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02/07/2018

Hydrogeochemical musings. The attached photo is of a large whitish blob of material which is being deposited by a spring adjacent to the Brecon Canal, near Gofilon, in turn near Abergavenny. At first I (rather cynically) assumed it was caused by a contaminated discharge, being precipitation of washing powder residue or whatever. However, further thought/investigation suggests there's very little upgradient which could be held accountable, and I'm now thinking it's a fairly spectacular tufa deposit. Time to get myself organised with a field bottle of dilute acid!

09/05/2018

Miraculously managed to schedule fieldwork during some great weather last week. Working on Dersingham Bog, NW Norfolk, with Ash Murray (Natural England site manager), Professor Andy Baird (Leeds University), and Jhon del Aguila Pasquel (Instituto de Investigaciones de la Amazonia Peruana). The main aim was to collect peat cores for Pb-210 dating, to test our theory that much of the shallow peat has accumulated recently following widespread peat mining for fuel. This involved advancing a drainage tube downwards by cutting the peat using florists scissors until the top of the tube was at ground level, when you could extract it by cutting across its base - slightly surreal (see photos), but extremely effective!!
Also downloading water level loggers, carrying out peat permeability tests and levelling in some dipwells and piezometers.
I also managed to dust off the panorama rig for the camera (again, see photos).
Great time had by all I think!

27/04/2018

A double helping of rare business publicity today!
#1. I gave a talk yesterday at The Hydrogeology of the Chalk conference at the Geological Society in London, titled (catchily...) "Simultaneous vulnerability and robustness of a rare basophilic fen wetland community in a Chalk-fed fen under long-term abstraction pressures", with co-authors Adrian Hutchings, Sue Morris, Helen Harfoot (all Jacobs at the time) and Emma Goddard (South East Water). Photo shows me in action, explaining how the site conforms largely to a generic conceptual model of fen ecohydrological functioning.
And #2. Another paper published from the Panama odyssey in 2015. Questions on testate amoeba should most definitely be directed to the lead author, Graeme Swindles @ Leeds University!

18/01/2018

The (in-)famous Llanwrtyd Wells bog-snorkelling championships take place on a small part of a much larger peatland called Waen Rydd. Previous studies have suggested that the northern part of Waen Rydd was a large raised bog, but its current complex micro-topography and community distribution are a result of extensive historical peat mining and drainage. For the last 12+ months NRW (through Rigare) have been logging and interpreting spatial and temporal variations in water table elevation. A large plastic sheet-pile dam has also been installed in a natural drainage constriction in order to raise water levels over a significant part of the site.
A visit today to download loggers and discuss peatland restoration options. Showery, a bit windy and a bit cold, but not as bad as it could have been - although took a long time to warm up when I got home!!

12/01/2018

A great day at Betley Mere & peatland in Staffordshire yesterday, re-confirming that air temperature is exceedingly dependent on whether the sun is out on a cold, anticyclonic day in winter!! The B&W photo is of part of the wet woodland which fringes part of the mere. Some very dry areas of peat to be investigated.....

16/10/2017

I’ve been inundated by a letter from a Mrs Trellis from North Wales who says, “I’m considering looking at the hydrology of what could charitably be described as the morass out the back here, but I’m really not sure how deep I should make my dipwells so that I can monitor the elevation of the phreatic water table effectively. Can you help?”
Well Mrs Trellis, I’m told there’s actually lots to do in North Wales, but if you’re committed I might be able to help. Before we embark on the nitty-gritty, may I congratulate you on your appreciation of the terms dipwell and phreatic water table, which saves quite a bit of time, although could I suggest that referring to your morass as a wetland might sound a bit more positive!
Now, it’s all a bit of a balancing act really, with two main considerations:
1. Dipwells need to be shallow enough that they don’t provide a conduit for flow in response to vertical hydraulic gradients. I’ll spare you the detail, but the worst-case here is creating your own geyser in the wetland, and having a profound effect on what you’re trying to measure – not good (left-hand example in the diagram).
2. They need to be deep enough to measure the lowest water table elevation that you might be interested in, which depends on the type of wetland you have out the back. The water table in sand-dune wetlands (dune slacks) can go to 2 m below the surface, but normally any lower than 1 m below the surface means either that it’s not a wetland or that it’s got very serious (and probably obvious) hydrological problems (centre example).
Experience leads me to installing 1 m long dipwells to around 0.9 m depth, unless there is evidence to suggest, or a requirement to do, something different. This eliminates the two problems above (right-hand example).
Good luck with your hydrometric endeavors, and don’t hesitate to write again on related subjects….

10/10/2017

I succumbed to the pleasures of a late afternoon coffee on Sunday, which led to listening to a short section of Rhod Sharp's Up All Night on R5, whilst sleeping in the van. The section concerned tourist 'attractions' where wild animals are kept for people to take selfies with them. Suitably shocked, here's my reaction. This is me with the small Cladium mariscus (a.k.a. saw sedge) bed in Corsydd Llangloffan (Pembrokeshire), early in the morning whilst downloading water level loggers. The presence of the Cladium bed suggests a small area of calcareous groundwater influence - I fear an uphill struggle in trying to get people to work harder for their wildlife kicks!

11/09/2017

An interesting day on Saturday, talking to CIEEM members about humid dune slack ecohydrology and the recent hydrological impact assessment in relation to the Cornelly quarries and Kenfig SAC - I think everyone enjoyed the day!!
Many thanks to Dave Carrington, Kenfig site warden, for letting us use the site facilities, and also for guiding the afternoon site walk (there's a risk we would still be in the dunes if I'd guided it, which was the original plan). Thanks also to Mike Shewring, for organising the event (and for the illustrating picture).

01/09/2017

We're offering the chance for those with a technical interest to visit Pen y Cymoedd windfarm (nr. Hirwaun, S Wales), and see how we have assessed and remediated impacts on peat hydrology. Slightly short notice I'm afraid as it's on Thurs 14th September (09:30-16:00). It will include technical talks, a field visit, discussion and hospitality! Drop me an email if you would like to come, and spread the word to others who might have an interest please.

23/05/2017

Pen y Cymoedd windfarm is fully operational, and is almost all handed over from the construction team to the developers. Our peat-related hydrological remediation works have come to fruition, and I spent yesterday downloading water level loggers at five separate sites where we are monitoring the hydrological effects.
The principle is to collect diffuse water flow in the peat in an upslope collector trench, root it around windfarm infrastructure in ditches and through culverts, and then to allow it to diffuse into the downslope peat from a recharge trench. The picture shows a full recharge trench, after the weekend rain, to the right, downslope of a wind turbine area. I'm sure this technique can be refined, and I'd urge some research on this topic.
Worth also mentioning that we spotted the first ducks, a pair, seen on site (to our knowledge) during the construction period swimming around in one of our recharge trenches - unexpected biodiversity gain alert!!
My thanks to Jones Brothers and Vattenfall for supporting and carrying out the work to a high standard.
Also, congratulations to Tom Burbidge, named CECA Most Promising trainee Engineer of 2017. Tom has done the on-site surveying for all my ecohydrological work on Pen y Cymoedd, and has been a pleasure to work with - a well deserved award.

02/05/2017

I'm currently looking at water table elevation data for two famous lowland raised bogs in West Wales, Cors Fochno and Cors Caron. The main aim is to assess whether the recorded water level regimes are favourable for the raised bog communities (mostly NVC M18), and if they aren't to investigate why they aren't. The problem is that there is no consensus on what a favourable water level regime for raised bogs looks like or, to turn it around, which aspects of a regime might be unfavourable (damaging) to the communities. There is reasonable consensus that water levels shouldn't fall below 20-30 cmbgl, but in terms of the micro-topography of a raised bog surface, what do we take as the ground level? One of the images is a related graphic from my course on wetland hydrology, and the picture is from a recent day on Cors Fochno doing some level surveying around the long-term monitoring dipwells.
I'd like to do a research project to determine eco-hydrological guidelines for raised bogs, and it might be something I look to crowd-fund. Any comments welcome...

14/04/2017

Never let routine get in the way of (albeit exceedingly meagre, in my case) creative talents - for example, whilst preparing to install water level loggers in a bog!!

26/03/2017

A great visit to Cors Caron on Thursday, near Tregaron. This mire complex was the subject of one of the first studies on raised bogs, reported in Godwin and Mitchell (1938)*. NRW commenced intensive water level monitoring in 2012, with the help of ten water level loggers from Peter Westerhuis (then SWS Ltd) in Delft, Netherlands. Fifteen extra loggers have been added since then, and the loggers are distributed evenly over the three main bog domes. Many thanks to Ali Chedgy (NRW) for kindly transporting me around the large West Bog in the Softrak (low ground pressure vehicle). Twenty-four data-loggers downloaded with absolutely no problems, which doesn't happen very often in my experience!! I must now analyse the water level data to understand the hydrological functioning of the site, and predict its response to restoration.
* http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1938.tb06957.x/abstract

19/03/2017

Today was the annual coming together of the absolute need to do something, during the end-of-Financial Year work madness, and the weather. Specifically, marking out vegetation cutting zones for a habitat management trial on Maerdy windfarm, between Rhondda Fawr and Rhondda Fach in South Wales. Strong gusty wind and horizontal rain, together with wind turbines whizzing around with intimidating swishing sounds. At least it wasn't cold. Are any waterproofs waterproof in these conditions after 5 hrs? Not impressed, and neither was the dog, who didn't even have the advantage of malfunctioning clothing.

27/02/2017

A brief visit to Waun Fignen Felen last week, high on the fells above the Dan yr Ogof showcave in the upper Swansea valley, South Wales. Visibility about 30 m for most of the day, as I installed dipwells and tried to make sense of the challenging erosional landscape and processes in the peat. Teg took a liking to what are probably 1000's of years old sticks, and then slept for two days when we got down (it's those whippet and greyhound genes, or so he tells me....)

04/02/2017

After a spell of wet and windy weather, with the raw cold that only the UK can offer (I haven't travelled much!), a chance to get out with Teg. And after the heavy rainfall of the last couple of days the extremely ephemeral spring on the Blorenge was flowing. It's at 290 mAOD, around 220 m above the Usk valley floor. Because it flows very rarely, the shallow runnel it flows down is indistinguishable from the rest of the grassy field normally. It emerges from the Brownstones of the Devonian Old Red Sandstone, but perhaps I suspect the influence of the Carboniferous Limestone further south beneath the Blorenge. The low effective porosity of the limestone can cause the water table to rise rapidly with rainfall, and its high flow potential would explain the productivity of the spring when flowing - it was hammering out at 20-30 l/s this morning. A great hydrogeological feature.

27/01/2017

Two "experts" discuss the wetness of all-too-incedent Panamanian rain, whilst Deyvis gets on with the job in hand - clearing the path to ensure that arboreal snakes and the like are kept at arm's length, and also finding himself a questionably functional rainhat. This storm felt like all of Abergavenny's annual rainfall in about 15 minutes!!

26/01/2017

And some nice pictures from Panama..... . Is it really over two years ago?!

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Cwm Cadlan

A bit of overtime today at Cwm Cadlan NNR, near Penderyn; a gem of mosaics of groundwater irrigated alkaline fen (NVC M10b) and base-rich wet grassland (M24b). Some mild frustration in trying to install 1 m long dipwells when the auger was frequently being refused at 10 or 20 cmbgl by hard ground, with the consolation that a bit of thought and resourcefulness will be required to do what I want to do. The video shows warmer (10-11 degC?) groundwater flowing beneath a surface layer of ice - who needs 1970 lava lamps anyway - there for everyone! (My media capabilities stop short of swinging the video through 90 deg, sorry!)