Mapping the Bournes of Great Britain

The Ordnance Survey released new Open Data datasets in March 2015, including a comprehensive shapefile of watercourses, the Open Rivers dataset. Being interested in groundwater-fed rivers I was curious to see the distribution of ‘bournes’ (typically ephemeral groundwater-fed streams). A map I made of the top six watercourse names is here.

I expected almost all ‘bournes’ would be chalk groundwater-fed streams but the Midlands has a lot of ‘bournes’ too. Mostly in the Midlands these are named ‘Bourne Brook’, a tautology (like all the River Avons). There is a handful of River Bournes as well.

But most of the ‘bournes’ are associated with the outcrop of the Chalk aquifer, as expected. A bourne is a small stream, which is typically ephemeral. Bournes that flow through the Chalk Downs are often associated with groundwater flooding – especially in the upper reaches which flow seasonally.

Watercourses named 'Bourn', 'Bourne' or 'Borne' and bedrock geology

Watercourses named ‘Bourn’, ‘Bourne’ or ‘Borne’ and bedrock geology

Mapping Names of Watercourses in Great Britain

The Ordnance Survey released new Open Data datasets in March 2015, including a comprehensive shapefile of watercourses, the Open Rivers dataset. Being interested in groundwater-fed rivers I was curious to see the distribution of ‘bournes’ (groundwater-fed streams).

First I grouped and plotted up all the river names. Whilst ‘river’ is ubiquitous, the names for smaller watercourses are not, and the geographic divisions are striking (below).

But then I wonder – is this a function of local dialect or of Ordnance Survey naming convention? I don’t know – does anyone?

Names of rivers in Great Britain, from Ordnance Survey Open Data

Names of rivers in Great Britain, from Ordnance Survey Open Data

Analysis of Water Quality Changes in a Brewery Borehole

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My client, a brewery in North West England, operates a groundwater abstraction to provide water for the brewing process. A reverse osmosis plant was installed in 2004. Since then water quality from the borehole has deteriorated; this has been monitored directly and has been experienced as increasingly frequent replacement of the plant membranes. I was asked to assess the available data, take and analyse water samples, and provide advice to recommend a remedial strategy. Continue reading

Researching Water-Friendly Slug Pellets

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UK drinking water sources are intermittently contaminated with metaldehyde released from slug pellets. There is no effective technique for its removal from drinking water so to avoid contamination of water supplies the water is often run to waste.

Lipodisqs®, developed and patented by Malvern Cosmoceutics Ltd (MCL), comprise a biodegradable nano-sized (20 nm) cylinder of polymer within which a lipid can be placed. Lipodisqs® are currently used to topically deliver poorly soluble cosmetic preparations, which can be dissolved in the lipid. With funding from Innovate_UK I commissioned MCL to investigate whether using Lipodisqs might offer a viable solution to these pollution problems.

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Why are Chalk Valleys Most Prone to Groundwater Flooding?

As I write this, communities in Dorset, Hampshire, Berkshire, Wiltshire, Surrey and West Sussex are suffering from groundwater flooding. Exceptional winter rainfall has caused the water table to rise above the ground surface, so that groundwater is emerging in springs, stream beds and sewers across the South of England. All of the villages in the news that I’ve seen, with groundwater flooding are on, or just downstream of, the Chalk aquifer (Chalk outcrop is pale green in the image below). Why the Chalk in particular?

Chalk groundwater flooding

Some locations with groundwater flooding, January 2014

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Insurance and Groundwater Flooding

A number of clients have been in touch, via GroundwaterFloodRisk.co.uk after buying a home, and then finding out that insurance terms are onerous because of perceived risk of groundwater flooding. Some insurers, as standard, exclude damage caused by ‘a rise in water level’. But shopping around, you can find insurers that don’t exclude this.

However, as with the companies providing homebuyers searches, some of these insurers aren’t applying groundwater susceptibility data appropriately. A recent client, despite having bought a home in an area of negligible risk of flooding from rivers or surface water, had an annual excess of £5000 for any damage caused by groundwater flooding. According to groundwater flooding susceptibility maps her property had ‘very high’ susceptibility. Fortunately I was able to provide a reality check on the map results that enabled my client to work with the insurers to get a sensible quote. Continue reading

Using groundwater model results to estimate baseflow contribution to flooding in Hull

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While we* were developing the groundwater resource model for the Yorkshire Chalk aquifer, we were asked to provide estimates of extreme baseflows to the River Hull headwaters. Most of the material in this post was delivered, on behalf of ESI Ltd, by Dr Steve Buss at the British Hydrological Society Pennines Group conference on Groundwater Flooding, in Leeds, on 1 October 2013.

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Ploughing up permanent pasture may cause elevated nitrate concentrations in public groundwater supply abstractions

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As part of a study into nitrate transport within groundwater catchments, for United Utilities, we* noted some interesting features in nitrate concentration trends of groundwater abstraction boreholes around Delamere, Cheshire. Most of the material in this post was delivered, on behalf of ESI Ltd, by Dr Steve Buss at the Meres and Mosses Forum conference, at Cholmondeley Castle, on 20 September 2013. Continue reading