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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.

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. [Display omitted] • An integrated reservoir simulation modelling approach for nexus analysis is used. • Water-energy nexus trade-offs during baseline and future scenarios are considered. • The system is unable to meet irrigation demand under baseline and all scenarios. • Energy demand for conveyance system is seven times higher than for irrigation. • Infrastructure expansion and more efficient agriculture needed if scenarios realise. [ABSTRACT FROM AUTHOR]

Water scarcity severely affects drylands threatening their food security, whereas, the oil and gas industry produces significant and increasing volumes of produced water that could be partly reused for agricultural irrigation in these regions. In this review, we summarise recent research and provide a broad overview of the potential for oil and gas produced water to irrigate food crops in drylands. The quality of produced water is often a limiting factor for the reuse in irrigation as it can lead to soil salinisation and sodification. Although the inappropriate use of produced water in irrigation could be damaging for the soil, the agricultural sector in dry areas is often prone to challenges in soil salinity. There is a lack of knowledge about the main environmental and economic conditions that could encourage or limit the development of irrigation with oil and gas effluents at the scale of drylands in the world. Cheaper treatment technologies in combination with farm-based salinity management techniques could make the reuse of produced water relevant to irrigate high value-crops in hyper-arid areas. This review paper approaches an aspect of the energy-water-food nexus: the opportunities and challenges behind the reuse of abundant oil and gas effluents for irrigation in hydrocarbon-rich but water-scarce and food-unsecured drylands. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Large quantities of water are required to produce the food for a nation, some of which is derived within the country and some associated with imported food commodities. In this study, we consider the spatially explicit potential impact of alternative healthier eating scenarios for the UK on global blue water scarcity using the concept of a water scarcity footprint. The water required to produce the food consumed by the UK was estimated at 52.6 Gm 3 /y of which 93% is from rainfall at the point where it falls and 7% is “blue” water withdrawn from surface and ground water resources. Five alternative healthier diets were considered and the impact on the blue water scarcity footprint was modest (ranging from −3% to +2% compared to baseline). However more significant impacts were projected on the geographical distribution of the blue water scarcity footprint. This study has shown that if current trade patterns continue, policies to promote healthier eating in the UK may contribute to increased blue water scarcity at home and in other parts of the world. The use of virtual water estimates and global datasets of water scarcity can help to understand the potential environmental impacts of alternative diets. [ABSTRACT FROM AUTHOR]

• Irrigation of jojoba with partially desalinated produced water can be sustainable. • Water-efficient irrigation with low salinity water is the least-cost reuse strategy. • Produced water reuse in irrigation is 2.5 times costlier than produced water disposal. • Oilfield produced water could be an irrigation water resource in hyper-arid areas. Produced water (PW) is the main waste stream generated from oil and gas extraction. Nowadays, half of the global PW volume is managed through environmentally controversial and expensive disposal practices, such as re-injection through deep wells. In dry areas such as in the Arabian Peninsula, PW could be reused to irrigate crops, creating environmental, economic and social value. However, the quality of most PWs remains challenging as their high salinity, sodicity and alkalinity can degrade soil fertility and crop yield. Mitigating these negative impacts is costly as it requires specific PW treatment and irrigation management. Thus, the environmental sustainability and the cost of irrigation with PW are uncertain. The aims of this paper was to assess the agro-environmental sustainability of irrigating crops with PW in hot and hyper-arid climate and to estimate the operating cost of reusing PW for irrigation in order to compare this PW management approach to PW disposal in terms of environmental impacts and financial cost. To this end, a soil-water model was used to simulate irrigation of jojoba (Simmondsia chinensis) with oilfield-PW. Different irrigation strategies combining over-irrigation, PW blending and desalination were tested to preserve the soil structural stability and the crop yield. The operational costs of identified sustainable scenarios were estimated using a cost analysis. In this case study, the simulations showed that using an irrigation volume up to ∼390 % of the crop water needs with a blend composed of raw and desalinated PW in a 2:1 ratio could preserve the soil structural stability and the crop yield. However, for irrigation, the least-cost option was to mix raw and desalinated PW in a 1:4 ratio and to reduce the irrigation amount to just meet the crop water needs. Although the cost of managing PW in irrigation remains up to 2.5 times higher than PW disposal, this practice might be competitive considering the crop value generated and the increasing need for sustainable alternatives to PW disposal. [ABSTRACT FROM AUTHOR]

• Irrigation efficiency is more than a performance indicator or water-savings panacea. • Managing irrigation efficiency supports water, food and energy goals. • Insufficient understanding of irrigation efficiency may impede policy goals. • The meanings and use of irrigation efficiency depend on spatial scale and viewpoint. • A matrix of scales and dimensions is proposed to explore irrigation efficiency. An effective placement of irrigation efficiency in water management will contribute towards meeting the pre-eminent global water challenges of our time such as addressing water scarcity, boosting crop water productivity and reconciling competing water needs between sectors. However, although irrigation efficiency may appear to be a simple measure of performance and imply dramatic positive benefits, it is not straightforward to understand, measure or apply. For example, hydrological understanding that irrigation losses recycle back to surface and groundwater in river basins attempts to account for scale, but this generalisation cannot be readily translated from one location to another or be considered neutral for farmers sharing local irrigation networks. Because irrigation efficiency (IE) motives, measures, effects and technologies play out at different scales for different people, organisations and purposes, and losses differ from place to place and over time, IE is a contested term, highly changeable and subjective. This makes generalisations for science, management and policy difficult. Accordingly, we propose new definitions for IE and irrigation hydrology and introduce a framework, termed an 'irrigation efficiency matrix', comprising five spatial scales and ten dimensions to understand and critique the promises, pitfalls and paradoxes of IE and to unlock its utility for addressing contemporary water challenges. [ABSTRACT FROM AUTHOR]

• Irrigation with blended produced water can be agro-environmentally sustainable. • Produced water reuse in irrigation is financially competitive. • Desalinating produced water is more costly than blending with treated sewage. • Water-efficient irrigation preserves aquifer quality and is the least-cost strategy. • Gas field-produced water could be an unconventional irrigation resource in Qatar. Produced water (PW) is the largest by-product generated from oil and gas extraction. Currently, half of the total PW volume is managed through environmentally-controverted and costly disposal practices. In dry regions, PW could be beneficially reused to irrigate crops reducing the overexploitation of freshwater resources. However, PW quality, and particularly its high salinity, sodicity and alkalinity, create uncertainties regarding the agro-environmental sustainability and the cost of this practice. The aim of this paper was to identify potential agro-environmentally sustainable irrigation schemes with gasfield-PW in hyper-arid Qatar and to estimate their operating costs. A soil-water model was used to simulate the irrigation of sugar beet with gasfield-PW under the climatic and soil conditions occurring in northern Qatar. Different irrigation strategies combining over-irrigation, PW blending with treated sewage effluent (TSE) and PW desalination were tested in order to protect the soil and the aquifer from salinisation and sodification. The operating costs of identified agro-environmentally sustainable scenarios were estimated through a cost analysis. In the case study, the simulations indicated that using an irrigation volume up to ∼300% of the crop water needs with a blend of two-thirds PW and one-third TSE (or desalinated PW) could preserve the soil stability, crop yield and groundwater quality. The least-cost option was to reduce the irrigation amount at a little over the crop water needs and mix PW with an equivalent volume of TSE or four equivalent volumes of desalinated PW which would cost $0.26/m3 and $0.46/m3 respectively. As traditional PW disposal practices cost between $0.06–$16.67/m3, reusing PW in irrigation is thus potentially a competitive PW management strategy for O&G firms. [ABSTRACT FROM AUTHOR]

• Produced water could be a non-conventional irrigation resource for farmers in drylands. • Soil salinisation and sodification threats were assessed for a wide range of water qualities. • Sustainability mainly depends on water quality, and then on soil type and climate aridity. • Soil drainage ability and gypsum content are important for reusing produced water. • Model simulations can help refine guidelines for the sustainable reuse of produced water in irrigation. 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. [ABSTRACT FROM AUTHOR]

Due to chronic immunosuppression, heart transplant recipients are at risk for developing malignancy, compromising long-term survival. A subset of our veteran heart transplant recipients have been exposed to Agent Orange, an herbicide which is linked to the development of hematologic malignancies and soft tissue sarcoma. We hypothesized that Agent Orange exposure would lead to a higher prevalence of post-transplant malignancy and decreased survival. We conducted a retrospective chart review of all 188 heart transplant patients who received their longitudinal care at the William S. Middleton Memorial Veterans Hospital since the program's inception on Oct. 1, 1993. Demographic data were collected for each patient. Proof of Agent Orange exposure was based on VA administrative review of service records. Univariate analysis was conducted to identify variables linked to the incidence of cancer. Multivariate analysis using a Cox Proportional Hazard Model was used to assess the influence of Agent Orange on the development of malignancy and post-transplant survival. Kaplan Meier analyses were used to assess survival and the incidence of cancer, stratified by Agent Orange exposure. Of the 188 patients, 113 have died. Malignancy accounted for 28% of the deaths. Fifty three percent of the patients developed malignancy after transplant (n = 100). Seventy seven developed skin cancer (41%), 46 developed solid organ cancer (24%), and 5 developed hematologic cancer (3%). Twenty nine patients were diagnosed with multiple malignancies (15%). Sixteen percent of our patients were exposed to Agent Orange (n=31). Univariate predictors of developing malignancy included older age at time of transplant (p<0.001), Caucasian race (skin cancer only), and pre-transplant ischemic cardiomyopathy (p=0.017). Multivariate analysis demonstrated that age at time of transplant reduced survival (p=0.021) and increased the likelihood of developing skin (p<0.0001) but not solid organ cancer. Agent Orange exposure did not affect overall survival (Figure 1) or risk for developing solid organ cancer but did increase the likelihood of acquiring basal cell carcinoma (p=0.019). Of the 5 patients who developed hematologic malignancy, 3 had Agent Orange exposure (p = 0.032). Survival and risk for developing solid organ malignancy following heart transplant were not influenced by Agent Orange contact. While the incidence of hematologic malignancy post-transplant was low, Agent Orange exposure may have contributed. [ABSTRACT FROM AUTHOR]

• Maintaining 'headroom' in licensed allocations help minimise the risk of negative impacts from water shortages. • Increasing system redundancy confers robustness but conflicts with pressures to maximise efficiency. • Pursuit of robustness and efficiency locks systems into rigid production pathways. • Financial pressures force growers to focus on persistence of robust outputs at the cost of adaptability and transformability. Food production systems worldwide are increasingly exposed to water shortage shocks. Social-ecological resilience theory provides insights into the qualities which confer production systems with the capacity to absorb shocks and persist, undertake adaptations and ultimately achieve desirable transformations. Combining findings from the analysis of a set of 15 semi-structured interviews and 92 survey responses from growers in the UK, this paper uses resilience theory to explore the factors affecting exposure to the risk of water shortages, and management responses, within outdoor field vegetable production systems that depend on supplemental irrigation. The findings confirm that growers predominantly aim to build resilience by seeking to maintain a buffer or 'headroom' in their water resources to minimise the possibility that a shortage will disrupt their output of marketable produce and/ or lead to financial loss. This buffering strategy confers robustness by increasing system redundancy (availability of spare resources). But building-in redundancy conflicts with regulatory and supply chain pressures to maximise water and production efficiency respectively. Whilst stability of supply to consumers is, for the most-part, achieved, the discrepant pursuits of robustness and efficiency lock agricultural systems into increasingly rigid production and sales pathways, limiting capacities for adaptation and transformation - dimensions of resilience which permit successful system evolution in the context of more extreme shocks and stresses. [ABSTRACT FROM AUTHOR]

Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The proposed methods are broadly similar and encompass both the computation of water use and its impacts, but differ in communication of a water footprint result. In this paper, we explain the role and goal of LCA and ISO-compatible water footprinting and resolve the six issues raised by Hoekstra (2016) in “A critique on the water-scarcity weighted water footprint in LCA”. By clarifying the concerns, we identify both the overlapping goals in the WFN and LCA water footprint assessments and discrepancies between them. The main differing perspective between the WFN and LCA-based approach seems to relate to the fact that LCA aims to account for environmental impacts, while the WFN aims to account for water productivity of global fresh water as a limited resource. We conclude that there is potential to use synergies in research for the two approaches and highlight the need for proper declaration of the methods applied. [ABSTRACT FROM AUTHOR]

• This paper is built on the outcome and recommendations from FAO LEAP guidelines. • An international consensus on water use assessment is presented. • Water footprint concepts and water use information are detailed and connected in relation with each other. • Water scarcity footprint and water productivity are recommended for the assessment of water use. • Water productivity is reported with fractions of green and blue water consumed. 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. [ABSTRACT FROM AUTHOR]