not yet supported it should be doable?
Yes it is available for next 36 hours, but TheBitterEnd was asking about historical data to compare to past events.

Offline TheBitterEnd

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #53 on: October 10, 2020, 04:40:18 pm »
I think the API includes rainfall records from weather stations, rather than radar data, which could be interpolated for sites in-between.

I could be wrong as I haven't actually tried the radar service yet, but there is documentation for how to fetch rainfall radar tiles using datapoint on the Met Office website, so unless this is no longer or not yet supported it should be doable?

I had a quick play with the radar API last night and it is possible to get tiles of radar data - this page gives the basics > https://www.metoffice.gov.uk/services/data/datapoint/inspire-layers-detailed-documentation

The met-office don't seem to give much info about zoom, style, and how to relate a tile to an actual location so it's a case of getting into the OGC WMTS 1.0.0 spec which didn't make things immediately obvious. If I'm bored at some point I might dig a bit deeper.

BTW, I don't see interpolating between gauge sites as being of much use for heavy localised showers, that's the strength of the radar  data for me.
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Offline mikem

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #54 on: October 11, 2020, 05:18:28 pm »
Yes, you are right there.

Offline blhall195

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Progress update
« Reply #55 on: October 15, 2020, 10:25:37 pm »
Finished the prototype of the cave river level logging device.

Currently it's a stand alone unit that can tell the date/time, the distance of the nearest object (river) using an ultrasonic distance sensor, then log to a micro SD card and display on a small LED screen. Once i've optimised the power settings it should be able to log for months at a time.



The display shows the date/time + how far away the nearest object is.



It also shows whether the SD card has initalised properly and if there are any data logging errors (this can be unplugged once it's set up and working to save power).




The log file is simply a CSV file with a time stamp and river height.



There's still alot to do in terms of optimising the design for minimal power consumption and finding a way to make it cave proof.

I currently have an IP67 rated junction box that I'll put a few packets of silica gel in and have the sensor extending out via a cable.

I'm planning on reducing the power consumption by:

- removing the LEDs
- making the sample frequency dependent on the hight of the cave water levels (e.g 1 data log every 15 min under normal conditions, every 5 min under flood conditions)
- setting the device to a sleep state when it's not doing anything

I'm thinking to use the kingsdale master cave streamway near the pitch as you go in from valley entrance as a pilot study, just because I enjoy doing the pull-throughs anyway and the water levels probably respond predictably to rain fall.

Just need to find some way of fixing the logger in the cave that won't piss people off.

The sensor I have is pretty cheap (£10) and the range/resolution isn't as good as some of the professional grade sensors on the market that cost over £100, I might see if the BCRA will buy me one for christmas :ang:
« Last Edit: October 15, 2020, 10:36:42 pm by blhall195 »

Offline Chocolate fireguard

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #56 on: October 16, 2020, 10:57:07 am »
You don't say what the range is, but the 81cm reading implies that the resolution is more than adequate, bearing in mind the changes produced by flooding and the likely second by second fluctuations in the bit of river it is looking at.

Re. making it cave proof, decades ago I built some photoflash slave units, using a circuit from Descent, and after many failures I found the only way to keep the water off the electronics was to pot everything apart from the batteries.
It's pretty final, but have you considered it?

Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #57 on: October 16, 2020, 11:55:03 pm »
From what people are saying it seems flood events can be quite sudden and short lived. I could alter the programming so that the sample frequency increase changes on a sliding scale directly proportional to the river level or increases the same rate as the rate of change of river level.

The range of the £10 sensor is about 5m with a cm resolution. The £120 sensor I want to buy has a range of 10m and mm resolution - but more importantly compensates for changes in humidity and temperature.

In terms of potting I hadn't considered this it's modular so could be a good idea for conserving the more expensive bits of the device like the sensor chip and then I just change the cheap components if it's compromised by water but my main priority would be finding a way to make it as water proof as possible inside the box, lots of silica gel around the seal and either washers or a cable glad for the sensor.

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Offline TonyG

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #58 on: October 19, 2020, 11:22:55 am »
Hi

I installed a very similar water height module in Pooles Cavern, worked fine for a couple of months over the lock-down, but eventually died due to water ingress, as most things do!
Bit more work to be done in 'potting' the sonic head.
The accuracy of the sonic unit is very dependent on the temperature, when using it outside an error of +/- 1cm (over 2m) can be seen during a warm day, luckily for cave use this is fine.
Details of the unit and other stuff is on my website.  goodsellsystems.ltd

Offline TheBitterEnd

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #59 on: October 19, 2020, 07:44:51 pm »
Radiospares and the like sell the sealed automotive ultrasonic transducers and they seem to survive the wet for years, just a thought.
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Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #60 on: October 19, 2020, 08:00:50 pm »
Hi Tony, yep to give you credit it did steal your ultra sonic sensor idea. I was going to use a pressure sensor and put the logging device under water, which would mean I could put it in more interesting places but the risk of damage/loss was too much for me to bear.



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Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #61 on: October 19, 2020, 08:38:32 pm »
Just watching Andrew Smith talking about the cave science research center in Poole cavern now, it looks like it might be a good place to do an bench mark test my loggers.



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Offline Edwardov

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #62 on: October 20, 2020, 08:46:31 am »
Hello all,

I stumbled across this thread after I had an idea a few days ago for using AI to monitor environmental conditions in underground spaces, namely mine air quality, but I equally thought that it could be applied to caves.

I am a data scientist in my day job where I used AI to solve a wide variety of problems and I have been a caver for several years now, so it made sense!

A great place for global hourly weather data is here https://rda.ucar.edu/datasets/ds094.1/

I too have come up against the problem of having insufficient data of scenario (external conditions) and outcome (cave water depth/air quality) for time-dependent supervised machine learning, but I have found this additional source which got me interested in finding equivalent data for UK caves https://carrollcave.org/?p=3328.

If you want to talk about the AI side of things or if you have any questions, let me know and I'll happily help you out in exchange for some cave data.

Cheers

Online AR

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #63 on: October 20, 2020, 09:16:33 am »
I'd suggest getting in touch with the BCRA, they've recently set up a permanent logging station in Poole's Cavern, Buxton. I can't remember offhand all of what's being monitored but they are keen to increase usage of the data. I think you can also get datasets from the nearby Harpur Hill weather station.
Dirty old mines need love too....

Offline Bob Mehew

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #64 on: October 20, 2020, 09:33:28 am »
I'd suggest getting in touch with the BCRA, they've recently set up a permanent logging station in Poole's Cavern, Buxton. I can't remember offhand all of what's being monitored but they are keen to increase usage of the data. I think you can also get datasets from the nearby Harpur Hill weather station.
The web site is at https://www.cave-science.org.uk/.  I also have some CO2 data for another cave which is puzzling.  PM me if you want more info.

Offline Edwardov

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #65 on: October 20, 2020, 10:06:46 am »
I'd suggest getting in touch with the BCRA, they've recently set up a permanent logging station in Poole's Cavern, Buxton. I can't remember offhand all of what's being monitored but they are keen to increase usage of the data. I think you can also get datasets from the nearby Harpur Hill weather station.
The web site is at https://www.cave-science.org.uk/.  I also have some CO2 data for another cave which is puzzling.  PM me if you want more info.

Thanks for the info both. The CO2 and meteorological data for Poole's Cavern look really interesting and I can add additional data (wind etc), but this is missing visitor data to really understand the relationship as clearly this will have an effect on the CO2 levels. Any idea if such data exist?

Offline Bob Mehew

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #66 on: October 20, 2020, 11:08:11 am »
... this is missing visitor data to really understand the relationship as clearly this will have an effect on the CO2 levels. Any idea if such data exist?
There is data from the early part of this year when no visitors went in due to the lock down.  Visitor numbers are probably tracked by the Buxton Civic Association but I don't know if they release them.  That will require some negotiation via the BCSC team.  See my PM. 

Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #67 on: October 20, 2020, 09:18:32 pm »
Hey Edwardov,

Yep, any help with the data interpretation would be great Ari Cooper Davis has expressed interest in helping with this also. I'm far more comfortable with the hardware side of things. And even then for this I'm merely modifying existing logger designs https://thecavepearlproject.org/how-to-build-an-arduino-data-logger/ with my primary motivation being to put together cheap and accurate enough loggers to get a better idea of how popular dales caves flood after it rains.

Quick update: I've now changed the design/code so I can turn the sensors and screen off when they're not needed to save power.



And done some experiments to see how efficient it is (see graph below), the bottom axis is about 20 seconds long*, I'm using a INA219 module to monitor current and voltage, the voltage holds steady at 3.3V while the current changes depending on what the device is doing. The device is in sleep mode by default, the plot shows 2 logging events, each event has 2 current peaks, the first is the sensor activating and taking a reading, the second is the SD card writing to file before going back to sleep I think.



In sleep mode it averages a power consumption of around 3 mA with 2 18650 cells so in theory should last around 2000 hours depending on the logging frequency.


« Last Edit: October 20, 2020, 09:27:21 pm by blhall195 »

Offline mikem

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #68 on: November 02, 2020, 06:25:07 pm »
Just to illustrate the problem of using rain gauge data -  in last 24 hours dartcom (at Princetown) recorded 40mm of rain, haytor is less than 15 miles away (still on the top of dartmoor, but in the rain shadow), but only got 10mm. Gauges on all sides of the moor (at lower altitudes) recorded no more than 5mm.

Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #69 on: November 02, 2020, 07:01:27 pm »
Just to illustrate the problem of using rain gauge data -  in last 24 hours dartcom (at Princetown) recorded 40mm of rain, haytor is less than 15 miles away (still on the top of dartmoor, but in the rain shadow), but only got 10mm. Gauges on all sides of the moor (at lower altitudes) recorded no more than 5mm.

I see, I've just applied for access to the Met Office's Nimrod System which apparently provides 1 km Resolution UK Rainfall Data from radar stations. There's almost certainly limitations to obtaining data in this way too but we'll see what it looks like.

https://catalogue.ceda.ac.uk/uuid/27dd6ffba67f667a18c62de5c3456350

I was going to get radar data from the Met Office DataPoint system but it looks like that is being discontinued soon. 

Offline mikem

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #70 on: November 03, 2020, 07:21:23 am »
The two I mentioned are the only ones I know in UK that are actually on hilltops, whereas majority are in the surrounding valleys. It's quite normal for rainfall at Princetown to be twice that at Haytor, but on this occasion, it was four times & that was not because the storm missed that point, it was just heavier on the top (prevailing weather side) of the moor.

Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #71 on: November 03, 2020, 09:49:46 am »
The two I mentioned are the only ones I know in UK that are actually on hilltops, whereas majority are in the surrounding valleys. It's quite normal for rainfall at Princetown to be twice that at Haytor, but on this occasion, it was four times & that was not because the storm missed that point, it was just heavier on the top (prevailing weather side) of the moor.

Kind of like this?



The good news is that this morning the MetOffice approved my application to access NIMROD high-resolution radar data until November 2023 when I will have to reapply, so will be interesting to see if this effect shows up on radar too.
« Last Edit: November 03, 2020, 10:03:06 am by blhall195 »

Offline mikem

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #72 on: November 04, 2020, 08:31:03 am »
It would be very interesting to see how the radar data for Princetown compares to what's actually recorded on dartcom, as a test of its accuracy. Is it only future events you'll have access to, or past as well? As there's not much rain forecast in immediate future (down here anyway).

Offline Andy Walsh

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #73 on: November 04, 2020, 09:03:42 pm »
note
Flooding can be delayed by 2 or more hours
See the Cave Explorers by Jim Eyres Pages 41-45 --A very violent thunderstorm + heavy rain before breakfast and a trip to a dry Easegill which flooded violently while they were underground a near miss
Also on page 45 he says that dry ground does not soak up water nor as he says does even dry sand-and it runs off if the ground is saturated so the most dangerous is after a prolonged drought or after prolonged drought A sudden thaw after a lot of snow on wet ground is impressive.Kingsdaleis quite good for delayed floods
Some places like Sleets Gill have a longish delay mainly due to delay supply from perculationwater supply

Offline blhall195

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Re: Is it safe to go caving yet? Modelling cave flood events in Yorkshishire
« Reply #74 on: November 04, 2020, 09:15:18 pm »
The radar data is past/present only, dates back almost 10 years with 5 min time resolution. Currently having trouble interpreting the files though, they're in a proprietary format that's hard to convert into something I can work with.



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