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

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 (r2 = 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 (r2 = 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.