The water–energy nexus: energy use for water supply in China

China’s strategy to meet increasing water demand is to increase the use of inter-basin transfer water and unconventional water. This study evaluates the energy requirements of this strategy by disaggregating and quantifying the regional energy use for water supply in 2020 and 2030; the energy use in 2014 is calculated to represent the present situation. We find that the energy use for water supply in 2014 amounted to 81 billion kWh. This value is expected increase to 90 and 109 billion kWh by 2020 and 2030, respectively. In 2030, the urban domestic sector will overtake the agricultural sector as the most energy-intensive sector, with major contribution from inter-basin transfer water.     

Sefficiency (sustainable efficiency) of water–energy–food entangled systems

Water–energy–food (WEF) entanglement is intensifying and technology is being presented as a crucial solution. But time and again the implemented alternative manifests results contrary to the objectives of design or management. To advance water security, transparent and complete input–output methodologies are needed. Here, a Sefficiency (sustainable efficiency) framework is used to reason through systemic analyses of options for WEF schemes by using water quantity within a comprehensive water balance, and quality and benefits in a multilevel water-use system. An energy regime (cost and normalized functions) and Sefficiency compute performance of four cases that show flaws both conceptually and practically in current policy and scientific tendencies.     

Ice–water heat exchange during ice growth in Lake Baikal

Using a custom-made thermistor chain frozen into the ice cover we obtained the first detailed information on distribution of temperature within ice and structure of the ice–water boundary layer during ice growth in Lake Baikal. A mathematical model of the heat transport in a multilayer ice–water system (Stefan problem) was developed and verified on results of in situ measurements. Effective coefficients of thermal diffusivity and ice–water heat fluxes were estimated from the inverse solution of the model and compared with direct flux estimates from the flux-gradient method. Both estimations agreed on flux values of 1–10 W m^− 2 and demonstrated strong synoptic variability in ice–water heat exchange. We estimated the thickness of viscous laminar sublayer under ice, as well as the thickness of the transitional layer on top of the turbulent water column. The thickness of the viscous sublayer of 1–1.5 cm in Lake Baikal was several times smaller than values reported previously from small lakes, suggesting high magnitudes of convective velocities and/or of the under-ice currents in Lake Baikal. Significant growth of the thermal diffusivity coefficient with increasing distance from the ice bottom was detected: its value at the top of the transition layer of under ice water was 10–40 times higher compared with its value in viscous laminar sublayer. This is also significantly higher than previous estimations in smaller freshwater lakes.     

Governance of transitions towards sustainable development – the water–energy–food nexus in Cyprus

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.     

To what end? Drip irrigation and the water–energy–food nexus in Morocco

This article draws on three case studies of drip irrigation adoption in Morocco to consider the water–energy–food nexus concept from a bottom-up perspective. Findings indicate that small farmers' adoption of drip irrigation is conditional, that water and energy efficiency does not necessarily reduce overall consumption, and that adoption of drip irrigation (and policies supporting it) can create winners and losers. The article concludes that, although the water–energy–food WEF nexus concept may offer useful insights, its use in policy formulation should be tempered with caution. Technical options that appear beneficial at the conceptual level can have unintended consequences in practice, and policies focused on issues of scarcity and efficiency may exacerbate other dimensions of poverty and inequality.     

Application of a water–energy–food nexus framework for the Duero river basin in Spain

This paper proposes a framework for the identification, assessment and analysis of the water–energy–food nexus at a basin scale. This methodology is applied to the Duero river basin in Spain to detect the most important conflicts derived from water, food and energy interdependencies. Some of the most important issues are the limitations posed by rising energy prices for irrigated agriculture due to modernization, limitations to water treatment, and the possible emergence of new water demands for energy by hydraulic fracturing for oil and gas and enhanced bioenergy.     

The water–energy–food (WEF) security nexus: the policy perspective of Bangladesh

This paper provides a review of the emerging literature on the water–energy–food (WEF) nexus and then analyses the nexus in the context of Bangladesh. Results suggest that the WEF nexus is not yet recognized in the policy documents of Bangladesh, while conflicts over these resources are growing. In order to reduce this contestation, ‘policy integration’ is recommended for implementing key policies in the WEF nexus.     

Interbasin water transfers at the US–Mexico border city of Nogales,Sonora: implications for aquifers and water security

Nogales, Sonora, on the US–Mexico border, employs interbasin water and wastewater transfers to address water scarcity in the context of a rising population, a warming climate, and cross-border institutional asymmetries. A unique feature of its geography and border context is Nogales's export of wastewater both north to the US and, starting with the August 2012 commissioning of a strategically positioned wastewater treatment plant, south to the Alisos basin, which is its principal drinking-water source. Thus, when the new plant is fully operational, it will result in indirect potable reuse of effluent via recharge of the source-water aquifer. This paper finds that such strategies contribute to increased water scarcity in Nogales, and to detrimental health, livelihood and environmental impacts in the source basin, thus raising questions about interbasin transfers as a principal water management strategy.     

Changing the nature of transboundary water agreements: the Israeli–Palestinian case

This abridged version of the proposal developed for Friends of the Earth Middle East presents the design for an agreement between Israelis and Palestinians to share water in a physically realistic, ecologically sustainable and socially equitable manner. Existing arrangements are, at best, inadequate and, in some cases, counterproductive. The proposal relies upon ongoing monitoring and mediation to achieve equitable and sustainable use. It presents why and how an agreement on water can be reached now, before resolving the full range of issues required in a Final Status Agreement between Israel and Palestine.     

Approach of water–salt regulation using micro-sprinkler irrigation in two coastal saline soils

This study aimed to investigate whether saline silt and sandy loam coastal soils could be reclaimed by micro-sprinkler irrigation. The experiments were run using moderately salt-tolerant tall fescue grass. Micro-sprinkler irrigation in three stages was used to regulate soil matric potential at a 20-cm soil depth. Continued regulation of soil water and salt through micro-sprinkler irrigation consistently resulted in an increasingly large low-salinity region. The application of the three stages of soil water–salt regulation resulted in an absence of salt accumulation throughout the soil profile and the conversion of highly saline soils into moderately saline soils. There were increases in the plant height, leaf width, leaf length, and tiller numbers of tall fescue throughout the leaching process. The results showed that micro-sprinkler irrigation in three soil water and salt regulation stages can be used to successfully cultivate tall festuca in highly saline coastal soil. This approach achieved better effects in sandy loam soil than in silt soil. Tall fescue showed greater survival rates in sandy loam soil due to the rapid reclamation process, whereas plant growth was higher in silt soil because of effective water conservation. In sandy loam, soil moisture should be maintained during soil reclamation, and in silt soil, soil root-zone environments optimal for the emergence of plants should be quickly established. Micro-sprinkler irrigation can be successfully applied to the cultivation of tall fescue in coastal heavy saline soils under a three-stage soil water–salt regulation regime.     

Policy options for promoting urban–rural cooperation in water management: a review

As most cities share their water basins with rural areas, an efficient and environmentally sensible urban water management system needs to consider the interplay between urban and rural water uses. This article analyses the three main challenges at this interface: increased competition for water resources (scarcity); flood management (abundance); and freshwater quality conservation (pollution). The merit of potential policy options is discussed from an economics perspective, taking examples from successful experiences in cities around the world. The benefits and challenges arising from enhanced coordination and integration between urban and rural water management are highlighted.     

Bioenergy,food security and poverty reduction: trade-offs and synergies along the water–energy–food security nexus

This article provides a review of trade-offs and synergies of bioenergy within the water–energy–food security nexus, with emphasis on developing countries. It explores the links of bioenergy with food security, poverty reduction, environmental sustainability, health, and gender equity. It concludes that applying the nexus perspective to analyses of bioenergy widens the scope for achieving multiple-win outcomes along the above aspects.     

Modelling large deformation and soil–water–structure interaction with material point method:Briefing on MPM2017 conference

The 1st International Conference on the Material Point Method for "Modelling Large Deformation and Soil–Water–Structure Interaction"(MPM2017)was held in Delft,The Netherlands on 10-13 January 2017.This is the first conference organised by the Anura3D MPM Research Community,following a series of international workshops and symposia previously held in The Netherlands,UK,Spain and Italy,as part of the European Commission FP7 Marie-Curie project MPM-DREDGE.We are delighted to present seven contributions in this Special Column of the Journal of Hydrodynamics,and take this opportunity to announce that the 2nd conference,MPM2019,will be held in Cambridge,UK in January 2019.     

A modeling study of ice–water processes for Lake Erie applying coupled ice-circulation models

A hydrodynamic model that includes ice processes and is optimized for parallel processing was configured for Lake Erie in order to study the ice–water coupling processes in the lake. A hindcast from April 2003 to December 2004 with hourly atmospheric forcing was conducted. The model reproduced the seasonal variation of ice cover, but the development of ice extent in January and its decay in March somewhat preceded the observations. Modeled lake circulation in ice-free seasons is consistent with previous studies for Lake Erie. Thermal structure of the lake was reasonably comparable to both satellite-derived observations and in-situ measurements, with mean differences ranging from − 2 °C to 4 °C, depending on the season. The impacts of ice–water stress coupling and basal melting of ice were examined based on numerical experiments. The results show that: 1) ice–water stress coupling significantly dampens the subjacent lake circulation in winter due to packed ice cover that slows down the surface water, and 2) basal melting of ice contributes to widespread ice cover in the lake. The demonstrated model validity could lead to further studies of ice–water processes in the lake, including interannual variation and impacts on ecosystems.     

Rapid assessment of the water–energy–food–climate nexus in six selected basins of North Africa and West Asia undergoing transitions and scarcity threats

Existing strategies for management of water scarcity in the Middle East and North Africa negotiate a complex system of trade-offs between water, energy, and food production. The effects of rural households' green water management practices on basin-level water, energy, food and carbon stocks and flows are sketched qualitatively in six basin agro-ecosystems. The case for increased strategic support for green agricultural water management practices appears stronger when weighed from the nexus perspective, rather than purely from the point of view of water balance and food production. Trade-offs under critical transitions affecting agricultural water use are explored, and the scope for quantitative monitoring is discussed.     

Public–private partnerships for water in Asia: a review of two decades of experience

This article reviews the development of public–private partnerships (PPP) in water services in Asia over the last two decades and situates the Asian experience within the wider global context. Through a comparative analysis of PPP data from two different sources, the article highlights the critical issue of how ‘private’ is defined in understanding the extent of PPP in Asia, due to the important role played by enterprises under mixed public and private ownership. The article identifies cyclical patterns of development of PPP in the water sector across countries and the use of hybrid contractual and institutional arrangements for PPPs.     

Criteria for assessing the level of land–water integration in planning instruments in Andalusia,Spain

Academia has come to realize that integrating water management and land resources can deliver a significant contribution to achieving sustainable outcomes. However, its implementation in daily practice is lagging behind. In order to address this knowledge–practice gap, this paper suggests the integration of land and water resources management can be improved through the incorporation of specific criteria in the territorial plans and river basin management plans. The proposed criteria were used to develop a methodology to assess the level of integration between water resources and land uses in current planning practice. The case of Andalusia in Spain provided the empirical focus.     

Nexus meets crisis: a review of conflict,natural resources and the humanitarian response in Darfur with reference to the water–energy–food nexus

Darfur has been widely used as a case study by both those arguing for causality between environmental scarcity and war and those disputing it. This article challenges that approach by drawing on debates taking place within Darfur, reflecting on both the conflict and the humanitarian response. It argues that reviewing Darfur on its own terms makes a stronger basis to identify transferable lessons for interventions elsewhere. It considers water, food and energy, and finds that supporting governance is an essential theme for promoting economic recovery and laying a foundation for a well-managed water–energy–food nexus.     

Desalination and water security in the US–Mexico border region: assessing the social,environmental and political impacts

In the western US–Mexico border region, both countries’ authorities look to desalination as a means to meet increased demands for dwindling supplies. In addition to several existing or planned desalination plants, plans exist to develop projects along Mexico’s coasts to convert seawater into freshwater primarily for conveyance and consumption in the United States. Even though desalination systems have the potential to increase water supply in the region, there are associated consequences, costs and constraints. To understand the impacts of such binational desalination systems, this paper assesses, through a water-security framework, the case of a proposed desalination plant on the Upper Gulf of California. The analysis suggests that for binational desalination systems, there are several key areas of impact against which the benefits of increased water supply must be weighed.