Using transmissivity, specific capacity and borehole yield data to assess the productivity of Scottish aquifers

Abstract

Aquifer properties data from more than 3000 groundwater sources across Scotland have been collated to form the Scottish Aquifer Properties Database, coordinated by the Scotland and Northern Ireland Forum for Environmental Research. The aim of the project was to better understand Scotland's aquifers, through the collation of a comprehensive set of quantitative data. Analysis of 157 transmissivity values, 307 specific capacity values and 1638 borehole yield values shows that Quaternary and Permo-Triassic age aquifers are the most productive, followed by those of Devonian and Carboniferous age. There is a strong correlation between specific capacity and transmissivity (r 2 = 0.8), and the former may be used as a reliable indicator of aquifer productivity where no transmissivity data are available. The correlation between transmissivity and borehole yield data is significant (r 2 = 0.57), although the quality of the yield data is lower overall than that of the specific capacity or transmissivity data. These data support recent categorization of bedrock aquifer productivity in Scotland, which until now has been validated only with limited quantitative datasets.

Characteristics of high-intensity groundwater abstractions from weathered crystalline bedrock aquifers in East Africa

“…There is generally a good relationship between transmissivity and borehole yield (e.g. Graham et al 2009). Where transmissivity data are available, they confirm the patterns observed in the borehole yield data.…”

Geological structure as a control on floodplain groundwater dynamics

“…Hydraulic properties of the basal glaciolacustrine sediments were not directly tested, but glaciolacustrine silts and clays elsewhere in Scotland typically have low permeability (Lewis et al 2006;MacDonald et al 2005: for silts typically 10 −3 -10 −1 m day −1 and for clays typically 5 × 10 −7 -10 −3 m day −1 (Lewis et al 2006). Bedrock transmissivity at the site was not directly measured, but Silurian greywacke aquifers elsewhere in southern Scotland have low productivity (Ó Dochartaigh et al 2015) with an estimated average transmissivity of~20 m 2 day −1 (Graham et al 2009).…”

The role of numerical modelling in understanding groundwater flow in Scottish alluvial aquifers

“…Therefore, there has not been similar regional studies, as undertaken in England, to underpin the hydrogeological understanding of Scottish aquifers. This has been improved in the last decade with studies such as the Dumfries Basin (Akhurst et al 2006) and the completion of an aquifer properties study (Graham et al 2009). …”

“…The Spey valley contains highly permeable sands and gravels of glacial, glaciofluvial and alluvial origin deposited as the glacial ice retreated. The glacial outwash material can be poorly sorted and variable in character over short vertical and horizontal distances (Graham et al 2009). Aquifer permeability is dependent on variable lithologies and grain size distribution and is therefore highly variable.…”

“…However, groundwater may be the only reliable source of water for rural communities (Robins 1995;MacDonald et al 2005) and it has played an increasingly important role in both private and public water supplies (Graham et al 2009). Despite groundwater being a relatively under-used resource, it has been recognized as a potential source of public water supply (PWS) for a number of decades.…”