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Representation of landscape hydrological connectivity using a topographically driven surface flow index.

Lane, S. N. and Reaney, S. M. and Heathwaite, A. Louise (2009) Representation of landscape hydrological connectivity using a topographically driven surface flow index. Water Resources Research, 45 (8). W08423. ISSN 0043-1397

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    Abstract

    This paper assesses the extent to which a topographically defined description of the spatial arrangement of catchment wetness can be used to represent landscape hydrological connectivity in temperate river catchments. A physically based distributed hydrological model is used to characterize the space‐time patterns of surface overland flow connection to the drainage network. These characterizations are compared with a static descriptor of the spatial structure of topographically controlled local wetness, called here the Network Index. Theoretically, if topography is the primary control upon hydrological response, the level of catchment wetness required to maintain connectivity along a flow path should be greater for flow paths that have a lower value of the topographically controlled local wetness. We find that our static descriptor can be used to generalize a significant proportion of the time‐averaged spatial variability in connectivity, in terms of both the propensity to and duration of connection. Although the extent to which this finding holds will vary with the extent of topographic control of hydrological response, in catchments with relatively shallow soils and impervious geology our index could improve significantly the estimation of the transfer of sediment and dissolved materials to the drainage network and so assist with both diffuse pollution and climate change impact studies. The work also provides a second reason for the concept that there are Critical Source Areas in river catchments: these arise from the extent to which that material can be delivered to the drainage network, as well as the generation of risky material itself.

    Item Type: Article
    Journal or Publication Title: Water Resources Research
    Additional Information: ©2009. American Geophysical Union. All Rights Reserved.
    Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
    Departments: Faculty of Science and Technology > Lancaster Environment Centre
    ID Code: 31422
    Deposited By: Mr Richard Ingham
    Deposited On: 15 Jan 2010 15:14
    Refereed?: Yes
    Published?: Published
    Last Modified: 26 Oct 2013 00:02
    Identification Number:
    URI: http://eprints.lancs.ac.uk/id/eprint/31422

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