As the basis of regional development, water-energy-food (W-E-F) is usually a bottleneck too. China’s strategy of sustainable development has been threatened and challenged by the spatially unbalanced distribution and the insufficient total amount of the water-energy-food supply, and the unbalanced socioeconomic development. Each year from 1997 to 2015, three pressure indices (i.e. water pressure index, energy pressure index and food pressure index) were decomposed into three orthotropic vectors by using principal component analysis, and the W-E-F pressure index were then calculated and created by vector synthesis method. For the thirty province units in China (no data are available for Hong Kong, Macao and Taiwan and no energy data for Tibet), after the temporal variations of the water pressure index, the energy pressure index, the food pressure index and the W-E-F pressure index were checked, eight variables (i.e. degree of per capita education, per capita GDP, per capita farmland area, per capita meat production, per capita aquatic product, population density, effective irrigation area, urbanization rate) which related to the W-E-F pressure were employed and three cross-section (i.e. 1997, 2004 and 2015) were chosen to carry out the geographically weighted regression (GWR) analysis. In the three developed GWR models, the dependent variable was the z-score standardized W-E-F pressure index differences between the start year and the end year, i.e. 1997 and 2004 (for model 1), 2004 and 2015 (for model 2), 1997 and 2015 (for model 3), and the eight independent variables were the respective z-score standardized differences (i.e. for the eight employed variables) between the start year and the end year. The factors which influence the variation of W-E-F index can be discovered from the developed GWR models and the conclusions are as follows: 1) The W-E-F pressure index rose initially and then declined from 1997 to 2015. Spatially, the W-E-F pressure decreased progressively from Southeast China to Northwest China, and larger pressure happened in Northeast China and those coastal provinces where urbanization level was higher. 2) The energy pressure index had made more significant contribution to the W-E-F pressure index than the water pressure index and the food pressure index. The energy pressure index was higher in central and east China and the water pressure index was bigger for those provinces in the north of Huaihe river. However, the food pressure index was higher for those coastal provinces in the south of the Yangtze River and for those provinces in west China. 3) In China, the water pressure index rose in most provinces, and the energy pressure index and the food pressure index declined in most provinces from 1997 to 2015. 4) The driving forces of the W-E-F pressure changes were different for the different phases. Overall, the same change direction was observed between most of the variables and the W-E-F pressure index. However, the opposite change direction existed between degree of per capita education and the W-E-F pressure index, so did between per capita GDP and the W-E-F pressure index. The main causes of the increased W-E-F pressure were the increased population density, the changed component of food supply, the conditions of food production and the economic development. The influences of socioeconomic factors on the W-E-F pressure rose progressively from 1997 to 2015. The effectual ways to reduce the W-E-F pressure were to improve the degree of per capita education and to reshape the economic development.
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HellegersP, ZilbermanD, StedutoP, McCornick P. Interactions between water, energy, food and environment: Evolving perspectives and policy issues[J]. , 2008, 10(S1): 1-10.
Major changes are occurring with far reaching implications for the existing equilibria or disequilibria in the water-energy-food-environment interface. The increased demand of energy worldwide will reflect directly and indirectly on water-dependent systems. Direct implications will come from higher energy prices, which make extraction and conveyance of water more costly. Indirect implications will be in the form of demand for alternative energy sources. It triggers demand for hydropower and remains a major driver驴along with some environmental policies驴for biofuel expansion. The key question is how these effects may alter water allocation and influence food security, rural poverty and environmental sustainability. This paper sets the background and context of this special issue by highlighting some of the major water-related policy issues related to the subject and provides an overview and synthesis of the papers in this special issue. Besides offering insight into how these papers address these questions in the practical context of few selected countries and basins, this paper also indicates some key areas for future research on the subject
BazilianM, RognerH, Howells M et al. Considering the energy, water and food nexus: Towards an integrated modeling approach[J]. , 2011, 39:7896-7960.
The areas of energy, water and food policy have numerous interwoven concerns ranging from ensuring access to services, to environmental impacts to price volatility. These issues manifest in very different ways in each of the three “spheres”, but often the impacts are closely related. Identifying these interrelationships a priori is of great importance to help target synergies and avoid potential tensions. Systems thinking is required to address such a wide swath of possible topics. This paper briefly describes some of the linkages at a high-level of aggregation – primarily from a developing country perspective – and via case studies, to arrive at some promising directions for addressing the nexus. To that end, we also present the attributes of a modelling framework that specifically addresses the nexus, and can thus serve to inform more effective national policies and regulations. While environmental issues are normally the ‘cohesive principle’ from which the three areas are considered jointly, the enormous inequalities arising from a lack of access suggest that economic and security-related issues may be stronger motivators of change. Finally, consideration of the complex interactions will require new institutional capacity both in industrialised and developing countries.
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The interconnectedness of water, energy and food production cycles translates into the interdependence of water, energy and food pricing. This paper interrogates the level of interconnectedness between these systems in South Africa and discusses how energy and water costs influence food prices in the country and affect the country's level of food security. The paper emphasizes that sustainable solutions to food security necessitate integrative thinking in the process of strategic planning for these resources.
HalbeJ, Wostl CP, Lange M A et al. Governance of transitions towards sustainable development the Water-Energy-Food Nexus in Cyprus[J]. , 2015, 40(5-6): 877-894.
This paper presents a methodological framework to analyse sustainability innovations in the water–energy–food nexus and strategies for governing transition processes towards their widespread implementation. An application to a case study in Cyprus shows the interrelations of several sustainability innovations in the water, energy and food sectors, and specific learning requirements that need to be addressed to achieve a transition towards sustainable development. The framework helps to explore systematically responsibilities of different stakeholders for the implementation of innovations and thereby provides critical information for reflexive governance processes.
KingC, JaafarH.Rapid assessment of the water-energy-food-climate nexus in six selected basins of north africa and west Asia undergoing transitions and scarcity threats[J]. , 2015, 31(3): 343-359.
KarlbergL, HoffH, Amsalu T et al. Tackling complexity: Understanding the food-energy-environment nexus in Ethiopia's Lake Tana sub-basin[J]. , 2015, 8(1): 710-734.
Ethiopia has embarked upon a rapid growth and development trajectory aiming to become a middle-income country by 2025. To achieve this goal, an agricultural development led industrialization strategy is being implemented which aims to intensify and transform agriculture, thereby boosting yields and, subsequently, economic returns. At the same time, the energy use which currently consists of more than 90% traditional biomass use is shifting towards increasing electricity production predominantly from large-scale hydropower plants, with the aim to improve access to modern energy sources. While the targets are commendable it is not clear that either all direct impacts or potential conflicts between goals have been considered. In this paper we evaluate and compare the impacts of alternative development trajectories pertaining to agriculture, energy and environment for a case-study location, the Lake Tana Subbasin, with a focus on current national plans and accounting for cross-sector interlinkages and competing resource use: the food-energy-environment nexus. Applying a nexus toolkit (WEAP and LEAP) in participatory scenario development we compare and evaluate three different future scenarios. We conclude that the two processes agricultural transformation and energy transition are interdependent and could be partly competitive. As agriculture becomes increasingly intensified, it relies on more energy. At the same time, the energy system will, at least in the foreseeable future, continue to be largely supported by biomass, partly originating from croplands. Two outstanding dilemmas pertaining to resources scarcity were identified. Water needed for energy and agricultural production, and to sustain ecosystem services, sometimes exceeds water availability. Moreover, the region seems to be hitting a biomass ceiling where the annual increments in biomass from all terrestrial ecosystems are in the same order of magnitude as biomass needs for food, fodder and fuel. We propose that a stakeholder-driven nexus approach, underpinned by quantitative and spatially explicit scenario and planning tools, can help to resolve these outstanding dilemmas and can support more consistent policy and decision making, towards improved resource productivities, lower environmental pressures and enhanced human securities.
Jalilov SM, VarisO, KeskinenM.Sharing benefits in Transboundary Rivers: An experimental case study of central Asian Water-Energy-Agriculture Nexus[J]., 2015(7):4778-4805.
Cooperation in transboundary river basins is challenged by the riparian countriesdiffering needs for water use. This is the case especially in Amu Darya Basin in Central Asia, where upstream Tajikistan is building the Rogun Hydropower Plant (RHP) to increase its energy security, while the downstream countries oppose the plant due to the feared negative impacts to their irrigated agriculture. Several experimental scenarios illustrate how the concept of benefit sharing could be used as a framework to investigate these water-energy-agriculture linkages in a transboundary context. Using a hydro-economic model, we investigate the economic benefits of various scenarios emphasizing agricultural and/or energy production, thus benefiting the riparian countries uniquely. Subsequently, we discuss how benefit-sharing arrangements with different forms of compensations could be used as a mechanism to facilitate transboundary cooperation. Our results indicate that several scenarios have a potential to increase the total energy-agriculture benefits in the basin. Yet, agreeing on the actual benefit-sharing mechanism between the countries poses special challenges as each may require countries to give up some of their anticipated maximum potential benefits. The presented scenarios provide a potential starting point for debates over benefit-sharing arrangements across countries needing to address the water-energy-agriculture nexus
DeclanC, EmmaaG, Delphine D et al. Climate and southern Africa’s water-energy-food nexus[J]. , 2015,5(9):837-846.
In southern Africa, the connections between climate and the water揺nergy揻ood nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven, for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and gross domestic product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water.
[DengPeng, ChenJing, Chen Dan et al. The evolutionary and characteristics analysis of the coupling and coordination among water, energy and food: Taking Jiangsu province as an example. , 2017,28(6):232-238.]
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StuartBrown, VincentL, Versace et al. Assessment of spatiotemporal varying relationships between rainfall, land cover and surface water area using geographically weighted regression[J]. 2012,17(3):241-254.
Traditional regression techniques such as ordinary least squares (OLS) are often unable to accurately model spatially varying data and may ignore or hide local variations in model coefficients. A relatively new technique, geographically weighted regression (GWR) has been shown to greatly improve model performance compared to OLS in terms of higher R 2 and lower corrected Akaike information criterion (AIC C ). GWR models have the potential to improve reliabilities of the identified relationships by reducing spatial autocorrelations and by accounting for local variations and spatial non-stationarity between dependent and independent variables. In this study, GWR was used to examine the relationship between land cover, rainfall and surface water habitat in 149 sub-catchments in a predominately agricultural region covering 2.6 million ha in southeast Australia. The application of the GWR models revealed that the relationships between land cover, rainfall and surface water habitat display significant spatial non-stationarity. GWR showed improvements over analogous OLS models in terms of higher R 2 and lower AIC C . The increased explanatory power of GWR was confirmed by the results of an approximate likelihood ratio test, which showed statistically significant improvements over analogous OLS models. The models suggest that the amount of surface water area in the landscape is related to anthropogenic drainage practices enhancing runoff to facilitate intensive agriculture and increased plantation forestry. However, with some key variables not present in our analysis, the strength of this relationship could not be qualified. GWR techniques have the potential to serve as a useful tool for environmental research and management across a broad range of scales for the investigation of spatially varying relationships.