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This paper explores the relationship between normalized vegetation index (NDVI) response to precipitation and temperature conditions by analyzing the spatial and temporal variation of vegetation cover (NDVI) in Mu Us Desert during 2000-2019. MODIS vegetation indices are designed to provide consistent spatial and temporal comparisons of vegetation conditions. Maximum Value Composites (MVC) is an internationally used statistical method for NDVI data. Based on MODIS remote sensing data, the NDVI of Mu Us Desert sandy land from 2000 to 2019 was analyzed by using the linear regression slope method. In 2000-2010 and 2010-2019, there was a difference in the change rate of vegetation index in Mu Us Desert, with the average slope of 0.0650/10a for the former and 0.0782/10a for the latter. The trends of NDVI values in the study area during 2000-2019 were roughly the same as those of precipitation, and slightly different from those of temperature, but the overall correlation between NDVI values and both was good. There is a significant positive correlation between NDVI and annual precipitation (0.687), and a weak correlation with temperature (0.264). The vegetation growth in Mu Us Desert is affected by both precipitation and temperature.

Climate change poses significant challenges to water resources and streamflow in Ethiopia, a country highly dependent on agriculture and vulnerable to environmental shifts. This paper reviews the current state of knowledge on climate change impacts on streamflow in Ethiopia, emphasizing factors driving these changes and drawing insights from relevant studies. The analysis encompasses hydrological responses to climate change, including alterations in precipitation patterns, temperature fluctuations, and changes in water availability. Additionally, the study examines the impact of land use changes on streamflow dynamics. Comparative insights from neighboring countries and river basins further illuminate the broader regional implications of climate change on water resources. According to the previous research reviewed in this paper, climate change, land use change, and increment in extreme events (drought) have affected the stream flow over the last decades. The findings underscore the urgent need for adaptive strategies and sustainable water management practices to mitigate the adverse effects of climate change on streamflow and ensure water security in Ethiopia and beyond. HIGHLIGHTS The review paper provides localized insights into climate change impacts.; It contributes valuable information for water resource managers and policymakers.; It assesses the risks posed by climate change to Ethiopia's hydro-meteorological conditions.; It explores the socioeconomic consequences of hydro-meteorological changes induced by climate change.; The review contributes to the scientific knowledge base.;

Climate change refers to long-term alterations in climate patterns across various regions of the world. As per the data availability and explanations given by different researchers, human exercises, particularly the burning of coal, deforestation, and the use of oil, have increased the temperature of the Earth by significantly improving the engagement of heat-absorbing gases in the environment. The above-stated ratio will increase proportionally in the future. Therefore, climate change is one of our biggest global challenges, and urgent action must be taken to reduce greenhouse gas emissions, and adapt to its effects, and ensure a long and healthy life for all. This paper examines the different aspects of the effects of climate change on different ecosystem elements, such as air, water, plants, animals, and human beings, with a notable focus on economic aspects. Finally, to better understand the situation, data in this report were collected from different media platforms, research mechanisms, guideline papers, newspapers, and other references. This review paper considers climate change mitigation and transformation worldwide in different sectors like human health, crop productivity, and the related economic impact. The conclusions emphasize that government monitoring is essential for countries' long-term growth through responsible resource management. HIGHLIGHTS This paper examines the different aspects of the effects of climate change on different ecosystem elements, such as air, water, plants, animals, and human beings, with a notable focus on economic aspects.; This paper also examines relief efforts, focusing on human health, biodiversity water resources and tourism.; This study also focuses on adaptation and mitigation strategies of climate change on different sectors.;

Non-stationary methods of flood frequency analysis are widespread in research but rarely implemented by practitioners. One reason may be that research papers on non-stationary statistical models tend to focus on model fitting rather than extracting the sort of results needed by designers and decision makers. It can be difficult to extract useful results from non-stationary models that include stochastic covariates for which the value in any future year is unknown. We explore the motivation for including such covariates, whether on their own or in addition to a covariate based on time. We set out a method for expressing the results of non-stationary models as an integrated flow estimate, which removes the dependence on the covariates. This can be defined either for a particular year or over a longer period of time. The methods are illustrated by application to a set of 375 river gauges across England and Wales. We find annual rainfall to be a useful covariate at many gauges, sometimes in conjunction with a time-based covariate. For estimating flood frequency in future conditions, we advocate exploring hybrid approaches that combine the best attributes of non-stationary statistical models and simulation models that can represent changes in climate and river catchments. [ABSTRACT FROM AUTHOR]

In the 21st century, climate change, which is predominantly caused by human activities, has emerged as a major global concern. This paper examines in depth the profound and multifarious effects of climate change on ecosystems and the ecosystem services they provide. It further investigates the complex connections between climate change and ecosystems, focusing on terrestrial, aquatic, and marine habitats. Notably, we emphasize the unique challenges confronting ecosystems in Southeast Asia, a region of ecological significance where the ocean economy is fundamental to human livelihoods. Climate change threatens ecosystem services in numerous ways, including the provision of food and water, climate regulation, nutrient cycling, and cultural importance. We emphasize the potential transformation of ecosystems from carbon sinks to carbon sources, which has implications for climate control. Moreover, changes in disease vectors and altered landscapes raise concerns for human health and cultural traditions. We emphasize the importance of international cooperation, as exemplified by the Paris Agreement, in mitigating climate change collectively. In addition, we advocate for the inclusion of indigenous communities and traditional ecological knowledge in conservation and restoration initiatives. This paper concludes by emphasizing the profound interdependence between ecosystems and human well-being and the urgency of taking action. HIGHLIGHTS Climate change impacts on aquatic ecosystems, terrestrial ecosystems, ecosystem services.; Future management.;

The paper presents prominent Nordic contributions to stochastic methods in hydrology and water resources during the previous 50 years. The development in methods from analysis of stationary and independent hydrological events to include non-stationarity, risk analysis, big data, operational research and climate change impacts is hereby demonstrated. The paper is divided into four main sections covering flood frequency and drought analyses, assessment of rainfall extremes, stochastic approaches to water resources management and approaches to climate change and adaptation efforts. It is intended as a review paper referring to a rich selection of internationally published papers authored by Nordic hydrologists or hydrologists from abroad working in a Nordic country or in cooperation with Nordic hydrologists. Emerging trends in needs and methodologies are highlighted in the conclusions. [ABSTRACT FROM AUTHOR]

Poor water quality is a widespread issue in urban rivers and streams in London. Localised pollution can have impacts on local communities, from health issues to environmental degradation and restricted recreational use of water. The Salmons and Pymmes Brooks, located in the London Borough of Enfield, flow into the River Lee, and in this paper, the impacts of misconnected sewers, urban runoff and atmospheric pollution have been evaluated. The first step towards finding a sustainable and effective solution to these issues is to identify sources and paths of pollutants and to understand their cycle through catchments and rivers. The INCA water quality model has been applied to the Salmons and Pymmes urban catchments in north-east London, with the aim of providing local communities and community action groups such as Thames21 with a tool they can use to assess the water quality issue. INCA is a process-based, dynamic flow and quality model, and so it can account for daily changes in temperature, flow, water velocity and residence time that all affect reaction kinetics and hence chemical flux. As INCA is process-based, a set of mitigation strategies have been evaluated including constructed wetland across the catchment to assess pollution control. The constructed wetlands can make a significant difference reducing sediment transport and improving nutrient control for nitrogen and phosphorus. The results of this paper show that a substantial reduction in nitrate, ammonium and phosphorus concentrations can be achieved if a proper catchment-scale wetland implementation strategy is put in place. Furthermore, the paper shows how the nutrient reduction efficiency of the wetlands should not be affected by climate change. [ABSTRACT FROM AUTHOR]

Climate change is widely acknowledged as a serious threat to global development, and Bangladesh is no exception; without a doubt, global warming has placed Bangladesh among the most vulnerable countries. The motivation behind this paper is to examine the effects of climate change by taking into account the changes in temperature and precipitation over time. This paper first evaluates the climate change impact on crop production by using a crop modeling framework and then constructs a dynamic computable general equilibrium (CGE) model. The result of this study finds that average gross domestic product (GDP) decreases by −6.17% and investment declines by −7.76% due to the climate change impact. The impacts of climate change on rice sectors were felt more intensely, increasing prices by 5.82 and 8.11%, reducing output by −3.08 and −3.7% collectively in 2030 and 2050. The agricultural sectors’ output declined more compared to the manufacturing, mining and gas, construction, service and transportation sectors, which indicates declines in agricultural labor and household income. In conclusion, the impact of climate change by analyzing the computable general equilibrium model in Bangladesh had been paid little attention in the past and this paper tried to fill the gaps and provide policy-makers with crucial information and guide government policies. HIGHLIGHTS Develops a dynamic computable general equilibrium (DCGE) model to evaluate how climate change may influence Bangladesh's economy by and large.; Significant decline observed in GDP, consumption, investment, savings, household income, export, and output.; Agricultural sectors shrank more compared to other sectors in the economy.;

One of the major crops produced in Saudi Arabia is the date palm tree, Phoenix dactylifera L., as it can tolerate the harsh desert climate. One of the largest palm production areas in Saudi Arabia is the Al-Hassa oases, it has approximately 3 million date palms. However, by the end of the 21st century (2071–2100), climate change impacts will create a strain on the date production industry in the Al-Hassa region. Therefore, current practices need to be altered and various strategies must be adopted as changing the industry or moving regions are not viable options. This paper examines the impact of possible global warming based on various general circulation models, regional climate models, and scenarios developed by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios on the climate in Al-Hassa by mid and end of the century. This paper discusses how these effects may impact date production and its distribution in the study area based on the resources available and on an individual, community, regional, national, and global scale. Possible options for sustaining the industry and what barriers or limitations may be faced by the proposed adaptation measures are discussed in this paper. HIGHLIGHTS There are no current studies specific to climate change effects on date production in Al-Hassa.; The region presents a unique challenge as it has springs and aquifers.; Actions need to be made to conserve agricultural production as there are not many other local production.; Prospects for better water management and agricultural practices need to be addressed.; Dates are one of the most important socioeconomic crops in Saudi Arabia.;

This paper discusses the response of climate change impact on future streamflow availability in Upper Awash River basin, Ethiopia. The change of climate was built using the CORDEX, RCM daily precipitation, maximum and minimum temperature under RCP4.5 and 8.5 scenarios. The climate model was examined in the historical period 1996–2015 for its ability to capture observed precipitation and temperature. Bias correction was performed on RCM temperature and precipitation to minimize the uncertainties that may occur from climate model projection. After the successful calibration and validation of the HBV hydrological model, streamflow was simulated for the periods of 2021–2040 and 2041–2060 and compared to streamflow of the baseline period 1996–2015 to investigate the changes. The results suggested that overall, following the precipitation increment, streamflow is expected to increase under both RCPs. The average monthly changes of streamflow are expected to increase by 40.1 and 29.4% under RCP4.5 and 16.9 and 18.5% under RCP8.5 scenarios for 2021–2040 and 2041–2060, respectively. Annual streamflow would increase by 28.5 and 23.95% under RCP4.5 and 8.5, respectively. The results of this work can help and inform the water resources planner and designer to frame an appropriate plan and management for the effective use of water in the future. HIGHLIGHTS This study focus on stream-flow response to projected climate change in the Upper Awash sub-basin, Ethiopia.; This paper coupled RCM with RCPs and HBV hydrological model.; Bias correction was performed on RCM temperature and precipitation.; Comparative analysis of the differences between projected and baseline stream-flow were discussed.; Overall projected stream-flow would increase under both RCP scenarios.;

In high altitude, scarcely gauged basins, climate change impact assessment on river discharge is important for sustainable management of water resources. These basins are sources for irrigation and hydropower generation in the region. Expected changes in precipitation and temperature can affect the basin's hydrological regime which will have consequential impacts on the dependent sectors. For quantifying the impacts of major climatic variables on hydrological processes, this paper examined bias-corrected GCM outputs coupled with a hydrological model – HBV for Chenab basin. Trend analysis shows that precipitation would decrease after the short-term period and temperature is expected to increase throughout the century. Simulated river discharge is expected to increase throughout the 21st century under both RCP 4.5 and RCP 8.5 scenarios. It is also observed that there would be a shift in seasonal discharge patterns with increased pre- and post-monsoon contributions. Increase in snow and ice melt contribution to the overall discharge is also expected and would range between 50 and 59% until 2100. This study concluded that expected increase in discharge volume coupled with shift in seasonal discharge pattern would impact the basin water management and thus it is important to consider the impact of climate change on the hydrological regimes of basins. HIGHLIGHTS Paper deals with the ungauged basin originating from the Himalayas and assesses shifts in seasonal discharge patterns which highlights increased pre- and post- monsoon contributions in annual discharge.; Output from the study is important for the data scarce Himalayan region and for better planning and management of water resources.;

In the context of climate change, salinity intrusion into rivers has been, and will be, one of the most important issues for coastal water resources management. A combination of changes, including increased temperature, change in regional rainfall, especially sea level rise (SLR) related to climate change, will have significant impacts on this phenomenon. This paper presents the outcomes of a study conducted in the Mekong Delta of Vietnam (MKD) for evaluating the effect of sea water intrusion under a new SLR scenario. Salinity intrusion was simulated by one-dimensional (1D) modeling. The relative sea level projection was constructed corresponding to the RCP 6.0 emission scenario for MKD based on the statistical downscaling method. The sea level in 2050 is projected to increase from 25 cm to 30 cm compared to the baseline period (in 2000). Furthermore, the simulated results suggested that salinity greater than 4 g/l, which affects rice yield, will intrude up to 50-60 km into the river. Approximately 30,000 ha of agricultural area will be affected if the sea level rise is 30 cm.

The recession of water levels of natural lakes and their associated impacts on wetland ecosystems is a serious issue worldwide. Poyang Lake (the largest freshwater lake in China) has experienced a heightened and prolonged water decline since the year 2000, which causes concern for associated ecological impacts. In particular, climate change, operation of the Three Gorges Dam (TGD), and high magnitude sand mining appear to be well-correlated with the occurrence of water decline in Poyang Lake. Though the above factors have been analyzed in previous studies, a comprehensive summary has never been compiled. This paper provides a detailed literary review highlighting the driving forces and possible impacts of the consistent water decline in Poyang Lake. We conclude here that the operation of TGD is a fundamental cause for the lake water decline, aggravated by climate change and sand mining. The water decline has caused a deterioration of water quality, as well as having given rise to a potential threat to the habitat of migratory birds and Yangtze finless porpoises. The paper intends to offer constructive references that can be used in decision-making for effective protection of water resources and lake ecosystems. HIGHLIGHTS This study provides the first review of driving forces of the water decline in Poyang Lake and its impacts.; We have chosen climate change, operation of Three Gorges Dam and sand mining to discuss the driving forces of water decline.; We have chosen four elements (water quality, landscape, migratory birds, and Yangtze finless porpoises) as representative examples to reveal severe influences on the water decline.;

This paper interrogates indigenous knowledge systems (IKS) based climate governance in water and land resource management in under-resourced areas of Zimbabwe. Water and land resources are fundamental for smallholder farmers and their productivity. The concept of IKS plays a significant role in climate change adaptation in Zimbabwe's rural communities. Climate change has a considerable influence on the success of agricultural production in the rural communities of Zimbabwe. Hence, it becomes fundamental to assess the community-based methods of climate governance. Qualitative multiple case study exploratory designs were employed with data collected through individual interviews with smallholder farmers, and thematic content analysis was used to analyse data. This study found that enhancing and embracing IKS is of paramount importance for inclusion in local-level strategies in the development process with special reference to climate governance in water and land resource management, particularly in under-resourced communities. It also established that the use of IKS enhances communities' adaptive capacity and it should not be conducted at the expense of scientific methods but rather should be employed in order to complement the existing scientific global knowledge systems. HIGHLIGHTS This paper interrogates the role of IKS in land and water resources sectors.; This study makes a striking contribution by revealing the strengths and weaknesses of IKS in climate change adaptation.; This paper recommends the incorporation of IKS into national climate change policy.;

We examine the relative impact of population increases and climate change in affecting future water demand for Sydney, Australia. We use the Weather and Research Forecasting model, a water demand model and a stochastic weather generator to downscale four different global climate models for the present (1990–2010), near (2020–2040) and far (2060–2080) future. Projected climate change would increase median metered consumption, at 2019/2020 population levels, from around 484 GL under present climate to 484–494 GL under near future climate and 495–505 GL under far future climate. Population changes from 2014/2015 to 2024/2025 have a far larger impact, increasing median metered consumption from 457 to 508 GL under the present climate, 463 to 515 GL under near future climate and from 471 to 524 GL under far future climate. The projected changes in consumption are sensitive to the climate model used. Overall, while population growth is a far stronger driver of increasing water demand than climate change for Sydney, both act in parallel to reduce the time it would take for all storage to be exhausted. Failing to account for climate change would therefore lead to overconfidence in the reliability of Sydney's water supply. HIGHLIGHTS This paper combines an urban water consumption model, regional climate models and a stochastic weather generator to generate probabilistic consumption forecasts.; This paper analyses the effect of climate change on urban water consumption.; This paper compares the relative effect of climate change and population on urban water consumption.; This paper analyses the effect of dwelling type on urban water consumption.; This paper compares the statistical properties of weather variables from different regional climate models.;

Many countries in the world, including South Africa, are water-stressed with increasing pressure on their water resources due to population growth, climate change, and inadequate funding. Post-independence in 1994, many policies and programmes were introduced by the government with the aim of promoting water management. While these policies and strategies achieved much in terms of water provision to communities and households, they failed to establish a water-conscious country with sufficient knowledge and expertise in water management. In addition, these policies and programmes are outdated, compartmentalised, complex, and lack robust water governance with resilient stakeholder partnerships that advance the more explicit second phase of the National Development Plan (NDP) to achieve water security under the threat of climate change. Using data collection tools inspired by the traditional method of participatory research, this paper analyses the structural and systematic factors hindering the implementation of comprehensive policies to achieve water security in South Africa. There is, therefore, an urgent need for South Africa to establish an independent water regulator to ensure coordination between different government departments, including the National Treasury, to strengthen weak governance capacity and to make it independent to attract private equity into the sector and to recover fiscal deficits in the water sector. Highlights The paper deals with water security in South Africa post-1994.; The country inherited a backlog of unfair water distribution due to the racial injustices of the past.; Post independence in 1994, the new government of South Africa introduced numerous policies and programmes to address the challenges in the water sector, while much have been achieved in terms of fair water distribution of water.; The policies and programmes have, however, failed to address other issues and constraints in the sector.;

Climate change and human interventions over the past few decades have significantly affected the groundwater resources in Ladakh Himalaya. Sparse or lack of suitable data and knowledge gaps are a major challenge in evaluating these impacts. Here, we synthesize the available data to assess the status of groundwater quantity, quality, withdrawal, and contamination in the Leh district of India. The study shows that glacier area has decreased by 40% whereas its volume has reduced by 25% since the Little Ice Age (∼1650 AD). The glacier melt, which influences the recharge, has reduced significantly. The growth of population by 15% per year, expansion of built-up area by 50%, and changes in the socio-ecology have further stressed the groundwater. The bore wells and groundwater draft have increased at ∼115 wells/year and ∼7 MCM/year, respectively. The increase of groundwater development by ∼26 times has reduced the reserves. Hence, for the sustainability of the resource, modeling and managing the impacts is urgently required. In this direction, this paper provides guidelines for researchers, policymakers, and water users to develop an integrative consortium management strategy for the sustainable utilization of the groundwater. HIGHLIGHTS Rise of temperature, high variability of precipitation, and change in its pattern have reduced the groundwater reserves of Ladakh Himalaya.; Population expansion, the tourism industry, urbanization, changes in land use, and water demands have also affected the groundwater and quality.; The need arises to model and manage the resources keeping the current and future scenario of the affecting factors in view.;

The objective of this paper is to assess climate change impacts on spatiotemporal changes in annual and seasonal runoff and its components in the basins of two large European rivers, the Vistula and the Odra, for future horizons. This study makes use of the Soil and Water Assessment Tool (SWAT) model, set up at high resolution, and driven by a multi-model ensemble (MME) of nine bias-corrected EURO-CORDEX simulations under two representative concentration pathways (RCPs), 4.5 and 8.5. This paper presents a wealth of illustrative material referring to the annual and seasonal runoff (R) in the reference period as well as projections for the future (MME mean change), with explicit illustration of the multi-model spread based on the agreement between models and statistical significance of change according to each model. Annual R increases are dominating, regardless of RCP and future horizon. The magnitude of the MME mean of spatially averaged increase varies between 15.8% (RCP 4.5, near future) and 41.6% (RCP 8.5, far future). The seasonal patterns show the highest increase in winter and the lowest in spring, whereas the spatial patterns show the highest increase in the inner, lowland part, and the lowest in the southern mountainous part of the basin. [ABSTRACT FROM AUTHOR]

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.

A traditional hydrologic water infrastructure design assumes that the climate is stationary, and that historic data reflect future conditions. The traditional approach may no longer be applicable since the earth's climate is not stationary. Thus, there is a need for a new way of designing water infrastructure that accounts for the effects of climate change by shifting the current static design paradigm to a more dynamic paradigm. Researchers have proposed several approaches accounting for climate change. In this paper, we group the approaches into five groups (adaptive management, inverse climate change impact, machine learning, flood frequency analysis, and soft computing approaches), outline each approach's strengths and weaknesses, and assess their applicability to the water infrastructure design. We find that the flood frequency analysis approach is most applicable to the water infrastructure design as it is the least disruptive in terms of standard hydrological analysis methods, is cost-effective, and adaptable to most basins. However, adaptive management approaches are best suited for uncertainty reductions since they provide opportunities to constantly adjust decisions based on improved climate change data. Combining these two approaches could provide an optimal way of accounting for non-stationarity. HIGHLIGHTS This study offers a summary of approaches to designing more climate-resilient water infrastructure.; This study extends the literature and knowledge of applicable approaches, allowing water managers to consider a broader suite of management options with stakeholders.; To our knowledge, this is the first comparative review of uncertainty approaches for addressing non-stationarity in water infrastructure design.;

This paper focuses on exploring the potential of Climate resilient agriculture (CRA) for river basin-scale management. Our analysis is based on long-term historical and future climate and hydrological datasets within a GIS environment, focusing on the Ajoy River basin in West Bengal, Eastern India. The standardized anomaly index (SAI) and slope of the linear regression (SLR) methods were employed to analyse the spatial pattern of the climate variables (precipitation, Tmax and Tmin) and hydrological variables (actual evapotranspiration (AET), runoff (Q), vapor pressure deficit (VPD), potential evapotranspiration (PET), and climate water deficit (DEF)) using the TerraClimate dataset spanning from 1958 to 2020. Future climate trend analysis spanning 2021 to 2050 was conducted using the CMIP6 based GCMs (MIROC6 and EC-Earth3) dataset under shared socio-economic pathway (SSP2-4.5, SSP5-8.5 and historical). For spatiotemporal water storage analysis, we relied on Gravity Recovery and Climate Experiment (GRACE) from the Center for Space Research (CSR) and the Jet Propulsion Laboratory (JPL) data, covering the period from 2002 to 2021. Validation was performed using regional groundwater level data, employing various machine learning classification models. Our findings revealed a negative precipitation trend (approximately −0.04 mm/year) in the southern part, whereas the northern part exhibited a positive trend (approximately 0.10 mm/year). HIGHLIGHTS The slope of the linear regression method was employed for the spatial distribution of the climatic and hydrological conditions (1958–2020).; Future climate trend analysis (2021–2100) has been executed through the CMIP6 (MIROC6 and EC-Earth3) SSP245, SSP585 and historical dataset.; A novel ensemble boosting machine learning algorithm was used for the validation of groundwater level.;

Urbanization and climate change are two potent forces shaping the contemporary environment. Urban rivers, integral to city life, are profoundly affected by these dynamics. While restoration efforts have yielded promising results, a persistent challenge lies in the inadequate consideration of geomorphic processes and climate change impacts in restoration planning. This study addresses this critical gap by proposing a novel approach for designing stable urban river geometries in ungauged basins. Leveraging the Soil Conservation Service (SCS) method in conjunction with General Circulation Model (GCM) data, our research focuses on determining design discharge and channel stability. Our principal finding, based on the incorporation of parameters related to precipitation, runoff, and effective discharge, indicates a projected 35% increase in the width of stable urban rivers in the future. These results underscore the urgency of integrating climate change considerations into urban river restoration initiatives. Neglecting this imperative aspect risks the failure of restoration projects, particularly in addressing geomorphic challenges intensified by climate change. This research offers a valuable framework for future restoration efforts, ultimately contributing to the resilience and sustainability of urban river ecosystems. HIGHLIGHTS The manuscript advocates for a resilience-centric approach to urban river management. It underscores the importance of recalibrating historical reference conditions to adapt to climate-induced alterations.; The findings have immediate and far-reaching implications for urban river restoration projects. By recognizing the profound imprint of climate change on river stability parameters, stakeholders can recalibrate their restoration strategies to align with evolving environmental conditions. This adaptability is pivotal for preserving and enhancing urban river ecosystems.; Determine the design discharge according to the effective and bankfull discharge in the future.; This paper proposed a method to use the initial abstraction ratio to determine the discharge with a return period in ungauged basins.;

The principles and degrees to which land use change and climate change affect direct runoff generation are distinctive. In this paper, based on the MODIS data of land use in 1992 and 2003, the impacts of land use and climate change are explored using the Soil Conservation Service Curve Number (SCS-CN) method under two defined scenarios. In the first scenario, the precipitation is assumed to be constant, and thus the consequence of land use change could be evaluated. In the second scenario, the condition of land use is assumed to be constant, so the influence only induced by climate change could be assessed. Combining the conclusions of two scenarios, the effects of land use and climate change on direct runoff volume can be separated. At last, it is concluded: for the study basin, the land use types which have the greatest effect on direct runoff generation are agricultural land and water body. For the big sub basins, the effect of land use change is generally larger than that of climate change; for middle and small sub basins, most of them suffer more from land use change than from climate change.

Urban drainage systems are in general failing in their functions mainly due to non-stationary climate and rapid urbanization. As these systems are becoming less efficient, issues such as sewer overflows and increase in urban flooding leading to surge in pollutant loads to receiving water bodies are becoming pervasive rapidly. A comprehensive investigation is required to understand these factors impacting the functioning of urban drainage, which vary spatially and temporally and are more complex when weaving together. It is necessary to establish a cost-effective, integrated planning and design framework for every local area by incorporating fit for purpose alternatives. Carefully selected adaptive measures are required for the provision of sustainable drainage systems to meet combined challenges of climate change and urbanization. This paper reviews challenges associated with urban drainage systems and explores limitations and potentials of different adaptation alternatives. It is hoped that the paper would provide drainage engineers, water planners, and decision makers with the state of the art information and technologies regarding adaptation options to increase drainage systems efficiency under changing climate and urbanization.

Due to increasing concern on developing measures for predictive adaptation to climate change impacts on hydrology, several studies have tended to be conducted on trends in climatic data. Conventionally, trend analysis comprises testing the null hypothesis H0 (no trend) by applying the Mann-Kendall or Spearman's rho test to the entire time series. This leads to lack of information about hidden short-durational increasing or decreasing trends (hereinafter called sub-trends) in the data. Furthermore, common trend tests are purely statistical in nature and their results can be meaningless sometimes, especially when not supported by graphical exploration of changes in the data. This paper presents a graphical-statistical methodology to identify and separately analyze sub-trends for supporting attribution of hydrological changes. The method is based on cumulative sum of differences between exceedance and non-exceedance counts of data points. Through the method, it is possible to appreciate that climate variability comprises large-scale random fluctuations in terms of rising and falling hydro-climatic sub-trends which can be associated with certain attributes. Illustration on how to apply the introduced methodology was made using data over the White Nile region in Africa. Links for downloading a tool called CSD-VAT to implement the presented methodology were provided. [ABSTRACT FROM AUTHOR]

Lake Urmia, as the largest lake in Iran, has suffered from water-level decline and this problem needs to be investigated accurately. The major reason for the decline is controversial. The current paper aimed to study the hydro-environmental variables over the Lake Urmia basin using remote sensing tools, artificial neural networks, wavelet transforms, and Mann-Kendall trend tests from 1995 to 2019 in order to determine the primary reason of the decline and to find the most important hydrologic periodicities over the basin. The results indicated that for the monthly-, seasonally-, and annually-based time series, the components with 4-month and 16-month, 24- and 48-month, and 2- and 4-year, respectively, are the most dominant periodicities over the basin. The agricultural increase according to the vegetation index and evapotranspiration and their close relationship with the water-level change indicated that human land-use is the main reason for the decline. The increasing agriculture, in the situations that the precipitation has not increased, caused the inflow runoff to the lake to decline and the remaining smaller discharge is not sufficient to stabilize the water level. Temperature time series, also, has experienced a significant positive trend which intensified the water-level change. [ABSTRACT FROM AUTHOR]

The uncertainty in the climate projection arising from various climate models is very common, and averaging such results poses a risk of underestimation or sometimes overestimation of impact in magnitude and frequency. Further, the performance of various climate models in monsoon degrades drastically due to the skewed nature. Under these circumstances, the performance of the climate model in the monsoon and non-monsoon periods is critical for accurate assessment. A multimodal approach has been used in the present work to quantify the uncertainty involved in the climate model using reliability ensemble averaging (REA). Based on AR6 of IPCC, the ensemble of 26 global climate models (GCMs) was used to evaluate the model performance and possible change in seasonal precipitation in four cities with distinct climate conditions, namely, Coimbatore, Rajkot, Udaipur, and Siliguri. The results show that non-monsoon and monsoon rainfall are expected to increase in all the regions. Most of the models perform poorly in simulating monsoon climate, especially in the monsoon period and are highly inconsistent spatially. The study also finds that the model performance is largely linked to the ratio of natural variability and mean. HIGHLIGHTS The paper discusses multimodal performance in climate change assessment in a monsoon-fed climate where the precipitation pattern is skewed.; Model bias for each climate model was quantified on a seasonal scale using Reliability Ensemble Averaging.; The performance of the GCMs largely depends on the ratio of natural variability to mean at regional level.; A reliable estimate of the change in climate variables is made using REA in CMIP6 framework for four climate scenarios, namely, SSP126, SSP245, SSP370, and SSP585.;

The paper aimed to evaluate the impacts of water pricing and quota policies under changing climatic conditions on the major production factors using economic-biophysical modeling. The data were collected by 382 questionnaires focusing on wheat, barley, cotton, alfalfa, and sugar beet crops in the 2017–2018 cropping year in North Khorasan Province, Iran. Climate change scenarios were defined as wet, moderate, and dry scenarios resulting from precipitation changes. The results showed that climate change scenarios reduce the total irrigated area of crops and total water used. Due to the effect of precipitation on crop yield, dry and moderate climate changes reduce the total gross income, while wet climate changes increase it. The scenarios of quota and pricing policies were then applied under climate change scenarios. The amount of water conserved by applying the quota policy was equal to the quota rate, while the impact of the pricing policy varied depending on the type of climate change. The highest amount of water conserved belonged to the conditions of dry climate change in Atrak and Central Desert catchments, which was about 6.8–8.6 and 3.83–14.48%, respectively. As the climate moves toward drought conditions in this province, the implementation of such policies can partially protect water resources. HIGHLIGHTS The effects of climate change and water policies scenarios were evaluated by an economic-biophysical modeling for the major crops in the 2017–2018 cropping year in North Khorasan province.; The climate change will reduce the irrigated area and the total gross income of farmers.; By the quota and pricing policies of water under climate change conditions, the available water for optimal consumption can be managed.;

The 2013-2015 drought in the Metropolitan Region of São Paulo exposed the lack of resilience of the regional water supply system, highly dependent on the Cantareira reservoirs. In this paper, inflows to each of the four main Cantareira reservoirs are tested for systematic change. Persistent trends in streamflow, rainfall, temperature and evapotranspiration are first evaluated. Streamflow was also tested for step change. Double-mass curves were employed to assess modification in the precipitation-runoff relationship. Subsequently, we used the climate elasticity method and the ABCD model to quantify the relative contribution of climate and human activities into the detected trends. Only Cachoeira and Atibainha sub-basins showed a significant downward trend in streamflow. The results for step change were also significant, and the year of occurrence coincided with breakpoints in precipitation-runoff relationship. For both Cachoeira and Atibainha, human activities had a more significant impact on streamflow reduction than climate variability. Land use and cover maps suggest that the reduction of pasture/abandoned land parallel to an increase in reforestation/silviculture is behind streamflow reduction. The results highlight the importance of coordinating land-use patterns and water management, as an important contributor beyond any considerations of a changing climate. Implications for better managing regional water resources are discussed. [ABSTRACT FROM AUTHOR]

Climate change coupled with urbanization and its increasing impervious surfaces have caused major challenges for the water sector worldwide. In Norway, an ageing infrastructure with already insufficient drainage capacities results in large amounts of runoff during high-intensity rainfall events causing frequent floods in urban areas. Due to limited available space to handle the future projected increase in stormwater, there is a need to utilize already occupied space for stormwater management, such as roads and streets, during extreme events. Limited research has been done on the design and applicability of urban streets as temporarily flood ways diverting stormwater to the nearest recipient. This paper will study the benefits and limitations of adapting urban streets as safe flood ways to route stormwater by modelling an urban street as a floodway. Streets as floodways will require additional hydraulic performance criteria and safety criteria. Performance criteria are identified and evaluated, and a method is proposed for the evaluation of urban streets applicability as floodways. The method can be used to evaluate the applicability of multifunctional streets used as urban floodways and can be adapted by municipalities as a decision support tool for stormwater management. [ABSTRACT FROM AUTHOR]

The Hamburg Water Group owns and operates a sewer network with a total length of more than 5,700 km. There has been increasing attention paid to the possible impacts of predicted changes in precipitation patterns on the sewer network infrastructure. The primary objective of the work presented in this paper is an estimation of the hydraulic impacts of climate change on the Hamburg drainage system. As a first step, simulated rainfalls based on the regional climate model REMO were compared and validated with long-term precipitation measurements. In the second step, the hydraulic effects on the sewer network of Hamburg have been analyzed based on simulated long-term rainfall series for the period of 2000-2100. Simulation results show a significant increase in combined sewer overflows by 50% as well as an increase in surcharges of storm sewer manholes. However, there is still a substantial amount of uncertainty resulting from model uncertainty and unknown development of future greenhouse gas emissions. So far, there seems to be no sound basis for the implementation of an overall climate factor for sewer dimensioning for the Hamburg region. Nevertheless, possible effects of climate change should be taken into account within the planning process for major sewer extensions or modifications.

The Star City rainwater harvesting system (RWHS) was featured in the December, 2008, issue of Water 21. The article highlighted that the RWHS has a 3,000 m3 rainwater tank used in water saving, flood mitigation, and emergency response. Since then, many news media, public officials, and people from both South Korea and abroad have visited the RWHS. In this paper, two years of the system's operational data are presented and its role in short- and long-term climate change adaptation is investigated. The downstream sewer system has become safe for a 50-year rainfall without upgrading the existing sewer system, which was designed for a 10-year period. The 26,000 m3 of water saved has reduced the energy requirement of transferring water from a distant area. The success of the Star City RWHS has influenced 47 cities across South Korea, including Seoul, to enact regulations on rainwater management. It has shown that decentralized rainwater management can supplement the existing centralized system to ensure its safety.

This paper describes a spatially explicit, physically based global model for water balance. Its key innovations include the fact that it comes with all data required for application, is very high spatial resolution (1 km or 1-hectare resolution) and yet global in extent and is particularly well suited to heterogeneous environments with little or no available data. The model, WaterWorld, is capable producing a hydrological baseline representing the mean water balance for 1950-2000 and allow users to apply ensemble scenarios for climate change or examine the impact of policy options for land cover change or land management interventions. WaterWorld is focused on policy support, especially in conservation hydrology and development applications and is delivered through a simple web interface, requiring little local capacity for use. The paper discusses the paucity of hydrological data and the urgency of hydrological problems in much of the less-developed world which reinforce the need for tools like WaterWorld. We discuss the types of hydrological problems that models might contribute to managing and the requirements of models applied to such problems. By way of example, applications of WaterWorld to understanding large-scale patterns o water resources and uncertainty around adaptation to climate change are described. [ABSTRACT FROM AUTHOR]