Use of non-parametric statistics as a tool for the hydraulic and hydrogeochemical characterization of hard rock aquifers by David Banks, Geir Morland, and Bjørn Frengstad Scottish Journal of Geology Volume 41(1):69-79 April 1, 2005 © 2005 Scottish Journal of Geology

Water leakages in the Hvaler tunnel (after Banks et al. Water leakages in the Hvaler tunnel (after Banks et al. (1992), reproduced with permission of the Geological Society Publishing House). Note that zones of water leakage and injection grouting do not necessarily coincide with fracture zones as detected by geophysics and in the tunnel itself. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Histogram showing the frequency distribution of the borehole yield data set for 24 boreholes in the Iddefjord Granite of Hvaler (Table 1). Histogram showing the frequency distribution of the borehole yield data set for 24 boreholes in the Iddefjord Granite of Hvaler (Table 1). David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Cumulative frequency distribution diagram for the borehole yield data set for 24 boreholes in the Iddefjord Granite of Hvaler (Table 1). Cumulative frequency distribution diagram for the borehole yield data set for 24 boreholes in the Iddefjord Granite of Hvaler (Table 1). The median is located at cumulative probability = 0.5, the 25th percentile at cumulative probability = 0.25 etc. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Cumulative frequency diagram showing yield distribution curves for Norwegian water boreholes in the Precambrian Iddefjord Granite, Cambro-Silurian metasediments of the Norwegian Caledonian terrain, and Precambrian gneisses. Cumulative frequency diagram showing yield distribution curves for Norwegian water boreholes in the Precambrian Iddefjord Granite, Cambro-Silurian metasediments of the Norwegian Caledonian terrain, and Precambrian gneisses. The '1001/h' guideline shows the approximate 10% yield for most lithologies (i.e. 90% of wells yield better than this figure).The 50% and 72% guidelines show the median yield and the 72% yield for the Iddefjord Granite. After Banks & Robins (2002) and based on data from Morland (1997). Reproduced with permission from the Geological Survey of Norway. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Cumulative plots of total predicted borehole yields from the i best wells out of b drilled. Cumulative plots of total predicted borehole yields from the i best wells out of b drilled. These plots are based on a Swedish data set of (rather good) boreholes, sited on the basis of Very Low Frequency (VLF) geophysical measurements (see Müllern (1980) for a description of the VLF technique), and with a median yield of 36001/h for single wells (note that the median yield of all Swedish hard rock wells, whether sited by VLF methods or not, is only some 6001/h (n = 59 000)). After Gustafson (2002) and reproduced with the permission of the Geological Survey of Norway. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Boxplots illustrating the distribution of borehole yields within different lithological subgroups in Norway (after Morland 1997). Boxplots illustrating the distribution of borehole yields within different lithological subgroups in Norway (after Morland 1997). The numbers on the left vertical axis refer to the lithological group (Table 2), those on the right give the total number of boreholes (#) in each subgroup. The 'box' of the boxplot contains the central interquartile range of data, with a line at the median value (and square parentheses giving the 95% confidence interval on the median). The 'whiskers' show the extraquartile data range, with squares showing extreme outlying data. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Morland's (1997) data set of Norwegian bedrock boreholes, with median normalized yield (1/h per drilled metre) plotted against lithological subgroup (see Table 2) in descending order from left to right. Morland's (1997) data set of Norwegian bedrock boreholes, with median normalized yield (1/h per drilled metre) plotted against lithological subgroup (see Table 2) in descending order from left to right. Also shown are median total yield (1/h per borehole) and median borehole depth (m). David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Correlation between well yield and total postglacial isostatic uplift; the diagram shows the median yield of boreholes in Norwegian Precambrian rocks per metre drilled depth as a function of annual land uplift. Correlation between well yield and total postglacial isostatic uplift; the diagram shows the median yield of boreholes in Norwegian Precambrian rocks per metre drilled depth as a function of annual land uplift. After Morland (1997); Banks & Robins (2002), and reproduced with the permission of the Geological Survey of Norway. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Boxplots displaying distribution of laboratory-determined pH values in Norwegian hard rock groundwater, sorted according to lithological groups (see Table 2). Boxplots displaying distribution of laboratory-determined pH values in Norwegian hard rock groundwater, sorted according to lithological groups (see Table 2). For comparison, boxplots are displayed on the extreme left showing: the entire data set for all hard rock groundwaters (‘Bedrock’, n - 1604), for groundwaters from superficial drift aquifers (‘Drift’, n = 72) and for n = 1 surface water works (‘Surface water’, n = 1). See Banks et al. (1998b, 2000). David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Boxplots displaying distribution of uranium concentrations (determined by ICP-MS, in jig/1) in Norwegian hard rock groundwater, sorted according to lithological groups (see Table 2). Boxplots displaying distribution of uranium concentrations (determined by ICP-MS, in jig/1) in Norwegian hard rock groundwater, sorted according to lithological groups (see Table 2). For comparison, the extreme right-hand boxplot shows the entire data set for all hard rock groundwaters (‘Bedrock’, n - 476). See Frengstad et al. (2000); Banks et al. (2000). The apparently elevated concentrations in group 72 are, on detailed inspection, also related to minor granitic inliers within that group (Frengstad et al. 2002). Data below the analytical detection limit are plotted at a value of half the detection limit for the purposes of graphical presentation. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology

Boxplots comparing distribution of selected parameters in granitic groundwater from the Hvaler Islands (n = 11) with granitic groundwater from the Isles of Scilly (n = 10). Boxplots comparing distribution of selected parameters in granitic groundwater from the Hvaler Islands (n = 11) with granitic groundwater from the Isles of Scilly (n = 10). Based on data published by Banks et al. (1998a). Data below the analytical detection limit are plotted at a value of half the detection limit for the purposes of graphical presentation. David Banks et al. Scottish Journal of Geology 2005;41:69-79 © 2005 Scottish Journal of Geology