Sunday 31st May 2015
At the last indoor meeting Chris Martin ( Clwyd-Powys Archaeological Trust,CPAT) gave a very interesting talk on the evolution of CPAT from its inception in 1975 to the present day. CPAT is one of four Welsh archaeological trusts, with most of its work being in the Clwyd-Powys area.
CPAT commenced for the recording of archaeological information obtained from excavations which then evolved to include all other types of archaeological data. The data was, at first, kept on paper records but then became computerised and known as the “ Historical Environmental Record”. Information for the records was obtained from a wide range of sources, including old maps, OS records, aerial photography and much more. The record itself covers many areas, including,standing stones, iron-age enclosures, Medieval castles, agricultural buildings and defence and industrial remains. More recently, not only the sites are recorded but the environment in which they are located is also recorded. Therefore information about turnpikes, strip fields and canals now appear in the record.
Chris then went on to explain the methodology of record collecting. There are two different methods used:Firstly, The registry of landscapes of outstanding and special historic interest in Wales and historic landscape characterisation. This looks at the historic content of the landscape and gives purely a narrative story. Secondly, the historic landscape aspect known as LANDMAP. This looks at the surviving historical elements in the modern landscape. It looks at different aspects within the landscape and then produces a digital map. Both of these methods were developed by Cadw, CCW (Countryside Council for Wales) and the Welsh Archaeological Trust. All the information gathered can be used to provide advice to planning authorities, farmers, landowners, and environmental organisations.
All the above was brought together by looking at the report produced on the Historic Settlements in Flintshire.
The next indoor meeting will be on Wednesday 17th June when Tony Thorpe will give a talk entitled: “Concretions and How they Form.”
Sunday 10th May 2015
The next event will take place on Wednesday 20th of May where guest speaker Chris Martin (CPAT) will deliver his talk “Historic Landscapes in Wales: the work of Clwyd Powys Archaeological Trust”
Tuesday 7th April 2015
The next event will be on the 15th of April, where Roy McGurn will be giving his talk on The Geology of War
Wednesday 25th March 2015
A very informative talk was given by Kevin Voyce ( Hydrogeologist, Environment Agency) on the strategic water resource management of the River Severn catchment.
The upper River Severn catchment, here in Mid-Wales, is underlain by Ordovician and Silurian mudstones, shales and grits. These rocks have a low permeability and therefore do not store water, so that most of the water stored is above ground. The Clywedog dam was built in the 1960's to regulate the flow in the River Severn. If flow in the river is low, a release valve can be opened to release water from the reservoir and into the river to provide flow. The ground water storage in Mid-Wales contrasts sharply with that found across the border in Shropshire. Here the rocks consist of Permo-Triassic sediments of sandstones and mudstones. The sandstones have large pore spaces and therefore large storage capacity and high transmissivity. A scheme for supplementing the River Severn flow via use of the ground water has been set up. This required the drilling of a line of boreholes which draw water from the groundwater reserves and pump the water into the river to enhance flow.
Thus the hydrogeologist needs to understand the properties of the rock, how much water it can store and its transmissivity. Also knowledge the presence of joints and faults in the rock is necessary as this can markedly affect storage and flow within the aquifer. Abstracting water from the aquifer may also lead to problems in nearby areas, for example with a wildlife reserve or a private borehole. Therefore safeguards must be put in place to protect other water users and monitoring must be undertaken. This includes checks on water levels, chemical analysis and monitoring of wildlife populations. The aim of the agency is to have a minimal environmental impact.
With growing population and therefore increasing requirements for water and the challenge of climate change the Environment Agency must work to be able to balance the growing needs with that of a dwindling resource. This will require water resource planning for the longer term and to secure the preservation of surface and ground water reserves.
The next meeting will be on Wednesday 15th April when club member Roy McGurn will give a talk entitled “ The Geology Of War”
On Sunday 26th April there will be a field trip to Hendre Quarry, near Ysbyty Ystwyth. Leader will be Prof. David James.
Tuesday 10th March 2015
The next event will be on the 18th of March where guest speaker Kevin Voyce of the Environment Agency will be giving a talk on "Strategic groundwater management"
