The Floods and Agriculture Risk Matrix: a decision support tool for effectively communicating flood risk from farmed landscapes

Intense farming plays a key role in high runoff rates. It is vital to communicate this risk to stakeholders and policy-makers effectively. There is great potential for agriculture to become a major component in managing flood risk. It is proposed here that lower flood risk can be achieved by reducing runoff rates from farmed landscapes. Hence, tools to evaluate and communicate management options are needed alongside improved understanding of runoff generation from farming systems. The Floods and Agriculture Risk Matrix is a decision support tool designed to assess the relative risk of flooding from farm land. The tool includes a series of pre-determined runoff scenarios to provide the end-user with a number of potential land-management practices and flood runoff management options to reduce runoff rates. Visual scenarios are used to illustrate the impact of good and bad practice on runoff rates. The level of risk associated with particular land-management options is represented by mapping a position on a Decision Support Matrix (DSM). Multiple questions allow the user to explore different management options and see the impact of decisions on the DSM. A nominal scoring system is used to rank higher or lower runoff risk. The end-user can then assess numerous land-use management options to lower the risk of rapid runoff. The objective is to encourage policy-makers and farmers to produce resilient local landscapes

Agricultural land use and flood risk management: Engaging with stakeholders in North Yorkshire

Recent changes in agricultural and flood defence policies create new opportunities for involving rural land use, in particular agriculture, in flood risk management. This paper presents the results of a case study on land management and flooding in the Laver and Skell catchments in North Yorkshire. The perceptions of local stakeholders were explored through interviews with farmers and discussions among stakeholders that were held, supported by the Floods and Agriculture Risk Matrix (FARM) tool, during a stakeholder workshop. These stakeholder perceptions are reviewed against scientific evidence. Temporary storage of runoff water on farmland was found to have potential to mitigate flooding, but the participating stakeholders thought that this was beyond farmers' responsibility of good farming practice. During the stakeholder workshop, it was therefore agreed among all participants that targeting funding is needed, as well as stakeholder engagement and demonstration farms, in order to successfully involve farmers in flood risk management.

Experimental investigation into the impact of a liquid droplet onto a granular bed using three-dimensional, time-resolved, particle tracking

An experimental investigation into the interaction that occurs between an impacting water droplet and a granular bed of loose graded sand has been carried out. High-speed imaging, three-dimensional time-resolved particle tracking, and photogrammetric surface profiling have been used to examine individual impact events. The focus of the study is the quantification and trajectory analysis of the particles ejected from the sand bed, along with measurement of the change in bed morphology. The results from the experiments have detailed two distinct mechanisms of particle ejection: the ejection of water-encapsulated particles from the edge of the wetted region and the ejection of dry sand from the periphery of the impact crater. That the process occurs by these two distinct mechanisms has hitherto been unobserved. Presented in the paper are distributions of the particle ejection velocities, angles, and transport distances for both mechanisms. The ejected water-encapsulated particles, which are few in number, are characterized by low ejection angles and high ejection velocities, leading to large transport distances; the ejected dry particles, which are much greater in number, are characterized by high ejection angles and low velocities, leading to lower transport distances. From the particle ejection data, the momentum of the individual ballistic sand particles has been calculated; it was found that only 2% of the water-droplet momentum at impact is transferred to the ballistic sand particles. In addition to the particle tracking, surface profiling of the granular bed postimpact has provided detailed information on its morphology; these data have demonstrated the consistent nature of the craters produced by the impact and suggest that particle agglomerations released from their edges make up about twice the number of particles involved in ballistic ejection. It is estimated that, overall, about 4% of the water-droplet momentum is taken up in particle movement

A low-cost bench-top research device for turbidity measurement by radially distributed illumination intensity sensing at multiple wavelengths

Presented here is a new bench-top research device for the measurement of the optical turbidity of natural sediment-laden water samples. This prototype device employs 18 unique angular measurement positions and a variety of user-selectable LED light sources. The motivation for this project was the need to generate more parameter-rich data sets pertaining to the light-scattering properties of natural sediment suspensions, and to address the issues raised by Kitchener et al. (2017) concerning the inconsistent calibration methodologies currently employed to quantify suspended sediment concentration (SSC) by optical turbidity measurement. The mechanical design comprises re-purposed waste plastic materials and 3D-printed parts. The active light-source control and monitoring hardware and firmware executes on the open-source Arduino embedded microcontroller platform. The modular light sensors plug into any of the angular measurement positions, providing a 0–5 V nominal output signal, which is readable by the user’s choice of data-acquisition system. The device will facilitate the highly detailed characterization of suspended sediment samples, providing 18 voltage output channels for analysis by the user. The precise calibration of the light sensors is by the use of neutral density (ND) filters in conjunction with light-source electrical current measurements, providing light-source intensity values as required. The empirical data provided by existing turbidity meters are acquired using incommensurate methodologies, and therefore they are not cross-comparable. A new methodology, described here, facilitates the cross-comparability of turbidity measurements