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. .

Integrated assessment model of water resources constraint intensity on urbanization in arid area

Water has become a key restricting factor of the urbanization process in developing arid areas.Based on qualitative and quantitative methods,we constructed an integrated in-dicator system to assess the status of water resources and urbanization system in arid area,and established an AHP model reformed by entropy technology to evaluate the temporal and spatial variations of water resources constraint intensity on urbanization.This model is ap-plied to the Hexi Corridor,a typical arid area in NW China.Results show that,water resources constraint intensity on urbanization in the Hexi Corridor is bigger in the east and smaller in the west.It has changed from the less strong constraint type into the strong constraint type from 1985 to 2005,yet it decreased appreciably in recent years.At present,most areas in the Hexi Corridor belong to the less strong or strong constraint type.Through rational adjustment of water resources and urbanization system,the Hexi Corridor can still promote water resources sustainable utilization and accelerate the urbanization process.This study suggests that the integrated assessment model of water resources constraint intensity on urbanization is an effective method to analyze the conflicts between water resources and urbanization system in arid area.

Modelling of Nature-Based Solutions (NBS) for Urban Water Management—Investment and Outscaling Implications at Basin and Regional Levels

This manuscript is an attempt to demonstrate effectiveness of nature-based solutions (NBS) and measures to reduce risk of flooding and environmental impact in urban settings. The nature-based solutions (NBS) were assessed as scenarios from experience of urban storm drainage and sewerage systems based on practices that improve urban water management through modelling using urban stormwater management model (SWMM). The model has been applied in a typical urban environment in the second city in Botswana, the City of Francistown, which has a population of more than one hundred thousand. By considering the 2-yr and 10-year storm events in a calibrated SWMM, NBS scenarios from a mix of low impact and drainage measures were considered. The considered NBS scenarios were used to determine their effectiveness in terms of reducing and controlling peak runoff, flood volumes, infiltration and evapotranspiration in the study area, which are vital in assessing the opportunity and challenge for sustainable management of water resources and associated tradeoff of investments in the urban contexts. The study demonstrates the usefulness of implementing effective measures for achieving NBS in urban context and possibility of outscaling at basin and regional levels.

On the Use of Agent Based Modelling for Addressing the Social Component of Urban Water Management in Europe

The paper aimed to provide a review of different tools that estimate how human behavior changes by water management strategies and quantify this change to support the decisions of urban water managers. To support decision makers, it is essential to be able to model the urban water system’s human part explicitly and link it to the hydro system’s response, rather than only explore the reaction of the system based on scenarios. To do so, tools are needed that can model the human part of the system, explore its reaction to potential changes and dynamically link back this to the techno-environmental model of the water system. This work reviews state-of-the-art ABMs that are publicly available focusing on the human part of the urban water system in Europe. The review leads to the proposals of three pillars for future development of ABMs for urban water management in Europe: end-user enablement;Machine Learning and Artificial Intelligence integration and adversaries modelling.

Urban water system theory and its model development and application

The urban water system theory is an extension of the basin water system science on an urban scale, providing a new systematic solution for the unbalanced human-water relationship and severe water challenges, such as waterlogging, black and odorous water, and ecological degradation caused by urbanization. Most existing studies on urban water systems have focused on individual water cycle processes linked with water supply and sewage treatment plants, but mutual feedback between the water cycle and its associated material circulation and water ecology, as well as human processes, still needs further exploration. In this paper, the concept, theory, and technical methodology of the urban water system were developed based on the water cycle and basin water system science. The Urban Water System 5.0(UWS 5.0) model was developed by integrating the Time Variant Gain rainfall-runoff Model with Urban water system(TVGM_Urban) in different underlying surface conditions for analyzing the natural-social water cycle processes and their associated water environmental and ecological processes and the influence of multiscale sponge measures. Herein, five major simulation functions were realized: rainfall-runoff-nonpoint source pollutant load,water and pollutant transportations through the drainage network system, terminal regulation and purification, socioeconomic water cycle, and water system assessment and regulation. The location for the case study used in this paper was Wuhan City. The findings showed that the entire urban water system should consider the built-up area and its associated rivers and lakes as the research object and explore the integrations among the urban natural-social water cycle and river regulations inside and outside of the city as well as the effects of socioeconomic development and sponge measures on the water quantity-quality-ecology processes. The UWS 5.0 model efficiently simulated the urban rainfall-runoff process, total nitrogen(TN) and total phosphorus(TP) concentrations in water bodies, and characteristic indicators of socioeconomic development. For the rainfall-runoff simulations, the correlation coefficient and Nash-Sutcliffe efficiency(NSE) fall under the excellent and good classes, respectively. For the TN and TP concentration simulations, results exhibited good bias and the correlation coefficients exceeded 0.90 for 78.1% of the sampled sites. The simulation of 18 socioeconomic indicators provided excellent bias, correlation coefficient, and NSE values of 100%, 83.3%, and 69.4% to total indicators, respectively. Based on the well-calibrated UWS 5.0 model, the source sponge,artificial enhancement, and source reduction-path interception-terminal treatment measures were optimized, which considerably mitigated waterlogging, black and odorous water, and lake eutrophication, respectively. The mitigation performance revealed that the maximum inundated area for a once-in-10-year rainfall event was reduced by 32.6%, the removal ratio of the black and odorous water area was 65%, the comprehensive trophic state index of water bodies was reduced by 37%, and the green development level of Wuhan City in 2020 increased from 0.56 to 0.67. This study is expected to advance the intersection and development of multidisciplinary fields(e.g., urban hydrology, environmental science, and ecology) and offer an important theoretical and technical basis for solving urban complex water issues and promoting green development of cities.

Coordination of Urbanization and Water Ecological Environment in Shayinghe River Basin,China

During the rapid industrialization and urbanization of China,urban agglomeration in river basin areas raises the problems of over-use of water resources and pollution of the water environment.Related research in China has mainly focused on the conflicts among economic growth,urban expansion and water resource shortages within admin-istrative boundaries.However,water environments are much more dependent on their physical boundaries than their administrative boundaries.Consistent with the nature of water environment,this study aims at analyzing coordination relationships between urban development and water environment changes within physical river basin boundaries.We chose the Shayinghe River Basin,China,as our case study area which is facing serious challenges related to water en-vironment protection.Then we classified 35 county-level administrative units into upstream,midstream and down-stream regions based on their physical characteristics;analyzed the coordination degree of urban agglomeration using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method;and constructed cooperative models using the Linear Programming (LP function) to simulate four scenarios of the coordination relationship be-tween urban population increase and water environment protection based on existing water resources and water pollu-tion data.The results show that the present coordinative situation in Shayinghe River Basin is not sustainable.In gen-eral,more than 50% administrative units are in the bad coordinative situation.In particular,the downstream region is under worse condition than the upstream and midstream regions.Cooperative models in scenario analyses indicate that the population scale set in existing urban master plannings is not coordinated with the water environment protection.To reach the goal of regional sustainable development,the total population needs to be controlled such that it will re-main at 4.5×10 7 or below by 2020 given the capacity of water environment.

Effectiveness of urban distributed runoff model for discharge and water depth calculation in urban drainage pipe networks

Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.

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.

感潮河段城市湿地水动力模拟及改善方案研究

湿地具有固碳释氧、涵养水源等作用,改善水体交换能力是湿地研究热点之一,但关于潮汐变动水位条件下湿地水体调控措施的探究相对较少。以长江南京段绿水湾湿地为例,建立平面二维水动力模型,开展感潮河段城市湿地水动力模拟及改善方案研究。计算不同水文条件及闸泵调度方案下湿地流场,分析潮位变动对绿水湾湿地水动力的影响,分析不同闸泵调度措施对水体流动性的改善效果。研究表明,闸泵联合调度可使枯季大部分区域水动力明显增强,但仍存在主槽外坑塘等局部滞水区,需通过湿地植被重构的方式提高水体自净能力。对易暴发藻类的4—5月,闸泵联合调度可较好改善绿水湾内上游区域的水动力条件,对于改善效果并不明显的下游区域建议增设补水点,降低水体富营养化风险。本研究可为绿水湾湿地的设计、建设与管理提供科学依据。

黄河流域关中平原城市群水资源利用效率与公平性评价

为提高黄河流域城市群水资源利用效率与公平性,推动黄河流域生态保护与高质量发展,以关中平原城市群为例,在采用水足迹与水行星边界方法分析水资源可持续利用水平的基础上,运用超效率SBM模型与GML指数探讨了城市群的水资源利用效率,并利用基尼系数与贡献系数评价了用水公平程度对城市群的影响。结果表明:2010—2019年,关中平原城市群水足迹、水赤字和灰水足迹分别下降了4.52%、3.62%和59.79%,水资源的不可持续性和水污染状况得到改善;水资源利用效率不高且未呈现增长趋势,技术效率与技术进步之间未实现良性互动;水资源占用相对公平,但水污染同城市发展及水资源承载能力之间的公平程度均有明显下降。

基于VSD模型的陕南城市群水资源脆弱性评价及影响因子研究

[目的]构建基于社会-经济-生态耦合作用下的陕南城市群水资源脆弱性模型,阐明水资源脆弱性状态,厘定影响因子,助力秦岭地区人水和谐。[方法]基于暴露度-敏感性-适应性(Vulnerability Scoping Diagram,VSD)对陕南城市群水资源脆弱性进行了评价,结合多元统计法,进一步识别了社会-经济-生态耦合作用下水资源脆弱性的影响因子。[结果]2011—2020年,陕南整体水资源脆弱性的变化趋势与商洛市最相似,除2011年极度脆弱外,基本保持在轻度脆弱状态,而汉中市和安康市的水资源脆弱性等级较高,水安全保障程度相对较低;陕南城市群水资源脆弱性的主控因子有生态环境用水量、人均水资源量、年降水量;优化生态环境用水量分配,加强对年降水量与人均水资源量监测,将成为陕南城市群降低水资源脆弱性新的工作重心。[结论]陕南城市群水资源系统安全性的提升与当地注重水生态文明建设以及与社会-经济协调发展有关。此外,构建的VSD模型适用于陕南城市群水资源脆弱性评价,可为缓解人-城-水矛盾提供理论指导。

基于DPSIR模型的秦岭北麓陕西城市群水安全评估及驱动因子识别

水安全评估是水资源开发利用与区域发展的基础。为了加强秦岭北麓陕西城市群可持续建设,助力秦岭“中央水塔”绿色发展,基于DPSIR模型构建秦岭北麓陕西城市群水安全评估体系,结合主客观综合赋权法与模糊综合评价法对区域2011~2021年水安全进行评估分级,并利用灰色关联度法分析其水安全的驱动因子。结果表明:秦岭北麓陕西城市群2011~2021年水安全状态变化具有一致性,波动中稳步提升。西安市水安全等级相较宝鸡市、渭南市上升趋势显著,于2021年转为无警状态;宝鸡市一直保持低警状态,而渭南市长期处于中警状态。陕西城市群的水安全状态及发展趋势与人均GDP、年降水量、人均用水量等10个驱动因子密切相关,其中经济因子是水安全等级呈现一致性的根本保证,社会和生态因子则是造成水安全差异性的主要原因。

城市河网工程群多目标联合调度优化模型

城市河网工程群联合调度优化是一项复杂的系统工程,涉及多种闸、泵、堰等水利工程,是多时段、多对象、多约束、多目标非线性优化问题。基于此,提出了面向河网水环境改善目标的水工程群多目标联合调度优化模型,综合运用了“水量水质模型—优化调度模型—优化求解算法—方案优选方法”耦合方式,构建面向河网水环境改善的工程群多目标联合调度优化模型,并采用EMMOPSO算法的优化模型求解、基于AHP-TOPSIS的联合调度方案优选,以实现对河网水工程群联合调度的优化与决策支持,选择了长三角地区某城市河网开展了优化模型关键技术的数值试验与案例分析。结果表明:相较于水工程常规调度方式,本优化模型可以减少河网生态引水量23.9%~28.5%、提升河网水体水质达标度11.8%~90.4%,优化模型能够支撑平原城市河网地区取得显著的防洪除涝、水资源调配、水环境改善等多方面的综合效益。

System Dynamics Model of Urban Water Resources Use and It’s Application

A new urban water resources use and forecasting model consturcted by comprehensive considering the balance between the supply and demand of the water resources system to an industry city and the feedback relationship of the water resources control policy,and by applying DYNAMO language is presented in this paper.It can give more rational data of urban water resources simulation and planning than that given by the growth rate trend forecasting method.

有效不透水面分布对城市雨水径流的影响

城市区域不透水面分布错综复杂,汇流路径多样,不透水面有效性及其产流机制成为城市水文学的热点问题。研究以北京市主城区为对象,构建了基于汇水路径的有效不透水面的识别方法,拟合出总不透水面与有效不透水面的经验公式,定量识别了不透水面有效性对北京市主城区雨水径流的影响。结果表明:考虑不透水面有效性能显著提升模型模拟精度,针对不同城市化阶段,在各种重现期降雨情景下设置不同有效不透水面比例并进行模拟,发现有效不透水面对低重现期降雨产流过程的影响远大于高重现期降雨产流过程,且城市化前期有效不透水面增加会导致较大洪峰增长率,而城市化后期影响减小。研究可为优化城市地面格局,减缓城市洪涝灾害损失提供科学参考。

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。

大直径城市供水管道水锤作用监测与计算方法研究

随着我国城市建设的发展,长距离供水管道应用众多,而在长距离供水管道设计过程中水锤作用不可忽视。使用高频动态压力传感器进行现场监测试验,对比传统水锤方程组和“FSI四方程模型”水锤计算的结果,并同时基于ABAQUS数值模拟软件开展相关数值模拟,对大直径供水管突然关机时产生的水锤作用进行研究。结果表明:在水锤作用下压应力最大部位位于管顶、管底内侧,拉应力最大部位位于管腰内侧;壁厚与应力和位移呈正相关,管径与应力呈正相关且与位移呈负相关,而管道埋深对其应力和位移的影响很小。研究的计算结果与数值模拟结果接近监测真实值,对水锤模拟有一定指导意义。

基于DPSR模型的城市水安全评价与保障能力提升

水安全评价是水资源开发利用与保护的基础,提升城市水安全有利于促进生态环境保护,支撑经济社会高质量发展。基于驱动-压力-状态-响应(DPSR)模型构建以资源安全、社会安全和经济安全为核心的水安全评价指标体系,运用熵权法确定指标权重,以长沙市为实例,对“十三五”期间城市水安全状况进行评估与分析。结果表明:长沙市水安全状况尽管从2018年“不安全”等级提升至2020年“安全”等级,但状态不稳定,进而制定了加强保水工程建设、提升水环境质量、加强水灾害防治能力3个方案,综合考虑方案投入成本并对比水安全提升效果,给出了先后实施方案2—方案1—方案3的长沙市水安全提升优化路径。