Thousands of small river weirs have been constructed over the last ca. 1000 years or more to provide power for milling and crushing ore, for industrialisation, electricity generation and navigation. Alternative power generation and transportation methods have left many of these structures obsolete and/or derelict. Recently, there has been a drive to create 'free-flowing' rivers with fewer or no barriers thereby increasing connectivity and improving ecology. Our first aim was to explore a range of literature and legislation on weir removal in the UK and identify the key benefits and drawbacks in removal that have emerged. We found that ecology was only one of many themes that could be used to justify weir removal or retention. Our second aim was to explore the issues involved with weir removal in a lowland river system in the UK based on the West Sussex Rother where three weirs were being considered for removal. The smothering of ecologically important river gravels by sand trapped behind these weirs and the subsequent release of this sand on removal emerged as a potentially new issue not identified in the literature reviewed. Our third aim was to explore management structures and key stakeholders involved in decision making in the Rother catchment, to establish whether a coordinated approach to delivering weir removal as part of a river management plan could be successfully delivered. We found many official and unofficial organisations have a legal or potentially legitimate interest in the Rother that could produce conflicting evidence for the benefits of weir removal. We conclude that strong leadership and good coordination are required to deliver a successful outcome that requires not only consideration of all the issues involved but which promotes public engagement, and the delivery of an evidence base by monitoring the consequences of any management action.

Localised runoff from cultivated areas carrying large quantities of eroded soil that causes damage to property and freshwater systems is referred to as 'muddy flooding'. It is widespread in western Europe though underreported in some countries. Muddy flooding is usually generated by heavy rainstorms and occurs where arable fields with little crop cover on high-risk soils are near to built-up areas and freshwater systems; and where runoff is enhanced due to reduced soil porosity and by the way land is managed. Crops such as maize and potatoes may generate large quantities of runoff before adequate cover is established and also after harvesting. Capping of silty or loamy soils, and compaction due to agricultural vehicles, increases the risk of runoff leaving the field and causing damage. Areas such as the Otter Valley in Devon, UK, and Voeren in Flanders, Belgium, have a history of recent muddy flooding linked to soil erosion. Effective mitigation measures to combat muddy flooding are well known, but adoption requires adequate incentives, regulation and technical advice delivered to farmers - as occurs in Flanders. Changes in land use and climate will continue to pose a threat of muddy flooding to communities. There is an urgent need to find solutions in the landscapes adjacent to communities, particularly those on high-risk erodible soils.

This article presents a commentary on a history of muddy flooding caused by soil erosion linked to maize cultivation, focusing on the Otter Valley in East Devon, UK. Research has associated soil erosion with compaction during maize harvesting and crop planting in moist soil conditions, which reduces the soil's ability to absorb rainfall and increases the risk of erosion runoff events. Careful soil management practices, such as planting early maize varieties, addressing soil compaction, and ensuring crop cover, can often mitigate these issues. A growing concern, however, is the flooding associated with summer storms, where intense rainfall over large areas of erodible land—left exposed after maize planting—exacerbates soil erosion. The case study highlights a severe muddy flooding event during the summer of 2023, underscoring the heightened risk posed by more frequent high‐intensity summer rainfall. The conclusion of this study is the need to avoid growing large areas of maize on erosion‐prone fields near properties and watercourses, as there are limited agronomic measures and solutions available to effectively prevent such flooding under these conditions.

The presentation of soil erosion on agricultural land, both to the expert and the public, frequently takes the form of pictures and descriptions of extreme events. These attention‐grabbing images are case studies of worst‐case scenarios and serve an important purpose of warning what may happen under certain circumstances; they also have a potential to mislead. On the other hand, long‐term studies of erosion are able to present extreme events in a more acceptable scientific context. Monitoring studies emphasise the importance of frequent, low‐magnitude runoff events and their ability to transport nutrients and pesticides to freshwater systems. Thus, the need for a balanced presentation of erosion which places extreme events in a broad context in space and time. Communicating with practitioners such as farmers requires the use of non‐conventional channels rather than the reliance on academic journals.

A great range and number of journals exist to promote and disseminate local knowledge in the areas of natural history, geology, geography and ecology. Many are still active; others are lost. The journals act as mouthpieces for local societies and are a repository of local knowledge. Some are hard to locate but the websites of local societies provide information on topics covered and the regularity of publication of the journals. The loss of journals seems to be the result of the pressure on academics to publish in international outlets and the growth of highly informative websites.

Agricultural landscapes that are intensively farmed, as in western Europe, face the challenge of a transition to more sustainable systems. Although erosion rates are relatively low in western Europe, the agricultural landscape is confronted by the need to mitigate the off‐site impacts of erosion. An important challenge is that of disrupting connectivity between runoff and sediment sources, often farmers' fields, and freshwater systems or local communities. Mitigation strategies should include monitoring of erosion rates and off‐site impacts and a mix of engineered and alternative measures such as buffer strips and retention ponds. Also needed are supportive government policies and actions including awareness of institutional memory problems and the promotion of farmer education. For the future, the risk of climate change must be appreciated and built into the planning of comprehensive mitigation strategies. Our perspective is that the overall aim should be a ‘sustainable agricultural landscape’ and not simply a reduction of erosion and runoff on farmers' fields.

M any so-called new developments in soil erosion research are in fact “evolutionary” in character— they are built on research foundations established during past decades. We need look no further than Hugh Hammond Bennett’s (1939) Soil Conservation to realize that we stand on the shoulders of giants. However, the significance of concepts such as “connectivity” has changed as perspectives have shifted during the last 50 years, from the experimental plot and field to the catchment (Boardman et al. 2022). Also, increased technical expertise in computing, geographic information systems (GIS), and remote sensing has certainly opened new possibilities. In this short personal perspective, we aim to review new developments from a European viewpoint. We start by noting that soil erosion research in Europe is firmly rooted in geomorphology, in contrast to the mainly agronomic foundations of North American erosion research.

ABSTRACTThe removal of barriers from rivers is a controversial topic. Barriers come in many forms including weirs, dams, sluices and bridges. Mills are listed in the 11th-century Domesday Book and shown on early Ordnance Survey (OS) maps, often with their use marked ‘corn’, etc. So, what are the arguments for removing them? As this article shows, these relate to the creation of more natural flow regimes and the re-establishment of a connection between the river channel and the floodplain. The most obvious practical benefit is that migratory fish will find their upstream passage easier. The disbenefits are provision of access for invasive species and the loss of flood control structures. On the River Rother in West Sussex, UK, the release of sediments stored behind weirs is a potential ecological hazard. In Britain, few barriers have been removed and instead fish ladders have been installed. In the USA and Europe, dam removal is well advanced. The European Commission (EC, 2020) aims to achieve 25,000km of ‘free-flowing rivers’ by 2030 with a focus on removing ‘obsolete barriers’.

Field-to-river flow of runoff and sediment in a lowland arable catchment in the south of England is explored from both field and modelling perspectives. Routes observed to be taken by flow and sediment on five study areas include many interactions between flow and 'landscape elements' (LEs), including those (field boundaries, paths, roads) of anthropogenic origin. We were able to satisfactorily replicate observed flow routes using a simple steepest-descent-with-overtopping model with a 5 m DEM. This was unexpected, considering the narrowness of linear LEs such as paths and tracks. However LE attributes showed considerable sensitivity: changing just one attribute of a single FE-flow interaction notably altered the route taken by simulated flow, while changing LE attributes notably affected synthetic hydrographs for flow reaching the river, suggesting similar impacts upon transported sediment reaching the river. Thus while simple steepest-descent and overtopping permits satisfactory replication of observed flow routes, it is likely that more explicit representation of LE-flow interactions is necessary in order to adequately capture the dynamics of field-to-river runoff and sediment transport, as must be done by catchment-scale erosion models. This will enable such models to better represent runoff speed and volume, and the flux and size distribution of transported sediment, with the aim of overcoming some broad limitations of such models as noted in earlier model validation studies. Finally, we consider the representation of some LE-flow interactions in several catchment-scale models, and discuss the ways in which such representation might be improved.

Farm ponds, reservoirs and in‐stream weirs exist in most lowland UK river catchments and often dominate natural features such as lakes, wetlands, floodplains and debris dams. Artificial structures have served multiple purposes, including provision of power for historic flour milling and iron ore crushing and provision of water for medieval fishponds, canals, crop irrigation and potable supply. Although unintentional, they can significantly affect longitudinal connectivity, including sediment delivery pathways, through river catchments.

Channel banks can contribute a significant proportion of fine-grained (<63 μm) sediment to rivers, thereby also contributing to riverine total particulate phosphorus loads. Improving water quality through better agricultural practices alone can be difficult since the contributions from non-agricultural sources, including channel banks, can generate a 'spatial mismatch' between the efficacy of best management applied on farms and the likelihood of meeting environmental objectives. Our study undertook a reconnaissance survey (n = 76 sites each with 3 profiles sampled) to determine the total phosphorus (TP) concentrations of channel banks across England and to determine if TP content can be predicted using readily accessible secondary data. TP concentrations in adjacent field topsoils, local soil soil type/texture and geological parent material were examined as potential predictors of bank TP. Carbon and nitrogen content were also analysed to explore the impacts of organic matter content on measured TP concentrations. The results suggest that channel bank TP concentrations are primarily controlled by parent material rather than P additions to adjacent topsoils through fertilizer and organic matter inputs, but significant local variability in concentrations prevents the prediction of bank TP content using mapped soil type or geology. A median TP concentration of 873 mg kg-1 was calculated for the middle section of the sampled channel bank profiles, with a 25th percentile of 675 mg kg-1, and 75th percentile of 1159 mg kg-1. Using these concentrations and, in comparison with previously published estimates, the estimated number of inland WFD waterbodies in England for which channel bank erosion contributes >20% of the riverine total PP load increased from 15 to 25 (corresponding range of 17-35 using the 25th and 75th percentiles of measured TP concentrations). Collectively, these 25 waterbodies account for 0.2% of the total inland WFD waterbody area comprising England.

Footpath erosion is a problem in many countries where recreational areas are impacted by large numbers of visitors. In the UK, in National Parks and on long-distance footpaths, erosion is a frequent occurrence. Park authorities spend considerable amounts of money on the maintenance and repair of paths. An assessment and measurement of change has been attempted using several methods including remote sensing, experimental trampling on selected slopes and direct measurement. Challenges remain as to where and how often to measure. This article provides examples of simple measurement approaches carried out before and after major walking and running events on long-distance footpaths.

Sunken lanes or hollow ways are widely recognised in southern England but have rarely been considered in the geological or geomorphological literature. They occur more frequently in internet sources and guides to walking routes and Green Lanes. Archaeologists have also described hollow ways at excavated prehistoric sites. The current review suggests that they are concentrated on certain soft Mesozoic lithologies but that any survey is likely to grossly underrepresent their frequency. However, high density areas in Somerset, the Chilterns, East and West Sussex, Dorset and the Weald can be identified. The sunken lanes are important elements of the cultural landscape with a close relationship to the underlying geology. Other factors, especially a long history of usage by people, animals and the development of tracks and roads, help to explain their distribution. Their importance as sites of biodiversity, geological and historical value suggests that more should be done to investigate, protect and record the sunken lanes of southern England.