Quantification of nitrate storage in the vadose (unsaturated) zone: a missing component of terrestrial N budgets

National terrestrial nitrogen budgets for many developed countries have been calculated as part of the management of impacts of N on the environment, but these rarely represent the subsurface explicitly. Using estimates of vadose zone travel time and agricultural nitrate loading, we quantify, for the first time, the total mass of nitrate contained in the vadose zone of aquifers in England and Wales. This mass peaked in 2008 at 1400 kt N (800 to >1700 kt N from sensitivity analyses) which is approximately 2.5 to 6 times greater than saturated zone estimates for this period and indicates that the subsurface is an important store of reactive nitrogen. About 70% of the nitrate mass is estimated to be in the Chalk, with the remainder split between the Permo-Triassic sandstones, the Jurassic Oolitic limestones and minor aquifers. Current controls on fertiliser application mean that the vadose zone is now a nitrate source and in 2015 we estimate the net flux from the unsaturated zone to groundwater to be 72 kt N/annum. The mass of nitrate in the vadose zone should be included in future terrestrial nitrogen budgets at national and global scales to improve ecosystem management. This article is protected by copyright. All rights reserved

Relative influence of changes in hydraulic conductivity with depth and climate change on estimations of borehole yields

Understanding the impact of climate change on borehole yields from fractured aquifers is essential for future management of groundwater resources. Although the impact of changes in hydraulic conductivity with depth (VKD) on groundwater levels is well established, the relative significance of climate change and VKD on borehole yield estimates is poorly understood. We hypothesize that VKD exerts a significant additional control on borehole yields under climate change which has not been considered in yield assessments to date. We developed a radial groundwater flow model of an idealised pumping borehole in the fractured Chalk aquifer of south-east England, and applied 11 VKD profiles based on a simple conceptual representation of variability in hydraulic conductivity with depth in the Chalk. For each VKD profile, we applied 20 climate scenarios and six constant pumping rates for the period 1962 – 2014. We then estimated borehole yields based on the derived lowest pumping water levels during key drought years (e.g. 1976). We show that VKD is more significant (p 0.1) in controlling lowest pumping groundwater levels. Hydraulic conductivity is as significant a control as climate on borehole yields, although responses are highly non-linear associated with pumping water level-pumping rate curves intersecting key yield constraints (e.g. pump intake depth, major inflow horizons). It is recommended that variations in hydraulic conductivity with depth are taken into consideration in future assessments of borehole yields under climate change when developing integrated water resources management plans. The approach presented is generic and can be applied across different aquifers where vertical heterogeneity is present

Analysis of climate variability and change in observational groundwater quality data

This report details Task 1 (“Evaluation of historical observational groundwater quality data”) of Phase 2 of the Environment Agency-BGS collaborative project “climate and land use change impacts on groundwater quality”. The objective of this task is to evaluate historical observational groundwater quality data held by the Environment Agency (EA) to determine the following: (1) the suitability of existing monitoring for future monitoring of long-term impacts of climate and land use change and (2) whether there is evidence for climate variability, and if possible, impacts of historical climate change in the observations. It was agreed in an EA-BGS kickoff meeting that this task would investigate climate variability and change in nitrate and groundwater temperature data. This task focusses on southeast England as a case study. Analysis of groundwater nitrate data held by the Environment Agency in WIMS has shown that a small number of sites meet the required time series length requirement for climate change impact monitoring in southeast England (30 years). The recent natural variability in climate combined with short record length means that any climate change impacts cannot be observed in the data provided. Cluster analysis has revealed different modes of temporal fluctuations in nitrate concentrations. The depth of groundwater flow system intercepted by the boreholes appears to control the long-term direction of change in groundwater nitrate concentrations. Non-linear and seasonal behaviour associated with climate variability are present in two clusters, which are weakly spatially coherent across the North and South Downs. Cross-correlation of nitrate time series with both raw and standardised indices of groundwater level and precipitation show that the extent of nitrate fluctuation appears to be controlled by precipitation and groundwater level fluctuation. This may be due to a combination of piston flow and changing groundwater flow paths. Under future climate change, nitrate fluctuations may change associated with the changing intersection of the water table and the legacy nitrate peak in the unsaturated zone. The timescales for land use change impacts on nitrate at the water table will vary substantially depending on the dominant process controlling nitrate fluctuations. Processes which represent a transfer of mass (bypass flow) will impact concentrations much more rapidly than processes representing a transfer of energy (piston flow). Analysis of groundwater temperature data for 20 boreholes has shown that, for 8 of 17 shallow boreholes with temperature data over 2012-2022, groundwater temperature trends are broadly consistent with current air temperature trends. 7 of these sites show increasing trends, with a mean trend of 0.66 °C/decade. Three deep interfluve sites show increases, with a mean trend if 0.38 °C/decade. It is likely that these trends are controlled by current and historical near-decadal trends in local air temperature for shallow and deep sites respectively. The remaining 8 shallow sites show inconsistent trends in comparison with local air temperature trends. For these sites it likely that in addition to air temperature trends, additional heat fluxes into the subsurface are occurring superimposed on changes in groundwater flow to the boreholes. The shallow sites show seasonal temperature fluctuations associated with propagation of air temperature signals, with seasonal range in groundwater temperature significantly negatively correlated with borehole depth. Three very shallow sites show diurnal fluctuations, although these fluctuations are below the accuracy of the sensors. The increases in groundwater temperature observed have some implications for other components of groundwater quality (e.g. biogeochemical cycles, stygofauna, pollutant (N, pesticide, LNAPL) degradation and for the role that groundwater discharges to surface water play in providing cold-water hydro-refugia to cold-water species during summer

Human Computer Interaction, Art and Experience

With contributions from artists, scientists, curators, entrepreneurs and designers engaged in the creative arts, this book is an invaluable resource for both researchers and practitioners, working in this emerging field

Inflammatory bowel disease psychological support pilot reduces inflammatory bowel disease symptoms and improves psychological wellbeing

This prospective service evaluation aimed to determine if integrated psychological support for patients with inflammatory bowel disease (IBD) enhanced outcomes. 75 patients were assessed and treated by a specialist liaison psychiatric service between 2015 and 2017; 43 received psychiatric intervention alone, 32 were referred for psychological intervention by clinical health psychologist; 26 completed this. Pre–post data (n=15 available) included global impression, quality of life, and psychiatric and IBD symptom scores. Referrer/patient satisfaction and cost-effectiveness were retrospectively calculated. Psychological intervention led to reductions in IBD symptoms (ΔSIBD; p=0.003), alongside improvements in depression scores (ΔPHQ-9, p=0.006) and global impression (ΔCGI; p=0.046). Patient/referrer satisfaction was very high. Indicative data comparing service utilisation 1 year before and after engagement found reductions in outpatient appointments and in imaging. This small study suggests consideration of increased access to integrated psychological support services to improve outcomes and gather further evidence of efficacy

Isotopic fingerprint for phosphorus in drinking water supplies

Phosphate dosing of drinking water supplies, coupled with leakage from distribution networks, represents a significant input of phosphorus to the environment. The oxygen isotope composition of phosphate (δ18OPO4), a novel stable isotope tracer for phosphorus, offers new opportunities to understand the importance of phosphorus derived from sources such as drinking water. We report the first assessment of δ18OPO4 within drinking water supplies. A total of 40 samples from phosphate-dosed distribution networks were analyzed from across England and Wales. In addition, samples of the source orthophosphoric acid used for dosing were also analyzed. Two distinct isotopic signatures for drinking water were identified (average = +13.2 or +19.7‰), primarily determined by δ18OPO4 of the source acid (average = +12.4 or +19.7‰). Dependent upon the source acid used, drinking water δ18OPO4 appears isotopically distinct from a number of other phosphorus sources. Isotopic offsets from the source acid ranging from −0.9 to +2.8‰ were observed. There was little evidence that equilibrium isotope fractionation dominated within the networks, with offsets from temperature-dependent equilibrium ranging from −4.8 to +4.2‰. While partial equilibrium fractionation may have occurred, kinetic effects associated with microbial uptake of phosphorus or abiotic sorption and dissolution reactions may also contribute to δ18OPO4 within drinking water supplies

Inflammatory bowel disease psychological support pilot reduces inflammatory bowel disease symptoms and improves psychological wellbeing

This prospective service evaluation aimed to determine if integrated psychological support for Inflammatory Bowel Disease (IBD) patients enhanced outcomes. 75 patients were assessed and treated by a specialist liaison psychiatric service between 2015 -2017; 43 received psychiatric intervention alone, 32 were referred for psychological intervention by clinical health psychologist; 26 completed this. Pre-post data (n=15 available) included: Global impression, quality of life, psychiatric and IBD symptom scores. Referrer/patient satisfaction and cost effectiveness were retrospectively calculated. Psychological intervention led to reductions in IBD symptoms (SIBD; p=0.003), alongside improvements in depression scores (PHQ-9, p=0.006) and global impression (CGI; p=0.046). Patient/referrer satisfaction was very high. Indicative data comparing service utilisation one year before and after engagement found reductions in outpatient appointments and in imaging. This small study suggests consideration of increased access to integrated psychological support services to improve outcomes and gather further evidence of efficacy

Ambient interaction and situational influence: case studies in public sites.

An audience's direct physical intervention is widely believed to be instrumental in the field of interactive art. However, this long established expectation faces new challenges through the increasing accessibility of a growing diversity of interactive technologies and ubiquitous smart media. Such innovations are often fully integrated components of interactive public artworks, many of which do not directly involve audiences or individuals as key agents in the functional or aesthetic realisation of the work. Based on three case studies of interactive artworks in public places, this article identifies an important characteristic of interactivity in interactive art, through the largely unexplored concept of 'Ambient Interaction' in which artworks are embodied and enacted through environmental conditions and situational influences rather than exclusively through people's intentional and direct physical engagement

Improved understanding of spatio-temporal controls on regional scale groundwater flooding using hydrograph analysis and impulse response functions

Controls on the spatiotemporal extent of groundwater flooding are poorly understood, despite the long duration of groundwater flood events and distinct social and economic impacts. We developed a novel approach using statistical analysis of groundwater level hydrographs and impulse response functions (IRFs) and applied it to the 2013/14 Chalk groundwater flooding in the English Lowlands. We proposed a standardised index of groundwater flooding which we calculated for monthly groundwater levels for 26 boreholes in the Chalk. We grouped these standardised series using k-means cluster analysis and cross-correlated the cluster centroids with the Standardised Precipitation Index (SPI) accumulated over time intervals between 1 and 60 months. This analysis reveals two spatially coherent groups of standardised hydrographs which responded to precipitation over different timescales. We estimated IRF models of the groundwater level response to effective precipitation for three boreholes in each group. The IRF models corroborate the SPI analysis showing different response functions between the groups. We applied identical effective precipitation inputs to each of the IRF models and observed differences between the hydrographs from each group. It is suggested this is due to the hydrogeological properties of the Chalk and of overlying relatively low permeability superficial deposits (recent unconsolidated sediments overlying the bedrock, such as clays and tills), which are extensive over one of the groups. The overarching controls on groundwater flood response are concluded to be a complex combination of antecedent conditions, rainfall and catchment hydrogeological properties. These controls should be taken into consideration when anticipating and managing future groundwater flood events. The approach presented is generic and parsimonious and can be easily applied where sufficient groundwater level and rainfall data are available

Managing groundwater supplies subject to drought: perspectives on current status and future priorities from England (UK)

Effective management of groundwater resources during drought is essential. How is groundwater currently managed during droughts, and in the face of environmental change, what should be the future priorities? Four themes are explored, from the perspective of groundwater management in England (UK): (1) integration of drought definitions; (2) enhanced fundamental monitoring; (3) integrated modelling of groundwater in the water cycle; and (4) better information sharing. Whilst these themes are considered in the context of England, globally, they are relevant wherever groundwater is affected by drought