National Water Inventory for Scotland (NWIS)

The National Waters Inventory for Scotland (NWIS) consists of surface and groundwater samples gathered over a 2 year timespan and analysed using novel analytical approaches not normally available from routine monitoring programmes. Measurements include:

- Isotopic characterisation to distinguish source provenance and transport processes within the natural ecosystem (Water δ2H and δ18O for source/flow pathway identification; Nitrate δ15N and δ18O for diffuse pollution source apportionment; Strontium 87Sr/86Sr for geological source apportionment).

- Organic matter characterisation to show the spatio-temporal variability of dissolved organic matter in the aquatic environment. The analysis measures the relationship between ultra-violet absorbance and dissolved organic carbon together with disinfection by-products (Trihalomethanes) formed from chlorination of naturally occurring organic and inorganic matter.

- Microbial characterisation shows Faecal Indicator Organism (Coliert©) concentrations in relation to catchment characteristics, improving our understanding of the transport of faecal micro-organisms and other pathogens.

Detailed description of the monitoring program measurements taken, including a map of the monitoring sites in:
Dawson, J.C.J., Avery, L.M., Baggaley, N.J., Cooper, P., Kemp, H.F., Meier-Augenstein, W., Brewer, M.J., Frew, D. and Dunn, S.M.: A National Waters Inventory for Scotland: new approaches to monitoring water quality. Proceedings of the BHS Eleventh National Symposium, Hydrology for a changing world, August 2012, Dundee.

Publication date: 2016-01-14


Study area
Temporal extent
2012-03-01    to    2014-05-01

Provenance & quality

Standard laboratory protocols and reference materials were used during analysis with resulting values falling within set detection levels.

Strontium isotope analysis methodology is described in: Bain, D.C. and Bacon, J.R., (1994) Strontium isotopes as indicators of mineral weathering in catchments. Catena, 22(3), pp.201-214. DOI:10.1016/0341-8162(94)90002-7

Oxygen and hydrogen analysis methodology is described in: Stöcker, F., Klaus, J., Pangle, L., Garland, T. and McDonnell, J., Isotope Hydrology: Monitoring Rainfall Events in Real Time. Retrieved Jan 20, 2017, from:

Nitrogen isotope analysis methodology is described in: Minet, E., Goodhue, R., Coxon, C.E., Kalin, R.M. and Meier-Augenstein, W. (2011) Simplifying and improving the extraction of nitrate from freshwater for stable isotope analyses. J. Environ. Monit., 13, pp.2062-2066. DOI: 10.1039/c1em10289c

Other contacts

Pat Cooper
The James Hutton Institute


Spatial representation type
Spatial reference system
OSGB 1936 / British National Grid


Topic categories
Biota , Environment , Farming , Inland Waters
Biological Quality Faecal Indicator Organisms National Tabular Water Quality