The importance of surface controls on overland flow connectivity in semi-arid environments: results from a numerical experimental approach

Reaney, S. M., Bracken, Louise J. and Kirkby, M. J. (2014) The importance of surface controls on overland flow connectivity in semi-arid environments: results from a numerical experimental approach. Hydrological Processes, 28 (4). pp. 2116-2128. ISSN 0885-6087

NRL_47304.pdf - Accepted Version

Download (523kB) | Preview
Official URL:


In semi-arid environments, the characteristics of the land surface determine how rainfall is transformed into surface runoff and influences how this runoff moves from the hillslopes into river channels. Whether or not water reaches the river channel is determined by the hydrological connectivity. This paper uses a numerical experiment-based approach to systematically assess the effects of slope length, gradient, flow path convergence, infiltration rates and vegetation patterns on the generation and connectivity of runoff. The experiments were performed with the Connectivity of Runoff Model, 2D version distributed, physically based, hydrological model. The experiments presented are set within a semi-arid environment, characteristic of south-eastern Spain, which is subject to low frequency high rainfall intensity storm events. As a result, the dominant hydrological processes are infiltration excess runoff generation and surface flow dynamics. The results from the modelling experiments demonstrate that three surface factors are important in determining the form of the discharge hydrograph: the slope length, the slope gradient and the infiltration characteristics at the hillslope-channel connection. These factors are all related to the time required for generated runoff to reach an efficient flow channel, because once in this channel, the transmission losses significantly decrease. Because these factors are distributed across the landscape, they have a fundamental role in controlling the landscape hydrological response to storm events.

Item Type: Article
Additional Information: Funding information: This work was funded by the School of Geography, University of Leeds, studentship to S. M. Reaney, financial support from the EU PESERA project and an RCUK Fellowship at Durham University. Prof. Rob Ferguson, Durham University, provided valuable support in refining this paper.
Uncontrolled Keywords: Runoff, Hydrological connectivity, CRUM, Surface, Vegetation, Slope, Semi-arid, Overland flow.
Subjects: F800 Physical and Terrestrial Geographical and Environmental Sciences
Department: Faculties > Engineering and Environment > Geography and Environmental Sciences
Depositing User: Elena Carlaw
Date Deposited: 21 Sep 2021 13:49
Last Modified: 21 Sep 2021 14:00

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics