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This paper uses a participatory approach to assess the level of understanding of the Water-Energy-Climate Change (WECC) nexus in South Africa. The aim is to initiate the development of well-coordinated, systematic, and holistic strategies to promote efficient management of the WECC and its implications in the country. The assessment follows the learnings from the Integrated Water Resource Management framework, which promotes a participatory approach in the administration of water resources. The paper reveals that, despite the reasonable level of understanding of WECC, it is still insufficient to promote an integrated approach mainly in policy development and planning for water and energy resources while averting climate impacts. This is exacerbated by limited coordination and consultation among various stakeholders. However, minimal efforts to promote an integrated approach in the management of the WECC sectors is observed. Despite these developments, the paper proposes that the participatory approach is feasible to promote holistic strategies and collaboration among stakeholders mandated to manage WECC sectors. Until approaches such as this are adopted within the institutional framework, this nexus will continue to impede the country's sustainable development endeavours. [ABSTRACT FROM AUTHOR]

A water crisis is an alarming issue in Balochistan. The persistent crises lead towards catastrophic future condition. Water is essential for human livelihood and other types of economic developments. A province that is situated in an arid zone where due to low rainfall is scarcity of water. The qualitative research methodology will be applied on this research paper. The data collection will take place through secondary sources i.e. books, magazines, journals and internet websites etc. The major causes for water crisis are shortage of rainfall, climate change, misuse of water, over-urbanization, global warming, non-availability of sufficient dams in Balochistan. There are severe implications and repercussions of water crisis in Balochistan. It leads towards agricultural crisis, loss of biodiversity, migration, drought condition, poor quality life and low income etc. There is a need to adopt a proper strategy that how to overcome the water crisis in Balochistan. The construction of dams, the public awareness, the re-cycling of water, aqueducts, desalination of water, improvement in sewerage system, rain water harvesting can enable us to overcome the water crisis. The sustainable water management approach will be applied to treat reuse and to control the wastage of water. The research will be conducted by keeping in view the socio-economic perspective. [ABSTRACT FROM AUTHOR]

Climate variability and change greatly affect agricultural and water resource management over West Africa. This paper presents the current characteristics and projected change in regional crop water demand (CWD), irrigation requirement (IR), and water availability (WA) over West Africa. Observed and simulated daily rainfall, minimum temperature, maximum temperature, and evapotranspiration are used to derive the above agro-meteorological and hydrological variables. For future periods, high-resolution climate data from three regional climate models under two different scenarios, i.e., representative concentration pathway (RCP) 4.5 and 8.5, are considered. Evaluation of the characteristics of present-day CWD, IR, and WA indicated that the ensemble mean of the model-derived outputs reproduced the prevailing spatial patterns of CWD and IR. Moreover, the wetter part of the domain, especially along the southern coast, was correctly delineated from the drier northern regions, despite having biases. The ensemble model also simulated the annual cycle of water supply and the bimodal pattern of the water demand curves correctly. In terms of future projections, the outcomes from the study suggest an average increase in the CWD by up to 0.808 mm/day and IR by 1.244 mm/day towards the end of the twenty-first century, compared to the baseline period. The hot-spot areas, where there is higher projected increment in CWD and IR, are over Senegal, Southern Mali, and Western Burkina Faso. In most cases, WA is projected to decrease towards the end of the twenty-first century by −0.418 mm/day. The largest decline in WA is found to be over Guinea and most of the eastern parts of West Africa. Despite the current under-utilization of the existing groundwater resources, the threat of global warming in reducing future WA and increasing CWD suggested caution on the scale of irrigation schemes and management strategies. The outcomes from the study could be a crucial input for the agricultural and water managers for introducing effective measures to ensure sustainability of irrigated farm lands. [ABSTRACT FROM AUTHOR]

The climate of Sri Lanka has been fluctuating at an alarming rate during the recent past. These changes are reported to have pronounced impacts on the livelihoods of the people in the country. Water is central to the sustainable functioning of ecosystems and wellbeing of mankind. It is evident that pronounced variations in the climate will negatively impact the availability and the quality of water resources. The ecosystem-based adaptation (EbA) approach has proved to be an effective strategy to address the impact of climate change on water resources in many parts of the world. The key aim of this paper is to elaborate the wide range of benefits received through implementation of EbAs in field level, watershed scale, and urban and coastal environments in the context of Sri Lanka. In addition, this paper discusses the benefits of utilizing EbA solutions over grey infrastructure-based solutions to address the issues related to water management. The wide range of benefits received through implementation of EbAs can be broadly classified into three categories: water supply regulation, water quality regulation, and moderation of extreme events. This paper recommends the utilization of EbAs over grey infrastructure-based solutions in adaptation to climate change in the water management sector for the developing region due its cost effectiveness, ecofriendliness, and multiple benefits received on long-term scales. The findings of this study will unequivocally contribute to filling existing knowledge and research gaps in the context of EbAs to future climate change in Sri Lanka. The suggestions and opinions of this study can be taken into account by decision makers and water resources planning agencies for future planning of actions related to climate change adaptation in Sri Lanka. [ABSTRACT FROM AUTHOR]

Water and water management are no longer related to environmental studies. There is a very strong link between water and a state's security, as well as its survival and development. A decline in water availability may lead to a collapse or even the extinction of a whole civilization. Sometimes referred to as a "water‐bankrupt" state, Iran is a case that underlines the close relation between water and security, from the perspective of survival and opportunities for development. Without a doubt, the Islamic Republic of Iran is among those countries that are the most affected by climate change and low water levels. The main goal of this paper is to analyze challenges related to water in Iran, including the political, security, economic, and social dimensions. [ABSTRACT FROM AUTHOR]

Hydrologic model forecasts have inherent uncertainties from input errors, lack of physical representation, and parameter equifinality. Accurate modelling results with reduced uncertainty are necessary for water resources management and decision-making, especially in a changing climate scenario. To this end, the hydrologic modelling community widely accepts the assimilation of satellite remote sensing data. This paper reviews the recent developments in hydrologic data assimilation (DA) focusing on progress in the role of satellite remote sensing data in reducing model uncertainty. [ABSTRACT FROM AUTHOR]

Semi-arid regions are known for erratic precipitation patterns with significant effects on the hydrological cycle and water resources availability. High temporal and spatial variation in precipitation causes large variability in runoff over short durations. Due to low soil water storage capacity, base flow is often missing and rivers fall dry for long periods. Because of its climatic characteristics, the semi-arid north-eastern region of Brazil is prone to droughts. To counter these, reservoirs were built to ensure water supply during dry months. This paper describes problems and solutions when calibrating and validating the eco-hydrological model SWIM for semi-arid regions on the example of the Pajeú watershed in north-eastern Brazil. The model was calibrated to river discharge data before the year 1983, with no or little effects of water management, applying a simple and an enhanced approach. Uncertainties result mainly from the meteorological data and observed river discharges. After model calibration water management was included in the simulations. Observed and simulated reservoir volumes and river discharges are compared. The calibrated and validated models were used to simulate the impacts of climate change on hydrological processes and water resources management using data of two representative concentration pathways (RCP) and five earth system models (ESM). The differences in changes in natural and managed mean discharges are negligible (< 5%) under RCP8.5 but notable (> 5%) under RCP2.6 for the ESM ensemble mean. In semi-arid catchments, the enhanced approach should be preferred, because in addition to discharge, a second variable, here evapotranspiration, is considered for model validation. [ABSTRACT FROM AUTHOR]

Water resources in Mediterranean regions are under increasing pressure due to climate change, economic development, and population growth. Many Mediterranean rivers have their headwaters in mountainous regions where hydrological processes are driven by snowpack dynamics and the specific variability of the Mediterranean climate. A good knowledge of the snow processes in the Mediterranean mountains is therefore a key element of water management strategies in such regions. The objective of this paper is to review the literature on snow hydrology in Mediterranean mountains to identify the existing knowledge, key research questions, and promising technologies. We collected 620 peer-reviewed papers, published between 1913 and 2016, that deal with the Mediterranean-like mountain regions in the western United States, the central Chilean Andes, and the Mediterranean basin. A large amount of studies in the western United States form a strong scientific basis for other Mediterranean mountain regions. We found that: (1) the persistence of snow cover is highly variable in space and time but mainly controlled by elevation and precipitation; (2) the snowmelt is driven by radiative fluxes, but the contribution of heat fluxes is stronger at the end of the snow season and during heat waves and rain-on-snow events; (3) the snow densification rates are higher in these regions when compared to other climate regions; and (4) the snow sublimation is an important component of snow ablation, especially in high-elevation regions. Among the pressing issues is the lack of continuous ground observation in high-elevation regions. However, a few years of snow depth (HS) and snow water equivalent (SWE) data can provide realistic information on snowpack variability. A better spatial characterization of snow cover can be achieved by combining ground observations with remotely sensed snow data. SWE reconstruction using satellite snow cover area and a melt model provides reasonable information that is suitable for hydrological applications. Further advances in our understanding of the snow processes in Mediterranean snow-dominated basins will be achieved by finer and more accurate representation of the climate forcing. While the theory on the snowpack energy and mass balance is now well established, the connections between the snow cover and the water resources involve complex interactions with the sub-surface processes, which demand future investigation. [ABSTRACT FROM AUTHOR]

Future changes in the climate system could have significant impacts on the natural environment and human activities, which in turn affect changes in the climate system. In the interaction between natural and human systems under climate change conditions, land use is one of the elements that play an essential role. Future climate change will affect the availability of water and food, which may impact land-use change. On the other hand, human land-use change can affect the climate system through bio-geophysical and bio-geochemical effects. To investigate these interrelationships, we developed MIROC-INTEG1 (MIROC INTEGrated terrestrial model version 1), an integrated model that combines the global climate model MIROC (Model for Interdisciplinary Research on Climate) with water resources, crop production, land ecosystem, and land use models. In this paper, we introduce the details and interconnections of the sub-models of MIROC-INTEG1, compare historical simulations with observations, and identify the various interactions between sub-models. MIROC-INTEG1 makes it possible to quantitatively evaluate the feedback processes or nexus between climate, water resources, crop production, land use, and ecosystem, and to assess the risks, trade-offs and co-benefits associated with future climate change and prospective mitigation and adaptation policies. [ABSTRACT FROM AUTHOR]

This study investigated the annual and seasonal rainfall variability at five selected stations of Amhara Regional State, by using the innovative trend analysis method (ITAM), Mann-Kendall (MK) and Sen's slope estimator test. The result showed that the trend of annual rainfall was increasing in Gondar (Z = 1.69), Motta (Z = 0.93), and Bahir Dar (Z = 0.07) stations. However, the trends in Dangla (Z = -0.37) and Adet (Z = -0.32) stations showed a decreasing trend. As far as monthly and seasonal variability of rainfall are concerned, all the stations exhibited sensitivity of change. The trend of rainfall in May, June, July, August, and September was increasing. However, the trend on the rest of other months showed a decreasing trend. The increase in rainfall during Kiremt season, along with the decrease in number of rainy days, leads to an increase of extreme rainfall events over the region during 1980-2016. The consistency in rainfall trends over the study region confirms the robustness of the change in trends. Innovative trend analysis method is very crucial method for detecting the trends in rainfall time series data due to its potential to present the results in graphical format as well. The findings of this paper could help researchers to understand the annual and seasonal variability of rainfall over the study region and become a foundation for further studies. [ABSTRACT FROM AUTHOR]

Abstract: While the number of environmental flows and water science programmes continues to grow across the globe, there remains a critical need to better balance water availability in support of human and ecological needs and to recognise the environment as a legitimate user of water. In water‐stressed areas, this recognition has resulted in friction between water users in the public and private sectors. An opportunity exists for practitioners to be on the forefront of the science determining best practices for supporting environmental water regimes. This Special Issue brings together a collection of environmental flows science and water management papers organised around three major themes: (1) method development and testing; (2) application case studies; and (3) efficacy evaluation. Contents of this Special Issue are intended to foster collaboration and broaden transferability of the information, technical tools, models and methods needed to support environmental water management programmes. The technical sophistication of methods and modelling tools, while important to the advancement of environmental water science, may come at the expense of easily interpretable outcomes that positively influence management decisions. Researchers need to be more proactive in translating the results of advanced modelling methodologies into user‐friendly tools and methods. This will allow stakeholders and water managers to proactively test alternative water allocation scenarios to help address growing human water demands in the face of droughts and changes in climatic patterns. The application of environmental flows science and water management strategies cannot be done in isolation. Implementation involves a complex decision‐making process that integrates ecological, hydrologic and social science across diverse multifaceted governance systems and requires active stakeholder involvement. Scientists and managers must strengthen partnerships at multiple scales to develop sensible science investment strategies so that collective knowledge can be translated into wise environmental water management decisions. [ABSTRACT FROM AUTHOR]

This paper applies an ontological politics approach for studying how complexity, uncertainty, and ignorance are being dealt with in the Netherlands by looking at how knowledges are produced and incorporated in decision-making on uncertain climate change. On the basis of work done in the Netherlands, this paper shows two things in particular. First, how decision making responses historically have been subject to change under the influence of floods and how the emergence of climate change has significantly changed these floods. Second, based on the analysis of processes dealing with a blue-green algae problem in a lake, climate change not only changed decision making responses but also changed the very reality that is being enacted. Consequently, this brings an ethical dimension to the fore, related to the intrinsic tension between the growing awareness that 'all is interconnected' on the one hand and the realization we cannot take all into account. [ABSTRACT FROM AUTHOR]

Climate variability and insufficient irrigation are primary constraints to stable and higher agricultural productivity and food security in Nepal. Agriculture is the largest global freshwater user, and integration of surface- and ground-water use is frequently presented as an strategy for increasing efficiency as well as climate change adaptation. However, conjunctive management (CM) planning often ignores demand-side requirements and a broader set of sustainable development considerations, including ecosystem health and economics of different development strategies. While there is generic understanding of conjunctive use, detailed technical knowhow to realize the CM is lacking in Nepal. This article presents a holistic framework through literature reviews, stakeholders consultations and expert interviews for assessing CM and implementation prospects from a systems-level perspective. We demonstrate the framework through a case study in Western Nepal, where climatic variability and a lack of irrigation are key impediments to increased agricultural productivity and sustainable development. Results show that knowledge of water resources availability is good and that of water demand low in the Western Terai. Additional and coordinated investments are required to improve knowledge gaps as well as access to irrigation. There is therefore a need to assess water resources availability, water access, use and productivity, to fill the knowledge gaps in order to pave pathways for CM. This paper also discusses some strategies to translate prospects of conjunctive management into implementation. • Customized framework development for assessing prospects for conjunctive management. • Conjunctive management status in western Nepal assessed by applying the framework. • Knowledge on water availability and demand are moderate and low, respectively. • Additional and coordinated investments required to improve access to irrigation. [ABSTRACT FROM AUTHOR]

Urban water managers need to adopt water demand management (WDM) as one of the ways to provide for the needs and demands of escalating urban populations, amidst the negative impacts of increased pollution loads and climate change on finite water resources. This paper reviews how urban water tariff structures could be designed to promote water conservation in households while also ensuring revenue sufficiency for the service providers and affordability for low-income households. As an example, the paper describes the case of Zaragoza (Spain), a city where implementation of a water-conserving tariff and providing economic incentives largely contributed to a 27% reduction in overall water consumption between 1996 and 2008, although the population of the city increased by 12%. Similar principles were adapted to model a water-saving, socially equitable tariff for the city of Kampala (Uganda). The proposed tariff for Kampala can save over 2·5 million m of water and generate an extra US$ 0·68 million of revenue per year, which could be used to extend water services to currently unserved households in low-income settlements. If implemented, the tariff could enhance economic efficiency, revenue sufficiency, social equity and service coverage. [ABSTRACT FROM AUTHOR]

Water is an important key to understand Maya society, especially water availability within a context of climatic changes. Increasing drought would have pushed the Maya water systems into collapse. This paper studies the Maya water systems from an action‐oriented perspective, in order to understand what challenges the Maya had to overcome when dealing with water. The systems found at Tikal serve as main example, allowing comparisons with other Maya sites. In this analysis, hydraulic‐ and agent‐based elements are combined in a model to investigate the performance of the water system within extreme weather conditions and changing human agency. The results suggest that the Tikal water system was able to cope with most of the extreme situations. Furthermore, model results allow proposing that the Maya did not anticipate on short‐term changes in external conditions. Generally, in Tikal surpluses of water may have been as important as shortages of water. The extensive system of drains and canals present at Tikal may have been built to move water from the center of the city rather than to supply water to lower situated reservoirs during the dry season. Such a water‐removal system could be less centrally orientated and organized than is often argued. This could also mean that organizational structures of water systems of different city centers (Tikal, Calakmul, and Caracol) were more similar than usually assumed. This article is categorized under: Human Water > Water as Imagined and Represented Engineering Water > Planning Water Science of Water > Water Quality [ABSTRACT FROM AUTHOR]

Climate change may result in reduced water supply from the Alps – an important water resource for Europe. This paper presents a multilingual platform that combines spatial and multi-criteria decision-support tools to facilitate stakeholder collaboration in the analysis of water management adaptation options. The platform has an interactive map interface that allows participants to select a location of their interest within the Alpine Arc. By utilising the decision-support tool, stakeholders can identify suitable adaptation solutions for different geographical units, according to their experience and preference. The platform was used to involve experts across Alpine borders, domains and decision-making levels, as well as a group of university students. The experts favoured the planning instruments for saving water, while the students inclined towards the measures that would improve water conservation. The initial results confirmed the suitability of the platform for future involvement of decision-makers in spatio-temporal analyses of adaptation pathways in the Alps. [ABSTRACT FROM AUTHOR]

This paper focuses on Australian water reform in a climate change context over the period between mid-2006 and end 2011, with a particular focus on the Murray Darling Basin (MDB). In Australia, during this period, the potential impacts from climate change became more central to the policy debate, and the implementation of what can be said to be a large-scale climate change adaptation programme commenced. The paper outlines the policy framework adopted by the government of the day and then draws out some of the key issues for water management against this background, and the attendant increased uncertainty. [ABSTRACT FROM PUBLISHER]

This study evaluates the effect on the availability of water resources for agriculture of expected future changes in precipitation and temperature distributions in north-western Africa. It also puts forward some locally derived adaptation strategies to climate change that can have a positive impact on water resources in the Chtouka Aït Baha region. Historical baselines of precipitation and temperature were derived using satellite data respectively from CHIRPS and CRU, while future projections of temperature and precipitation were extracted from the Coordinated Regional Climate Downscaling Experiment database (CORDEX). Projections were also generated for two future periods (2030–2049 and 2080–2099) under two Representative Concentration Pathways: RCP4.5 and RCP8.5. Regional climate models and satellite data outputs were evaluated by calculating their bias and RMSE against historical baseline and observed data. Under the RCP8.5 scenario, temperature in the region shows an increase by 2 °C for the 2030–2049 time period, and by 4 to 5 °C towards the end of the 21st century. According to the RCP4.5 scenario, precipitation shows a reduction of 10 to 30% for the period 2030–2049, up to 60% for 2080–2099. Outputs from the climate change projections were used to force the HEC-HMS hydrological model. Simulation results indicate that water deficit at basin level will likely triple towards 2050 due to increase in water demand and decrease in aquifer recharge and dam storage. This alarming situation, in a country that already suffers from water insecurity, emphasizes the need for more efforts to implement climate change adaptation measures. This paper presents an assessment of 38 climate change adaptation measures according to several criteria. The evaluation shows that measures affecting the management of water resources have the highest benefit-to-efforts ratio, which indicates that decision makers and stakeholders should increasingly focus their efforts on management measures. [ABSTRACT FROM AUTHOR]

Frequent water stress episodes affecting urban hubs have caused a shift in urban water management towards integrated approaches and motivated a search for alternative water resources. Large-scale rainwater harvesting on the municipal scale can overcome the disadvantages of climate dependence and the volume restrictions associated with small-scale collection facilities. In this paper, two tools based on the urban metabolism concept are used to determine the water self-sufficiency potential of urban systems from urban runoff: a simple water self-sufficiency potential indicator and a socioeconomic water flow accounting scheme, which includes water losses. Both tools are applied to a densely populated coastal area that exemplifies urban centres in the Mediterranean. This approach is useful for regions with restricted data availability on water use and facilitates information dissemination to policy makers. The results indicate a significant water self-sufficiency potential for the area of study, even under projections of reduced precipitation in the area. [ABSTRACT FROM PUBLISHER]

As the central product of the BMBF-KLIMZUG-funded Joint Network and Research Project (JNRP) 'dynaklim - Dynamic adaptation of regional planning and development processes to the effects of climate change in the Emscher-Lippe region (North Rhine Westphalia, Germany)', the Roadmap 2020 'Regional Climate Adaptation' has been developed by the various regional stakeholders and institutions containing specific regional scenarios, strategies and adaptation measures applicable throughout the region. This paper presents the method, elements and main results of this regional roadmap process by using the example of the thematic sub-roadmap 'Water Sensitive Urban Design 2020'. With a focus on the process support tool 'KlimaFLEX', one of the main adaptation measures of the WSUD 2020 roadmap, typical challenges for integrated climate change adaptation like scattered knowledge, knowledge gaps and divided responsibilities but also potential solutions and promising chances for urban development and urban water management are discussed. With the roadmap and the related tool, the relevant stakeholders of the Emscher-Lippe region have jointly developed important prerequisites to integrate their knowledge, to clarify vulnerabilities, adaptation goals, responsibilities and interests, and to foresightedly coordinate measures, resources, priorities and schedules for an efficient joint urban planning, well-grounded decision-making in times of continued uncertainties and step-by-step implementation of adaptation measures from now on. [ABSTRACT FROM AUTHOR]

A portfolio of water management strategies now exists to contribute to reach water demand and supply targets. Among them, integrated water resource management has a large potential for reducing water disagreement in water scarcity regions. Many of the strategies are based on well tested choices and technical know-how, with proven benefits for users and environment. This paper considers water management practices that may contribute to reduce disagreement in water scarcity areas, evaluating the management alternatives in the Mediterranean basins of Europe, a region that exemplifies other water scarcity regions in the world. First, we use a model to compute water availability taking into account water management, temporal heterogeneity, spatial heterogeneity and policy options, and then apply this model across 396 river basins. Second, we use a wedge approach to illustrate policy choices for selected river basins: Thrace (Greece), Guadalquivir, Ebro, Tagus and Duero (Spain), Po (Italy) and Rhone (France). At the wide geographical level, the results show the multi-determinant complexities of climate change impacts and adaptation measures and the geographic nature of water resources and vulnerability metrics. At the local level, the results show that optimisation of water management is the dominating strategy for defining adaptation pathways. Results also show great sensitivity to ecological flow provision, suggesting that better attention should be paid to defining methods to estimate minimum ecological flows in water scarcity regions. For all scales, average water resource vulnerability computed by traditional vulnerability indicators may not be the most appropriate measure to inform climate change adaptation policy. This has large implications to applied water resource studies aiming to derive policy choices, and it is especially interesting in basins facing water scarcity. Our research aims to contribute to shape realistic water management options at the regional level and therefore provide information to climate change, agricultural and water policies. [ABSTRACT FROM AUTHOR]

Water and resource availability in sufficient quantity and quality for anthropogenic needs represents one of the main challenges in the coming decades. To prepare for upcoming challenges such as increased urbanization and climate change related consequences, innovative and improved resource management concepts are indispensable. In recent years we have developed and applied the urban harvest approach (UHA). The UHA aims to model and quantify the urban water cycle on different temporal and spatial scales. This approach allowed us to quantify the impact of the implementation of water saving measures and new water treatment concepts in cities. In this paper we will introduce the UHA and its application for urban water cycles. Furthermore, we will show first results for an extension to energy cycles and highlight future research items (e.g. nutrients, water-energy-nexus). [ABSTRACT FROM AUTHOR]

This paper demonstrates the impracticality of a comprehensive mathematical definition of the term 'drought' which formalises the general qualitative definition that drought is 'a deficit of water relative to normal conditions'. Starting from the local water balance, it is shown that a universal description of drought requires reference to water supply, demand and management. The influence of human intervention through water management is shown to be intrinsic to the definition of drought in the universal sense and can only be eliminated in the case of purely meteorological drought. The state of drought is shown to be predicated on the existence of climatological norms for a multitude of process-specific terms. In general, these norms are either difficult to obtain or even non-existent in the non-stationary context of climate change. Such climatological considerations, in conjunction with the difficulty of quantifying human influence, lead to the conclusion that we cannot reasonably expect the existence of any workable generalised objective definition of drought. [ABSTRACT FROM AUTHOR]

We present an integrated hydrology/water operations simulation model of the Tuolumne and Merced River Basins, California, using the Water Evaluation and Planning (WEAP) platform. The model represents hydrology as well as water operations, which together influence water supplied for agricultural, urban, and environmental uses. The model is developed for impacts assessment using scenarios for climate change and other drivers of water system behavior. In this paper, we describe the model structure, its representation of historical streamflow, agricultural and urban water demands, and water operations. We describe projected impacts of climate change on hydrology and water supply to the major irrigation districts in the area, using uniform 2°C, 4°C, and 6°C increases applied to climate inputs from the calibration period. Consistent with other studies, we find that the timing of hydrology shifts earlier in the water year in response to temperature warming (5–21 days). The integrated agricultural model responds with increased water demands 2°C (1.4–2.0%), 4°C (2.8–3.9%), and 6°C (4.2–5.8%). In this sensitivity analysis, the combination of altered hydrology and increased demands results in decreased reliability of surface water supplied for agricultural purposes, with modeled quantity-based reliability metrics decreasing from a range of 0.84–0.90 under historical conditions to 0.75–0.79 under 6°C warming scenario. [ABSTRACT FROM AUTHOR]

Projections of future water availability are required by water managers and policy makers in order to take action to mitigate some of the potentially negative impacts of climate change on water supplies in the urban, agricultural and environmental sectors. However, in order to do this, these projections must have some level of confidence associated with them, and even if this is the case, the research community must make the data and/or information available in a format that is directly usable by water managers and policy makers. This paper presents results from a water availability study recently carried out across southeastern Australia as part of the South Eastern Australian Climate Initiative. More importantly, it shows how the results of this study have been used in defining a range of plausible future streamflow scenarios to be used by water resource managers in the state of Victoria in updating its water supply-demand strategies for the next 50 years. Climate change projections for this region were summarised by creating "dry", "wet" and "median" future runoff scenarios for 2030 and 2060 based on the second driest, second wettest and median global climate model (GCM) results. These results were then averaged across 27 catchments covering the state of Victoria. We contend that in areas such as the state of Victoria where there is near-unanimous agreement among GCMs as to the direction of climate change impacts on rainfall, along with theoretical understanding consistent with changes in large scale circulation in a warmer world, projected changes in water availability can be used by water resource planners to assist them in better planning for future changes in supply. [ABSTRACT FROM AUTHOR]

Abstract: Assessments concerning the effects of climate change, water resource availability and water deprivation in West Africa have not frequently considered the positive contribution to be derived from collecting and reusing water for domestic purposes. Where the originating water is taken from a clean water source and has been used the first time for washing or bathing, this water is commonly called “greywater”. Greywater is a prolific resource that is generated wherever people live. Treated greywater can be used for domestic cleaning, for flushing toilets where appropriate, for washing cars, sometimes for watering kitchen gardens, and for clothes washing prior to rinsing. Therefore, a large theoretical potential exists to increase total water resource availability if greywater were to be widely reused. Locally treated greywater reduces the distribution network requirement, lower construction effort and cost and, wherever possible, minimising the associated carbon footprint. Such locally treated greywater offers significant practical opportunities for increasing the total available water resources at a local level. The reuse of treated greywater is one important action that will help to mitigate the reducing availability of clean water supplies in some areas, and the expected mitigation required in future aligns well with WHO/UNICEF (2012) aspirations. The evaluation of potential opportunities for prioritising greywater systems to support water reuse takes into account the availability of water resources, water use indicators and published estimates in order to understand typical patterns of water demand. The approach supports knowledge acquisition regarding local conditions for enabling capacity building for greywater reuse, the understanding of systems that are most likely to encourage greywater reuse, and practices and future actions to stimulate greywater infrastructure planning, design and implementation. Although reuse might be considered to increase the uncertainty of achieving a specified quality of the water supply, robust methods and technologies are available for local treatment. Resource strategies for greywater reuse have the potential to consistently improve water efficiency and availability in water impoverished and water stressed regions of Ghana and West Africa. Untreated greywater is referred to as “greywater”; treated greywater is referred to as “treated greywater” in this paper. [Copyright &y& Elsevier]

Abstract: Over the past decades, the cost-effectiveness principle or a cost–benefit analysis has typically been employed as an assessment tool for the expansion of drinking water utilities. With changing public awareness of the inherent linkages between greenhouse gas emissions and climate change, the addition of this new consideration in the assessment regime has altered the landscape of the traditional evaluation matrix. This paper presents a comparative evaluation based on a suite of carbon footprint and cost data associated with 20 expansion alternatives for a systematic priority analysis of a drinking water infrastructure system in South Florida. [Copyright &y& Elsevier]

This paper is designed to present the likely impact of climate change on groundwater resources in general and Libya in particular. State of the art reviews on recent research studies, and methodology to assess the impact of climate change on groundwater resources shows that climate change poses uncertainties to the supply and management of water resources. It outlines to demonstrate that how climate change impact assessment plays a vital role in forming the sensitive water balance rarely achieved in most area owing to precipitation variability's and seasonality. It demonstrates that how large increases in water demand with very little recharge from precipitation have strained Libya's groundwater resources resulting in declines of groundwater levels and its quality, especially on Libyan coastal areas where most of the agriculture, domestic and industrial activities are concentrated. Based on several research studies it demonstrates that how policy and decision making process using best practices for monitoring, analyzing and forecasting variation of climate is a way forward to cope with the impact of sea level rise, and combat some water supplies in vulnerable areas that are becoming unusable due to the penetration of salt water into coastal aquifers (Jifara Plain, Sirt, Jebal El-Akhdar). Finally, a number of Global Climate Models (GCM) are reviewed to demonstrate that how better understanding of climate and climate change forecasting helps in devising appropriate adaptation strategies due to the impact of climate change. [ABSTRACT FROM AUTHOR]

This paper examines the actions toward the reduction of greenhouse gas emissions to the atmosphere that Greece has implemented to comply with international conventions and the Kyoto Protocol. It also concerns the analysis and processing of climate variables and the assessment of the impact of climate change on water resources in Northern Greece and on some critical water management issues, such as reservoir storage and water supply for agriculture and domestic use. Initially, a monthly conceptual water balance model was applied to estimate runoff values in the entrance of the Polyfyto reservoir under the UKHI equilibrium scenario referring to the year 2100. It was found that the mean annual runoff, mean winter runoff and summer runoff values will be reduced. Increases of the risks associated with the annual quantities of water supply have been observed. [ABSTRACT FROM PUBLISHER]

Summary: The hydrological cycle has been substantially influenced by climate change and human activities. It is therefore of utmost importance to analyze the impact of climate change on hydrology, particularly on a regional scale, in order to understand potential future changes of water resources and water-related disaster, and provide support for regional water management. However, during the evaluation of climate change impact on hydrology or water resources, large uncertainty exists. In this paper, the Soil Water Assessment Tool (SWAT) model is used to investigate the potential impact of climate change on hydrology of the upper reaches of Qiantang River Basin, East China, for the future period 2011–2100. The uncertainty is considered by employing upgraded reliability ensemble averaged GCM climate projections under three emission scenarios A1B, A2 and B1 for three different stages of the future period. These projections are downscaled and used in the hydrological model. Impact of climate change on precipitation, potential evapotranspiraton and river runoff is then investigated. The model calibration and validation outcomes show reasonable performance of the SWAT model. The final results suggest that annual river runoff will likely decrease almost under all emission scenarios and time stages of the future period. Particularly, at Jinhua Station, substantial decrease of annual river runoff can be noticed, indicating less water resource possibly available for the region in future. Simulated monthly patterns show that the largest decrease will likely occur in winter while increases will occur in summer, implying possible more water-related disasters in this region. However, it is also noticed that the change signs/amount could be different under different emission scenarios and time stages, indicating large uncertainty involved in the impact analysis. [ABSTRACT FROM AUTHOR]

Summary: The climate scenarios of the IPCC suggest that adaptation to future climate change will be required. The North Sea Region, a marginal sea of the Atlantic Ocean between Great Britain, Scandinavia, Germany, the Netherlands and Belgium, is particularly affected due to rising sea level and a changing water balance. Water management plays a key role in sustainable management of natural and societal resources. This paper presents a participatory study of community approaches to regional adaptation to climate change. Water management adaptation options to regional climate induced changes until 2050 were developed together with stakeholders for the Wesermarsch County (Northern Germany). Available information on expected regional climate change and a modelling study on hydrological change suggested that adaptation of water management will be required until 2050. A regional stakeholder forum formulated a vision on how the Wesermarsch should look like in 2050. Following the holistic approach of collaborative planning, two stakeholder groups developed an adaptation portfolio on how urban and rural areas could adapt their water management to cope with the expected changes. Since most of the stakeholders do not want the county to undergo significant changes in terms of landscape and land use, they proposed technical measures to enforce flood protection and enhance the performance of the existing water management system. Adaptation in terms of land use change was not proposed although information on comparable examples from similar regions was available. To justify the proposed adaptation options, available information on expected climate change impacts was used selectively. Uncertainty in model projections was partly ignored to legitimate suggesting inflexible (technical) adaptation measures. However, collaborative planning proved to be helpful for a joint adaptation to climate change at the regional scale. Stakeholders as well as scientists took active part in the participatory learning process as required by EU directives. [Copyright &y& Elsevier]

Summary: Public water supply systems are designed to maintain water supply through extended periods of dry weather without excessive cost or environmental damage. During a drought, water suppliers can take further measures to enhance supplies or reduce demand. The introduction of drought measures is usually formalised in a drought plan, but there is often little evidence that the plan will prove successful during a range of feasible droughts. As the climate changes, recent hydrological data may be a poor guide to future drought, and planned actions may prove insufficient to maintain adequate water supplies. This paper describes a method for testing the resilience of water company drought plans to droughts that are outside recent hydrological experience. Long severe droughts of the nineteenth century provide an opportunity to test water supply system behaviour in a range of realistic droughts. The method developed combines system modelling with an interactive approach that asks water system managers to work through the actions that they would take at different stages of the drought, without knowledge of subsequent drought development. The approach was tested for two contrasting English water resource systems. In both cases, the existing water supply and drought planning measures succeeded in maintaining water supply, but significant demand restrictions and engineering measures had to be introduced. Wider use of the method by water supply planners should allow the refinement of drought and water supply plans, and will also create increased awareness of the actions necessary to manage a range of droughts. [ABSTRACT FROM AUTHOR]

Abstract: Although spate irrigation systems are risk-prone, they can be an important component for livelihood security in semi-arid areas. Spate uses water (flood water), which upstream users often do not require, as rainfall during these periods is more than sufficient. The use of this flood water for spate irrigation is therefore a good opportunity to convert water with a low opportunity cost to high value water. As more rivers are closing, due to socio-economic and climate changes, spate irrigation may become increasingly relevant in semi-arid areas. Spate irrigation systems pose institutional and technical challenges: collective action is challenged by complex upstream–downstream interactions between users within the system, and the high labour demands for regular reconstruction of temporary diversion weirs and intake structures. This paper describes a spate irrigation system in Makanya village, Tanzania that emerged in response to increased upstream water use. We use three of the four dimensions (hydrological, hydraulic and sociological) of spate irrigation proposed by to assess the Makanya spate irrigation system. The Makanya spate irrigation system has an organisational structure that is similar to the canal irrigation (furrow) committees located upstream, and effectively deals with the institutional demands of managing water in spate irrigation systems. Water allocation is reminiscent to the water sharing arrangements existing in the full irrigation system, which previously was in place at the site and in the high- and midlands of the Makanya catchment and therefore set this system apart from the traditional spate irrigation practice elsewhere. Technically, a major challenge is the reconstruction of the head works after each flood. Another aspect is the changes in the river bed. Flash floods carry sediments that deposit on the fields, raising the elevation of the irrigated land every year and making it increasingly difficult for the river water to enter the plots. Improving system efficiency through modernisation of the diversion and distribution structures in this case is not feasible due to the huge amounts of sediments delivered to the system each year. Instead investments in conjunctive use of groundwater could be the solution because it involves a relatively small intervention, minimises the physical disturbance of the system, and therefore is likely to respect the existing locally developed water management arrangements. [Copyright &y& Elsevier]

Abstract: In the North China Plain (NCP), while irrigation using groundwater has maintained a high-level crop productivity of the wheat–maize double cropping systems, it has resulted in rapid depletion of groundwater table. For more efficient and sustainable utilization of the limited water resources, improved understanding of how crop productivity and water balance components respond to climate variations and irrigation is essential. This paper investigates such responses using a modelling approach. The farming systems model APSIM (Agricultural Production Systems Simulator) was first calibrated and validated using 3 years of experimental data. The validated model was then applied to simulate crop yield and field water balance of the wheat–maize rotation in the NCP. Simulated dryland crop yield ranged from 0 to 4.5tha−1 for wheat and 0 to 5.0tha−1 for maize. Increasing irrigation amount led to increased crop yield, but irrigation required to obtain maximum water productivity (WP) was much less than that required to obtain maximum crop yield. To meet crop water demand, a wide range of irrigation water supply would be needed due to the inter-annual climate variations. The range was simulated to be 140–420mm for wheat, and 0–170mm for maize. Such levels of irrigation applications could potentially lead to about 1.5myear−1 decline in groundwater table when other sources of groundwater recharge were not considered. To achieve maximum WP, one, two and three irrigations (i.e., 70, 150 and 200mmseason−1) were recommended for wheat in wet, medium and dry seasons, respectively. For maize, one irrigation and two irrigations (i.e., 60 and 110mmseason−1) were recommended in medium and dry seasons, while no irrigation was needed in wet season. [Copyright &y& Elsevier]

Economically optimal operational changes and adaptations for California's water supply system are examined for a dry form of climate warming (GFDL CM2.1 A2) with year 2050 water demands and land use. Economically adaptive water management for this climate scenario is compared to a similar scenario with the historical climate. The effects of population growth and land use alone are developed for comparison. Compared with the historic hydrology, optimized operations for the dry climate warming scenario raise water scarcity and total operation costs by $490 million/year with year 2050 demands. Actual costs might be somewhat higher where non-economic objectives prevail in water management. The paper examines the economical mix of adaptation, technologies, policies, and operational changes available to keep water supply impacts to such modest levels. Results from this screening model suggest promising alternatives and likely responses and impacts. Optimized operations of ground and surface water storage change significantly with climate. Dry-warm climate change increases the seasonal storage range of surface reservoirs and aquifers. Surface reservoir peak storage usually occurs about a month earlier under dry-warm climate change. [ABSTRACT FROM AUTHOR]

This paper introduces a new methodology for quantifying the total resilience of water resources management scenarios. The climate change impacts on water supply and demand have been investigated using a calibrated soil and water assessment tool (SWAT) and a MODSIM water allocation model. Several criteria have been defined to measure five aspects of water resources systems resilience. The first aspect defines resilience as system strength against crossing a performance threshold (reliability). In the second aspect, if the system crosses the performance threshold, the recovery rate of the system after a disturbance is evaluated. The violation from the performance threshold has been measured as the third aspect (vulnerability), which considers the failure's severity. The fourth aspect is the resilience under extreme events with unknown occurrence probability, which includes four sub-criteria, namely rapidity, robustness, resourcefulness, and redundancy (4 R). Finally, the fifth criterion considers the ecological condition of the system (ecological index). To compare water resources management scenarios (alternatives), an analytical evidential reasoning-based (ER) approach has been used. To show the applicability of the proposed methodology, it has been applied to the Zarrinehrud river basin, which is the leading water supplier of Lake Urmia in Iran. As one of the largest saline lakes globally, this lake has been suffering from drastic desertification and salinization in the past two decades. The grade-based results of the performance criteria are synthesized into a grade-based total resilience criterion to facilitate the comparison of water resources management scenarios. It is shown that a scenario which results in 40% reduction in agricultural water demand until 2023 has the highest resilience and an acceptable construction and operational cost. • A total resilience criterion is proposed for assessing water resources systems. • This criterion can evaluate the resilience against events with known and unknown probability. • The grade-based values of performance criteria are estimated and combined using ER. • The previous resilience evaluations /have underestimated the critical conditions. • The total cost and resilience of the selected scenario are 1272.5 × 106 $ and 0.85. [ABSTRACT FROM AUTHOR]

• CIRFs are useful for exploring risks of system failure under climate change. • Synthetic streamflow series are generated using SA and linked to climate conditions. • Logistic regression relates system responses to climate drivers. • System failure defined according to performance (reliability) and threshold. • LR model detects climate conditions which would require adaptation. Climate Impact Response Functions (CIRFs) can be useful for exploring potential risks of system failure under climate change. The performance of a water resource system can be synthesized through a CIRF that relates climate conditions to system behavior in terms of a specified threshold of deliveries to demands or environmental flow requirements. However, in highly regulated water resource systems this relationship may be quite complex, depending on storage capacity and system operation. In this paper we define a CIRF for these types of systems through a multivariable logistic regression (LR) model where a binary variable (system response) is explained by two continuous variables or predictors (precipitation and temperature). The approach involves generating multivariate synthetic inflow time series and relating them to specific climate conditions. Next, these inflows are used as inputs in a water management model, and the outcome is coded as a binary variable (failure or its absence) depending on selected vulnerability criteria. To identify the time span before the failure event in which climate variables are relevant, we characterized drought development stages through relative standardized indices. Mean values of precipitation and temperature for the selected time span are computed and used as explanatory variables through a LR model, which is validated using data from several climate models and scenarios. Results show that the predictive capacity of LR models is acceptable, so that they could be used as screening tools to detect challenging climate conditions for the system which would require adaption actions. [ABSTRACT FROM AUTHOR]

Wang, Y.P.; Jiang, R.G.; Xie, J.C.; Zhao, Y., and Li, F.W., 2020. Water resources management under changing environment: A systematic review. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 29–41. Coconut Creek (Florida), ISSN 0749-0208. Under the influences of climate change, human activities and socioeconomic development, the water resources management (WRM) has become more complex and uncertain. The paper visualizes and quantifies the knowledge base, domain and structure of the WRM using the bibliometric analysis and knowledge map. The visualized knowledge maps are used to investigate the development trend, scientific collaboration, subject categories, core research topics and the newest research fronts of the WRM. 9028 publications on the WRM were retrieved from the Web of Science Core Collection databases for the period of 1990-2018. Results indicated that the research on the WRM maintained an increasing trend for the past 29 years. China contributed the most publication, and Germany cooperated the most with other countries/regions, which were two active contributors of the WRM research. The co-word analysis and burst detective analysis of keywords showed that climate change and ecosystem were the research hotspot of the WRM knowledge base. The co-occurrence analysis and burst detective analysis of subject categories found that the Environmental Sciences & Ecology and Green & Sustainable Science & Technology were the core direction of the WRM knowledge domain. Solving the practical problems through model simulation was the core of the WRM knowledge structure under the changing environment using the cluster analysis and document co-citation analysis. It is suggested that the WRM managers should take the sustainable and adaptive development as goal, ensure the health and integrity of the ecosystem, integrate stakeholders into the WRM, which should help to make the WRM more adaptable under changing environment. [ABSTRACT FROM AUTHOR]

• Low and narrow level of adoption. Most of farmers not implementing technologies. • Farmer's, farm, and water community characteristics affect irrigation adoption. • Relative abundance of the resource discourages the adoption of technologies. • Irrigating the whole farm produces the largest negative effect on adoption. This paper examines the adoption of irrigation technologies and the underlying diversity in terms of intensity of adoption in 2 irrigated valleys in Central Chile. Results show a low and narrow range of adoption, with only 30 % of farmers adopting technologies. Through a Latent Class Analysis, 2 types of farmers were identified, a small group comprising moderate to intensive users, and a second one consisting of the majority of farmers mostly constrained in natural capital. Furthermore, the econometric analysis indicates that education, diversification, continuous access to water, and perception of water reliability increase the adoption. Conversely, higher water-land ratios, presence of community reservoirs, and earthen canals reduce the uptake. Overall, the dominance of fruit and horticulture production, access to agricultural credits, and full irrigation of the farm are the main drivers of adoption. The latter is a critical factor, indicating a relative abundance of water resources, which, alongside contextual characteristics, discourages farmers from implementing technologies. The low adoption rate, as well as the hindering factors, will challenge public and private organizations to design and implement policies aiming to improve water reliability and management. To generate incentives and increase awareness on the scarcity of the resource in the light of the predicted reductions in water availability because of climate change will be crucial as well. [ABSTRACT FROM AUTHOR]

As a typical alpine marsh wetland on the Qinghai-Tibet Plateau, the Zoige Wetland plays an important role in the water source recharge of Yellow River. Meanwhile, it is more sensitive to climate change. Therefore, it is necessary to study the hydrological cycle of Zoige Wetland and the impact of climate change, which will also provide important support and reference for the study of hydrological process, and protection of wetland water resources in Alpine areas. Based on the distributed hydrological model, this paper analyzed the runoff process in the Zoige wetland basin, and explored the trend of runoff variation in the Zoige wetland basin under different climate change scenarios in the next 30 years from 2020 to 2050. The impact of climate change on wetland runoff were also discussed. Results showed that the runoff in the Zoige Wetland basin decreased under the future climate change scenario. The rate of runoff reduction was the largest in Machu station, followed by Zoige station, and finally Tangke station. The reduction in non-flooding runoff is significantly higher than that in the flood season. The runoff during non-flood season in the Zoige Wetland basin from 2020 to 2050 will decrease by more than 25% in the future climate change scenario. The sharp decline in non-flooded runoff may have an impact on the protection of the Zoige Wetland and the management of water resources in the middle reaches of the Yellow River and downstream areas. This poses more stringent requirements for the protection of the Zoige Wetland in response to future climate change. Under future climate change scenarios, how to strengthen the management and protection of wetland water resources and prevent the degradation and atrophy of wetlands is the issue we need to further discuss and consider. [ABSTRACT FROM AUTHOR]

Human activities and climate change are two key factors influencing the variation of the total amount of available surface and groundwater, hereafter termed water resources. Quantitatively separating their impacts remains a challenge. To this end, we used time-varying Budyko-type equations and a hierarchical Bayesian model in this paper to separate their impacts in 31 provincial-level divisions of China. The time-varying Budyko-type equations treat the Budyko equation parameter w as a variable, which depends on human activities (represented by per capita gross regional production) and climate change (represented by temperature and precipitation). The hierarchical model quantifies the uncertainty of parameters and the interrelation between covariates across regions in China. The results show that the time-varying Budyko-type equation can improve the fitting capability for water resources in China. The hierarchical Bayesian model, which considered spatial dependence, reduced the uncertainty of the parameters compared to spatially independent counterparts. For most regions of China, human activities reduce water resources while climate change increases them. Southeastern China is the most influenced area, and its water resources decreased approximately 50 mm because of human activities. This study can provide a basis for water resource management under climate change and human activity constraints in China. [ABSTRACT FROM AUTHOR]