Temporal and spatial variability of stream waters in Wales, the Welsh borders and part of the West Midlands, UK — 1. Major ion concentrations

Temporal and spatial variability of stream waters in Wales, the Welsh borders and part of the West Midlands, UK — 1. Major ion concentrations Pages 3479-3491 M. G. Hutchins, B. Smith, B. G. Rawlins, T. R. Lister Close preview | Purchase PDF (315 K) | Related articles | Related reference work articles Abstract Abstract Spatial and temporal controls on major ion stream water chemistry are assessed using hydrochemical survey data for Wales and the West Midlands, and time-series data from the intensively studied Plynlimon catchment (mid-Wales). Spatial variations in stream water chemical composition are interpreted in relation to the environmental chemistry of the major ions and controls such as bedrock geology, land-use, anthropogenic activities and atmospheric inputs. Piper diagrams are used to illustrate compositional variation, allowing comparison to be made between samples of widely varying Total Dissolved Solids (TDS). Spatial and temporal data sets are overlaid on Piper plots to determine the relative importance of these two factors in controlling major ion chemistry. Bedrock geology, atmospheric input and land-use can satisfactorily explain compositional variation in the spatial data set. Combined analysis of the spatial and temporal data sets indicated that the variation in cation composition at the Plynlimon site is considerably more constrained than that on the corresponding anion diagram. Time-series data sets for sites of different bedrock geology and at a range of distances from sources of marine derived solute inputs are necessary for further investigation of the relative importance of temporal and spatial controls on major ion stream water chemistry.