Professor Sim M. Reaney

Professor Sim M. Reaney

Professor in Catchment Hydrology

Talks and presentations

See a map of all the places I've given a talk.

How ‘Leaky’ Should a Leaky Dam Be?

April 02, 2025

Talk, River Restoration Centre Conference, Brighton, England

A. D. Jones (Durham University), J. L. A. Knapp (Durham University), S. M. Reaney (Durham University), I. Pattison (Heriot Watt)

The effect of land surface characteristics on runoff generation and nitrate fluxes from a Kenyan tea plantation

April 17, 2024

Talk, EGU, Vienna, Austria

Aaron Neill (1), Suzanne Jacobs (2), Lutz Breuer (3), and Sim Reaney (4)

1 Institute of Hazard, Risk and Resilience, Durham University, Durham, United Kingdom (aaron.james.neill@gmail.com) 2 Centre for International Development and Environmental Research (ZEU), Justus Liebig University, Giessen, Germany. 3 Institute for Landscape Ecology and Resources Management (ILR), Justus Liebig University, Giessen, Germany. 4 Department of Geography & Institute of Hazard, Risk and Resilience, Durham University, Durham, United Kingdom.

Modelling and using structural and functional connectivity

March 01, 2018

Talk, University of Palermo, Palermo, Italy

The understanding of hydrological connectivity is often broken down into two distinct types: functional and structural (see Bracken et al 2013). Functional connectivity refers to the dynamic feedbacks that occur within the short timescale of storm events, such as surface flow dynamics and erosion – deposition of the soil surface. Structural connectivity refers to the controls that the fixed characteristics of the environment, for example, landscape topography and vegetation pattern, have on the strength of the connectivity over long time scales. This paper presents how both functional and structural connectivity can be modelled and examples of how the structural connectivity approach has been used as a key dataset within a spatial decision support system.

Spatial targeting of diffuse pollution mitigation features: from landscapes to sub-catchments within the SCIMAP approach.

May 29, 2017

Talk, SCIMAP User Group Meeting 2016, The Hague, Netherlands

The design of diffuse pollution mitigation schemes at the landscape scale is difficult since the spatial structure of the landscape means that not all land contributes equally. The variation in sources, related to land management, soils and geology, and the pattern of hydrological connectivity mean that critical source areas are distributed across the landscape. If diffuse pollution mitigation measures can be targeted to intercept these critical source areas, they can be more effective and hence the same water quality improvement can be achieved at lower cost and with a lower impact on agricultural activities.

Spatio-temporal dynamics in phytobenthos structural properties reveal insights into agricultural catchment dynamics and nutrient fluxes

December 01, 2016

Talk, In the proceedings of AGU Fall Meeting Abstracts, San Francisco, USA

Low order streams are spatially extensive, temporally dynamic, systems within the agricultural landscape. This dynamism extends to the aquatic communities within these streams, including the phytobentos, which demonstrates considerable resilience to diffuse anthropogenic nutrient pressures and changing climate dynamics. The phytobenthos community can substantially contribute to the food web, in particular diatoms, which dominate photo-autotrophic assemblages in low order streams. Diatoms are widely used in ecological monitoring because of their high sensitivity to environmental condition, but knowledge is limited on the ecological effects of winter disturbances and variance introduced by multiple and interacting pressures (N, P, sediment), introducing bias in understanding temporal dynamics in benthic diatom communities. Using the environmental time series data from long term monitoring within the River Eden Demonstration Test Catchment programme, we assess the impact of multiple hydro-chemical stressors on phytobenthic community resilience, and synthesize the impact of an extreme winter event. Monthly data from diatom communities collected in the Eden DTC from March 2011 to present show that river flow, strongly coupled to precipitation, is a key driver of these communities. Discharge has a direct effect on communities through scouring, but is also tightly correlated to nutrient delivery, such that 80% of the annual TP load arrives in 10% of the time. Trophic Diatom Index (TDI) values demonstrated considerable resilience by the stability of inter-monthly TDI scores over 5 seasonal cycles against the characterised highly variable hydrological regime. This research demonstrates that well characterised winter disturbances are critical to understanding drivers of aquatic dynamics. This has implications for catchment diffuse pollution policy, farm management and economics, given the climate projections of increases in frequency and intensity of extreme winter events, which may alter instream nutrient fluxes.

Tackling landscape scale pressures on in-stream water quality and flood risk: Predicting and simulating hydrological connectivity

March 02, 2015

Talk, Stirling University, Stirling, Scotland

To tackle the challenges of flood risk, poor water quality and degraded ecological health, there is a need to go beyond the management of point pressures and take a full landscape view of the problem. Central to this high level view is the concept of hydrological connectivity, which describes the ease with which water and associated materials, can move across the landscape to the rivers or lakes. Therefore, understanding connectivity and the spatial pattern of source areas is key to making predictions of the critical source areas for diffuse pollution and flood risk sources and this identification allows for the spatial targeting of mitigation measures in the landscape.

The River Edendtc Project A National Demonstration Test Catchment

April 01, 2012

title: “The River EdenDTC Project A National Demonstration Test Catchment” collection: talks permalink: /talks/2012-04-01-The-River-EdenDTC-Project-A-National-Demonstration-Test-Catchment date: 2012-04-01 venue: ‘In the proceedings of EGU General Assembly Conference Abstracts’ citation: ‘C. Benskin, B. Surridge, C. Deasy, C. Woods, D. Rimmer, E. Lees, G. Owens, J. Jonczyk, J. Quinton, M. Wilkinson, “The River EdenDTC Project: A National Demonstration Test Catchment.” In the proceedings of EGU General Assembly Conference Abstracts, 2012.’ location: “Vienna, Austria” type: “Talk”

Understanding nutrient connectivity at the landscape scale: The use of the SCIMAP approach in the UK and Ireland

December 01, 2011

Talk, In the proceedings of AGU Fall Meeting Abstracts, San Francisco, USA

Many approaches to understanding diffuse pollution risk at the landscape scale have focused on its ‘sources’ and ‘mobilisation’ with a basic representation of the effect of connectivity between the landscape the receiving waters. Connectivity will determine whether source areas become critical source areas and create problems in the receiving waters. It is the landscape position of a source, both in terms of its upslope contributing area and its downslope flow path, that determine the likelihood of a connection being made. The SCIMAP approach, developed at Durham and Lancaster Universities with the Environment Agency, has taken a strongly connectivity driven approach, set within a risk based framework. SCIMAP aims to predict the location in the catchment that is most likely to be the source of an in stream water quality problem derived from diffuse pollution. The predictions are generated at a 5m-pixel level, to give within field estimates of risk and connectivity, and applied to whole landscapes (from 1 to 2000 km2 +) to give a broad overview of the issues. Recent work has shown that there is significant value in adding a detailed connectivity treatment when predicting measured patterns of water quality. The SCIMAP approach to diffuse pollution risk mapping has been applied by: the Environment Agency under the Catchment Sensitive Farming program; the Teagasc ‘Agricultural Catchments’ program; the Defra funded ‘River Eden Demonstration Test Catchment’; and various river and wildlife trusts in the UK. This poster shows an overview of the SCIMAP approach and the results from both the Teagasc ‘Agricultural Catchments’ and the EdenDTC projects.