Landslides in the East Midlands

Great Britain is not a country renowned for its large landslides. It lacks the extreme climatic events and the mountainous regions that are associated with catastrophic landslides events elsewhere in the world. Nevertheless, landslides in Britain do have significant societal and economic impacts. Meteorological Office statistics have shown that 2012 was the second wettest year since collation of national records began in 1910. Tragically, this also saw the highest number for many years of fatalities due to landslides, including those at Burton Bradstock in Dorset and at Looe in Cornwall. Even so, these landslides contrast with recent events in China, in Afghanistan and in Washington, USA, where large and calamitous events claimed many lives. However, landslides are common enough in Great Britain, and there is currently a heightened awareness of these geological hazards, and this was largely due to extensive media reports in 2012 and 2013

National Underground Asset Register : assessment of additional use cases - resilience planning

Working in partnership with the Geospatial Commission (GC), the Iceberg Industry Group delivered a workshop (Nov 2019) looking at additional applications and benefits, (over and above strike avoidance), that may be realised by the creation of an underground asset register and better subsurface data use. Twelve use cases were reviewed and prioritised by delegates during the workshop. Resilience Planning (including flood risk) was one of the top 5 use cases identified. This document, prepared by the British Geological Survey, forms a more detailed review of the Resilience Planning use case and provides information on the strategic case for change, economic case and feasibility, along with case studies and user applications

The National Landslide Database of Great Britain: acquisition, communication and the role of social media

The British Geological Survey (BGS) is the national geological agency for Great Britain that provides geoscientific information to government, other institutions and the public. The National Landslide Database has been developed by the BGS and is the focus for national geohazard research for landslides in Great Britain. The history and structure of the geospatial database and associated Geographical Information System (GIS) are explained, along with the future developments of the database and its applications. The database is the most extensive source of information on landslides in Great Britain with over 17,000 records of landslide events to date, each documented as fully as possible for inland, coastal and artificial slopes. Data are gathered through a range of procedures, including: incorporation of other databases; automated trawling of current and historical scientific literature and media reports; new field- and desk-based mapping technologies with digital data capture, and using citizen science through social media and other online resources. This information is invaluable for directing the investigation, prevention and mitigation of areas of unstable ground in accordance with Government planning policy guidelines. The national landslide susceptibility map (GeoSure) and a national landslide domains map currently under development, as well as regional mapping campaigns, rely heavily on the information contained within the landslide database. Assessing susceptibility to landsliding requires knowledge of the distribution of failures, an understanding of causative factors, their spatial distribution and likely impacts, whilst understanding the frequency and types of landsliding present is integral to modelling how rainfall will influence the stability of a region. Communication of landslide data through the Natural Hazard Partnership (NHP) and Hazard Impact Model contributes to national hazard mitigation and disaster risk reduction with respect to weather and climate. Daily reports of landslide potential are published by BGS through the NHP partnership and data collected for the National Landslide Database are used widely for the creation of these assessments. The National Landslide Database is freely available via an online GIS and is used by a variety of stakeholders for research purposes

Antecedent precipitation as a potential proxy for landslide incidence in South West UK

This paper considers the effects of antecedent precipitation on landslide incidence in the UK. During 2012-2013 an extraordinary amount of precipitation resulted in an increase in the number of landslides reported in the UK, highlighting the importance of hydrogeological triggering. Slope failures (landslides on engineered slopes) in particular caused widespread disruption to transport services and damage to property. SW England and S Wales were most affected. Easy-to-use and accessible indicators of potential landslide activity are required for planning, preparedness and response and therefore analyses have been carried out to determine whether antecedent effective precipitation can be used as a proxy for landslide incidence. It is shown that for all landslides long-term antecedent precipitation provides an important preparatory factor and that relatively small landslides, such as slope failures, occur within a short period of time following subsequent heavy precipitation. Deep-seated, rotational landslides have a longer response time as their pathway to instability follows a much more complex hydrogeological response. Statistical analyses of the BGS landslide database and of weather records has enabled determination of the probability of at least one landslide occurring based on antecedent precipitation signals for SW England and S Wales. This ongoing research is of part of a suite of analyses to provide tools to identify the likelihood of regional landslides occurrence in the UK

Creation of a national landslide domain map to aid susceptibility mapping in Great Britain

The need to develop a national map that characterises landslides across Gr eat Britain has long been recognised by the British Geological Survey as part of its strategic role providing hazard information to stakeholders. Hierarchical landslide domains represent areas of similar physiographic , meteorological, climatic and geologi cal characteristics that shaped the style of landsliding. Developed to underpin current research into how different types of landslides and terrains will be affected by changing environmental conditions , the map further assists development of a national l andslide susceptibility map with conditioning factors tailored to a specific domain. This paper considers the role of national - scale land systems mapping to create a Landslide Domain Map , the refinement of a national model using landslide inventories to b etter reflect the spatial extent and characteristics of landslides within domain s . The distribution of landsliding in Great Britain is a product of the complex range of lithologies and geomorphological processes active under a range of climatic conditions. The domain s represent landslides across a series of unstable slopes ranging from very large, ancient landslides formed under periglacial climate conditions to small, modern failures , particularly along transport infrastructure corridors . Although analysis of the National Landslide Database broadly informed the nature of landsliding within a specific domain, expert knowledge was needed to supplement it especially in areas where recent mapping had not taken place. Targeted data collection is planned in data - poor domains to supplement the database . Further domain - specific research is ongoing and includes development of semi - empirical process - specific models involving the weighting of critical factors in order to refine the current national landslide susceptibi lity map, GeoSure. As a n example of this refinement , this paper discusses an improved debris flow model for the Scottish Highlands

Geological and geomorphological influences on a recent debris flow event in the Ice-scoured Mountain Quaternary domain, western Scotland

Debris flows in settings that have experienced net glacial erosion within the UK's Ice-scoured Quaternary domain are the result of a complex interaction of a range of geological and geomorphological factors. On the 11th of August 2016 a rainfall-triggered debris flow deposited 100 t of sediment onto local road and rail infrastructure blocking transport between town of Fort William and port of Mallaig in north-west Scotland. The debris flow occurred in an ice-scoured setting, where current 1:50,000-scale geological maps suggest that little or no sediment is expected on the valley slopes. In this study, we show how weathering and mass-wasting processes have interacted with bedrock structures to fill localised depressions with sediment on the upper parts of the slope. The intense rainfall event of August 2016 caused the destabilisation of this localised sediment, with eventual failure along bedrock joint surfaces resulting in two debris flows. This study demonstrates the combination of processes that can result in thick accumulations of sediment on slopes that are otherwise generally lacking in superficial sediment cover. These sediment accumulations have the potential to pose a significant landslide hazard in areas that might previously have been thought of as lower susceptibility. The research illustrates a need to improve understanding and representation of sediment thickness and distribution on hill slopes – particularly those that show an absence of superficial deposits at the scale of currently available geological maps

Putting climate resilience in its place: developing spatially literate climate adaptation initiatives

Understanding the socioeconomic, cultural, historical and political nuances of a place is essential for realising effective local decision-making for climate action. People are central to understanding place-based risk and resilience, with consideration of inequality and vulnerability required for effective place-based climate adaptation. Temporality is important. Place is not fixed, but changes over time, together with the community that inhabits it. Discussing and sharing community knowledge increases the likelihood of successful creation and implementation of climate adaptation practices. A sense of place can be deployed to build connections between people, across policy and between scales

The Brownfield Ground Risk Calculator: a new spatial decision support tool for estimating ground risk and remediation costs for site located in Greater Manchester, UK

The Greater Manchester Brownfield Ground Risk Calculator (BGR_calc) is a Geographical Information System (GIS) spatial decision support tool designed to provide an early indication of potentially abnormal ground conditions and the indicative costs of mitigating them. This is important because abnormal ground conditions can affect the viability of the constructing of new homes on post-industrial brownfield sites. Multi-criteria decision analysis methods were used process and utilise over 30 input dataets. BGR_calc comprises four primary outputs, each represents a different set of ground risk or cost mitigation characteristics that occur within the Greater Manchester area, presented alongside their associated input data. Each output comprises risk scores (scored between 0 to 1) or risk mitigation cost estimates (£) presented as 50 m grid cells and site based summaries for over 2000 individual sites. BGR_calc makes the assumption that all brownfield land evaluated will be used to develop two storey residential housing at a density of 30 houses per hectare. Ground risk scores reflect the nominal risk that soil and groundwater contamination and soil and rock hazards might pose to human health, controlled waters and the structural integrity of new homes. The scores are derived from data on sources of contamination or ground conditions resulting from previous land-uses and/or natural processes, the presence of exposure pathways and sensitive receptors (residents, water resources and homes). For there to be a risk, the source, pathway and receptor components must be linked. Risk mitigation cost estimates represent the amount that might need to be paid to develop a brownfield site over and above ‘normal’ development costs. No allowance is made in BGR_calc for the financial benefits of pre-existing infrastructure, proximity to services and employment that brownfield land usually have but these ought to be considered within the overall economic evaluation of individual sites

Geochemistry and related studies of Clyde Estuary sediments

Geochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1 m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity