A Triple Nexus Water-Energy-Housing (WEH) Framework Modelling towards Improved Decision-Making in Humanitarian Operations

Given the challenges facing most humanitarian operations worldwide, a change of approach is needed to ensure greater sustainability of humanitarian settlements right from the planning stage. Some studies attribute unsustainability to inadequate provision of basic resources and highlight the apparent bottlenecks that prevent access to the meaningful data needed to plan and remedy problems. Most operations have relied on an “ad hoc ism” approach, employing parallel and disconnected data processing methods, resulting in a wide range of data being collected without subsequent prioritization to optimize interconnections that could enhance performance. There have been little efforts to study the trade-offs potentially at stake. This work proposes a new framework enabling all subsystems to operate in a single system and focusing on data processing perspective. To achieve this, this paper proposes a Triple Nexus Framework as an attempt to integrate water, energy, and housing sector data derived from a specific sub-system within the overall system in the application of Model-Based Systems Engineering. Understanding the synergies between water, energy, and housing, Systems Engineering characterizes the triple nexus framework and identifies opportunities for improved decision-making in processing operational data from these sectors. Two scenarios illustrate how an integrated platform could be a gateway to access meaningful operational data in the system and a starting point for modeling integrated human settlement systems. Upon execution, the model is tested for nexus megadata processing, and the optimization simulation yielded 67% satisfactory results, demonstrating that an integrated system could improve sustainability, and that capacity building in service delivery is more than beneficial.

Assessing the Water-Energy-Food-Ecosystems Nexus in Smart Irrigation: A Potato Farming Case Study in Lebanon

This study examines the Water-Energy-Food-Ecosystems (WEFE) nexus in Lebanese agriculture, with a focus on the shift from conventional surface irrigation techniques to advanced smart irrigation systems in the Bekaa region, specifically targeting potato cultivation. The study quantitatively analyzes the interaction among water, energy, and agricultural outputs at the farm scale using the WEFE Nexus framework for scenario analysis. It evaluates variations in water productivity, environmental effects, and economic outcomes, offering a detailed view of existing practices and their sustainable improvement potential. The WEFE Nexus assessment demonstrates that smart irrigation integration significantly decreased resource usage: water consumption was reduced by 58%, diesel fuel use for irrigation dropped by 57%, and the demand for labor and fertilizers decreased by 47% and 49%, respectively. This change led to enhanced crop yields and increased resource efficiency, demonstrating the potential of smart irrigation as a transformative strategy for sustainable agriculture in Lebanon and other arid areas. Economic analysis showed that farmers could recover the costs of installing the smart irrigation system within 3 months. The findings highlight the need for further research on integrating smart irrigation with renewable energy, showing potential for sustainable agricultural development. .

A Quantitative Assessment Framework for Water, Energy and Food Nexus

This paper presents a quantitative assessment framework of the Water, Energy and Food (W-E-F) nexus. The proposed approach allows integrated quantitative assessments by considering all the W-E-F intersectoral linkages and the competing demand for W-E-F resources to evaluate future development scenarios. Firstly, the conceptual model adopted for the proposed framework is presented. Secondly, a detailed methodological framework is introduced to serve as W-E-F nexus evaluation and planning platform. At the practical level, the model is applied to evaluate the W-E-F nexus in Lebanon. Finally, the conclusions and further developments are presented.

Water-Energy-Food Nexus: A Coupled Simulation and Optimization Framework

Water, Energy and Food (WEF) nexus systems are developed to model and analyze interactions across and between WEF sectors. WEF nexus simulation models permit evaluating the direct and indirect WEF quantitative interaction effects in response to change of technology and/or demand. Optimization models can help to find the optimal combinations of WEF nexus system policy options and parameters that lead to the best performance of the system. This paper describes a framework for integrating quantitative WEF nexus simulation model (the Q-Nexus Model) with an optimization tool, which will give policy makers the ability to compromise best policy options based on WEF nexus simulator. The developed method is then applied to the numerical experiment and the results are discussed. Lastly, the conclusions and further developments are presented.

Evaluation of Technology Change Effects on Quantitative Assessment of Water, Energy and Food Nexus

The quantitative assessment framework of the water, energy and food (WEF) nexus proposed by [1] permits the analysis of the WEF as an interconnected system of resources that directly and indirectly affect one another. The model performs simulation of policy options and scenarios that respond to quantitative variations of the use of WEF resources. One of the key outcomes of the mathematical formulation of the model is the WEF nexus intersectoral technology matrix. In order to take advantages and analyzing policy options of adopting high efficient intersectoral use technologies, WEF intersectoral use intensities and intersectoral allocation coefficients are introduced to the technology matrix of the nexus model proposed in [1]. The developed method is then applied to evaluate the WEF nexus case study of Lebanon. Lastly, the conclusions and further developments are presented.

Water-Energy-Food Nexus： Comparative Scenarios and Public Policy Perspectives from Some Latin American Countries Regarding Biogas from Agriculture and Livestock

Latin American and the Caribbean countries have one of the world＇s largest sources of renewable energy. Nonetheless, it estimated that nearly three-quarters of their energy consumption relies on the use of fossil fuels, with most of the countries being net importers, ultimately imposing a marked economic and political dependence on those energy commodities. Therefore, the opportunity lies in a higher utilization of various renewable energy resources, which contribute to the country＇s energy security while promoting significant environmental benefits. This manuscript aimed to provide a comparative analysis of current energy scenarios of six Latin American countries （Mexico, Honduras, Nicaragua, Brazil, Chile and Ecuador） to evaluate their policies, programs and strategies implemented in the search for greater participation of renewable energy, with a special attention to biogas. Given the importance of the water-energy-food nexus that could foment the use of renewable energies under conditions of water scarcity, a qualitative data comparison was accomplished, considering biogas production potential, biogas projects and CO2 emissions.

The Great Lapse: Climate Change, Water Resources and Economic Risks in the Great Lakes

The striking vastness of the world’s largest surface freshwater resource, the Laurentian Great Lakes, has generated the fallacy that they are not highly vulnerable to climate change. This fallacy has created a great lapse in our research and understanding of the effects of climate change on the Great Lakes, which are approaching critical environmental thresholds and jeopardizing ecosystem services. This article takes the novel approach of correcting the disconnect between the perception of vastness and the reality of vulnerability to climate change in the Great Lakes, and takes an additional novel step to link the water risks with the economic risks. The primary purpose is to demonstrate the interdependence of the freshwater ecosystem services affected by climate change with the economies that are highly dependent on those freshwater services in the Great Lakes region. Although many believe that environmental science or ethical arguments should be sufficient to warrant action on climate change, evidence shows that policy-makers are not compelled to generate advances unless there are strong economic components. This article highlights the leading edge of climate science for the Great Lakes, having conducted 32 in depth interviews with experts in microbiology, ecology, and limnology, among others, but it also adds substantively to previous work by providing economic evidence of water risks in the agricultural sector and energy sector, which constitute over $6 trillion in value and jobs that are specifically dependent on lakes waters. The article concludes by articulating three specific conclusions: the economic viability of the agricultural sector and the energy sector are jeopardized by loss of federal funding for climate change adaptation in the water sector;the existing policies such as between sectors such as the Farm Bill and Energy Future Bill are mal-aligned and should be aligned with the water sector;and negative environmental externalities including factors that exacerbate climate change should be incorporated into the true cost of water so we can more accurately conduct ecosystem valuation and, thus, address the true economic and environmental cost of climate change on the Great Lakes and our greatest water resources. This paper has not previously been published.

Energy Consumption in the Municipal Water Supply Sector in the Kingdom of Bahrain

Water-energy nexus is an emerging issue that receives considerable attention in the world in general and in the Gulf Cooperation Council (GCC) countries in particular. The GCC countries depend mainly on energy generated from fossil fuels to produce drinking water. Yet, the amount of water-related energy use in Bahrain remains unexplored. This study aims to quantify the amount of energy used in the water supply cycle for the first time in Bahrain using quantitative methods. A bottom-up approach for data collection was adopted where data for the three main stages of the water supply in Bahrain: water production, water transmission, and water distribution were collected. Results show that the water production stage consumes about 97% of the total energy consumption in the water supply sector, followed by water transmission (2.9%) and water distribution (0.1%). Comparisons conducted with best practices in the world show that water desalination plants in Bahrain consume relatively high amounts of energy to produce water based on the desalination technology used. This study calls for focusing on the production stage in achieving energy efficiency since it is the largest consumer and where losses are occurring based on the benchmarking. This study also recommends investigating the share of electricity and thermal energy consumed in the water supply cycle in Bahrain in addition to the wastewater treatment sector. This is imperative to provide a holistic overview of the water-related energy use in Bahrain.

Model predictive control for water management and energy security in arid/semiarid regions

This paper aims to develop a realistic operational optimal management of a water supply system in an arid/semiarid region under climate change conditions.The developed model considers the dynamic variation of water demand,rainfall,weather,and seasonal change in electricity price.It is mathematically developed as a multi-constraint non-linear programming model based on model predictive control principles.The model optimises the quantities of water supplied by each source every month and improves the energy efficiency in a water supply system with multiple types of sources.The effectiveness of the developed MPC model is verified by applying it to a case study and comparing the results with those obtained with an open loop model.Results showed that using the MPC model leads to a 4.16%increase in the water supply cost compared to the open loop model.However,when considering uncertainties in predicting water demands,aquifer recharges,rainfall,and evaporation rate,the MPC model was better than the open loop model.Indeed,the MPC model could meet the water demand at any period due to its predictability of variations,which was not the case with the open loop model.Moreover,a sensitivity analysis is conducted to verify the capacity of the developed model to deal with some phenomena due to climatic changes,such as in rainfall.

Water-Energy Prototype Model for the NEMS Modeling Platform: Thermoelectric Water Demand and Its Implications on Regional Electricity Market

A simplified energy-water prototype model has been developed at the National Energy Technology Laboratory (NETL) as a part of a larger effort to comprehensively model energy-water interactions. The NETL Water-Energy Model (NWEM) prototype passively couples a variety of data on water supply, water availability, and power plant water use with the National Energy Modeling System (NEMS) power generation forecasts. NWEM operates at a watershed level and its efficacy in resolving local water supply and water-use trade-offs was demonstrated using data from Sandia National Laboratory along with a water supply scenario projected by the World Resources Institute (WRI). The prototype model only passively utilized a forecast of power generation from an existing forecast;the model’s choices were limited to purchases or retrofitting to meet future water supply constraints. NETL is continuing to integrate the water sub-module into the NEMS framework, which will allow active interaction between the water market and power markets, extending the industry’s ability to re-dispatch its generating units with the price of water as one of the variable costs.

中国水-能-粮耦合系统协同安全发展战略研究

水是水-能-粮(WEF)耦合系统的核心要素,为保障国家粮食和能源安全,必须加强水资源管理,坚持水资源、能源和粮食协同安全发展。在系统总结国内外WEF耦合系统纽带关系研究进展、科学认识WEF基本内涵的基础上,分析了我国各省份水资源、能源、粮食开发利用过程中存在的问题,揭示当前WEF耦合系统发展面临的能源需求持续增长与能源安全结构性矛盾日益凸显、不稳定因素加剧粮食安全风险、资源不匹配带来水资源约束趋紧、高质量发展对水-能-粮-生提出更高要求四大挑战,围绕区域特点和高质量发展目标,针对性提出了区域可持续发展模式与策略。研究建议,在西北资源富集地区,通过“四水四定”、水权交易及调水工程缓解水资源短缺;在京津冀地下水超采区,优化粮食安全布局,强化水与能源协同调控;在东北粮食增产区,拓展粮食生产空间,保护水资源合理开发利用;在南方水资源丰沛区,深化农业供给侧结构性改革,统筹“水风光储”一体化开发,以期为实现绿色低碳的可持续发展路径提供科学支撑与决策参考。

A REVIEW OF THE SUSTAINABILITY OF RESIDENTIAL HOT WATER INFRASTRUCTURE:PUBLIC HEALTH,ENVIRONMENTAL IMPACTS,AND CONSUMER DRIVERS

Residential water heating is linked to the primary source of waterborne disease outbreaks in the United States,and accounts for greater energy demand than the combined water/wastewater utility sector.Furthermore,home water heating is the second largest energy consumer in the home and thus represents an integral part of the water-energy nexus.To date,there has been little practical research that can guide decision-making by consumers,public health officials and regulators with regards to water heater selection and operation to minimize energy costs and the likelihood of waterborne disease.Scientific uncertainties associated with existing“green”advice have potentially created misguided policy with long-term negative repercussions.This review is aimed at defining the current state of knowledge related to hot water infrastructure and in highlighting current gaps in the research.While there are many sustainability claims of certain water heater types(i.e.,hot water recirculation systems and instantaneous water heaters)these claims have not been substantiated in head-to-head testing of the interplay between water temperature,energy,microbial growth,and scaling,all measures that need to be better defined.

OPTIMIZATION OF ELECTRIC HOT WATER RECIRCULATION SYSTEMS FOR COMFORT,ENERGY AND PUBLIC HEALTH

Hot water recirculation systems(RECIRC)are labeled green and are sometimes mandated in local plumbing codes.Previous work conducted under non-optimized operation schemes demonstrated that these systems actually waste energy and water versus standard(STAND)water heater counterparts.Optimization of RECIRC system operation by minimizing pump operation did improve energy efficiency 6-60%,saving consumers 5-140%annually in associated utility costs.However,STAND systems were still more energy efficient than any of the RECIRC systems.With respect to factors that might influence pathogen growth,reducing RECIRC pump operations increased disinfectant residual by as much as 560%as compared to the baseline RECIRC system;however,STAND systems still had 25-250%more total chlorine residual than any of the RECIRC systems.At 60℃operating temperature,STAND systems have 30-230%more volume at risk for pathogen growth(e.g.,volume with temp 37-46℃)than any of the RECIRC systems.Thus,in the context of“green”design,RECIRC systems provide a convenience to consumers in the form of nearly instant hot water,at a cost of higher capital,operating and overall energy costs.RECIRC systems have distinct advantages in controlling pathogens via thermal disinfection but disadvantages in control via secondary disinfection residual.

WATER AND ENERGY SAVINGS FROM ON-DEMAND AND HOT WATER RECIRCULATING SYSTEMS

Electric hot water recirculation and on-demand instant hot water systems have been identified as“green”water systems due to purported energy and water savings,and some municipalities and districts even require green systems in residences.The performance of these devices have never been rigorously tested and evaluated.This work aims to address that gap by conducting a comparative,head-to-head study evaluating energy efficiency,temperature profiles and consumer issues such as cost and quality of system for two“green”water heating systems as compared to a standard water heater.Not only did the standard system outperform the hot water recirculation system with respect to temperature profile during flushing,but the standard system also operated with 32-36%more energy efficiency.Although the recirculation system did in fact save some water at the tap,when factoring in the energy efficiency reductions and associated water demand,recirculation systems actually consumed up to 7 gallons more water per day and cost consumers more money.On-demand systems operate with virtually 100%energy efficiency,but cannot be used in many circumstances dependent on scaling and incoming water temperature,and may require expensive upgrades to home electrical systems and use of low/ultra low flow showerheads.Although additional research is necessary to better understand nuances of electric water heating in the context of the water-energy nexus,this research provides a first step for rational decision making by regulators,public health officials,manufacturers and consumers.

海水淡化厂与区域水-能耦合系统的协同调度

海水淡化厂具有能量密集、运行灵活的特点,是理想的电力需求响应资源。然而,现有关于淡化厂与电网协同运行的研究大多关注电网和淡化厂的一体化调度、无法适应双方自主决策的工程场景,对淡化厂运行约束的刻画也比较粗糙。该文研究反渗透淡化厂与区域水-能耦合系统(waterenergy nexus,WEN)的协同运行方法。首先,考虑淡化厂的生产流程、调节特性和运行约束,分别建立传统及新能源淡化厂的水-能管理模型;其次,在保障两类淡化厂和区域WEN自主决策和信息隐私的条件下,提出以双方调度计划互动为载体的“激励型”和“价格型”两种协同运行机制及调度模型,并提出基于二阶锥松弛和McCormick包络的求解方法。用算例验证所提协同运行机制、调度模型及求解方法的有效性。

国内外“水-能源-粮食”纽带关系研究的发展现状与热点分析

当今,为了缓解水、能源、粮食3种资源供需矛盾对国际社会造成的沉重压力,从而促使对“水-能源-粮食”纽带关系的探究成为了国际学术界一项热门的研究课题。为了把握国内外“水-能源-粮食”纽带关系研究的发展脉络,以便能够为未来的“水-能源-粮食”纽带关系研究提供科学的理论依据和研究建议,本文决定将Web of Science核心合集数据库与中国知网(CNKI)数据库作为数据来源,利用VOSviewer和CiteSpace计量软件对以往的“水-能源-粮食”纽带关系研究进行梳理,通过对该研究领域所涉及的文献数量、作者合作情况、国家合作情况等信息的可视化呈现,以突发关键词为重点,从时间维度角度来探究“水-能源-粮食”纽带关系研究的发展概况与变化趋势。研究结果表明:1)2010—2022年对“水-能源-粮食”纽带关系的研究已受到国内外学术界的一致重视,论文发文数量呈现出持续增长的趋势,并且各研究国之间均存在着较为密切的合作关系。2)可持续发展、气候变化、治理、研究模型是以往研究文献中出现次数较多的关键词,不但反映出对“水-能源-粮食”纽带关系研究要基于可持续发展的前提之下,而且还拓宽了该纽带关系的研究范围、研究视角、研究方法。3)2010—2022年对“水-能源-粮食”纽带关系的研究已经从纽带关系的内部机制拓展至纽带关系的外部环境,研究方法也由较多的定性分析转向了定量化的模拟预测分析。4)经关键词时间线演进趋势和突现强度分析表明,当前学术界对于“水-能源-粮食”纽带关系的研究已呈现出由初步探索向着纵深解析的转变,并且新的研究方法已被学术界广泛应用于对“水-能源-粮食”纽带关系的探索之中。

“水资源-能源”纽带关系视角下西北地区能源产业可持续发展路径研究

基于“水资源-能源”纽带关系视角,利用Vensim PLE软件构建因果关系流图以分析西北地区水资源与能源之间的关联,设定常规发展、节水节能政策深入落实、节水节能技术改进、能源产业结构改善等情景,并采用系统动力学模型模拟比较2022—2030年GDP、单位能源生产用水量、万元GDP能源消费量和能源紧缺程度4项指标在不同情景下的发展趋势。结果表明:西北地区经济水平将持续提升,单位能源生产用水量、万元GDP能源消费量、能源紧缺程度将持续下降;与常规发展情景相比,其他情景中西北地区GDP、能源生产用水效率的提升幅度和万元GDP能源消费量、能源紧缺程度的下降幅度将更大;节水节能政策深入落实对万元GDP能源消费量、能源紧缺程度改进效果最为明显,节水节能技术改进则对单位能源生产用水量的抑制作用较为明显,能源产业结构改善能兼顾对单位能源生产用水量、万元GDP能源消费量、能源紧缺程度的约束效果。提出以节水节能政策深入落实、节水节能技术改进、能源产业结构升级等为主导的能源产业可持续发展路径,以促进西北地区能源产业的可持续发展。

黄河中游地区水-能-粮-碳纽带关系模拟与韧性调控

水资源、能源、粮食和碳排放等对区域发展水平和生态环境质量有重要影响,其相互作用构成了复杂的纽带关系,对于区域绿色协调发展至关重要。以黄河中游地区为研究对象,采用系统动力学来探索水-能-粮-碳的关联模式,根据1999—2019年黄河中游地区的水资源、能源、粮食、碳排放现状的基础数据梳理这4个子系统的耦合关系,并对其未来30年的发展变化进行仿真模拟,从抵抗性、恢复性和适应性3个方面构建韧性评价指标体系来评价整个系统。研究结果表明:①在常规发展模式下,预计2050年水资源及粮食不会出现明显的供需缺口,而能源消费缺口会随着社会经济的发展越变越大。②每个情景的3个分数都存在差异,其中多子系统优先发展的情景在抵抗性、适应性及恢复性3个方面的表现均优于其他情景。③情景11的4个子系统都优先发展时及情景10的能源、粮食及社会经济子系统优先发展时,韧性指数从2020—2050年整体是最高的;情景11的碳排放量最低,水资源、能源及粮食供需指数都相对较高,因此情景11为最优发展模式。

基于水—能源—粮食纽带关系的能源绿色效率及区域差异研究

基于水—能源—粮食纽带关系建立多维投入—产出指标体系研究能源绿色效率,包括从静态方面构建MetaSBM-DDF模型测算能源绿色全要素生产率,从动态方面构建Luenberger模型测算能源绿色全要素生产率指数(GLTFP),并分解其要素贡献和地区差异性。结果表明:产出要素的无效率是整体无效率的主要推动力,且期望产出要素的相对贡献呈下降趋势,非期望产出要素的相对贡献呈上升趋势。能源绿色全要素生产率的区域差异明显,东部沿海能源绿色全要素生产率代表最佳技术前沿,而东北地区、长江中游和西南地区是三大低值区。GLTFP年均增长率为4.5%,其中技术进步是GLTFP增长的核心动力且贡献度达121.06%,而技术效率对GLTFP增长有制约作用且贡献度年均下降0.9%,产出要素生产率变动是推动GLTFP增长的核心要素,且非期望产出要素、投入要素、期望产出要素对GLTFP增长的贡献率依次递减。

基于土地利用的水—能—碳关联研究:理论框架与关键问题

研究目的:构建基于土地利用的水—能—碳关联研究框架,并提出该领域研究的关键问题,以期从多要素耦合视角深化土地学科的交叉研究,并为面向多目标权衡的土地利用优化提供参考。研究方法:文献归纳法,理论解析法,综合分析法。研究结果:(1)土地是人类经济社会活动的资源基础、承载空间和“刚性”要素,土地利用结构、功能、强度和布局直接决定了水—能—碳的相互作用格局和强度,并深刻影响水—能—碳关联关系。(2)基于土地利用的水—能—碳关联研究的核心是:开展不同时空尺度水—能—碳关联的“格局—过程—机理—优化—调控”研究,从“自然—社会”二元视角揭示土地利用及其变化对水—能—碳要素的关联强度、组合格局、耦合特征和远程流动的影响机理,阐明基于“要素—空间—系统”的土地利用与水—能—碳的相互影响与反馈机制,识别水—能—碳关联系统风险并提出基于土地利用的协同优化方案和配置对策。研究结论:未来应基于不同尺度土地利用变化及用地转型的视角,重点从影响机制、远程流动、精细化模拟、优化调控和多要素权衡等方面开展水—能—碳关联研究,从多尺度、多视角阐明土地利用对水—能—碳关联的影响机制,探索水—能—碳协同约束下的土地利用格局优化方案。