Understanding the spatial and temporal dynamics of catchment systems is crucial to understanding how hydrological behaviour may change over time and how this impacts on crucial aspects of catchment management such as flood generation, water resource management and the sources and fluxes of sediment, nutrients and contaminants. A combined statistical analysis was undertaken to assess whether similar catchment groupings respond to changing climatic drivers in the same way. A k-means cluster and PCA analysis grouped catchments in four clusters, which were differentiated by their topographical differences between lowland and upland catchments. Lowland catchments exhibited similar behaviours to changing trends of key hydroclimatic variables whereas more upland catchments showed diverse responses. We assessed the behaviour of 8 mesoscale catchments with increasing lowland areas for spatial and temporal runoff dynamics via the application of environmental tracers (stable isotopes and Gran alkalinity). Mean transit times were estimated using a lumped convolution integral model and lowland catchments with greater coverage of sedimentary bedrock exhibited longer turnover for water and solute fluxes. Tracer data was then implemented into a conceptual rainfall-runoff model to develop a model, which could represent both spatial and temporal dynamics rather than simply recreating the observed stream hydrograph. Finally, we assessed the role of dominant landscape characteristics (urban environments and grazing pastures) on the sources and fluxes of microbial contaminant risk to water quality. Catchments which had larger urban coverage and higher portion of grazing pastures yielded higher concentration fluxes of faecal coliforms which provided a first-order approximation of water quality risk at the catchment scale.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:575387 |
| Date | January 2012 |
| Creators | McGrane, Scott James |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=195978 |
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