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New challenges of food security in Northwest China: Water footprint and virtual water perspective Texto completo
2020
Liu, Xian | Shi, Lijie | Engel, Bernie A. | Sun, Shikun | Zhao, Xining | Wu, Pute | Wang, Yubao
In this study, the water footprint (blue, green and grey WF) and virtual water theory were used to uniform measure the new challenges (population growth, population urbanization, dietary structure change, energy industry development, grain trade and climate change) of food security in Northwest China. Moreover, this study quantified the demand for new challenges to water resources from 2000 to 2016, and then evaluated their impact on water resources and food security in Northwest China. The results showed that in 2000–2016, population growth caused the food consumption WF to increase from 153.8 Gm³ to 159.6 Gm³, with an average annual growth rate of 0.4%. The ratio of per capita consumption of WF of urban residents to rural areas has increased from 80.3% to 120%. The per capita food consumption in the region increased by 1.3% annually due to changes in dietary structure. However, with the increase of water use efficiency, the WF decreased by 0.3% per year. Among them, the total consumption WF of food rations decreased by 51.9%, with an average annual decrease of 4.4%, and that of meat, dairy products and aquatic products increased by 2.4%, 10.8% and 3.0% per year, respectively. From the economic point of view, the development of the energy industry has increased the competition index of energy-grain to water resources from 0.22 to 0.49. Due to climate change, although the precipitation increased at a rate of 3.2 mm/yr, the increase in ET₀ was 3.3 mm/yr, and thus the demand for water resources in agricultural production increased. Based on the results, this paper suggests to carry out measures such as optimizes crop planting structure, adopts effective biological, agricultural technologies, guides healthy food consumption structure, strengthens international food trade and biofuel use and so on to reduce the WF of grain crops and energy industry. Ultimately, the goal of reducing regional water stress and ensuring food security is achieved.
Mostrar más [+] Menos [-]Fluoroquinolone pollution of food, water and soil, and bacterial resistance Texto completo
2015
Rusu, Aura | Hancu, Gabriel | Uivaroşi, Valentina
Fluoroquinolones are a valuable synthetic antibacterial class widely used in the treatment of infectious diseases both in humans and animals. Until recently, it has been thought that bacterial resistance to fluoroquinolones develops very slowly. Nowadays, there are multiple studies that reveal the alarming occurrence of bacterial resistance and there is a high risk of becoming therapeutically useless. The emergence of this phenomenon comes from injudicious usage in therapy, the presence of residues and their metabolites in food of animal origin and also in sewage, compost and domestic waste, which end up in soil and water sources. In the present paper, we reviewed important issues regarding fluoroquinolones impact on the environment in connection with the development of bacterial resistance: (1) the presence of fluoroquinolones as pollutants in soil, surface waters, and food. Fluoroquinolones are persistent with high specificity to interact with soil compared to other antibiotics. Pollution of water sources raises concerns regarding the effects of small concentrations (ng L⁻¹) on human health and also of the environment. The non-therapeutic use in animal farms conducts to food pollution; the cultivated plants could concentrate the fluoroquinolones (over 100 μg L⁻¹); (2) the increase of bacterial resistance to fluoroquinolones occurring with specific mutations in the target enzymes as well by the plasmid-mediated resistance and active efflux of the cell; (3) international regulations of the fluoroquinolone residues in food that are far to encompass all compounds; (4) fluoroquinolones residues analysis with standardized methods should provide limits of detection lower than maximum residue limit values; and (5) trends and perspectives: (a) a wider process of harmonization of regulations; (b) the fluoroquinolones restriction, necessary for low levels of bacterial resistance; (c) the soil and waste water purification methods; (d) the practice of soil planting scheme as an alternative; and (e) an environmental label in order to facilitate the selection of drugs.
Mostrar más [+] Menos [-]Planning water-energy-food nexus system management under multi-level and uncertainty Texto completo
2020
Yu, L. | Xiao, Y. | Zeng, X.T. | Li, Y.P. | Fan, Y.R.
In this study, a multi-level interval fuzzy credibility-constrained programming (MIFCP) method is developed for planning the regional-scale water-energy-food nexus (WEFN) system. MIFCP can not only deal with uncertainties expressed as interval parameters and fuzzy sets, but also handle conflicts and hierarchical relationships among multiple decision departments. The MIFCP approach is then applied to planning the WEFN system of Henan Province, China. Solutions of three different decision targets in various hierarchy levels, five scenarios with different decision makers’ objectives and five credibility levels toward different necessity degrees are examined. Several findings in association with various planting structures, water resources demand, energy consumption, fertilizer and pesticide utilizations and system benefits are achieved. Results reveal that the future total irrigation water can decrease by 1.49% from years 2020–2025. Results also disclose that the total cultivated area can change by 1.91% owing to the variation of fertilizer and pesticide change. Compared to single level programming (SLP) and bi-level programming (BP) approaches, the MIFCP-WEFN model can help decision-makers identify the optimal agricultural water resources management schemes by means of the leadership of water resources managers as well as the feedback of two diverse followers (i.e. energy managers and agricultural managers).
Mostrar más [+] Menos [-]Multi-stage stochastic fuzzy random programming for food-water-energy nexus management under uncertainties Texto completo
2020
Ji, Ling | Zhang, Beibei | Huang, Guohe | Lu, Yan
A hybrid inexact optimization model is developed for food-water-energy nexus system management with the consideration of complex uncertainties and decision makers’ risk tolerance. A multi-stage stochastic fuzzy random programming (MSFRP) model is tailored to tackle variables with deeper uncertainties, a mixture of fuzzy and random fuzzy characteristics. Allowing to reflect decision makers’ subjective opinion and risk preference, it can provide decision makers the tradeoff information between system benefit and risk attitude. The proposed model was applied to an agricultural area Shandong Province, China with the aim of maximum total system benefits. The valuable managerial insights on optimal cultivated land distribution, water resource allocation, and energy supply strategies are provided for decision makers under uncertainties. Meanwhile, the pesticide and fertilizer consumption for crop planting, and the carbon emission embodied in per unit crop supply are also quantitatively estimated. Moreover, by setting different water resource availability scenarios, the impacts of future water resource conditions on optimal management strategies under climate change are evaluated and discussed. The results suggested that rice would be the critical crop with the largest planting area for food security during the planning horizon. Under scarcer water resource conditions, the system benefits would reduce due to more desalination water consumption and planting strategy adjustment. However, it would lead to less carbon emission embodied in per unit crop supply and relieve local carbon emission control pressure. Compared to the conventional multi-stage stochastic programming, the developed MSFRP can be more effective to reflect the optimistic and pessimistic attitude of decision makers and deal with future scenario information with deeper uncertainties.
Mostrar más [+] Menos [-]Food Security and Climate Change in the Asia-Pacific Region: Evaluating Mismatch between Crop Development and Water Availability Texto completo
2011
s p wani | v sadras | s huda | x mei
S Huda, V Sadras, S P Wani, X Mei, 'Food Security and Climate Change in the Asia-Pacific Region: Evaluating Mismatch between Crop Development and Water Availability', International Journal of Bio-resource and Stress Management, vol. 2(2), pp.137-144, Puspa, 2011 | Phenological development is the single most important attribute of crop adaptation to shifting climates. Climate change may alter the rate of phenological development and the amount and distribution of rainfall during the growing season. These changes may in turn result in mismatch between water demand by crops and water availability from rainfall. This paper illustrates how an understanding of the impact of climate shifts on key crops will enable the Asia-Pacific farmers, community workers and policy agencies to better prepare and adapt to climate change. Strategies include changes to existing policy and practices, for example, timing of planting, managing rainwater resources, use of new varieties, disease management protocols, alternate crops and shift in geographic distribution of crops. An international project is described which combines a new analysis of realized changes in meteorological parameters, and use of estimates from published work on future climates to assess temporal shifts in crop phenology, likely shifts in the pattern of rain and water availability, mismatch between crop phenology and water availability, and the expected consequences of this mismatch for food security
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