Browsing by Author "Hess, Tim"

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    Assessing the environmental impacts of healthier diets. Final report to Defra on project FO0427
    (2018-09-27) Williams, Adrian; Morris, Joe; Audsley, Eric; Hess, Tim; Goglio, Pietro; Burgess, Paul; Chatterton, Julia; Pearn, Kerry; Mena, Carlos; Whitehead, Peter
    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.
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    Assessing the environmental sustainability of irrigation with oil and gas produced water in drylands
    (Elsevier, 2019-07-06) Echchelh, Alban; Hess, Tim; Sakrabani, Ruben; de Paz, José Miguel; Visconti, Fernando
    Produced water (PW) is the largest by-product of the oil and gas industry. Its management is both economically and environmentally costly. PW reuse for irrigation offers an alternative to current disposal practices while providing water to irrigators in drylands. The aim of this investigation was to evaluate the environmental effects of irrigation with PW. The SALTIRSOIL_M model was used to simulate the irrigation of sugar beet with 15 PWs of a wide range of qualities in four climates of different aridity and on four contrasting soil types. The impacts on soil salinity, sodicity and pH as well as on crop yield and drainage water salinity were estimated. Well-drained soils with low water content at field capacity (Arenosol) are less sensitive to salinisation while a relatively high gypsum content (Gypsisol) makes the soil less vulnerable to both sodification and salinisation. On the contrary, clayey soils with higher water content at field capacity and lower gypsum content must be avoided as the soil structural stability as well as a tolerable soil electrical conductivity for the crop cannot be maintained on the long-term. Soil pH was not found to be sensitive to PW quality. Drainage water quality was found to be closely linked to PW quality although it is also influenced by the soil type. The impact of drainage water on the aquifer must be considered and reuse or disposal implemented accordingly for achieving sustainable irrigation. Finally, increasing aridity intensifies soil and drainage water salinity and sodicity. This investigation highlights the importance of adapting the existing irrigation water quality guidelines through the use of models to include relevant parameters related to soil type and aridity. Indeed, it will support the petroleum industry and irrigators, to estimate the risks due to watering crops with PW and will encourage its sustainable reuse in water-scarce areas.
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    Building consensus on water use assessment of livestock production systems and supply chains: outcome and recommendations from the FAO LEAP Partnership
    (Elsevier, 2021-01-23) 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; Palharess, Julio Cesar Pascale; Pirlo, Giacomo; Pfister, Stephan
    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
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    The challenges of developing an irrigation strategy for UK agriculture and horticulture in 2020: industry and research priorities
    (CABI, 2020-10-14) Knox, Jerry W.; Kay, M. G.; Hess, Tim; Holman, Ian P.
    In many countries, including the UK, water resources are under intense stress with recent droughts highlighting the risks to the security of supplies for different sectors including domestic water supply, industry, agriculture (including horticulture), power generation and the environment. A changing climate with greater rainfall uncertainty, coupled with new regulations, increasing competition for water and demands for sustainable development will only exacerbate the current situation, with major supply-demand imbalances expected over the next few decades. In the UK, irrigated agriculture constitutes a volumetrically small but economically high value use of water, to maximise crop yields and quality. However, the importance of irrigation is also changing; driven by the intensification and transformation of the agricultural sector, the need to recognise water as an 'essential' use, policy incentives to increase domestic food production and an industry imperative to increase water use efficiency and ensure agricultural expansion can continue to underpin the rural economy. This review considers the key climate and water-related risks facing the agricultural and horticultural crop sectors, the various environmental, regulatory and business externalities or 'drivers for change', and the strategic priorities for action, both from industry and research perspectives.
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    Climate change and water in the UK – past changes and future prospects
    (SAGE, 2015-02-09) Watts, Glenn; Battarbee, Richard W.; Bloomfield, John P.; Daccache, Andre; Hess, Tim; Knox, Jerry; Weatherhead, E. Keith
    Climate change is expected to modify rainfall, temperature and catchment hydrological responses across the world, and adapting to these water-related changes is a pressing challenge. This paper reviews the impact of anthropogenic climate change on water in the UK and looks at projections of future change. The natural variability of the UK climate makes change hard to detect; only historical increases in air temperature can be attributed to anthropogenic climate forcing, but over the last 50 years more winter rainfall has been falling in intense events. Future changes in rainfall and evapotranspiration could lead to changed flow regimes and impacts on water quality, aquatic ecosystems and water availability. Summer flows may decrease on average, but floods may become larger and more frequent. River and lake water quality may decline as a result of higher water temperatures, lower river flows and increased algal blooms in summer, and because of higher flows in the winter. In communicating this important work, researchers should pay particular attention to explaining confidence and uncertainty clearly. Much of the relevant research is either global or highly localized: decision-makers would benefit from more studies that address water and climate change at a spatial and temporal scale appropriate for the decisions they make.
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    Coping with drought and water scarcity: lessons for the agricultural sector
    (Cranfield University, 2021-10-15 09:33) Holman, Ian; Knox, Jerry; Hess, Tim; McEwen, Lindsey; Salmoral Portillo, Gloria; Rey Vicario, Dolores; Hannaford, Jamie; Grove, Ivan; Thompson, Jill; Quinn, Nevil
    This report, an output from the UKRI-funded Drought and Water Scarcity Programme, synthesis the insights for the agricultural sector. It considers how drought and water scarcity affect different types of agriculture; whether we can forecast drought and its impacts and how drought and water scarcity impacts on agriculture be reduced?
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    DailyET
    (Cranfield University, 2019-06-04 12:19) Hess, Tim
    A simple on-screen calculator to calculate daily, or monthly reference evapotranspiration from weather data according to the Penman, Modified Penman (FAO24), Penman Monteith (FAO56) or Hargreaves methods.
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    Data for "Increasing Resilience of the UK Fresh Fruit and Vegetable System to Water-Related Risks"
    (Cranfield University, 2020-10-14 16:02) Hess, Tim; Zurek, Monika; Ingram, John
    Transcripts from structured telephone interviews with stakeholders across the UK fresh fruit and vegetable system.
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    Evaluating landscape metrics for characterising hydrological response to storm events in urbanised catchments
    (Taylor and Francis, 2020-05-12) Miller, James D.; Stewart, Elisabeth; Hess, Tim; Brewer, Timothy R.
    Hydrological response of an urban catchment to storm events is determined by a number of factors including the degree of urbanisation and distribution and connectivity of urbanised surfaces. Therefore, the ability of spatially averaged catchment descriptors to characterise storm response is limited. Landscape metrics, widely used in ecology to quantify landscape structure, are employed to quantify urban land-cover patterns across a rural-urban gradient of catchments and attribute hydrological response. Attribution of all response metrics, except peak flow, is improved by combining lumped catchment descriptors with spatially explicit landscape metrics. Those representing connectedness and shape of suburban and natural greenspace improve characterisation of percentage runoff and storm runoff. Connectivity and location of urban surfaces are more important than impervious area alone for attribution of timing, validating findings from distributed hydrological modelling studies. Findings suggest potential improvements in attribution of storm runoff in ungauged urban catchments using landscape metrics.
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    Evaluating the impacts of agricultural development and climate change on the water-energy nexus in Santa Elena (Ecuador)
    (Elsevier, 2023-12-22) Chengot, Rishma; Zylberman, Raphael; Momblanch, Andrea; Salazar, Oswaldo Viteri; Hess, Tim; Knox, Jerry W.; Rey, Dolores
    A combination of a changing global climate coupled with rapid socio-economic development is putting unprecedented pressure on water, energy, and food resources. Addressing these issues within a nexus approach can help to identify appropriate management practices and strategic policies to ensure natural resources are used more sustainably thus avoiding exacerbating issues of water scarcity and food insecurity. In this study, we used an integrated water resource planning and irrigation model (WEAP) to assess emerging water-energy nexus issues on the Santa Elena peninsula in Ecuador. Simulated water demands showed that current water resources availability is insufficient to meet full irrigation requirements, especially during the dry season. Annual average energy demand for water conveyance in the SEP was significantly higher than for irrigation with 94.5 GWh and 13.5 GWh being used, respectively. Future challenges associated with changes in agricultural irrigation and urban demands within the SEP were evaluated using scenario analysis. This included considering various scenarios such as agricultural expansion, climate change, population growth, and a shift to export-oriented agriculture. The study underscores the significance of nexus thinking in guiding policy and decision-making in Santa Elena, although the limited data prevents its use in an operational framework. The benefits of adopting an integrated modelling approach to analyse water and energy nexus trade-offs are also discussed.
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    The exposure of a fresh fruit and vegetable supply chain to global water-related risks
    (Taylor and Francis, 2018-10-15) Hess, Tim; Sutcliffe, Chloe
    We have combined estimates of the UK’s supply of fresh fruit and vegetables (1996 – 2015) with estimates of water requirements and water scarcity in producing countries, to identify where the supply is exposed to physical, regulatory and reputational water risks and how this has changed over time. Some 76% of the freshwater consumed in the supply of fresh fruit and vegetables to the UK is withdrawn overseas. The supply chain is particularly exposed to water risks in Spain, Egypt, South Africa, Chile, Morocco, Israel and Peru. Exposure has increased over time.
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    Fruit and Veg vs. the Future game
    (Cranfield University, 2019-08-20 09:39) Hess, Tim; Craven, Joanne
    Fruit and Veg. vs. the Future is a hybrid board / role-play game about water risks in the UK fresh fruit and vegetable system, aimed at industry stakeholders. The game allows players to put together fruit and vegetable systems and pit them against different future scenarios, to see who the winners and losers are and how we can increase the resilience of the overall supply chain to water related risks.These files contain all the playing boards and materials.
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    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
    (Frontiers, 2019-06-04) Comber, Alexis; Collins, Adrian L.; Haro Monteagudo, David; Hess, Tim; Zhang, Yusheng; Smith, Andrew; Turner, Andrew
    This paper describes the development and application of a novel and generic framework for parsimonious soil-water interaction models to predict the risk of agro-chemical runoff. The underpinning models represent two scales to predict runoff risk in fields and the delivery of mobilized pesticides to river channel networks. Parsimonious field and landscape scale runoff risk models were constructed using a number of pre-computed parameters in combination with live rainfall data. The precomputed parameters included spatially-distributed historical rainfall data to determine long term average soil water content and the sensitivity of land use and soil type combinations to runoff. These were combined with real-time live rainfall data, freely available through open data portals and APIs, to determine runoff risk using SCS Curve Numbers. The rainfall data was stored to provide antecedent, current and future rainfall inputs. For the landscape scale model, the delivery risk of mobilized pesticides to the river network included intrinsic landscape factors. The application of the framework is illustrated for two case studies at field and catchment scales, covering acid herbicide at field scale and metaldehyde at landscape scale. Web tools were developed and the outputs provide spatially and temporally explicit predictions of runoff and pesticide delivery risk at 1 km2 resolution. The model parsimony reflects the driving nature of rainfall and soil saturation for runoff risk and the critical influence of both surface and drain flow connectivity for the risk of mobilized pesticide being delivered to watercourses. The novelty of this research lies in the coupling of live spatially-distributed weather data with precomputed runoff and delivery risk parameters for crop and soil types and historical rainfall trends. The generic nature of the framework supports the ability to model the runoff and field-to-channel delivery risk associated with any in-field agricultural application assuming application rate data are available.
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    High level review of the Optimum Water Use methodology for agriculture following the 2018 drought in England
    (Cranfield University, 2019-04-25) Knox, Jerry W.; Hess, Tim
    1. Context. After a spate of relatively average to ‘wet’ summers in England from an irrigation perspective, the heatwave and protracted dry conditions in 2018 highlighted the significant agronomic and economic importance of water resources for agricultural irrigation and the risks to production that can arise when abstractions are restricted. From an abstraction licensing perspective (licensed volume and reasonable need) 2018 also provides a useful ‘reference’ year against which actual irrigation applications (depths applied) can be compared against theoretical ‘design’ dry year requirements. It also offers an opportunity to gather feedback from abstractors on their management practices, how they coped with the drought conditions and any lessons learnt in order to support the EA in providing abstractor guidance to support improved decision-making in future drought years. Following discussion with EA staff, this short study was commissioned to produce a Technical Briefing Note for the irrigated agriculture sector in England ahead of the 2019 spray irrigation season. The intention was that the report would include a brief agroclimatic assessment of 2018 and provide additional information to complement the EA Spray Irrigation (SI) Prospects Information which is distributed to abstractors each year. This Technical Briefing Note summarises the aim and objectives of the study, the methodological approaches developed and the key findings that emerged from the analyses.
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    How can we avoid eating ourselves out of water?
    (Nature Publishing Group, 2021-04-15) Hess, Tim
    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.
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    ‘I think this is where this lovely word “sustainability” comes in’: Fruit and vegetable growers' narratives concerning the regulation of environmental water use for food production
    (Wiley, 2023-05-02) Sutcliffe, Chloe; Knox, Jerry W.; Hess, Tim
    This article concerns UK commercial fruit and vegetable growers’ narratives regarding the sustainability of water use for food production. In it we explore their perspectives on efforts by regulators to limit agricultural withdrawals of water from the natural environment in line with EU Water Framework Directive objectives, alongside their views on retailer sustainability commitments. Discourse analysis is used to investigate how the growers contested restrictive regulation, constructed their identities, portrayed other supply chain stakeholders, and conveyed their social relations with them. Using Erving Goffman's theory of frontstage and backstage performances, the implications for the growers’ water management decisions and their internalisation of sustainability agendas for water are examined. Whilst the growers gave accounts of purposely misrepresenting their water withdrawal practices and their discourse illustrated significant polarisation between environmental and agricultural interests, their underlying commitment to environmental sustainability was ambivalent, with both anti and pro-environmental attitudes expressed. The growers also frequently gave critiques of superficial sustainability in fresh produce supply chains. We argue that, given contemporary shifting definitions of agricultural identities, settings in which their construction is negotiated can provide windows of opportunity for conventional growers to engage in genuine pro-environmental performances that may deepen their assimilation of environmental goals and commitment to sustainable water use.
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    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
    (Elsevier, 2015-09) Hess, Tim; Chatterton, Julia; Daccache, Andre; Williams, Adrian
    Food production is a major contributor to a country's environmental burden. However, the burdens associated with individual foods vary significantly due to differing agricultural systems and locations, post-harvest storage, manufacturing and transport requirements. Dietary choices can therefore have a significant impact on the overall burdens associated with food consumption. Previous studies have generally considered changes in the proportion of animal-based foods in the diet or changes to a vegetarian, or a vegan diet. Using a life cycle assessment approach and data from published sources supplemented by original analysis, we estimated the blue water scarcity footprint and greenhouse gas emissions associated with the production, manufacture and distribution of three popular starchy carbohydrate foods as consumed in the United Kingdom – British fresh potatoes, Italian dried pasta and Indian dried basmati rice. Although similar to pasta in terms of greenhouse gas emissions per unit carbohydrate, when considered on the basis of typical portion size, potatoes have lower greenhouse gas emissions than pasta or basmati and the blue water scarcity footprint of basmati is two orders of magnitude greater than potatoes or pasta. The increasing preference for pasta and rice and reduction in household purchases of fresh potatoes in the United Kingdom over the period 1981–2010 has resulted in an increase in blue water scarcity footprint and a transfer of burdens from the United Kingdom to Italy and India, however the increased greenhouse gas emissions associated with rice and pasta has been, more or less, compensated by a reduction in emissions associated with purchases of potatoes. This paper has shown that dietary choices within food groups (in this case starchy carbohydrates) have a significant impact on an individual's contribution to greenhouse gas emissions and blue water scarcity footprint. The life cycle assessment approach is useful for understanding where the impacts of dietary choices occur and can inform the supply chain about where efforts should be targeted to reduce those impacts.
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    Impacts of 2018 drought on agriculture in the UK - Interview responses
    (Cranfield University, 2021-01-04 09:08) Hess, Tim; Holman, Ian; Knox,Jerry
    Summarised responses from interviewees on the impacts of drought in 2018 on agriculture and potential strategies for mitigation. The responses have been anonymised and and information that could be used to identify individuals of businesses has been redacted.
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    Implementing precision irrigation in a humid climate - Recent experiences and on-going challenges
    (Elsevier, 2014-06-22) Daccache, Andre; Knox, Jerry W.; Weatherhead, E. K.; Daneshkhah, Alireza; Hess, Tim
    There is growing scientific interest in the potential role that precision irrigation (PI) can make towards improving crop productivity, and increasing water and energy efficiency in irrigated agriculture. Most progress has been made in arid and semi-arid climates for use in high value crop production where irrigation costs coupled with concerns regarding water scarcity have stimulated PI innovation and development. In temperate and humid climates where irrigation is supplemental to rainfall, PI is less developed but nevertheless offers scope to make more effective use of rainfall, help reduce the non-beneficial losses associated with irrigation (deep drainage, nitrate leaching) and provide farmers with evidence to demonstrate environmentally sustainable practices to processors and retailers. This paper reports on recent experiences in developing precision irrigation in UK field-scale agriculture, drawing on evidence from field research and modelling studies. By combining data from these sources, a critical evaluation focusing on selected technical, agronomic and engineering challenges that need to be overcome are described, including issues regarding PI scheduling, and the delineation of irrigation management zones to ensure compatibility with existing methods of overhead irrigation. The findings have relevance to other countries where irrigation is supplemental and where precision agriculture is gaining popularity.
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    Increasing resilience of the UK fresh fruit and vegetable system to water-related risks
    (MDPI, 2020-09-11) Zurek, Monika; Garbutt, George; Lieb, Theresa; Hess, Tim; Ingram, John
    The many economic, regulatory and environmental pressures on growing, processing, distributing and retailing UK-produced fresh fruit and vegetables (FF&V) are managed by a complex set of actors before reaching the consumer. Much of this production takes place in the driest parts of the country which are characterised as “water scarce”. While physical risk is a key component of water-related risks to growers, different actors in the system face other types of risk, such as supply chain risks, food safety risks, reputational risks and/or regulatory risks. In this paper we reveal how different types of actors in the UK FF&V system perceive and frame water-related risks, what risk management strategies they employ and how they envision a FF&V system more resilient to water-related risks. Using interviews with actors from across the system, as well as governmental and nongovernmental actors influencing the system, we unpack the complex nature of the FF&V system. This provides insights into the different ways system actors assemble around water-risk and highlights that, if resilience-building activities at the individual actor level are not coordinated, there is a high risk that they are undermining overall system resilience