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Limited research has been directed toward coastal protection infrastructure compared to other types of infrastructure, despite the increasing global population in low-elevated coastal regions and the threats posed by climate change. This paper presents a risk-based asset management framework for coastal protection structures that improves accuracy with each inspection. The framework consists of five components: the Coastal Asset Inventory (CAI), Inspection and Condition Assessment (ICA) module, Backward Markovian Deterioration Model (BMDM), Forward Markovian Deterioration Model (FMDM), and Intervention Policy Engine (IPE). The framework addresses challenges in accurately predicting coastal structure deterioration due to uncertainties in wave loading conditions and the need for frequent inspections. It is applied to rubble-mound breakwaters in Alexandria, Egypt. The BMDM and FMDM models are developed based on inspection data, and the IPE optimizes interventions considering structural condition, risk thresholds, and budget constraints. Results showed that long-term deterioration estimates occur at an accelerated rate with an increase in inspection points, triggering earlier interventions. However, the framework proves reliable even with only two inspection points, allowing asset managing agencies to implement the model based on the structural condition at the year of construction and a minimum of two inspections. The proposed risk-based asset management framework provided a comprehensive approach to managing coastal protection infrastructure, reducing risks to life and property. By accurately predicting deterioration and optimizing intervention decisions, the framework can greatly assist in the effective management and maintenance of coastal assets. This is vital in ensuring the safety of coastal populations facing global climate change and demographic growth. Coastal protection structures are crucial for safeguarding coastal populations in the face of climate change and demographic growth. This research paper introduces a risk-based asset management framework for coastal protection structures, with practical applications for coastal management agencies and practitioners. The framework addresses the challenges of predicting coastal structure deterioration and optimizing intervention decisions. The framework consists of five components: the Coastal Asset Inventory (CAI), Inspection and Condition Assessment (ICA), Backward Markovian Deterioration Model (BMDM), Forward Markovian Deterioration Model (FMDM), and Intervention Policy Engine (IPE). It has been successfully applied to rubble-mound breakwaters in Alexandria, Egypt. The practical implications are significant: The framework enables asset managers to make informed decisions on coastal infrastructure maintenance and interventions, reducing risks to life and property. It provides a comprehensive approach to managing coastal protection infrastructure and ensuring the safety of coastal populations. By accurately predicting deterioration and optimizing interventions, the framework supports effective management and maintenance of coastal assets. Its reliability and flexibility make it a valuable tool for coastal management practitioners, promoting sustainable development and safeguarding coastal areas. With its potential for broader application, this risk-based asset management framework offers practical solutions for coastal protection worldwide. [ABSTRACT FROM AUTHOR]

The global rise in urban energy demand poses severe environmental and economic health challenges. We need adaptive policies in urban planning to reduce the need for urban energy. This has become a prominent agenda in urban planning, encompassing social (education and innovation in consumption), economic (real pricing), and physical (urban morphology) aspects. This research aims to investigate the influential role of urban form, particularly the physical environment, on energy performance. The methodological approach is centered on conducting analytical-comparative research to examine how urban form influences theoretical energy requirements. Yazd City is selected as a case study because of its distinctive features and traditional approaches to urban sustainability, which have been largely overlooked in previous energy consumption investigations. In a broader comparative context, five tissue types (morphological units) have been selected from Rome, Barcelona, Madrid, and Venice and used as the analytical basis of the study. The research categorizes urban forms into three levels: macro (fabric), medium (block), and micro (building patterns). Heating, cooling, and total energy consumption were computed at each level. The findings indicate that, at the macroscale, the Barcelona fabric offers the highest potential for adaptation in the hot, dry climate of Yazd City. Moreover, the paper analyzes the most recurring morphological indices in the tissues and proposes guidelines for new developments tailored to Yazd City's unique climatic conditions. By focusing on urban form's impact on energy performance, this research contributes to the broader understanding of sustainable urban planning. It offers valuable insights for energy-sensitive urban development in other contexts facing similar climate challenges. [ABSTRACT FROM AUTHOR]

With the ever-increasing emphasis on climate change and sustainability, there is growing interest in using environmentally friendly coastal structures. In addition to engineering and cost factors, the construction global warming potential (GWP) can and should be an influencing factor in the selection and design of the structures. Therefore, knowledge of construction GWP facilitates informed decision-making in coastal projects to achieve climate goals. Considering the number of Icelandic-type berm breakwater (IceBB) structures worldwide, this structure's design method is commonly accepted in coastal protection projects. In this paper, the construction process of an IceBB was assessed for its GWP and compared with concrete armor unit protection of a conventional rubble mound breakwater (ConRMB). The assessment and comparison were made for constructing a breakwater to protect the port of Thorlakshofn in southwest Iceland. The life cycle assessment (LCA) methodology was applied to calculate the construction carbon footprint of the structures using GaBi software, version 10.6.1. Using the International Union for Conservation of Nature (IUCN) criteria for nature-based solutions (NBS) and based on the existing literature, the characteristics of IceBB were briefly explored. The results showed that the construction of IceBB has a lower GWP than ConRMB, mainly due to using natural rock armor instead of concrete armor units. Furthermore, the results indicated that IceBB characteristics meet the IUCN criteria for NBS and thus can be granted as a (hard) NBS coastal structure. Acknowledging the advantages of IceBB, adopting this structure in coastal protection projects could meaningfully contribute to climate change mitigating policies. [ABSTRACT FROM AUTHOR]

Building simulation tools can empower architects to evaluate and optimize the performance of their designs. Therefore, it is essential to integrate building performance simulation modeling from an early design stage. A critical part of the simulated environment is the weather file. It is a compilation of 20–30 years of historical weather and hourly data on temperature, solar radiation, wind speed, and wind direction. The accuracy and contextual relevance of said data are of utmost importance to the integrity of the analysis. Current energy modeling weather files are unlikely to include any indication of risk from potential climate change. Hence, there is a need to incorporate climate change projections in energy simulations and prepare architects to understand better the evolution of design strategies echoing such climate change in different climate zones. This paper describes the process of using the CCWorldWeatherGen tool to morph Energy Plus Weather files of 17 North American cities in key climate zones into three simulated scenarios representing 2020, 2050, and 2080, corresponding to a 1.5°C global temperature rise. By simulating the impact of the morphed weather files on five commercial building models, this paper outlines a database echoing the projected climate change impacts within the selected locations and highlights the critical impact of passive design strategies in facilitating indoor thermal comfort while limiting energy consumption. [ABSTRACT FROM AUTHOR]

Reducing carbon emissions in the construction sector is essential in a period of climate emergency. Disassembly and reuse of structural members are considered to reduce the carbon emissions from the construction and deconstruction of buildings. In this context, it is important to review the current state of the art to provide a framework for the development of future structural systems that can enable the easy disassembly and reuse of steel-framed buildings. This paper (1) presents a review of more than 100 documents to discuss the feasibility of disassembly and reuse of structural members; (2) develops detailed schematic illustrations to explain the design concepts and the underlying mechanics governing the behavior of demountable connections; (3) sheds lights on the technical and design challenges to implement disassembly and reuse of the structural members; and (4) defines future research needs to facilitate the disassembly and reuse of the structural members. [ABSTRACT FROM AUTHOR]

Flood embankments are generally designed by assuming steady-state flow conditions and dry soil above the phreatic surface. However, steady-state conditions are rarely achieved and a significant portion of the embankment remains unsaturated upon a flood event. If transient water flow and partial saturation are considered, the flood embankment can be designed with steeper slopes on the landside, which may lead to significant savings in terms of earthfill material (i.e., embodied carbon) and footprint (i.e., habitat suppression and expropriation costs). This paper examines the case of flood embankments in the tidal area of the Elbe River in Germany. These embankments must be retrofitted by raising their crest from 5 to 7 m because of the new projection of extreme river levels due to climate change. In this paper, the conventional "prescriptive" design consisting of raising the embankment by maintaining the 1:3 inclination of the landside slope is compared with the "performance-based" design where the inclination of the slope on the landside could be potentially increased up to 1:1, which is shown to be sustainable if partial saturation and transient water flow are considered. Raising the flood embankment with 1:1 landside slope (rather than 1:3) could lead to expropriation cost savings on the order of €3.9 M/km. For the case of a newly built embankment of 7 m height, the saving would become €4.5 M/km. An approximate estimation of embodied carbon suggests that the carbon saving would be on the order of 3,100–4,200 tCO2e/km. [ABSTRACT FROM AUTHOR]

From the Rocky Mountains in the US to the Sea of Cortez in Mexico, the Colorado River is one of the most managed and monitored rivers in the world. As decreasing river flows from drought and climate change continue to impact the Colorado River Basin, the US federal government, seven US states, and Mexico have signed agreements that would reduce deliveries, including a Drought Contingency Plan (DCP), an agreement among the US states and the Bureau of Reclamation, and Minute 323 (a treaty agreement between the US and Mexico). As part of the DCP, the US Bureau of Reclamation (Reclamation) committed to increasing conservation efforts to augment storage in Lake Mead. This paper presents an analysis of Reclamation's Decree Accounting Reports that record water deliveries and conservation savings from 1964 to 2019. Overall, this analysis illustrates that (1) the agency has implemented significant conservation actions over the last three decades, (2) the agency has responded to increased accounting needs as dictated by national and international management agreements, (3) some actions have resulted in environmental costs, and (4) future actions could be designed to avoid environmental harms while also augmenting Lake Mead levels. As climate change continues to constrain Colorado River water supply, detailed accounting may help reveal areas for potential efficiencies or demonstrate where the greatest levels of savings have been reached while ensuring that environmental and social benefits are preserved. Over the last 100 years, humans have changed the path and personality of the Colorado River by distributing water to cities, communities, and agricultural fields to support over 40 million people. Throughout the twentieth century, the US federal government, seven US, and Mexico signed agreements enabling development of Colorado River water. By the early 21st century, as it became evident that water demands and climate change were reducing available supplies, these same governments signed agreements to reduce pressure on the river. All these agreements have, in part, been tracked by the US federal agency that manages the river, the Bureau of Reclamation (Reclamation), through Decree Accounting Reports. Since 1964, these reports have recorded how water is or is not accounted for that might be important to the future of the river. This paper examines those reports and reveals four main findings: (1) Reclamation has implemented numerous water conservation projects, (2) they have responded to new management agreements, (3) some of their actions have impacted the environment, and (4) there are proactive ways they can reduce environmental impacts and bolster water supplies in the future. [ABSTRACT FROM AUTHOR]

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. [ABSTRACT FROM AUTHOR]

The US Gulf and Atlantic coasts are often struck by severe hurricanes that cause massive economic and life losses. Climate change and structural aging are expected to exacerbate the risk associated with hurricane hazards. Appropriate methodologies are needed to assess and mitigate these effects through improved design and retrofit solutions that rigorously account for the associated uncertainties, such as performance-based engineering methodologies. This paper extends the performance-based hurricane engineering (PBHE) framework to account for the hazard nonstationarity induced by climate change effects. The newly extended nonstationary PBHE framework was implemented by performing a loss analysis on a benchmark low-rise single-family house over a 50-year design service life, for which climate change effects were accounted for by using a recently developed predictive model for hurricane wind speed distributions. The effects of different modeling assumptions and solution approaches (including approximate estimates, time discretization, interpolation techniques, and models for annual discount rates), different locations, and different climate change scenarios on the means and standard deviations of the total losses were investigated. The performance comparison of different storm mitigation strategies was also performed as an application example. In general, the proposed methodology provides consistent results under different modeling assumptions; however, the modeling assumptions for the annual discount rates can affect significantly the results. Based on the analysis results and within the limitations of the present implementation of the nonstationary performance-based hurricane engineering framework, climate change effects are generally significant, with estimated increases contained between 13.2% and 38.1% for the total loss means, and between 2.5% and 12.4% for the standard deviations of the total losses for the benchmark structure at the reference location of Pinellas Park, Florida. The extended nonstationary PBHE framework was able to identify the optimal retrofit strategy in terms of costs and benefits for any given combination of structures, residential developments, locations, and climate scenarios. The proposed nonstationary PBHE framework represents an advancement in performance-based engineering because it provides a rigorous approach to account for climate change effects. This framework has immediate practical applications, such as those shown in this paper, and could be further extended to other natural and human-made hazards. [ABSTRACT FROM AUTHOR]

This paper examines the life-cycle wind resistant performance of a constructed long-span suspension bridge in the coastal region of China, aiming to quantify the multisource time-variant effects and uncertainties and offering a reference for designs of long-span bridges in the future. Randomness from modal frequencies, damping ratios, and identification uncertainty of flutter derivatives (FDs) was considered; then, their effects on probability of flutter failure and probability of exceeding the predefined buffeting response root-mean square (RMS) are discussed. Firstly, results of full-track tropical cyclone (TC) simulation under various climate warming scenarios are reviewed; then, the time-variant probability density function (PDF) of annual extreme wind speed is discussed. Secondly, 6-year modal frequencies and damping ratios of a long-span suspension bridge with a center-slotted section were extracted by fast Bayesian FFT method with structural health monitoring (SHM) data, which were utilized to explore the deterioration rules of structural properties. Thirdly, FDs were modeled from a probabilistic perspective based on complex Wishart distribution, which were identified in the turbulent flow and the frequency domain by Bayesian inference. The posterior distributions of FDs, namely identification uncertainty, were quantified by Markov chain Monte Carlo (MCMC) sampling. This paper finds that for flutter resistant performance, the time-variant effects (i.e., modal frequencies and PDFs of extreme wind speed) will make the flutter failure probability seven times larger than the initial value; for the probability of exceeding the predefined buffeting response RMS, however, the time-variant effects will make a negligible difference. [ABSTRACT FROM AUTHOR]

There has been a rapid development of the nuclear industry on account of climatic change caused by global warming. The most favorable rocky sites for nuclear power plants are exhausted worldwide, and now nuclear facilities are proposed on soil sites. In a soil site, a combined piled raft foundation (CPRF) system can provide the desired level of performance for a nuclear structure under seismic loading conditions. The combined system of the nuclear structure with the CPRF involves complex dynamic interactions between the pile, soil, raft, and the superstructure. In the existing literature, the dynamic behavior of the CPRF system supporting massive and stiff structures is not well studied and investigated. Due to the highly nonlinear dynamic characteristic of the CPRF system supporting massive and stiff reactor buildings, this paper adopts interface nonlinearities (separation and sliding) through the master and slave concept, concrete and reinforcement material nonlinearities through the concrete damage plasticity model for piles and superstructures, and an equivalent linear approach considering soil degradation and damping with Mohr–Coulomb postyielding hardening behavior for the soil. After the successful validation of the modeling approach with the results of the experimental testing, the different aspects of the CPRF of reactor building are investigated, such as amplification, pile and raft behavior, pile–raft coefficient, separation and sliding, contact pressure, nonlinearity in the piles, and the response of the superstructure. This study indicates that the peripheral piles of the CPRF system could prevent the separation of the raft from the soil. The numerical result shows that damage in the CPRF system occurs near the top portion of the pile. The presented procedure to develop the combined model for the seismic analysis in the time domain could help to formulate guidelines for safety-related nuclear structures resting on the CPRF system. Several countries are planning and building new nuclear reactors to meet their increasing demand for clean electricity. The most favorable rocky sites to construct nuclear power plants are exhausted worldwide; therefore, some upcoming nuclear reactors are supported on a soil site. The seismic safety of nuclear power plants is paramount because their failure may cause disasters. Hence, the problem of soil–structure interaction becomes vital for nuclear power plants (NPPs) due to the building of nuclear structures under unfavorable ground conditions. The present study describes the methodology to assess piled raft–supported NPP behavior under extreme earthquake events. The presented approach will be helpful to consultants and designers working in the nuclear field. The present study will help to formulate guidelines for the seismic safety of NPPs that rest on soil sites. [ABSTRACT FROM AUTHOR]

Adapting reservoir operation to a changing climate is important to improve water system performance toward benefits including water security, and energy production. However, managers still need to know if and how reoperation can also assist long-term mitigation of climate change impacts on aquatic ecosystems, creating, for example, opportunities to revert fish migration and recruitment losses. This paper investigates the operational adaptive capacity of water systems to mitigate climate change impacts on both hydropower and aquatic ecosystems, with a detailed representation of fish species recruitment response to flow regime changes. The methodology framework combines hydroclimatic modeling, explicit stochastic reservoir operation modeling, and predictive modeling of migratory fish recruitment abundance, illustrated using the large-scale hydropower system of the Paraná River Basin in Brazil. Results identified that operating policies can be adapted to improve hydropower production under a changing climate with drier conditions by 2% to 8% compared with current operating policies. Although insufficient to eliminate all energy losses that climate change may cause, the optimized operation provided flexibility to adjust flow releases and reduce the likelihood of future severe multiyear deficits, which are very harmful to fish populations. Adapting operation to climate change sacrificed fish recruitment performance over a few years of the time horizon to maintain an overall higher storage, but it also improved the chances of producing flow releases in magnitude, timing, and duration during long drier periods that prevented more severe impacts of climate change on fish recruitment and population. This indicates that it might be possible to have synergies in adapting reservoir operation to not only prevent energy losses, but also to improve fish recruitment under climate change. The ecosystem resiliency under adapted operation increased up to 2 times compared with the isolated climate change effect. [ABSTRACT FROM AUTHOR]

This paper reviews the development of snow load research since the contemporary introduction and calibration of the ANSI A58-1982 provisions (and subsequent ASCE 7-88). The ASCE 77-88 ground snow loads were based on the data and methods available at the time and subsequently updated in 1995. The provided loads are based on 50-year mean recurrence intervals, with design loads for each category being obtained through a combination of partial safety and importance factors. Changes and improvements in snow load design over the last 40 year necessitate a reconsideration of the original calibration of these safety and importance factors. This paper discusses the need for a movement away from a uniform-hazard snow load design approach in combination with uniform load and importance factors, in favor of reliability-targeted design snow loads. This paper reviews the concept of reliability targeted loads as a means of meeting the ASCE 7 goal of uniform risk/reliability in the US. This paper further describes the incremental changes in both reliability and snow load research that will culminate in a change from uniform hazard (i.e. 50-year) loads to uniform-reliability loads. The purpose of this paper is to describe the motivation for, and historical context of E 7, the forthcoming changes to design ground snow loads in ASCE 7-22. Furthermore, the paper discusses the future of snow load prediction and its impact on the engineer and the code, particularly in regards to the implications of climate change for future snow load design. [ABSTRACT FROM AUTHOR]

This paper provides an outlook on the effects of climate change and the severity and frequency of extreme weather events on the performance of flexible pavements across North America. Now more than ever, the climate is changing at a rapid pace, which will alter long-term environmental loading parameters and extreme weather events. Such alterations will pose implications for the design, maintenance, and rehabilitation of flexible pavements, especially in terms of their serviceability, safety, and functionality. In northern Canada, roads are founded on various terrain types, including thaw-sensitive ice-rich permafrost underlying terrains. Such roads have experienced signs of embankment and pavement damage, which are usually induced by the degradation of the underlying permafrost due to climate change. Therefore, the development and implementation of new permafrost thaw mitigation techniques for vulnerable roads are essential and will be discussed in this paper. Resilient flexible roads should be designed to withstand the conditions that are likely to occur during their design life, taking into account the impact of the climate change on pavement performance in response to daily and seasonal changes in heat, precipitation, freeze–thaw cycles, and extreme weather events. [ABSTRACT FROM AUTHOR]

Increasing population and water use, rising pollution of water resources, and climate change affect the quantity and quality of water resources. Reservoir operation is an important tool for water supply that can be optimized by simulation-optimization considering the impact of climate change on water quality. This study presents a simulation-optimization approach linking the CE-QUAL-W2 hydrodynamic model with the firefly algorithm k -nearest neighbor (FA-KNN) model to obtain optimal reservoir discharges to achieve water quality objectives under climate change conditions. The developed algorithm overcomes the computational burden of CE-QUAL-W2. The FA-KNN hybrid algorithm is employed to optimize the total dissolved solids (TDS) while achieving computational efficiently beyond what could be achieved with CE-QUAL-W2 simulations alone. This paper's approach is evaluated with the Aidoghmoush Reservoir (East Azerbaijan, Iran). Overall, 36 simulation-optimization scenarios for dry and wet years under baseline and climate change conditions are evaluated by considering three initial water levels for the reservoir (minimum, average, and normal) and three thresholds for assessing the hybrid algorithm. The TDS released from the reservoir in wet years would be acceptable for agricultural use; in dry years, on average, the TDS would not be acceptable for 24 days per year under climate change. The reservoir in winter undergoes complete mixing; it becomes stratified in spring and summer, and it is close to complete mixing in the autumn. The highest TDS in the reservoir would occur during the summer in dry years under climate change, reaching TDS of approximately 2,645 g/m3. [ABSTRACT FROM AUTHOR]

Multiobjective water resources systems require long-term operational plans that consider vulnerability to failure under nonstationary conditions due to climate change. The paper presents a probabilistic decision-making framework under hydroclimatic nonstationary assumptions to evaluate the robustness of the preselected plans and identify the optimal plan using a genetic algorithm approach. The framework incorporates a new metric for maximum allowable time to apply the adaptations and maintaining operational targets without penalties. The framework has four stages for climate exposure identification, production of water supply scenarios, generation of water demand scenarios, and evaluation of system performance. Hydrologic variables considered include precipitation, temperature, and wind speed. The Diyala River Basin in Iraq was used as a case study to test the effectiveness of the framework. Three synthetic preselected plans were developed by reducing the demand ratios of the system. Results indicate that current operational rules are robust for flood protection but vulnerable in drought periods. Precipitation changes were dominant in flood and drought management, and temperature and wind speed change effects were significant during drought. Results demonstrated the framework's effectiveness to quantify detrimental climate change effects, provide long-term guides for operational planning, and identify the upper limit of application time of the adaptation strategies in the system to avert the climate change impact. Framework application suggests an optimal adaptation strategy, robustness examination of the presuggested plans, and identification of the maximum allowable time for the robust plans. [ABSTRACT FROM AUTHOR]

Heritage buildings are considered unique assets with a significant value for the country where they are situated that must be conserved or preserved for the coming generations. However, heritage sites, as any other site where a construction is present, experience tremendous risks that impact both the condition and the withstanding of the building or asset they include. Therefore, a risk management framework is essential for these sites and buildings, in particular to be able to decide how to respond and act upon foreseeable risks when they occur or even before experiencing them. This study starts with investigating the most dominant risks in the heritage buildings context with a focus on Yemeni sites, and consequently 38 Yemeni experts in the field of heritage building management were surveyed to examine the identified risks in three case study heritage sites in Yemen. The significance of the risks as well as their impact, likelihood, and detectability levels were measured using an analytic hierarchy process (AHP) basis that reduces the subjectivity of the expert opinions. After risks were analyzed, a suitable response action was therefore suggested to manage and minimize risk impacts as much as possible. In addition to the relative scoring for the priority of each identified risk, an overall risk proneness metric is presented in this paper that can be used to compare the vulnerability of different heritage buildings and/or sites for a strategic efficient budget allocation for the management and preservation of those areas. The preliminary results revealed that armed conflicts, climate change, and flooding are three of the most critical risk factors in Yemeni heritage buildings. This framework is expected to aid heritage building managers in identifying the correct course of actions to prevent or mitigate risks from disturbing the heritage sites and help preserve their value and significance. [ABSTRACT FROM AUTHOR]

This paper presents a practical approach to adaptive management of dam risk based on robust decision-making strategies coupled with estimation of climate scenario probabilities. The proposed methodology, called multi-prior weighted scenarios ranking, consists of a series of steps from risk estimation for current and future situations through definition of the consensus sequence of risk reduction measures to be implemented. This represents a supporting tool for dam owners and safety practitioners in making decisions for managing dams or prioritizing long-term investments using a cost-benefit approach. This methodology is applied to the case study of a Spanish dam under the effects of climate change. Several risk reduction measures are proposed and their impacts are analyzed. The application of the methodology allows for identifying the optimal sequence of implementation measures that overcomes uncertainty from the diversity of available climate scenarios by prioritizing measures that reduce future accumulated risks at lower costs. This work proves that such a methodology helps address uncertainty that arises from multiple climate scenarios while adopting a cost-benefit approach that optimizes economic resources in dam risk management. [ABSTRACT FROM AUTHOR]

Adaptation to climate change requires careful evaluation of infrastructure performance under future climatic extremes. This study demonstrates how a multidisciplinary approach integrating geotechnical engineering, hydrology, and climate science can be employed to quantify site-specific impacts of climate change on geotechnical infrastructure. Specifically, this paper quantifies the effects of changes in future streamflow on the performance of an earthen levee in Sacramento, California, considering multiple modes of failure. The streamflows for historical (1950–2000) and projected (2049–2099) scenarios with different recurrence intervals were derived from routed hydrological simulations driven by bias-corrected global climate models. The historical and future flood levels were then applied in a set of transient coupled finite-element seepage and limit equilibrium slope stability analyses to simulate the levee subjected to extreme streamflow. Variability in hydraulic and mechanical properties of soils was addressed using a Monte Carlo sampling method to evaluate and compare the probability of failure of the levee under different historical and future climate scenarios. Three individual modes (underseepage, uplift, and slope stability) along with lower and upper bounds for the combined mode of failure were examined. The results showed that incorporating future floods into levee failure analysis led to considerable reductions in the mean factor of safety and increases in the levee's probability of failure, suggesting that risk assessment based on historical records can significantly underestimate the levee's failure probability in a warming climate. Despite inherent uncertainties in future projections and substantial variability across climate models, evaluating infrastructure against projected extremes offers insights into their likely performance for the future. [ABSTRACT FROM AUTHOR]

Motivated by the emerging need for long-term and sustainable reservoir management, this paper developed a multicriteria decision-making (MCDM) model of reservoir operation with consideration of balanced applicability in both the past and the future. The proposed method consists of four modules: (1) the multiobjective optimization model of reservoir operation is built based on historical streamflow and then solved by the evolutionary multiobjective direct policy search (EMOPDS) with the nondominated sorting genetic algorithm-II (NSGA-II); (2) an evaluation criteria matrix is made considering the benefits and risks of the same objectives under future climate change; (3) objective interrelationships are qualitatively identified by visual analytics and quantitatively described by the structural equation model (SEM); and (4) an objective-based space coordinate system (SCS) is established to calculate the evaluation criteria weights based on SEM results, from which the optimum Pareto solution is determined by a decision-making function. The Three Gorges Reservoir (TGR) was selected as a case study, which simultaneously provides hydropower generation (pow), ecology (eco), and water storage (stor). Results indicate that eco negatively interacts with both pow and stor; however, pow is positively correlated with stor. Moreover, the design of the SCS-MCDM model can significantly improve benefits in both pow and stor and slightly sacrifice benefit in eco, compared with fuzzy optimum selection (FOS)-1 and FOS-2. Generally, the SCS-MCDM model outperforms FOS-1 and FOS-2 in terms of benefits for past and future and robustness in operation process under climate change. Therefore, the SCS-MCDM model facilitates decision makers to make a sustainable and balanced decision for reservoir management under uncertain climate change. [ABSTRACT FROM AUTHOR]

Green building (GB) is gaining increased acceptance in the construction industry as a viable solution for meeting the growing demand for environmentally friendly or healthy buildings. However, the uptake of GB technologies is not as apparent as it should have been. This paper aims to examine the criticality of various barriers preventing the wider adoption of GB technologies. Results from statistical analyses of 104 questionnaire survey responses from GB experts around the world are presented. The results validated the criticality of 19 of the 26 barriers used for the survey. Respondents from different countries and with diverse backgrounds displayed broad consensus on the criticality levels of the barriers. Resistance of stakeholders to change and higher cost are identified as the most critical barriers to implementing GB technologies. Generally, the various groups of respondents shared similar views on the number of barriers affecting the industry; however, respondents with more than 15 years of experience in GB perceived fewer barriers. The factor analysis showed that the barriers to GB technologies adoption could be grouped into five main interrelated components, which suggest the need for holistic and integrated strategies to overcome the barriers. The findings of this paper could help policy makers identify specific problems in GB technologies adoption and develop suitable strategies for their wider uptake. From the perspective of international experts, this study contributes to the body of knowledge about GB barriers. [ABSTRACT FROM AUTHOR]

Climate change has a different impact on each member of society. To reduce the damage caused by climate change, adaptation activities are being initiated, such as expanding the capacity of social infrastructures, and each stakeholder wants these adaptations to work in his or her favor. Therefore, a methodology is needed to determine adaptation measures that are most beneficial to all members of society. In this paper, a framework is proposed for producing an adaptation strategy that minimizes conflict between stakeholders. This framework casts the process of organizing climate change adaptations as a game and defines each community member as a stakeholder, each adaptation measure as a strategy, and the minimization of loss from future climate change as a payoff. In a case study involving sea level rise in Suncheon Bay, Korea, this framework is used to generate an optimal plan for minimizing conflicts while considering the losses of the central government, local governments, and local communities. The game theoretic results from the proposed framework enable a balanced distribution of responsibilities among stakeholders to achieve infrastructure adaptation to climate change. [ABSTRACT FROM AUTHOR]

Ongoing changes in global climate are expected to alter the hydrologic regime of many river basins worldwide, expanding historically observed variability as well as increasing the frequency and intensity of extreme events. Understanding the vulnerabilities of water systems under such uncertain and variable hydrologic conditions is key to supporting strategic planning and design adaptation options. In this paper, we contribute a multiobjective assessment of the impacts of hydrologic uncertainty on the operations of multipurpose water reservoirs systems in arid climates. We focus our analysis on the Dez and Karoun river system in Iran, which is responsible for the production of more than 20% of the total hydropower generation of the country. A system of dams controls most of the water flowing to the lower part of the basin, where irrigation and domestic supply are strategic objectives, along with flood protection. We first design the optimal operations of the system using observed inflows and evaporation rates. Then, we simulate the resulting solutions over different ensembles of stochastic hydrology to partition the impacts of streamflow and evaporation uncertainty. Numerical results show that system operations are extremely sensitive to alterations of both uncertainty sources. In particular, we show that in this arid river basin, long-term objectives are mainly vulnerable to inflow uncertainty, whereas evaporation rate uncertainty mostly affects short-term objectives. Our results suggest that local water authorities should properly characterize hydrologic uncertainty in the design of future operations of the expanded network of reservoirs, possibly also investing in the improvement of the existing monitoring network to obtain more reliable data for modeling streamflow and evaporation processes. [ABSTRACT FROM AUTHOR]

Technological advances in forecasting the Earth's climate offer a potentially useful tool to support planning and management decisions in water resources. Previous research has found that the implementation of new ideas and practices are impeded by many challenges such as low forecast skill, institutional obstacles, and political disincentives to innovation. To better understand barriers to forecast use at seasonal-to-interannual, decadal, or longer time scales, this paper evaluates a diffusion of innovations (Do!) framework to assess the adoption of hydroclimatic forecasts by water managers in the Northeast United States. Specifically, this paper seeks to understand how five innovation characteristics, relative advantage, compatibility, complexity, trialability, and observability, influence the rate of adoption. Methods used for this analysis include the distribution of a survey, interviews, and a literature review. Results indicated that while much attention has focused on institutional obstacles, in the Connecticut River Basin obstacles were related to characteristics of the forecasts themselves. Evaluation of the DoI makes clear that the challenges to forecast use are common to all innovations. [ABSTRACT FROM AUTHOR]

Irrigation is the major user of total water use in most of the tropical countries located in Southeast Asia. Therefore, knowledge on future changes in irrigation demand in the context of climate change is very important for long-term planning and management of water resources of the region. This paper investigated the changes in irrigation water demand in an intensive irrigated area of Malaysia under climate change scenario. Global circulation models (GCMs) outputs are downscaled using statistical downscaling model (SDSM) to project the future changes in rainfall and temperature at local scale. The irrigation water demand estimation model known as CROPWAT is calibrated and validated with historical data and then used to project the future changes in irrigation demand under SDSM projected climatic condition. The results show that temperature and rainfall in the area will increase by 0.2° C and 4% per decade, respectively over the time period 2020-2099. The changes in climate will reduce irrigation water demand at a rate of 0.9% per decade in the area. However, the irrigation demand will be much more variable in future, and therefore, the major challenge in water resources management will be to handle the uncertainty. It is expected that the seasonal and annual variations in irrigation demand projected by the study will help in operating reservoirs and sustainable management of water resources in the region in the context of climate change. [ABSTRACT FROM AUTHOR]

This paper focuses on the development of simplified mathematical models of the cryosphere which may be useful in further understanding possible global climate change impacts and in further assessing future impacts captured by global circulation models (GCMs). The mathematical models developed by leveraging the dominating effects of freezing and thawing within the cryosphere to simplify the relevant heat transport equations are tractable to direct solution or numerical modeling. In this paper, the heat forcing function is assumed to be a linear transformation of temperature (assumed to be represented by proxy realizations). The output from the governing mathematical model is total ice volume of the cryosphere. The basic mathematical model provides information as a systems modeling approach that includes sufficient detail to explain ice volume given the estimation of the heat forcing function. A comparison between modeling results in the estimation of ice volume versus ice volume estimates developed from use of proxy data are shown in the demonstration problems presented. [ABSTRACT FROM AUTHOR]

With the advent of climate change, it is thought that desiccation cracking of soil will lead to increases in damage to buried infrastructure. Desiccation cracking is a complex phenomenon that historically has been very difficult to model either numerically or analytically. Therefore, there is a need for knowledge on such models to be advanced rapidly. This paper discusses the introduction of cohesive cracks to model fracture attributable to desiccation. The cohesive crack method does not have the limitations of linear elastic fracture mechanics, namely, that an initial notch must be present and that the bulk material must behave in a linear elastic manner. This paper describes how the cohesive crack method has been successfully used to model laboratory desiccation tests of a clay soil. It is shown that, in addition to the tensile strength, the magnitude of fracture energy specified for the material has an impact on crack propagation. The cohesive crack method is proposed as a tool for the numerical modeling of desiccation cracking in many diverse fields. [ABSTRACT FROM AUTHOR]

Although many recent studies have quantified the potential effects of climate change on water resource systems, the scientific community faces now the challenge of developing methods for assessing and selecting climate change adaptation options. This paper presents a method for assessing impacts and adaptation strategies to global change in a river basin system at different temporal horizons using a hydroeconomic model. First, a multiobjective analysis selects climate change projections based on the fitting of the climate models to the historical conditions for the historical period. Inflows for climate change scenarios are generated using calibrated rainfall-runoff models, perturbing observed meteorological time series according to the projected anomalies in mean and standard deviation. Demands are projected for the different scenarios and characterized using economic demand curves. With the new water resource and demand scenarios, the impact of global change on system performance is assessed using a hydro-economic model with reliability and economic indices. A new economic loss index is defined to assess the economic equity of the system. Selected adaptation strategies are simulated to compare performance with the business-as-usual scenario. The approach is applied to the Jucar River water resource system, in eastern Spain, using climate projections from the European Union (EU) ENSEMBLES project. Results show that the system is vulnerable to global change, especially over the long term, and that adaptation actions can save €3-65 million=year. [ABSTRACT FROM AUTHOR]

Severe hurricanes in coastal areas have caused enormous human and economic losses. Furthermore, the intensity and frequency of future hurricanes may increase due to the potential impact of climate change. Due to common underlying climatological causes, interrelations may exist between successive hurricane events. This paper proposes a novel approach for modeling the temporal correlation in hurricane frequency and develops an analytical method that reflects this correlation to estimate the statistical properties of cumulative hurricane damage. The method provides a closed-form solution to the mean and variance of hurricane damage, and can be used to assess the impacts of temporal correlation and nonstationarity in hurricane events quantitatively. The applicability of the method is demonstrated through a case study of Miami-Dade County, Florida, in which it is found that the nonstationarity in hurricane events increases the mean value of hurricane damage over a future period of 100 years, while the temporal correlation increases its variance. [ABSTRACT FROM AUTHOR]

Global warming and climate change have increased the frequency of heavy precipitation. Heavy rainfall results in a large amount of water entering roadways within a short time period. Water remains in the pavement system for a certain time period, reduces strengths and moduli of granular bases and subgrades, and induces pavement distresses. Geotextiles are commonly used in roadways for drainage purposes, which require soil saturation. However, soil saturation does not always exist in roadways to enable gravity drainage of water by conventional geotextiles. Wicking geotextile, a new type of woven geotextile, was recently introduced to the market to remove moisture from unsaturated soils. The wicking geotextile includes special hydrophilic and hygroscopic 4 deep groove fibers with multichannel cross sections, which can induce high capillary force to wick water out of moist soil without saturation of soil. The ability and rate of this geotextile to remove water from moist soil depends on several factors, including temperature and relative humidity. In this study, a series of laboratory tests under controlled temperature and relative humidity were conducted to quantify the water removal rate of the wicking geotextile. A half length of the wicking geotextile was submerged in water tanks, and the other half was hung outside of the tanks. The water wicked from the tank into the geotextile evaporated into the air. Such tests were conducted under 12 different test conditions (i.e., different temperatures and relative humidities). Test results demonstrated that the wicking geotextile could remove water from the water tank at a certain rate. Three commonly used methods available in the literature were adopted to quantify the water removal rate of the wicking geotextile based on vapor pressure, temperature, and relative humidity. A new concept of equivalent water evaporation length of a wicking geotextile is proposed in this study. It should be pointed out that the tests presented in this paper aimed to determine the maximum water removal capacity of the geotextile given sufficient water supply. [ABSTRACT FROM AUTHOR]

The most comprehensive tools for producing climatic scenarios and consequently hydrological predictions are atmospheric-ocean general circulation models (AOGCMs). This paper evaluates the performance of those models. Possible scenarios of temperature and rainfall in the base period (1971-2000) for the Aidoghmoush basin located in East Azerbaijan are estimated with seven AOGCMs. A hydrological model is first calibrated for the basin and then monthly time series of temperature and rainfall resulting from AOGCMs in the base period are input to the hydrological model. The mean observed runoff (MOR) weighting method is employed to assess the effectiveness of each climate model to produce runoff. An appropriate probability distribution is chosen and relevant statistical parameters extracted and compared with observed runoff statistical parameters. Results show that the hybrid and Hadley Centre Coupled Model, version 3 (HadCM3) models with respective correlation coefficients of 97% [root mean square error (RMSE) = 2.09 m3/s, mean absolute error (MAE) =1.51 m3/s, and Nash Sutcliffe efficiency (NSE) = 0.89] for the hybrid model and 90% (RMSE = 3.22 m3/s, MAE = 2.58 m3/s, and NSE = 0.87) for the HadCM3 model can best simulate runoff. Comparison of the results of the probability distributions and the transition probability matrix from the AOGCM models with observed runoff shows that the hybrid and HadCM3 models with respective correlation coefficients of 91% (RMSE = 0.07 m3/s, MAE = 0.004 m3/s, and NSE = 0.80) and 86% (RMSE = 0.14 m3/s, MAE = 0.04 m3/s, and NSE = 0.78) yield reliable outputs. [ABSTRACT FROM AUTHOR]

Nexus thinking is critical to jointly address growing water, energy, and food security challenges. This paper evaluates the water, energy, and food nexus (WEFN) in the Indus River of Pakistan using the Indus Basin Model Revised—Multi Year, a hydro-agro-economic model extended with an agricultural energy use module. Impacts of a range of climate change scenarios on the WEFN in the Indus Basin were modeled and then the potential of different alternative water allocation mechanisms and water infrastructure developments to address growing water, energy and food security concerns in the country were assessed. Results show growing water and energy use under hotter and wetter climate conditions. While more flexible surface water allocation policies can mitigate negative climate change impacts on agricultural water and energy use allowing for larger crop and hydropower production, such policies might also increase the inter-annual variability of resource use. Moreover, a more flexible surface water allocation policy would increase surface water use in the basin, while groundwater and energy use would be lower. Study results can inform the WEFN in areas with similar hydro-climatic environments, such as California and Central Asia. Further integration of a groundwater model and an energy market model and explicitly addressing changes in food and energy demand as a result of demographic dynamics are three areas for future study. [ABSTRACT FROM AUTHOR]

Climate change and an increase in the number of hazards and/or their intensities may increase the probability of failure associated with civil infrastructure systems. Understanding how natural hazards affect the life-cycle performance of highway bridges can lead to improved preparedness prior to extreme disasters and can ultimately benefit society. In this paper, a framework for time-variant loss and resilience assessment of highway bridges under time-dependent multiple hazards is presented. The effects of earthquakes and floods on bridges are both investigated. The life-cycle hazard losses with and without aging effects and climate change are computed. Additionally, the probabilistic changes in the hazard intensity and frequency resulting from climate change on the total life-cycle hazard loss are also investigated. The proposed framework is applied to a highway bridge located in California. [ABSTRACT FROM AUTHOR]

This paper evaluates two established decision-making methods and analyzes their performance and suitability within a water resources management (WRM) problem. The methods under assessment are info-gap (IG) decision theory and robust optimization (RO). The methods have been selected primarily to investigate a contrasting local versus global method of assessing water system robustness to deep uncertainty, but also to compare a robustness model approach (IG) with a robustness algorithm approach (RO), whereby the former selects and analyzes a set of prespecified strategies and the latter uses optimization algorithms to automatically generate and evaluate solutions. The study presents a novel area-based method for IG robustness modeling and assesses the applicability of utilizing the future flows climate change projections in scenario generation for water resource adaptation planning. The methods were applied to a case study resembling the Sussex North Water Resource Zone in England, assessing their applicability at improving a risk-based WRM problem and highlighting the strengths and weaknesses of each method at selecting suitable adaptation strategies under climate change and future demand uncertainties. Pareto sets of robustness to cost are produced for both methods and highlight RO as producing the lower cost strategies for the full range of varying target robustness levels. IG produced the more expensive Pareto strategies due to its more selective and stringent robustness analysis, resulting from the more complex scenario ordering process. [ABSTRACT FROM AUTHOR]

This paper analyzes long-term trends and sudden changes in hydro-climatic variables (i.e., runoff) in Iran's Aidoghmoush basin during 1971-2000 using the nonparametric Mann-Kendall test and curves of cumulative runoff versus rainfall and cumulative runoff versus temperature The use of the Mann-Kendall test with a 99% confidence level revealed a decreasing trend in annual rainfall and total runoff and an increasing trend in temperature. A sudden change in the gradient of the cumulative curves in 1988 indicated that the relation between climatic variables and runoff is influenced by human activities (agricultural water use). The interval 1971-2000 was separated into a baseline interval (1971-1988) and an impact interval (1989-2000), during which human activities affected runoff. The five-parameter hydrologic model of IHACRES (Identification of unit Hydrographs and Component flows from Rainfall, Evaporation, and Streamflow data) was calibrated and verified over the baseline interval to determine the contribution of human activities and climatic variability to the change in runoff. Runoff was simulated with the hydrologic model for the interval 1989-2000, during which human activities reduced runoff. Results show that climate variability and human activities decreased the runoff in the Aidoghmoush river basin by 79 and 21%, respectively. [ABSTRACT FROM AUTHOR]

Considerable research has been carried out on the optimization of water distribution systems (WDSs) over the last three decades. In previous research, attention has mainly focused on the minimization of cost, due to the high expenditure associated with the construction and maintenance of such systems. However, the impacts of WDSs on the environment usually have not been considered adequately. The recent increasing awareness of sustainability and climate change, especially global warming, has led to research where greenhouse gas (GHG) emissions are considered. In the study described in this paper a multiobjective genetic algorithm for WDS optimization has been used as an explorative tool to investigate the trade-offs between the traditional economic objective of minimizing costs and an additional environmental objective of minimizing GHG emissions. The impacts of minimizing GHG emissions on the results of WDS optimization have been explored for a case study in this paper. The results indicate that the inclusion of GHG emission minimization as one of the objectives results in significant trade-offs between the economic and environmental objectives. Furthermore, a sensitivity analysis has been conducted by using different discount rates in a present value analysis for computing both ongoing costs and GHG emissions. The results obtained show that the Pareto-optimal front is very sensitive to the discount rates used. As a result, the selection of discount rates has a significant impact on final decision making. [ABSTRACT FROM AUTHOR]

This paper presents a comparative evaluation of methods for climate-based estimation of the net inflow rate into Lake Okeechobee, Fla. The estimated net inflow rate is used by the South Florida Water Management District (SFWMD) to support the management and operations of the Lake Okeechobee hydrologic system. The first method evaluated in this paper (Croley) uses rainfall outlooks provided by the National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC) to calculate a weighed average of historical inflow values for each month. The second method evaluated in this paper (SFWMD Empirical) uses a linear regression on statistics of historical data to predict the net inflow rate. These two methods were developed and have been used operationally by the SFWMD since 2000. Three new methods are presented and comparatively evaluated to gauge their ability in estimating net inflow rates. The first two of these methods are based on CPC issued forecasts in decile probability density format. The remaining method is based on a subsampling technique for “peer” wet/dry years in the historical record and is found to yield better results in a retrospective analysis. For extreme climatic events on the historical record, CPC rainfall outlooks are found not to yield a large enough shift in probabilities for forecasts to match observed net inflow rates; this is especially noticeable during El Niño Southern Oscillation events. Recommendations are made for potential improvements to climate-based net inflow rate estimation methods, particularly in regard to their ability to reproduce observed results for net inflow into Lake Okeechobee in the presence of an extreme climatic event, as well as over an extended climatological period. [ABSTRACT FROM AUTHOR]

Harvested stormwater is now being considered as an alternative water source in a number of cities because of concerns over water scarcity and population growth. However, the availability of this source varies as a result seasonality and climate change. This paper introduces an approach for optimizing the design of a stormwater harvesting scheme including aquifer storage and recovery that explicitly takes into account future climate change and its impact on the optimal design of the scheme. The proposed approach also accounts for the externalities associated with the use of harvested stormwater. The approach is applied to a specific case study in South Australia, considering four possible climate scenarios for planning horizons of 2030 and 2050 and the additional benefits of reducing withdrawals from the river source and the salinity of the water supplied. Results show that climate change will reduce the yield and the net present value (NPV) of the optimal stormwater scheme. They also indicate that there is a trade-off between the average NPV and the variation of the NPV across the different climate scenarios: smaller basins and a smaller wetland are selected to maximize the average NPV, while, to minimize the range of the NPV values, larger harvesting basins and smaller wetlands are implemented. For the case study, the externalities considered have a small impact on the overall cost-effectiveness of the solutions. [ABSTRACT FROM AUTHOR]

Harvested stormwater is now being considered as an alternative water source in a number of cities because of concerns over water scarcity and population growth. However, the availability of this source varies as a result seasonality and climate change. This paper introduces an approach for optimizing the design of a stormwater harvesting scheme including aquifer storage and recovery that explicitly takes into account future climate change and its impact on the optimal design of the scheme. The proposed approach also accounts for the externalities associated with the use of harvested stormwater. The approach is applied to a specific case study in South Australia, considering four possible climate scenarios for planning horizons of 2030 and 2050 and the additional benefits of reducing withdrawals from the river source and the salinity of the water supplied. Results show that climate change will reduce the yield and the net present value (NPV) of the optimal stormwater scheme. They also indicate that there is a trade-off between the average NPV and the variation of the NPV across the different climate scenarios: smaller basins and a smaller wetland are selected to maximize the average NPV, while, to minimize the range of the NPV values, larger harvesting basins and smaller wetlands are implemented. For the case study, the externalities considered have a small impact on the overall cost-effectiveness of the solutions. [ABSTRACT FROM AUTHOR]

Hydroelectric power systems are largely characterized by variability and uncertainty in water resource obligations. Market volatility and the growing number of operational obligations for flood control, navigation, environmental obligations, and ancillary services (including load-balancing requirements for renewable resources) further the need to quantify sources of uncertainty. The variations caused by these factors require the hydropower system to have enough upward and downward flexibility for control technologies, such as dynamic optimal control load-following, unit commitment, or automatic generation, to be effective. Therefore, it is increasingly important to identify measures of operational flexibility to better manage uncertainty and operational obligations. The objective of this paper is to present and discuss approaches for assessment of operational flexibility as a function of dynamic states and control input and how the available operational flexibility can be used by hydropower producers in a comprehensive optimization reformulation to accommodate business procedures to drive the system in an efficient, safe, and interpretable way. The authors consider simple metrics such as power capability and its derivatives as indicators for upward flexibility and effective energy storage capability for downward flexibility. Test results based on the Federal Columbia River power system (FCRPS), managed by the Bonneville Power Administration, Army Corps of Engineers, and Bureau of Reclamation, are presented and demonstrate how operational flexibility can be assessed and that role it plays in short-term operations. [ABSTRACT FROM AUTHOR]

The potential impact of climate change on the existing drainage infrastructure has been an essential aspect of many hydrological studies. Climate change that will increase the intensity of precipitation will also increase the magnitude of the design discharge and thus would probably result in adverse effects on the existing drainage facilities. This paper aims to evaluate the potential impact of rainfall intensity variation due to climate change on the existing drainage infrastructure by investigating whether (1) the stormwater drainage infrastructure designed for preclimate conditions is able to sustain future higher discharges, and (2) new design guidelines are necessary to be established to include the potential rainfall intensity variation due to climate change. A case study was conducted using 34 years of rainfall data (1980-2013) obtained from the National Climatic Data Center (NCDC). These data and the weather scenario data projected by the four run global circulation model (GCMs) under the three emissions scenarios coupled with stochastic weather generator model which generates dailyweather time series statisticallywere used to update the current intensity-duration-frequency curve to reflect the rainfall intensity variation due to climate change. Furthermore, runoff simulation using a storm and sanitary software program was performed to analyze whether the increase in the intensity of rainfall due to climate changewould have an adverse impact on the current drainage systemto convey excess runoff. The results showed thatmost elements of the current drainage infrastructure in the boundary of the study areawere inadequate to convey excess runoff. However, climate change magnifies the problems that already exist in an aging drainage infrastructure. Furthermore, considering the rehabilitation or replacement rates of these aging infrastructures are relatively slow, emphasismust not lie only on the future climate change, but also on identifying the weak spots in the system coupled with, the economic and environmental factors before any changes in design criteria can be recommended due to climate change. [ABSTRACT FROM AUTHOR]

While the authors of current bridge management systems (BMSs) have noted the need for expanding the systems to include more functional aspects of bridge performance, to date no method has been proposed for the incorporation of bridge rating against climate change impacts. This paper presents a new procedure for extending the asset management scope for highway bridges to incorporate the bridges' resilience or vulnerability against climate change impacts. The proposed procedure draws from the projected demands of climate change--a worldwide phenomenon that is expected to produce its most dramatic impacts in cold regions. The following bridge resilience indicators are proposed: abutment washout, pier scour, abutment erosion, deck flooding, and abutment permafrost stability. The formulations for the proposed indicators require weights to be assigned to each indicator. The other requirement comprises capacity measures that indicate how well a bridge is equipped to withstand the projected climatic effects. The new procedure has been applied to 14 highway bridges in the Canadian Arctic to demonstrate how public investments in transportation infrastructure could be better managed and protected. The method comes with an Inspection Form that transportation agencies and their bridge inspectors can use for rating bridges on climate change resilience. [ABSTRACT FROM AUTHOR]

Future projection of air temperature and precipitation due to climate change plays an important role in shaping the water resources management plans in arid and semi-arid countries such as the United Arab Emirates (UAE). The effect of local topography, land use, and sealand contrasts are generally dwarfed in the coarse global circulation models [ocean atmosphere global climate models (OAGCMs)] results. Statistical downscaling (SD) is a statistical tool relating OAGCM outputs (predictors) to finer local observed weather data (predictands) to improve future predictions. SD is used in this study to downscale the Hadley Model (HadCM3) predictors using local observations at two stations representing the dominating bioclimatic zones in the UAE. The paper proposes a rigorous and systematic methodology to guide the selection of dominant predictors in the projection scenarios. The proposed methodology is applied for the UAE but can be easily adopted for any other area. The calibrated model, used to project future scenarios in the region, revealed a range of increase of the annual mean maximum temperature of 2.79-3.80°C and a range of reduction of annual precipitation of 16.80-37.00% by 2080 at the considered stations. Impacts of climate change on the UAE's water resources management are discussed in light of the downscaled estimates for temperature and precipitation. Because a major portion of the water resources is devoted to agriculture, temperature impacts are quite significant. However, the impacts of precipitation are hardly detectable at the national scale. Instead, the impacts of reduced precipitation will be of more localized significance in mountainous regions that are critically dependent on precipitation for water resources. [ABSTRACT FROM AUTHOR]

Concurrent incidence of heavy rainfall events and coastal storm surges can cause damages of exponential proportion to the coastal habitants and infrastructures. Super Storm Sandy and hurricane Irene were wake up calls that the floodplains and evacuation zones in New York City need major revision. Federal and State emergency agencies have been working on revising the appropriate maps and spatial tools for planning and management purposes. This paper presents an integrated scheme for floodplain delineation in coastal areas, considering the combined effect of inland and coastal flooding. The proposed scheme is applied to the Bronx River watershed in the Bronx section of New York City. Consideration of inland and coastal flooding is provided by developing a conceptual rainfall-runoff model and a sea level simulation model. Climate change has intensified the intensity and frequency of extreme rainfall events and storm surges in the region. In order to evaluate climate change impacts on floodplain, projections from two GCMs (General Circulation Models) for A1B (balanced) and A2 (medium-high emissions) climate change scenarios are used. Change factor methodology is employed to downscale the GCMs' outputs. Flooding scenarios are defined based on the frequency analysis of the projected runoff and water level for different recurrence intervals. This is a key issue in planning and management of coastal region considering different levels of acceptable risk. Inundation maps of the coastal floodplain are created for each flooding scenario using a geographic information system (GIS) platform. Result shows that long-term average of runoff and water level in the region in a 30-year period will be increased by 42% and 0.46 m respectively. The study finds that the effect of sea level rises on floodplain extent is greater than changes in runoff. In order to plan for effective flood risk management strategies in urban areas, the spatial analysis and mapping of flood inundation should be implemented. This study emphasizes the importance of updating the delineation of coastal floodplains as a part of planning and management of land use zoning and future developments in coastal regions. [ABSTRACT FROM AUTHOR]

Human-induced climate change caused by greenhouse gas (GHG) emissions has become a significant concern. Although water distribution systems (WDSs) provide an essential service, they also contribute to the release of GHG emissions through the use of electricity from fossil fuel sources for pumping purposes. In this paper, the reduction of both costs and GHG emissions associated with the pumping operation of WDSs is considered. Actual (time-varying) emissions factors (EFs) for the South Australia electricity grid from February 2011 to January 2012 with a 5-min time step are used to evaluate pumping operational GHG emissions and are compared with the use of an average EF, which does not consider the time dependency of EFs. An estimated (typical) 24-h EF curve, which aims to replicate the important aspects of the time dependency of actual EFs, is developed and compared for use in place of actual EFs, for when the actual variations in EFs cannot be accurately predicted for the future. Additionally, modified estimated 24-h EF curves, representing different amounts of renewable energy (wind generation) penetration, are considered to test the sensitivity of solution development to the magnitude of the variations of timedependent EFs. Through the multiobjective optimization of pumping operations of a case study WDS, it is shown that solutions found using actual EFs can minimize GHG emissions by moving pumping to low-EF times of the day. Conversely, solutions found using an average EF can only minimize GHG emissions by pumping more consistently during the day. Additionally, solutions found using the estimated 24-h EF curve are very similar to those found using the actual EFs, suggesting that the estimated 24-h EF curve can accurately replicate the important characteristics of the time dependency of EFs and can be used in place of actual EFs to find solutions of reduced pumping operational costs and GHG emissions. Furthermore, solutions found using the modified estimated 24-h EF curves show that the development of solutions is dependent on the magnitude of the variations of time-dependent EFs. [ABSTRACT FROM AUTHOR]

It is well known that crop coefficients are not necessarily transferrable from one location to another, for a variety of reasons. For example, the United Nations Food and Agricultural Organization (UN FAO) 24 publication on evapotranspiration listed ranges of midseason crop coefficients for particular crops, depending on wind speed and humidity. In the more recent UN FAO 56 publication, an equation was presented that adjusted crop coefficients for wind speed, humidity, and crop height. Climate correction is important for sharing and adjusting crop coefficient data. However, it was found that the FAO 56 equation gave inaccurate corrections for a crop having the same characteristics as the reference crop surface, and it is likely that it also will be inaccurate for other crop surfaces. Consequently, the aim of this research was to develop and test a new method to correct midseason crop coefficients for climate differences. Climate data were used from the California Irrigation Management Information System and a similar approach was used to develop standardized reference evapotranspiration equations for short and tall canopies, to develop and test the new method. The method estimates the aerodynamic resistance of crops in a base climate as an inverse function of wind speed. This function of wind speed was used in a modified Penman-Monteith equation to account for climate effects on midseason crop coefficients in nonbase climates. The methodology to account for climate data and estimate midseason crop coefficient values in a nonbase climate from base climate crop coefficients is presented in this paper. [ABSTRACT FROM AUTHOR]

Managing urban storm water is challenging under the best of situations, and due to projected increases in intensity of rainfall events, is exacerbated by climate change. Institutional and individual aspects of urban storm water management and the implications for low-impact development (LID) are presented. The paper frames storm water as a public good provision issue in order to build on existing knowledge about that kind of social dilemma. This topic is then examined in more detail through stakeholder interviews conducted in Somerville, Massachusetts, United States. Interviews were completed at a variety of management levels, from household to regional planning level, and are related back to the theory of public good provision. Finally, synthesis of theory and practice results in specific recommendations for urban storm water management, based on revising the storm water institutional framework, showcasing redevelopment opportunities, and facilitating education and awareness through local NGOs. [ABSTRACT FROM AUTHOR]

The extreme phenomena induced by climate change have generated new interest in analyses of wave runup on beaches. Extreme runup quantification is essential for coastal management and protection against coastal flooding. Several formulations deduced from empirical studies are available for runup estimation, although scattering is high when applied to practical cases. This paper presents the results of a physical model experiment carried out in the Laboratory for Maritime Experimentation at CEDEX on three sand bed beaches with uniform slopes of , , and . The performance of each formulation is discussed with the aim of choosing the best formulations available for coastal engineering. A new formulation is proposed that accounts for beach slope. Choosing the most extreme beach profile prior to a storm reaching the shore in this formulation provides the required model for risk analysis. [ABSTRACT FROM AUTHOR]

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. [ABSTRACT FROM AUTHOR]

Climate projections in many U.S. metropolitan areas show increases in daily temperature, and potential shifts in rainfall patterns toward stronger, more intense storms. At the same time, metropolitan regions continuing to experience population growth face the prospect of areal expansion and higher land-use intensities. The possible coupling of such developmental changes and more frequent intense precipitation events poses a litany of well-known challenges to storm-water management. This paper reports survey research that examines the experiences and expectations of engineers, planners, and other agency staff in storm-water management in the Washington-Baltimore metropolitan region in the context of climate change. We find that staff from jurisdictions with a high degree of development and strong population growth, and those with more work experience, engagement with climate issues in their work, and greater belief that scientists understand climate change, exhibit a higher level of concern with the potential threat of climate change on storm water runoff. [ABSTRACT FROM AUTHOR]