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Hierarchical controls on river channel morphology in montane catchments in the Cairngorms, Scotland

The character of montane channel morphology and associated hierarchical controls was investigated in the Dee catchment, Cairngorm Mountains, north-east Scotland. Montane channel morphology in Scotland is of considerable importance given its relatively undisturbed condition in a UK context, variety and for providing habitat for several important lotic species. Nine distinctive sub-catchments were chosen to investigate the linkages between landscape controls and channel morphology distribution. The distribution of channel morphology at the reach scale was mapped using an expanded version of a process-based classification system originally developed in the Pacific northwest, USA. Continuous mapping revealed a wide variety and irregular distribution of channel morphology that is influenced primarily by a suite of glacigenic valley bottom controls. Differences in channel morphology distribution were apparent between catchments reflecting the influence of unique landscape evolution histories. In addition, fifty reaches exhibiting a variety of morphology and associated geomorphic setting, were surveyed in the field to explore in more detail controls on channel morphology. The results generally confirm the relevancy of the typology in the region and the dominant control exerted by slope. However the importance of scale, local controls and the regional geomorphic context was also highlighted. Finally, GIS approaches to channel characterisation at the catchment scale were tested to assess their potential usefulness for catchment management applications. By using a combination of the previous results, GIS models were calibrated and tested to predict the distribution of channel type and Atlantic salmon spawning habitat. The accuracy of channel type predictions were compromised by the model criteria and quality of geospatial data used. However the potential utility of the spawning habitat model as a first order method for screening habitat suitability over large areas was demonstrated.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:558573
Date January 2009
CreatorsAddy, Stephen
PublisherUniversity of Aberdeen
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=135792

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