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Author Archive for Sim Reaney

Dr. Sim Reaney is a catchment hydrologist and modeller based in the Department of Geography at Durham University.

EdenDTC presentations at AGU Fall Meeting 2016

The EdenDTC team had five presentations at the American Geophysical Union Fall Meeting in 2016 covering different aspects of the project. These poster presentations covered an overview of the project, the use of the Treatment Train for diffuse pollution mitigation, the observed nitrogen dynamics, new approaches to sampling soil P levels and the impacts on the ecological health.

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Dedra Banks Aerial 360

This 360 degree photoshere was taken over the mitigation catchment’s outlet station near the Dedra Banks farm. You can click and drag the image to see the landscape and the land management. This image was taken on the 14th June 2016.

What is the cost to a farm of diffuse pollution?

What is the cost to a farm of diffuse pollution? from Sim Reaney on Vimeo.

This video discusses the costs of diffuse pollution losses to farmers based on the monitoring data from the EdenDTC project. The video also discusses the potential mitigation actions that could be taken to minimise the losses.

An Introduction to the Defra Demonstration Test Catchments (DTC) Programme

The Demonstration Test Catchments (DTC) programme was established in December 2009 to inform the mitigation of agricultural water pollution across farmed landscapes in England. We have taken a ‘learning by doing’ approach to develop, test and demonstrate suites of measures at landscape scale that are practical within commercial farming systems. Our approach recognises the river catchment as an appropriate spatial unit for understanding and managing water quality, whilst balancing the demands of food production and environmental protection. The diffuse, and often sporadic, weather-driven nature of agricultural pollution means that understanding the effectiveness of mitigation measures requires a long-term monitoring approach, both pre- and post-implementation of on-farm interventions. Applying this at a catchment scale in the DTCs has required interaction between broad communities of stakeholders, regulators and scientists. We are now working on upscaling our findings from case-study sub-catchments to generate best practice for wider catchment management.

The summary document guides readers through the conceptual framework that we are using to develop bespoke on-farm mitigation strategies, by illustrating each of the steps through example case studies. It also sets out emerging findings from phase 1 and describes the ongoing programme of work (phase 2) to 2017.

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Dominant mechanisms for the delivery of fine sediment and phosphorus to fluvial networks draining grassland dominated headwater catchments

Science of The Total Environment523 (1) 178–190

Abstract

Recent advances in monitoring technology have enabled high frequency, in-situ measurements of total phosphorus and total reactive phosphorus to be undertaken with high precision, whilst turbidity can provide an excellent surrogate for suspended sediment. Despite these measurements being fundamental to understanding the mechanisms and flow paths that deliver these constituents to river networks, there is a paucity of such data for headwater agricultural catchments. The aim of this paper is to deduce the dominant mechanisms for the delivery of fine sediment and phosphorus to an upland river network in the UK through characterisation of the temporal variability of hydrological fluxes, and associated soluble and particulate concentrations for the period spanning March 2012–February 2013. An assessment of the factors producing constituent hysteresis is undertaken following factor analysis (FA) on a suite of measured environmental variables representing the fluvial and wider catchment conditions prior to, and during catchment-wide hydrological events. Analysis indicates that suspended sediment is delivered to the fluvial system predominantly via rapidly responding pathways driven by event hydrology. However, evidence of complex, figure-of-eight hysteresis is observed following periods of hydrological quiescence, highlighting the importance of preparatory processes. Sediment delivery via a slow moving, probably sub-surface pathway does occur, albeit infrequently and during low magnitude events at the catchment outlet. Phosphorus is revealed to have a distinct hysteretic response to that of suspended sediment, with sub-surface pathways dominating. However, high magnitude events were observed to exhibit threshold-like behaviour, whereby activation and connection of usually disconnected depositional zones to the fluvial networks results in the movement of vast phosphorus fluxes. Multiple pathways are observed for particulate and soluble constituents, highlighting the challenges faced in mitigating the delivery of contaminant fluxes to headwater river systems.

The full paper is available at:  http://www.sciencedirect.com/science/article/pii/S0048969715002739

Soil science video by Phil Haygarth

DTC Newletter

You can download the latest DTC Newsletter, which covers all three DTC sites, here: DTC Newsletter Dec 2013

 

MSc research on diffuse pollution in the River Eden catchment using SCIMAP by Steph Dixon

Steph Dixon has completed her MSc by Research that looked at how to incorporate temporal issues associated with rural diffuse pollution within the SCIMAP risk mapping framework. The full Masters by Research thesis is on the Durham University e Thesis site at http://etheses.dur.ac.uk/6895/

The Effects of Land Management and Predicted Climate Change on Hydrological Connectivity and Diffuse Fine Sediment Pollution Risk within the River Eden Catchment.

There is a growing recognition that future management of the water quality in UK rivers will depend upon an improved understanding of the effects of projected climate change on catchment systems. Until recently, little attention has been given to the secondary effects that climate change may have. However, it is now becoming clear that successful management will depend upon research into factors beyond the primary changes in soil moisture and river flows. One area of particular concern is the way climate change may alter patterns of diffuse pollution of fine sediment, with associated impacts on river flora and fauna.
If the UK is going to meet the stringent targets laid out in the EU Water Framework Directive, then urgent management of diffuse pollution is required. In 2012 only 28% of water bodies met their ecological potential or good status and 67% of river water bodies cite diffuse pollution as a key pressure which is preventing improvement and the achievement of good ecological status (Environment Agency, 2012). For management solutions to be cost-effective, they need to be targeted at the key problem areas within a catchment. This research uses the River Eden catchment in Cumbria as a test catchment and applies a hydrological simulation model, risk mapping framework and risk filter to the area in order to determine current connectivity and diffuse pollution trends. From this toolkit, projections of the future patterns of risk are calculated.

The SCIMAP based toolkit predicted that the fine-sediment erosion risk varies spatially across the River Eden catchment. Locations deemed to be most at risk of causing a fine-sediment pollution issue are in the lower reaches of the catchment where intensive arable farming is found. When risks were modelled temporally, variations depending upon vegetation cover and average monthly rainfall were found. It was noted that the presence of autumn-sown crops could reduce risk over a year whilst spring-sown crops are likely to increase fine-sediment erosion risks.

Several conclusions are drawn from this research: 1) it has been shown that the SCIMAP framework is an effective way of identifying critical source areas of diffuse pollution and could prove an invaluable tool to environmental managers; 2) the important role that autumn-sown crops can play in minimising erosion risk has been shown to be applicable in the River Eden catchment and the best way to incorporate this into crop cycles highlighted; 3) through the use of projected climate change data and a hydrological simulation model, it has been shown that the location of critical source areas are likely to change as a result of projected climate change and associated variability in rural land management. This highlights the need for continuous catchment-wide monitoring and management of hydrological connectivity and associated diffuse pollution risks.