Erosion is a major threat to soil resources in Europe, and may impair their ability to deliver a range of ecosystem goods and services. This is reflected by the European Commission's Thematic Strategy for Soil Protection, which recommends an indicator-based approach for monitoring soil erosion. Defined baseline and threshold values are essential for the evaluation of soil monitoring data. Therefore, accurate spatial data on both soil loss and soil genesis are required, especially in the light of predicted changes in climate patterns, notably frequency, seasonal distribution and intensity of precipitation. Rates of soil loss are reported that have been measured, modelled or inferred for most types of soil erosion in a variety of landscapes, by studies across the spectrum of the Earth sciences. Natural rates of soil formation can be used as a basis for setting tolerable soil erosion rates, with soil formation consisting of mineral weathering as well as dust deposition. This paper reviews the concept of

Suspended sediment is a natural part of river systems and plays an essential role in structuring the landscape, creating ecological habitats and transporting nutrients. It is also a common management problem, where alterations to sediment quantity and quality negatively impact ecological communities, increase flood hazard and shorten the lifespan of infrastructure. To address these challenges and develop appropriate sustainable management strategies, we need a thorough understanding of sediment sources, pathways and transport dynamics and the drivers that underlie spatial and temporal variability in suspended sediment transport in rivers. However, research to date has not sufficiently addressed the temporal complexity of sediment transport processes, which is limiting our ability to disentangle the hydro-meteorological, catchment, channel and anthropogenic drivers of suspended sediment transport in rivers. This review critically evaluates previously published work on suspended sediment dynamics to demonstrate how the interpretation of sediment sources and pathways is influenced by the temporal scale and methodology of the study. To do this, the review (i) summarizes the main drivers of temporal variation in suspended sediment transport in rivers; (ii) critically reviews the common empirical approaches used to analyze and quantify sediment sources and loads, and their capacity to account for temporal variations; (iii) applies these findings to recent case studies to illustrate how method and timescale affect the interpretation of suspended sediment transport dynamics; and finally (iv) synthesizes the findings of the review into a set of guidelines for a multi-timescale approach to sediment regime characterization. By recognizing a priori that study design and temporal scale have an impact on the interpretation of SS dynamics and employing methods that address these issues, future research will be better able to identify the drivers of suspended sediment transport in rivers, improve sediment transport modelling, and propose effective, sustainable solutions to sediment management problems.

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Quantifying the extent of soil erosion at a fine spatial resolution can be time consuming and costly; however, proximal remote sensing approaches to collect topographic data present an emerging alternative for quantifying soil volumes lost via erosion. Herein we compare terrestrial laser scanning (TLS), and both unmanned aerial vehicle (UAV) and ground photography (GP) structurefrom-motion (SfM) derived topography. We compare the cost-effectiveness and accuracy of both SfM techniques to TLS for erosion gully surveying in upland landscapes, treating TLS as a benchmark. Further, we quantify volumetric soil loss estimates from upland gullies using digital surface models derived by each technique and subtracted from an interpolated pre-erosion surface. Soil loss estimates from UAV and GP SfM reconstructions were comparable to those from TLS, whereby the slopes of the relationship between all three techniques were not significantly different from 1:1 line. Only for the TLS to GP comparison was the intercept significantly different from zero, showing that GP is more capable of measuring the volumes of very small erosion features. In terms of costeffectiveness in data collection and processing time, both UAV and GP were comparable with the TLS on a per-site basis (13.4 and 8.2 person-hours versus 13.4 for TLS); however, GP was less suitable for surveying larger areas (127 person-hours per ha À1 versus 4.5 for UAV and 3.9 for TLS). Annual repeat surveys using GP were capable of detecting mean vertical erosion change on peaty soils. These first published estimates of whole gully erosion rates (0.077 m a À1 ) suggest that combined erosion rates on gully floors and walls are around three times the value of previous estimates, which largely characterize wind and rainsplash erosion of gully walls.

The detrimental environmental impacts of soil erosion and sediment production are well documented, and this has increased pressure on landscape architects, construction engineers and site contractors to ensure that 'best management practice' is used to prevent sediment movement from vulnerable slopes. European Union policy in this area aims to minimize soil erosion losses in order to protect water, land and soil resources.Geotextiles (or erosion control mats and blankets), made from natural or synthetic fibres, can be installed on bare soil slopes, to protect against the erosive forces of wind, surface runoff, rainfall and waves. However, the extensive range of products available and yet limited performance data on erosion control geotextiles can make the selection process difficult for end users. This paper presents one method to evaluate the effectiveness or ability of geotextiles in controlling soil erosion. Taking a geomorphological approach, the sub-processes of erosion (rainsplash and overland flow) are simulated separately to assess the ways in which different geotextile products interact with, and thus influence, the processes of soil detachment and transport.The results show that some products are successful at controlling rainsplash detachment and transport, but are less efficient at controlling the erosivity of overland flow. Other products have the opposite effect. This level of analysis helps identify effective products, as well as highlighting the physical characteristics required of a geotextile to maximize its effect on limiting detachment and transport of soil particles.

Soil erosion is a key threat to ecosystem services. This study assesses the cost-effectiveness of erosion control measures based on an ecosystem services approach. The economic appraisal consists of an assessment (i.e. quantification and valuation) of the on-site and off-site impacts of soil erosion, and its mitigation, on ecosystem services. Many erosion control measures result in negative financial and economic returns. This explains why farmers are generally reluctant to implement erosion control measures without compensation. Based on the assessment described in this study, tramline management, mulching, buffer strips, high-density planting and sediment traps are the most costeffective erosion control measures for agriculture in the UK. Contour ploughing also appears to be cost-effective, but this measure is not appropriate in all circumstances and therefore cannot be widely promoted. However, actual cost-effectiveness of erosion control measures will differ for local circumstances, and it is therefore advised that individual assessments are made at farm level or field level before recommendations are made to farmers.

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