Andy J. Howard

Holocene environmental change in the Yorkshire Ouse basin and its influence on river dynamics and sediment fluxes to the coastal zone

Abstract Geomorphological, geochemical and geochronological investigations of Holocene fluvial sedimentary sequences have been undertaken within a range of upland, piedmont and lowland valley floor reaches in the Yorkshire Ouse catchment, northern England. The aims of these studies have been to: (a) evaluate the effects of prehistoric and historic land-use change on catchment erosion and sediment delivery to river channels and floodplains; (b) establish the degree to which episodes of river erosion and sedimentation are controlled by climate-related variations in flood regime; and (c) assess the spatial heterogeneity of river response to environmental change and how this is likely to influence short- and long-term sediment storage, as well as sediment transfer to the Humber Estuary. Similar discontinuities in the Holocene alluvial record are evident at many sites in the Yorkshire Ouse catchment, though local differences in river sensitivity to externally imposed change have resulted in a complicated and often unique relationship between river behaviour and environmental change. The large proportion of particulate-borne contaminant metals (resulting predominantly from historical mining) stored in the Vale of York strongly indicates that sediment delivery from the Ouse catchment to the Humber Estuary during the Holocene may have been relatively low. This suggests that the degree of connectivity between river, estuarine and coastal transport systems, as well as spatial and temporal variations in fluvial sediment storage, are the key controls of long-term land-ocean sediment fluxes.

New Approaches to Mapping and Managing Palaeochannel Resources in the Light of Future Environmental Change: A Case Study from the Trent Valley, UK

Abstract Abandoned river channels may provide rich primary sources of palaeoenvironmental and cultural information elucidating landscape evolution, climate change, vegetation history and human impact, especially since the beginning of the Holocene epoch. However, although potentially an important resource, palaeochannels are not often recorded systematically and only rarely enjoy robust statutory protection (in the UK as Sites of Special Scientific Interest). In consequence, it is challenging to mitigate and manage this important geoarchaeological resource effectively within the UK planning framework. Whilst palaeochannels have long been recognised on aerial photographs and historic maps, the advent of airborne laser scanning (Lidar) and other remote-sensing technologies has provided a hitherto unforeseen opportunity to record such landforms and related features at a catchment scale. This paper provides a case study from the Nottinghamshire reach of the Trent Valley, where a desk-based methodology that is now being extended across the entire catchment has been developed for recording, geospatially locating and defining the attributes of observed palaeochannels. After outlining the methodology, we consider how this approach to resource management can aid archaeological research and future heritage management, especially in the light of predicted climate and environmental change.

Protecting the Historic Environment from Inland Flooding in the UK: Some Thoughts on Current Approaches to Asset Management in the Light of Planning Policy, Changing Catchment Hydrology and Climate Change

Abstract The impacts of both summer and winter flooding have been acutely felt across the inland areas of the UK over the last decade and under scenarios of future climate change, such events are likely to become more commonplace. Whilst significant emphasis is inevitably placed during such emergencies on securing basic major infrastructure (transport, power and water), there is also a need to consider how best to protect the Historic Environment. A recent Historic England funded project undertaken by the authors has sought to map the distribution of historic sites against known flood hotspots in Worcestershire to create a GIS resource tool for use by emergency planners and other non-heritage specialists. In addition to the development of a project GIS, a number of further studies were undertaken to consider best practice for flood alleviation, explore the impacts of past events on infrastructure and communities, and the building of resilience through community action. During the lifecycle of the project, a number of key issues and challenges were identified with respect to mitigating and managing the impacts of flooding upon the Historic Environment, before, during and after such events. The Met Office’s decision to begin naming severe storms from the autumn of 2015 and the associated devastating impacts of early examples, such as ‘Desmond’ and ‘Frank’ are leading to an ever-increasing focus on extreme events; therefore, the themes explored in this paper have resonance beyond the administrative boundaries of Worcestershire and are presented within the broader framework of environmental management.