Urbanisation impacts on storm runoff along a rural-urban gradient

Miller, James David ORCID: https://orcid.org/0000-0002-7705-8898; Hess, Tim. 2017 Urbanisation impacts on storm runoff along a rural-urban gradient. Journal of Hydrology, 552. 474-489. 10.1016/j.jhydrol.2017.06.025

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Official URL: https://doi.org/10.1016/j.jhydrol.2017.06.025

Abstract/Summary

Urbanisation alters the hydrological response of catchments to storm events and spatial measures of urban extent and imperviousness are routinely used in hydrological modelling and attribution of runoff response to land use changes. This study evaluates whether a measure of catchment urban extent can account for differences in runoff generation from storm events along an rural-urban gradient. We employed a high-resolution monitoring network across 8 catchments in the south of the UK - ranging from predominantly rural to heavily urbanised - over a four year period, and from this selected 336 storm events. Hydrological response was compared using volume- and scaled time-based hydrograph metrics within a statistical framework that considered the effect of antecedent soil moisture. Clear differences were found between rural and urban catchments, however above a certain threshold of urban extent runoff volume was relatively unaffected by changes and runoff response times were highly variable between catchments due to additional hydraulic controls. Results indicate a spatial measure of urbanisation can generally explain differences in the hydrological response between rural and urban catchments but is insufficient to explain differences between urban catchments along an urban gradient. Antecedent soil moisture alters the volume and timing of runoff generated in catchments with large rural areas, but was not found to affect the runoff response where developed areas are much greater. The results of this study suggest some generalised relationships between urbanisation and storm runoff are not represented in observed storm events and point to limitations in using a simplified representations of the urban environment for attribution of storm runoff in small urban catchments. The study points to the need for enhanced hydrologically relevant catchment descriptors specific to small urban catchments and more focused research on the role of urban soils and soil moisture in storm runoff generation in mixed landuse catchments.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.jhydrol.2017.06.025
UKCEH and CEH Sections/Science Areas:	Reynard
ISSN:	0022-1694
Additional Keywords:	urbanisation, storm runoff, hydrological response, antecedent soil moisture, catchment descriptor
NORA Subject Terms:	Hydrology
Date made live:	07 Sep 2017 11:55 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/517476

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.jhydrol.2017.06.025

UKCEH and CEH Sections/Science Areas:

Reynard

ISSN:

0022-1694

Additional Keywords:

urbanisation, storm runoff, hydrological response, antecedent soil moisture, catchment descriptor

NORA Subject Terms:

Hydrology