117 results on '"Hess, Tim"'
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2. A scale-based framework to understand the promises, pitfalls and paradoxes of irrigation efficiency to meet major water challenges
- Author
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Lankford, Bruce, Closas, Alvar, Dalton, James, López Gunn, Elena, Hess, Tim, Knox, Jerry W, van der Kooij, Saskia, Lautze, Jonathan, Molden, David, Orr, Stuart, Pittock, Jamie, Richter, Brian, Riddell, Philip J, Scott, Christopher A, Venot, Jean-philippe, Vos, Jeroen, and Zwarteveen, Margreet
- Published
- 2020
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3. The impact of changing food choices on the blue water scarcity footprint and greenhouse gas emissions of the British diet: the example of potato, pasta and rice
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Hess, Tim, Chatterton, Julia, Daccache, Andre, and Williams, Adrian
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- 2016
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4. The impact of climatic variability over the period 1961-1990 on the soil water balance of upland soils in the North East Arid Zone of Nigeria
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Hess, Tim M. and Stephens, William
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577.5709669 - Abstract
Over the period 1961 – 90 the North East Arid Zone of Nigeria experienced a decline in annual rainfall totals and increased aridity which placed increasing pressure on rain fed, millet-based farming systems. The changes in seasonal rainfall total and distribution have been examined and it has been shown that the rate of decline has been consistent across the region. The decline has been dominated by reduction in the number of rain days during the middle of the rainy season and there is no evidence of a significant change in the length of the growing season. Over the same time period, there has been a small, but significant, increase in mean air temperature which has resulted in a small increase in potential evapotranspiration. Other climatic parameters (vapour pressure, solar radiation and wind speed) appear to have remained stable, although the paucity and dubious quality of much of the historical meteorological data make rigorous statistical analysis difficult. A water balance model (BALANCE) developed by the author, was calibrated for a millet crop grown on a typical sandy loam soil in Maiduguri (Nigeria). The model was necessarily parsimonious, but was shown to perform well when calibrated against observed soil water content. However, the empirical nature and high sensitivity of key parameters relating to bare soil evaporation and drainage mean that it is difficult to parameterise the model by laboratory, or independent field measurements. Applying the calibrated model to daily rainfall and average evapotranspiration data from Nguru (Nigeria) for the period 1961 – 93 showed that, with the exception of extreme drought years, the increased aridity would have had little impact on the viability of traditional millet and millet-cowpea intercropping systems prior to the early 1980s. However, after that date, predicted seasonal millet transpiration, and hence predicted yields, have declined, and long duration cowpea intercrops, which were traditionally matured on residual soil moisture after the millet harvest have had insufficient water. Whilst the BALANCE model has been useful in examining the impact of climatic variability on agro-hydrology, it is not a crop physiological model and the interaction between soil water and crop development is poorly represented. The model cannot, therefore be applied with confidence to investigate the potential yield benefits of physical or agronomic interventions to alleviate the impacts of aridity. Although more complex models exist to do this, they require detailed parameterisation of the crop physiology, which was not possible within the scope of this study.
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- 1991
5. Food System Resilience: Concepts, Issues, and Challenges
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Zurek, Monika, primary, Ingram, John, additional, Sanderson Bellamy, Angelina, additional, Goold, Conor, additional, Lyon, Christopher, additional, Alexander, Peter, additional, Barnes, Andrew, additional, Bebber, Daniel P., additional, Breeze, Tom D., additional, Bruce, Ann, additional, Collins, Lisa M., additional, Davies, Jessica, additional, Doherty, Bob, additional, Ensor, Jonathan, additional, Franco, Sofia C., additional, Gatto, Andrea, additional, Hess, Tim, additional, Lamprinopoulou, Chrysa, additional, Liu, Lingxuan, additional, Merkle, Magnus, additional, Norton, Lisa, additional, Oliver, Tom, additional, Ollerton, Jeff, additional, Potts, Simon, additional, Reed, Mark S., additional, Sutcliffe, Chloe, additional, and Withers, Paul J.A., additional
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- 2022
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6. The ecological research needs of business
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Armsworth, Paul R., Armsworth, Anastasia N., Compton, Natalie, Cottle, Phil, Davies, Ian, Emmett, Bridget A., Fandrich, Vanessa, Foote, Matthew, Gaston, Kevin J., Gardiner, Phil, Hess, Tim, Hopkins, John, Horsley, Nick, Leaver, Natasha, Maynard, Trevor, and Shannon, Delia
- Published
- 2010
7. How can we avoid eating ourselves out of water? [News & Views]
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Hess, Tim
- Subjects
Health humanities ,Hydrology - Abstract
Agriculture is the main contributor to global water scarcity but not all diets contribute equally. Modifying what, and how much, we eat could reduce the impact of our diets on global water resources.
- Published
- 2021
8. No safe place: Prevalence and correlates of violence against conflict-affected women and girls in South Sudan
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Ellsberg, Mary, primary, Ovince, Junior, additional, Murphy, Maureen, additional, Blackwell, Alexandra, additional, Reddy, Dashakti, additional, Stennes, Julianne, additional, Hess, Tim, additional, and Contreras, Manuel, additional
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- 2020
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9. Research challenges in evaluating gender-based violence response services in a refugee camp
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McAlpine, Alys, primary, Bacchus, Loraine J., additional, Muuo, Sheru W., additional, Muthuri, Stella K., additional, Bangha, Martin, additional, Izugbara, Chimaraoke, additional, Franchi, Giorgia, additional, Hess, Tim, additional, Spangaro, Jo, additional, Pearson, Rachel, additional, and Hossain, Mazeda, additional
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- 2020
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10. Increasing Resilience of the UK Fresh Fruit and Vegetable System to Water-Related Risks
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Zurek, Monika, primary, Garbutt, George, additional, Lieb, Theresa, additional, Hess, Tim, additional, and Ingram, John, additional
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- 2020
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11. Resilience of Primary Food Production to a Changing Climate: On-Farm Responses to Water-Related Risks
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Hess, Tim, primary, Knox, Jerry, additional, Holman, Ian, additional, and Sutcliffe, Chloe, additional
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- 2020
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12. Disability, violence, and mental health among Somali refugee women in a humanitarian setting
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Hossain, Mazeda, primary, Pearson, Rachel, additional, McAlpine, Alys, additional, Bacchus, Loraine, additional, Muuo, Sheru W., additional, Muthuri, Stella K, additional, Spangaro, Jo, additional, Kuper, Hannah, additional, Franchi, Giorgia, additional, Pla Cordero, Ricardo, additional, Cornish-Spencer, Sarah, additional, Hess, Tim, additional, Bangha, Martin, additional, and Izugbara, Chimaraoke, additional
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- 2020
- Full Text
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13. Assessing the environmental impacts of healthier diets. Final report to Defra on project FO0427
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Williams, Adrian, Morris, Joe, Audsley, Eric, Hess, Tim, Goglio, Pietro, Burgess, Paul, Chatterton, Julia, Pearn, Kerry, Mena, Carlos, and Whitehead, Peter
- Abstract
Summary: oncern about the public health impacts of dietary habits in the UK have led to initiatives to encourage healthier eating, notably in the dietary guidelines represented of the eatwell plate (FSA, 2007) and the Eatwell Guide (NHS, 2016c). A change in UK dietary habits towards healthier eating would result in changes in the type and quantities of food items in the national diet, with implications for agricultural, food and allied industries. More specifically, this could lead to changes in land use and farming practices, both for the UK and its trading partners, with associated effects on greenhouse gas emissions and other environmental impacts. In this context, and sponsored by Defra, this study set out using a series of scenarios to assess the environmental impacts of changing dietary habits and specifically the adoption of healthier eating in the UK, and in broad terms some of the likely social and economic impacts on the agricultural and food sector, through a set of hypothetical scenarios. The main objectives were to: i) determine the consumption of food under possible future food consumption scenarios in the UK, including the eatwell plate; ii) quantify the production of agricultural commodities needed to meet the food needs of each scenario; iii) quantify the environmental impacts of food commodity production and consumption by scenarios, and iv) identify, in broad terms, the possible economic and societal impacts of dietary changes. The authors thank Defra for funding and supporting the project and all the stakeholders who participated in the project and helped greatly in shaping and quantifying the dietary change scenarios. The authors also thank others who contributed in other ways, e.g. nutritional advice from Prof Joe Millward of Surrey University.
- Published
- 2018
14. Modelling NDVI from decadal rainfall data in the North East Arid Zone of Nigeria
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Hess, Tim, Stephens, William, and Thomas, Graham
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Nigeria -- Natural history ,Rain and rainfall -- Analysis ,Communications satellites -- Usage ,Vegetation and climate -- Surveys ,Environmental issues - Abstract
The decadal rainfall over the preceding seven months can help predict Normalized Difference Vegetation Index (NDVI) in the North East Zone of Nigeria through satellite imagery. The NDVI is a tool for monitoring vegetation growth and deciphering changes in vegetation consequent to decadal rainfall data in a particular region. The model for computing NDVI is independent of location and annual rainfall and can be extended to record NDVI data prior to the period of satellite imagery. The model also explains the inter-seasonal and intra-seasonal differentials in NDVI.
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- 1996
15. Identifying trade-offs and reconciling competing demands for water - integrating agriculture into a robust decision-making framework
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Knox, Jerry W., Haro Monteagudo, David, Hess, Tim M., and Morris, Joe
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modelling ,climate change ,risk ,uncertainty ,water resources ,agriculture - Abstract
Increasing demands for water, driven by population growth and socio‐economic development, environmental regulations and future climate uncertainty, are highlighting limitations on water supplies. This water‐energy‐food‐environment nexus is not confined to semi‐arid regions but is emerging as a key business, societal and economic risk in humid and temperate countries, where abundant water supplies and regulation have historically coped with fluctuating demands between industry, power generation, agriculture, domestic supply and the environment. In the UK, irrigation is supplemental to rainfall, consumptive in use and concentrated in the driest years and most resource‐stressed catchments. This paper describes an empirical application of a mixed methods approach to integrate agriculture into a robust decision‐making framework, focusing on a water‐stressed region in England. The approach shows that competing demands between sectors can be reconciled and that potential options or portfolios compatible with multi‐sectoral collaboration and investment can be identified. By combining model outputs to forecast the impacts of climate and socio‐economic change on agricultural demand within a regional water resource simulator, future spatial estimates of demand were derived. A set of search and tracked metrics were used to drive multi‐criteria searches to identify preferred supply and demand management orientated portfolios. The methodological challenges in forecasting agricultural demand, defining acceptable ‘trade‐offs’, managing scale and uncertainty issues and the importance of engendering open dialogue between stakeholders is described. The study provides valuable insights for countries where similar emergent issues regarding conflicts over water demand exist.
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- 2018
16. A Generic Approach for Live Prediction of the Risk of Agricultural Field Runoff and Delivery to Watercourses: Linking Parsimonious Soil-Water-Connectivity Models With Live Weather Data Apis in Decision Tools
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Comber, Alexis, primary, Collins, Adrian L., additional, Haro-Monteagudo, David, additional, Hess, Tim, additional, Zhang, Yusheng, additional, Smith, Andrew, additional, and Turner, Andrew, additional
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- 2019
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17. Meta-analysis of climate impacts and uncertainty on crop yields in Europe
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Knox, Jerry W., Daccache, Andre, Hess, Tim M., and Haro Monteagudo, David
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fungi ,food and beverages - Abstract
Future changes in temperature, rainfall and soil moisture could threaten agricultural land use and crop productivity in Europe, with major consequences for food security. We assessed the projected impacts of climate change on the yield of seven major crop types (viz wheat, barley, maize, potato, sugar beet, rice and rye) grown in Europe using a systematic review (SR) and meta-analysis of data reported in 41 original publications from an initial screening of 1748 studies. Our approach adopted an established SR procedure developed by the Centre for Evidence Based Conservation constrained by inclusion criteria and defined methods for literature searches, data extraction, meta-analysis and synthesis. Whilst similar studies exist to assess climate impacts on crop yield in Africa and South Asia, surprisingly, no comparable synthesis has been undertaken for Europe. Based on the reported results (n = 729) we show that the projected change in average yield in Europe for the seven crops by the 2050s is +8%. For wheat and sugar beet, average yield changes of +14% and +15% are projected, respectively. There were strong regional differences with crop impacts in northern Europe being higher (+14%) and more variable compared to central (+6%) and southern (+5) Europe. Maize is projected to suffer the largest negative mean change in southern Europe (−11%). Evidence of climate impacts on yield was extensive for wheat, maize, sugar beet and potato, but very limited for barley, rice and rye. The implications for supporting climate adaptation policy and informing climate impacts crop science research in Europe are discussed.
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- 2016
18. Disability, violence, and mental health among Somali refugee women in a humanitarian setting.
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Hossain, Mazeda, Pearson, Rachel, McAlpine, Alys, Bacchus, Loraine, Muuo, Sheru W., Muthuri, Stella K., Spangaro, Jo, Kuper, Hannah, Franchi, Giorgia, Cordero, Ricardo Pla, Cornish-Spencer, Sarah, Hess, Tim, Bangha, Martin, and Izugbara, Chimaraoke
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WOMEN refugees ,AT-risk people ,ABUSED women ,MENTAL health ,INTIMATE partner violence ,POST-traumatic stress ,MENTAL health screening - Abstract
Background. There is limited evidence on the relationship between disability, experiences of gender-based violence (GBV), and mental health among refugee women in humanitarian contexts. Methods. A cross-sectional analysis was conducted of baseline data (n = 209) collected from women enrolled in a cohort study of refugee women accessing GBV response services in the Dadaab refugee camps in Kenya. Women were surveyed about GBV experiences (past 12 months, before the last 12 months, before arriving in the refugee camps), functional disability status, and mental health (anxiety, depression, post-traumatic stress), and we explored the inter-relationship of these factors. Results. Among women accessing GBV response services, 44% reported a disability. A higher proportion of women with a disability (69%) reported a past-year experience of physical intimate partner violence and/or physical or sexual non-partner violence, compared to women without a disability (54%). A higher proportion of women with a disability (32%) experienced non-partner physical or sexual violence before arriving in the camp compared to women without a disability (16%). Disability was associated with higher scores for depression (1.93, 95% confidence interval (CI) 0.54-3.33), PTSD (2.26, 95% CI 0.03-4.49), and anxiety (1.54, 95% CI 0.13-2.95) after adjusting for age, length of encampment, partner status, number of children, and GBV indicators. Conclusions. A large proportion of refugee women seeking GBV response services have disabilities, and refugee women with a disability are at high risk of poor mental health. This research highlights the need for mental health and disability screening within GBV response programming. [ABSTRACT FROM AUTHOR]
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- 2020
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19. A sweet deal? Sugarcane, water and agricultural transformation in Sub-Saharan Africa
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Hess, Tim M., Sumberg, J., Biggs, T., Georgescu, M., Haro Monteagudo, David, Jewitt, G., Ozdogan, M., Thenkabail, P., Daccache, Andre, Marin, F., and Knox, Jerry W.
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Water resources ,Impact ,Agriculture ,Development ,Sugar ,Livelihoods - Abstract
Globally, the area of sugarcane is rising rapidly in response to growing demands for bioethanol and increased sugar demand for human consumption. Despite considerable diversity in production systems and contexts, sugarcane is a particularly “high impact” crop with significant positive and negative environmental and socio-economic impacts. Our analysis is focused on Sub-Saharan Africa (SSA), which is a critical region for continued expansion, due to its high production potential, low cost of production and proximity, and access, to European markets. Drawing on a systematic review of scientific evidence, combined with information from key informants, stakeholders and a research-industry workshop, we critically assess the impacts of sugarcane development on water, soil and air quality, employment, food security and human health. Our analysis shows that sugarcane production is, in general, neither explicitly good nor bad, sustainable nor unsustainable. The impacts of expansion of sugarcane production on the environment and society depend on the global political economy of sugar, local context, quality of scheme, nature of the production system and farm management. Despite threats from climate change and forthcoming changes in the trade relationship with the European Union, agricultural development policies are driving national and international interest and investment in sugarcane in SSA, with expansion likely to play an important role in sustainable development in the region. Our findings will help guide researchers and policy makers with new insights in understanding the situated environmental and social impacts associated with alternative sugar economy models, production technologies and qualities of management.
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- 2016
20. Understanding the LCA and ISO water footprint: A response to Hoekstra (2016) “A critique on the water-scarcity weighted water footprint in LCA”
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Pfister, Stephan, primary, Boulay, Anne-Marie, additional, Berger, Markus, additional, Hadjikakou, Michalis, additional, Motoshita, Masaharu, additional, Hess, Tim, additional, Ridoutt, Brad, additional, Weinzettel, Jan, additional, Scherer, Laura, additional, Döll, Petra, additional, Manzardo, Alessandro, additional, Núñez, Montserrat, additional, Verones, Francesca, additional, Humbert, Sebastien, additional, Buxmann, Kurt, additional, Harding, Kevin, additional, Benini, Lorenzo, additional, Oki, Taikan, additional, Finkbeiner, Matthias, additional, and Henderson, Andrew, additional
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- 2017
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21. Meta-analysis of climate impacts and uncertainty on crop yields in Europe
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Knox, Jerry, primary, Daccache, Andre, additional, Hess, Tim, additional, and Haro, David, additional
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- 2016
- Full Text
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22. Preliminary modelling of the effects of land use and management change on available water
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Holman, Ian P. and Hess, Tim M.
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Modelling, climate change, landuse change, land use, water - Abstract
This report is part of the "Land use, climate change & water availability (Phase 2a)" project which was commissioned and funded by the Department for Environment, Food and Rural Affairs (Defra). It provides an initial quantification of the effects of changes in land use and land management on average annual Hydrological Effective Rainfall (AAHER) and Potential Baseflow uising a soil water balance model (WaSim). The effects were considered in present and future climates by using the FutureFlows climate change ensemble. The changes modelled were informed by the plausible future land use and management changes (induced by climate or social change by the 2050s) identified in the literature review in Task B - in particular regarding changes in land use (e.g., changes in agricultural and forest areas) and changes in cropping calendars and sowing/harvest dates.
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- 2014
23. Development of a range of plausible future land use, land management and growing season changes
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Holman, Ian P. and Hess, Tim M.
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climate change, water, landuse, land use - Abstract
This report is part of the "Land use, climate change & water availability (Phase 2a)" project which was commissioned and funded by the Department for Environment, Food and Rural Affairs (Defra). Based on a review of the literature, it describes plausible characteristics of future land use and management changes (induced by climate or social change by the 2050s) that are likely to influence water availability.
- Published
- 2014
24. Scale impacts on spatial variability in reference evapotranspiration
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Hess, Tim, primary, Daccache, Andre, additional, Daneshkhah, Ali, additional, and Knox, Jerry, additional
- Published
- 2016
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25. A framework for assessing technology and management options to reduce water losses
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Hess, Tim M. and Knox, Jerry W.
- Abstract
Water saving in agriculture often refers to reducing the amount of water abstracted or diverted and used for different purposes. However, this is not the only option: reductions in water use can also be achieved by using appropriate techniques for irrigation, applying relevant management practices, using water from alternative sources or influencing behaviour – for example, via awareness-raising, dissemination of best practices, regulation, water pricing and/or the use of financial incentives. While these options or responses will help to reduce pressure on water resources, if implemented in isolation they limit the extent to which water is actually ‘saved’. More often, they need to be considered as part of a broader integrated approach to water management. This paper presents a framework for identifying areas in which scope for achieving water savings exists and then reviews the possible means of action and the constraints to implementation. The framework is intended to inform polices aimed at improving the sustainability and allocation of water to irrigated agriculture. http://www.ippublishing.com
- Published
- 2013
26. The water footprint of Irish meat and dairy products
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Hess, Tim M., Chatterton, Julia, and Williams, Adrian
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Dairy ,Meat ,Footprint ,Water - Abstract
The water consumption of a range of dairy and beef production systems was estimated for four locations in Ireland using the Cranfield Life Cycle Assessment (LCA) systems model. This included direct water consumption (for drinking, washing, cleaning, etc.) as well as virtual water in the diet (that is, water that had been used to grow grass and concentrate feedstuffs). This was partitioned into “blue” water that is abstracted from rivers or groundwater, or taken from mains water supplies, and “green” water that is rain water used by growing plants at the place where the rain falls. In general, intensive systems have a lower water consumption per unit of output than extensive systems as the higher water consumption per head is offset by high output. The water consumption of dairy-beef systems is lower than for suckler beef because most of the water use by the dairy cow is allocated to the dairy system, whereas for suckler systems, the water use of the suckler cow is included for the first year. It is clear that the vast majority of the total water consumption for all the systems studied is green water. It can be argued that green water use has negligible environmental impact as it has a low, or negligible opportunity cost. The rain water consumed by growing grass or feed crops could only be used for growing alternative vegetation, that is, it could not be used to substitute for water for domestic or industrial consumption for example. Therefore, there is no water benefit in saving green water. The blue water consumption is very small for both milk and beef under all systems. Drinking water accounts for almost half of the blue water used by dairy systems, and almost all of that consumed by beef systems. Therefore, technologies that reduce the wastage / leakage in on farm drinking water systems can reduce the overall water consumption. For dairy systems the remainder of the blue water consumption is associated with milk cooling and cleaning of the milking parlour and yards. The amount of blue water associated with growing feed is trivial. For dairy, twice as much blue water is consumed in the processing of milk compared to the livestock and feed systems. For dairy-beef and suckler beef, blue water consumption on the farm 2.5 and 7.4 times as much as used in the processing stage respectively. Most water use on Irish livestock farms is from groundwater (90%) and mains water (10%). Generally, widespread abstraction pressures on groundwater are not significant in Ireland and the impact of water use would be expected to be small, however, there are some localised cases where abstraction pressures are impacting on groundwater levels (EPA, 2008). This highlights the very local scale of hydrological impacts and suggests that even though the average water consumption of Irish beef and dairy production is very small, in certain places it may be contributing to depletion of groundwater resources and water conservation may be encouraged. The Water Stress Index can be used to normalise the blue water consumption and to derive an index of water equivalent (H2Oe) that reflects both the volume of blue water consumed and relative stress on water in the producing region. For dairy systems, the normalised water footprint of milk production (at the farm gate) ranges from 0.12 litres H2Oe/litre fat and protein corrected milk (FPCM) for high yielding autumn calving systems in the south of Ireland to 0.17 for low-yielding, spring calving systems in the south-east. For beef systems, the normalised water footprint of milk production (at the farm gate) ranges from 0.24 litres H2Oe/kg for extensive dairy beef systems in the south of Ireland to 0.98 for autumn calving, extensive finishing systems in the south-east. These figures are very low compared to other livestock producing regions. Bord Bia (Irish Food Board)
- Published
- 2012
27. The water footprint of English beef and lamb production
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Chatterton, Julia C., Hess, Tim M., and Williams, Adrian G.
- Subjects
meat ,Lamb ,Water footprint ,Beef - Abstract
Recent reports highlighting large quantities of water required to produce a kilo of meat have attracted media attention, leading to debates over the role of meat in a sustainable diet. Such reports frequently quote figures based on global averages and therefore conceal significant regional variation, ignoring the source of the water required and local climatic conditions. This report attempts to quantify the water footprint of English beef and lamb production, combining the water simulation model Wasim and the Cranfield Life Cycle Assessment model to calculate the water required to produce a tonne of beef and lamb meat. This method accounts for all water required by grass and crops in addition to drinking water and other requirements. Water use is considered in three categories; green, blue and grey water. Results show that beef has a water footprint of 17,700 m3/t carcase weight and lamb 57,800 m3/t. Of these, 84% and 97% respectively is green water use, i.e. evapotranspiration of rainfall on crop and grassland. Without this breakdown there is no distinction between rainfall and irrigation supply (blue water), which means that UK beef production may appear similar in impact to countries where irrigation of feed crops is dominant. This report highlights the importance of considering water use in context; in this case, for a temperate, wet climate such as England where crop and grassland water requirements are adequately met by green water from rainfall. Upland and hill production systems have higher water footprints, mostly because grass yield is lower. However, it is shown that rainfall surplus per tonne grass production is still highest in these regions, so that export of water for other human purposes is possible from these regions. EBLEX
- Published
- 2011
28. Wasim - Tutorial Manual
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Hess, Tim M.
- Subjects
Salinity ,Tutorial ,Drainage ,Irrigation ,Model - Abstract
This manual is an output of Project R6879, funded by DFID under the Knowledge and Research (KAR) Programme. The work was undertaken by HR Wallingford and Cranfield University (at Silsoe), with the active participation of the International Waterlogging and Research Institute (IWASRI), Pakistan. A case study tutorial for use with the Wasim soil water balance simulation model, based on irrigated potatoes in the UK.
- Published
- 2011
29. Weather and lower prices cut heating costs
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Hess, Tim
- Subjects
Heating -- Economic aspects ,Fuel -- Prices and rates -- Economic aspects ,Company pricing policy ,Business ,Petroleum, energy and mining industries - Abstract
Warmer temperatures and lower energy prices have contributed to a reduction in EIA's current forecast average heating expenditures this winter compared with the forecast in the October 2015 Winter Fuels [...]
- Published
- 2016
30. Hans Sahl : ein deutsch-jüdischer Autor zwischen alter und neuer Welt
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Hess, Tim
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Institut für Jüdische Studien und Religionswissenschaft ,ddc:200 - Abstract
Inhalt: 1. Hans Sahl - ein moderner „Ahasver" 2. Deutsch-jüdische Literatur - zwangsläufig Exilliteratur? 3. Ein „ewiger Außenseiter" auch für die Exilforschung?
- Published
- 2008
31. A water balance simulation model for teaching and learning – WaS
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Hess, Tim M. and Counsell, Chris
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Salinity ,Teaching ,Drainage ,Water Balance ,Irrigation ,Simulation - Abstract
Developed by HR Wallingford and Cranfield University (with support from the UK Department for International Development), WaSim is a computer-based training package for the teaching and demonstration of issues involved in irrigation, drainage and salinity management. WaSim is a daily water balance model that simulates the soil water / salinity relationships in response to different management strategies (e.g. drainage designs and water management practices) and environmental scenarios (e.g. weather data, soil types, cropping patterns).
- Published
- 2008
32. Risk Assessment at Rail Grade Crossings: The Event Window
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Hess, Tim
- Subjects
Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods - Abstract
Current accepted tools in risk assessment include techniques such as Fault and Event Tree analysis to predict the level of safety risk. To date, use of these tools at Grade Crossings has been limited and analysis has reverted to safety performance statistics to correlate results. There has been a missing link in modeling to be able to provide meaningful estimates of safety risk. Until now practitioners have been unable to use factors such as sighting, conspicuity, train speed, and human behavior characteristics within their numerical techniques. Working for Network Rail, the Railway operation company in the United Kingdom (UK) Halcrow has been using theoretical techniques to quantify safety risk at grade crossings. During this work we have applied a new tool in modeling safety risk, the Event Window. Using this concept, we have been able to relate variables such as sighting, user perception and predict human error against a timeline. The nearer a moving train to a grade crossing the less likely a user will cross in error. The advantage of this technique is that it takes into account the one common factor in past accidents, how users incorrectly judge train speed. In this paper we shall address the following questions: What is the benefit of quantifying the safety risk at a grade crossing? How do these risk assessments help organizations responsible for risk at grade crossings discharge their duties? What is the quality or usefulness of different types of evidence in building up these models? How can we improve on existing risk assessment techniques to make more informed and location specific decisions on grade crossing safety? How does the Event Window assist us in predicting safety risk? Tim Hess, AIMechE, Halcrow Group Ltd Jim Haile BSc CEng MIMechE, Halcrow Group Ltd
- Published
- 2005
33. Franz Kafka: Die Amtlichen Schriften. Herausgegeben von Klaus Hermsdorf und Benno Wagner / [rezensiert von] Tim Hess
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Hess, Tim
- Subjects
Institut für Jüdische Studien und Religionswissenschaft ,ddc:200 - Abstract
rezensiertes Werk: Kafka, Franz: Amtliche Schriften / Hrsg. von Klaus Hermsdorf, Benno Wagner. - Frankfurt am Main : Fischer, 2004. - 1024 S. ISBN 978-3-10-038183-5
- Published
- 2005
34. A framework for integrating flood defence and biodiversity in washlands in England
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Morris, Joe and Hess, Tim M.
- Subjects
floodplains ,flood defence ,washlands ,biodiversity - Abstract
Concerns about increased flood risk and loss of biodiversity in lowland areas, coupled with changing priorities in the countryside have drawn attention to the potential contribution that managed washlands can make to improved flood management, habitats and wildlife. Following a review of research literature, a survey of flood managers and conservation officers, and an evaluation of selected case sites in England, a framework to help integrate potential flood management and biodiversity opportunities was constructed. This framework consists of three components, namely: a Hydraulic classification which categorises washlands according to degree of hydraulic control; a Habitat classification which captures attributes of washland hydrology that define the type of existing or potential habitats; and, a Menu of Interventions to “engineer” or manage particular flooding and soil wetness regimes and thereby better exploit habitat potential. Washlands were also categorised by main type of benefit whether this is flood management, conservation, or in the case of integratedwashland, a balance of the two. The advantages of alternative administrative and funding arrangements for washlands, whether land acquisition or annual payment to existing land owners, were also explored. It was concluded that the classification of washland flooding and water level regimes can help to define habitat potential. It can also help to guide hydraulic engineering and management actions that can be taken to realise this potential. Although there is potential synergy between flooding and biodiversity under some flood regimes, biodiversity benefits mainly depend on the management of water regimes following flood events. There is a clear need to “join up” hitherto fragmente
- Published
- 2005
35. Integrated washland management for flood defence and biodiversity
- Author
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Morris, Joe, Hess, Tim M., Gowing, D. J., Leeds-Harrison, Peter B., Bannister, N., Vivash, R. M., and Wade, M.
- Abstract
In the context of growing interest in finding sustainable solutions to flood management in England and Wales, this study set out to determine the extent to which benefits to flood management and biodiversity can be achieved through an integrated approach to the creation and management of ‘washlands’. For the purpose of the study, a washland is defined as “an area of the floodplain that is allowed to flood or is deliberately flooded by a river or stream for flood management purposes, with potential to form a wetland habitat”. Following a questionnaire survey of engineers and conservationists, a review of selected sites, and a workshop of key stakeholders, it was concluded that there is both scope and willingness to exploit potential synergy. It appears, however, that until now most washlands have either been used mainly for flood storage or for wetland habitat, and there has been only a limited attempt to integrate the two objectives. In many respects, the opportunity for integrating biodiversity depends on the ability to maintain wet conditions on the washland beyond the period of the flood event, and this largely depends on the dominant land use. The scope is greatest where the washland is under grass or woodland, and actions can be taken to ‘engineer’ or manage soil wetness regimes which serve biodiversity interests. Such water management plans and related biodiversity targets are best designed into washland management from the outset, rather than as an afterthought, when conflicts of interest are likely to arise. While there is much interest in pursuing an integrated approach, lack of funding for biodiversity on washlands and the relative complexity of preparing the washland case for appraisal appear to constrain washland development. Nevertheless, washlands are perceived by engineers and conservationists alike to offer potentially sustainable solutions to flooding, enabling biodiversity targets to be met within an integrated approach to catchment flood management. Recommendations were made to: • improve, through the use of guidance and training, understanding between engineers and conservationists of how flood management and biodiversity objectives can be simultaneously achieved; • consider the establishment of a biodiversity fund to support the biodiversity components of washland schemes; • develop practical guidance on the formulation of washland management plans that exploit biodiversity potential by managing wetness conditions in washlands beyond the flood-event period; • review how washland creation and management can be integrated and help to deliver the objectives of Biodiversity Action Plans and Catchment Flo
- Published
- 2004
36. Review of the effects of energy crops on hydrology
- Author
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Stephens, William, Hess, Tim M., and Knox, Jerry W.
- Abstract
1) MAFF has recently launched a scheme to support the expansion of the area of energy crops grown in England in order to meet the nation’s Kyoto targets for the reduction in CO2 emissions. This has highlighted concerns about the possible effects of willow short rotation coppice (SRC) and Miscanthus on the hydrology of catchments in which they are grown. High levels of water use by these crops could result in less surface runoff, decreased aquifer recharge and hence reduced stream flow (Chapter 1
- Published
- 2001
37. Minimising the environmental impacts of irrigation by good scheduling
- Author
-
Hess, Tim M.
- Subjects
Irrigation ,Irrigation scheduling - Abstract
Irrigation constitutes a major user of water resources at a time, and in places, where resources are at their lowest. Also, by maintaining the soil in a wetter state, it increases the annual drainage, which can affect the leaching of nitrates into the groundwater. Irrigation scheduling involves, firstly, deciding the most appropriate irrigation plan (i.e. what soil water deficit to allow and how much to apply at that deficit) and secondly, deciding what is the soil water deficit on any particular day. Good scheduling will aim to meet the goals of irrigation (optimise production / quality / aesthetics) whilst minimising the water used and other adverse environmental impacts. The main techniques for scheduling irrigation in the UK are direct measurement of soil water content and water balance modelling. ‘Bad’ irrigation scheduling can result from an inappropriate irrigation plan, inaccurate soil water measurement, errors in water balance modelling or uncertainty over the actual amount of water applied at each irrigation. Either will result in under- or over-watering. A case study for potatoes grown in a medium textured soil in Silsoe (Beds) examined the impact of poor scheduling on average annual irrigation water requirement and the risk of nitrate leaching. The water requirement is very sensitive to errors in estimating evapotranspiration or the field-capacity water content of the soil, but less so to errors in the amount of water applied. Increasing the trigger soil water deficit can also minimise the water requirement. Over-irrigation, due to a poor irrigation plan can increase the summer drainage and risk of nitrate leaching, however, over-watering due to inaccurate scheduling predominantly results in increased winter drainage which may have a positive impact on nitrate concentrations and winter recha
- Published
- 1999
38. Irrigation Demand and On-Farm Water Conservation in England and Wales
- Author
-
Weatherhead, E. K., Knox, Jerry W., Morris, Joe, Hess, Tim M., Bradley, R. Ian, and Sanders, Catherine L.
- Subjects
water demand ,maps ,England and Wales ,water conservation ,GIS ,irrigation - Abstract
The study confirmed that water use for agricultural irrigation is increasing, both in area irrigated and depths applied, and is increasingly concentrated on the more valuable crops. Underlying volumetric growth was 3% per annum from 1982 to 1995. On-farm reservoir capacity doubled from 1990 to 1995, but 90% of the water still came from summer abstraction in 1995, mostly from rivers and streams.
- Published
- 1997
39. Climate change impacts on crop productivity in Africa and South Asia
- Author
-
Knox, Jerry, primary, Hess, Tim, additional, Daccache, Andre, additional, and Wheeler, Tim, additional
- Published
- 2012
- Full Text
- View/download PDF
40. Evapotranspiration Estimates for Water Balance Scheduling in the UK
- Author
-
Hess, Tim M.
- Subjects
Evapotranspiration ,ETgage ,Atmometer ,ET - Abstract
This paper compares the use of different methods for estimating reference evapotranspiration (ETo) for irrigation scheduling in the UK. Methods include use of long-term averages, daily weather data and evaporimeters. The results from a single trial in Silsoe in 1996 suggest that, with careful maintenance and measurement, a modified atmometer such as the ETgage, can give estimates of ETo which are close to those obtained using the Penman-Monteith equation.
- Published
- 1996
41. Estimating Green Water Footprints in a Temperate Environment
- Author
-
Hess, Tim, primary
- Published
- 2010
- Full Text
- View/download PDF
42. Ecohydrology of a seasonal wetland in the Rift Valley: ecological characterization of Lake Solai
- Author
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De Bock, Tanguy, primary, Kervyn de Meerendré, Baptiste, additional, Hess, Tim, additional, and Gouder de Beauregard, Anne‐Christine, additional
- Published
- 2009
- Full Text
- View/download PDF
43. Spot Treatment of Granular Hexazinone in Wild Blueberries
- Author
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Yarborough, David E., primary and Hess, Tim M., additional
- Published
- 1998
- Full Text
- View/download PDF
44. Abstract 10720: Ischemic Evaluation in Patients Presenting With Atrial Fibrillation With Rapid Ventricular Rates and Elevated Troponin Levels Does Not Impact Outcomes.
- Author
-
Haigh, Peter, Swearingen, Sean, Chaddha, Ashish, Hess, Tim, and Wright, Jennifer
- Published
- 2018
45. Building consensus on water use assessment of livestock production systems and supply chains: Outcome and recommendations from the FAO LEAP Partnership
- Author
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Boulay, Anne-Marie, Drastig, Katrin, Amanullah, Chapagain, Ashok, Charlon, Veronica, Civit, Bárbara, DeCamillis, Camillo, De Souza, Marlos, Hess, Tim, Hoekstra, Arjen Y., Ibidhi, Ridha, Lathuillière, Michael J., Manzardo, Alessandro, McAllister, Tim, Morales, Ricardo A., Motoshita, Masaharu, Palhares, Julio C.P., Pirlo, Giacomo, Ridoutt, Brad, Russo, Valentina, Salmoral, Gloria, Singh, Ranvir, Vanham, Davy, Wiedemann, Stephen, Zheng, Weichao, and Pfister, Stephan
- Subjects
2. Zero hunger ,Livestock production ,Water scarcity footprint ,13. Climate action ,Water productivity ,Water footprinting ,Water use assessment ,15. Life on land ,6. Clean water - Abstract
The FAO Livestock Environmental Assessment and Performance (LEAP) Partnership organised a Technical Advisory Group (TAG) to develop reference guidelines on water footprinting for livestock production systems and supply chains. The mandate of the TAG was to i) provide recommendations to monitor the environmental performance of feed and livestock supply chains over time so that progress towards improvement targets can be measured, ii) be applicable for feed and water demand of small ruminants, poultry, large ruminants and pig supply chains, iii) build on, and go beyond, the existing FAO LEAP guidelines and iv) pursue alignment with relevant international standards, specifically ISO 14040 (2006)/ISO 14044 (2006), and ISO 14046 (2014). The recommended guidelines on livestock water use address both impact assessment (water scarcity footprint as defined by ISO 14046, 2014) and water productivity (water use efficiency). While most aspects of livestock water use assessment have been proposed or discussed independently elsewhere, the TAG reviewed and connected these concepts and information in relation with each other and made recommendations towards comprehensive assessment of water use in livestock production systems and supply chains. The approaches to assess the quantity of water used for livestock systems are addressed and the specific assessment methods for water productivity and water scarcity are recommended. Water productivity assessment is further advanced by its quantification and reporting with fractions of green and blue water consumed. This allows the assessment of the environmental performance related to water use of a livestock-related system by assessing potential environmental impacts of anthropogenic water consumption (only “blue water”); as well as the assessment of overall water productivity of the system (including “green” and “blue water” consumption). A consistent combination of water productivity and water scarcity footprint metrics provides a complete picture both in terms of potential productivity improvements of the water consumption as well as minimizing potential environmental impacts related to water scarcity. This process resulted for the first time in an international consensus on water use assessment, including both the life-cycle assessment community with the water scarcity footprint and the water management community with water productivity metrics. Despite the main focus on feed and livestock production systems, the outcomes of this LEAP TAG are also applicable to many other agriculture sectors., Ecological Indicators, 124, ISSN:1470-160X, ISSN:1872-7034
46. Characterising urban catchments for explaining storm runoff and application in UK flood estimation
- Author
-
Miller, James, Brewer, Tim R., and Hess, Tim M.
- Subjects
551.48 ,Landscape metrics ,catchment descriptors ,flood estimation handbook ,impervious ,urban extent ,hydrological model - Abstract
The impacts of urbanisation on catchment hydrology have been the focus of investigation over the last few decades, but quantifying and predicting the impacts remains an ongoing area of active research. One such area has been improving characterisation of urban land cover to predict urbanisation impacts whereby lumped catchment characterisation of urban land cover limits the ability of attribution and modelling methods to consider the spatial role of land cover in runoff response. This thesis evaluates the potential for spatially explicit characterisations of urban land cover based on landscape metrics, commonly employed in landscape ecology, to explain storm runoff in urban catchments and their application in UK flood estimation methods. Rainfall and channel flow monitoring across two towns containing 18 variably urbanised sub-catchments were used to provide high-resolution time-series of rainfall and runoff and to identify storm events which were quantified using a range of hydrological metrics. Analysing storm runoff along a rural-urban gradient showed a lumped measure of urban extent can generally explain differences in the hydrological response between rural and urban catchments but not between more urbanised catchments in which soil moisture does not play a contributing role. Using high resolution geospatial data can improve the representation of the urban environment and landscape metrics can better represent the form and function of urban land cover, improving estimates of the index flood QMED over lumped catchment descriptors. Regression analysis of hydrological metrics showed the potential of landscape metrics for explaining inter-catchment differences in rainfall-runoff and point to the importance of considering the location and connectivity of urban surfaces. Landscape metrics provide a workable means of overcoming the limitations inherent in using lumped characterisation of complex urban land cover and their ability to express connectivity, size and location of urban land cover promises potential applications in hydrological applications such as UK design flood estimation methods.
- Published
- 2019
47. Modelling phosphorus removal capacity and longevity in land treatment systems
- Author
-
Batista Segui, María del Mar, Hess, Tim M., and Tyrrel, Sean
- Subjects
Modelling ,longevity ,retention ,soil ,wastewater tertiary treatment - Abstract
The wastewater industry is facing an increase in regulatory pressure to reduce excessive phosphorus (P) release to rivers. To address this issue there is a need for sustainable treatments, especially in small sewage treatment works (STW) (< 2000 inhabitants) which constitute 75 % of the systems in the UK. Land treatment systems (LTS) have long been used to treat wastewater, principally as a tertiary treatment at small rural sites. LTS are able to remove phosphorus but there are some uncertainties regarding their treatment capability. This research aims to address these uncertainties by developing improved estimations of P removal potential and longevity in LTS in the context of a sustainable water industry. First, the existing knowledge and tools available in long-term P removal behaviour are reviewed. Second, the soil P removal efficiency and accumulation in an LTS case study are estimated. Finally, the case study is used to develop a conceptual and mathematical model of P dynamics in LTS integrating water and solute transport in soils. The model is used to explain system behaviour in order to estimate system longevity under different soil conditions and management scenarios. This research demonstrates that LTS can contribute to P removal for a number of years as a tertiary treatment for small STW and that through a combination of hydrological and solute transport modelling it is possible to get a prediction of P removal and longevity of LTS. Results indicate the need for an alternative methodology to assess P removal capacity that does not only rely on inputs and outputs while able to detect if the system is saturated and the need of improved methodological assessment of sorption processes over time. Further development of the current model to reduce limitations, mainly related to vegetation management and P transformation in the different soil pools, will support LTS contribution to the sustainable management of wastewater treatments and the enhancement of the ecosystem services that they provide.
- Published
- 2017
48. Processes controlling the sources and transport dynamics of suspended sediment in rivers
- Author
-
Vercruysse, Kim, Grabowski, Robert, and Hess, Tim M.
- Subjects
Timescale ,fluvial geomorphology ,connectivity ,hydro-meteorology ,sediment fingerprinting ,processes - Abstract
Human activity has disturbed the natural suspended sediment (SS) balance and the associated geomorphological and ecological functioning of many rivers. Yet, predicting and managing SS is challenging because the processes controlling SS transport over multiple timescales are not well understood. The aim of this research is to improve the prediction and management of SS by investigating the hydro-meteorological and catchment processes driving temporal variation in SS transport. The objectives are (i) to assess SS transport over multiple timescales to uncover the scale-specific processes and process interactions that determine temporal variation in SS transport; (ii) to apply and test a sediment fingerprinting approach based on infrared spectrometry to identify dominant SS sources; and (iii) to evaluate the role of variations in sediment sources in controlling SS concentrations in response to hydro-meteorological variables. The research was carried out in the River Aire, UK. The findings show that SS transport in the River Aire is highly event-driven and supply-limited, while also being influenced by long-term changes in land use. Over the studied period, the dominant SS source was grassland, and its contribution was mainly controlled by antecedent moisture conditions. On the contrary, urban street dust, which was also a dominant sediment source, was less hydrologically driven. The research also demonstrated that while infrared-based fingerprinting can be used to estimate SS source contributions with acceptable model errors, sediment apportionment is strongly influenced by the degree of discrimination between source classes. In order to improve methods to quantify SS transport and sources, and to identify sediment management needs, this research underscores the need to (i) recognise different timescales of SS transport to identify the underlying processes; (ii) develop better approaches for source classification and discrimination to accurately represent the sediment in rivers; and (iii) establish further knowledge on sediment sources variations in different contexts and over multiple spatial and temporal scales.
- Published
- 2017
49. Microtopographic enhancement of land-based wastewater treatment
- Author
-
Tyrrell, Sean R., Hess, Tim M., and Tyrrel, S.
- Subjects
628.3 ,Ridge and furrow ,furrow irrigation ,nutrient-removal ,vegetation-diversity ,tertiary-treatment ,phosphorus ,nitrate ,ammonia - Abstract
There is a regulatory tension within wastewater treatment, between the requirement to meet tightening consents and the need to reduce the carbon footprint of treatment processes. With 75% of wastewater treatment works serving populations of less than 2,000, low-energy tertiary treatment options suitable to small rural works need to be developed. One option that lends itself particularly well to small works is land-based wastewater treatment (LBWWT). The aim of this research was to evaluate the role of LBWWT in the UK water industry and investigate the impact ridge-and-furrow enhanced microtopography (MT) may have upon a particular type of LBWWT - slow-rate (SR) infiltration. This was achieved through meeting three objectives. Firstly, the use of LBWWT was reviewed and assessed. Secondly, the impact of ridge-and-furrow enhanced MT upon the vegetation diversity and nutrient removal of a SR- LBWWT was established by means of a three year field trial. Finally, the cost- effectiveness of SR-LBWWT and the impact of ridging and furrow irrigation upon cost-effectiveness were evaluated using Cost-Effectiveness Analysis (CEA). The first objective comprised of a review of the historical and current use of LBWWT, a review of the relevant changing legislation to identify what may be required of LBWWT and an assessment of LBWWT’s potential to meet these requirements. The result of the evaluation found that, based upon the literature, SR-LBWWT is ‘fit-for-purpose’ as tertiary treatment for small treatment works. To meet the second objective, a SR-LBWWT system trial was established at a small wastewater treatment works in Knowle, Hampshire. The trial consisted of three clay-loam grass plots irrigated with secondary treated effluent. There were two configurations of trial plot - flat and ridge-and-furrowed. Effluent (sub- surface soil water) nutrient concentrations were monitored as was vegetation diversity. In addition a number of physical, hydrological and biogeochemical parameters were monitored and hydrological modelling carried out. Mean nutrient removal performances of 90% for ammonia, 72% for nitrate, and 91% for phosphate were observed with the ridge-and-furrowed plot. Ridging and furrow irrigation was found to not have a significantly detrimental effect upon the trial plots’ removal performance for ammonia, nitrate or phosphate. Extrapolation modelling suggested, however, that this would not be the case for LBWWT systems on predominantly clay or sand soils. Ridging and furrow irrigation was found to have a statistically significant positive effect upon the vegetation diversity of the LBWWT trial plots; with mean final year Shannon-Wiener values of 0.96 and 0.69, for the ridge-and-furrowed and non-ridged plots, respectively. For the final objective, analysis found that SR-LBWWT are cost-effective when compared to horizontal sub-surface flow constructed wetlands (HSSFCW), an established low-energy treatment option. Mean cost-effectiveness ratio values of £208.5 and £262.7 per % effectiveness were observed for LBWWT and HSSFCW, respectively. Following the field trial CEA was extended to include ridge-and-furrowed SR-LBWWT systems. This found that ridging and furrow irrigation improves the cost-effectiveness of SR-LBWWT serving small populations, reducing the mid cost-effectiveness ratio to £193 per % effectiveness. This is a result of the cost-reducing effect of ridge-and-furrowing over laser-level grading; and based upon the findings of the trial that ridging and furrow irrigation can be achieved (in clay-loam soil slow-rate systems) without significant detriment to the water treatment effectiveness of LBWWT. The main conclusions of this thesis are: that SR-LBWWT has a role to play in the UK water industry, as tertiary treatment for small wastewater treatment works. That SR-LBWWT is cost-effective in relation to HSSFCW. That ridging and furrow irrigation increases that cost-effectiveness by reducing the construction and operational costs. That ridging and furrow irrigation can be employed without significant detriment to a SR-LBWWT system’s water treatment performance. And finally, that ridging and furrow irrigation can have a positive impact upon the establishment vegetation diversity of a SR-LBWWT system.
- Published
- 2016
50. The influence of catchment characteristics on river flow variability
- Author
-
Chiverton, Andrew, Hannaford, Jamie, Holman, Ian P., Prudhomme, Christel, Hess, Tim M., and Bloomfield, John
- Subjects
551.48 - Abstract
Hydrology is yet to fully understand the role that catchment characteristics have in determining a river’s response to precipitation variability. This thesis assesses the influence that catchment characteristics have on modulating a river’s response to changes in precipitation throughout the UK. Central to this aim is the concept of the precipitation- to-flow relationship (the transformation of precipitation into river flow), which is characterised using the Variogram, a way of indexing temporal dependence (i.e. the average relationship between river flow on a given day and river flow on the previous days). Firstly, 116 catchments were grouped into four clusters, based on the shape of their variogram, which significantly differed in their catchment characteristics demonstrating that catchment characteristics control how, on average, precipitation is transformed into river flow. Furthermore, over 70% of un-gauged catchments could be clustered correctly using information about their soil type, slope and the percentage of arable land. Secondly, a new method which identifies the changes in the variogram parameters over 5-year overlapping moving windows was developed to investigate temporal changes in the variogram parameters. This method was successfully demonstrated to detect changes in multiple aspects of artificially perturbed river flow time series (e.g. seasonality, linear changes and variability). On average >70% of the variability in the catchment variogram parameters was explained by the precipitation characteristics, although there was large variability between catchments. Finally, the influence that the catchment characteristics have on the temporal changes in the variogram parameters was analysed, demonstrating that rivers in relatively impermeable upland catchments have a relationship with precipitation which is closer to linear and less variable than lowland, permeable catchments. This thesis contributes significant new knowledge that can be used for both assessing how individual catchments are likely to respond to projected changes in precipitation and in informing data transfer to un-gauged catchments.
- Published
- 2015
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