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To address ongoing threats from human pressures and climate changes, water managers and users require a visual tool that provides accurate information about the health of waterbodies for decision making. However, there is a lack of less sophisticated methods, such as biotic scoring, to assess the health of rivers in West Africa. To bridge this gap, we have developed a macroinvertebrate-based scoring system for monitoring the health of rivers in the Sahelian regions. We adopted a multi-habitat sampling approach to collect macroinvertebrates using hand nets, and these specimens were identified mostly to family taxonomic level using keys. We recorded more than 75 taxa of macroinvertebrates, each assigned relative sensitivity scores to human disturbances ranging from 1 (very tolerant) to 10 (highly sensitive). The Burkina Biotic Score System (BBIOSS) and the Average Score Per Taxa (ASPT) demonstrated a strong and significant correlation with environmental variables, including anthropogenic pressures types (r = 0.6; p < 0.01) making it a robust tool for monitoring rivers. Here, our findings revealed that all taxa scored are expected to be those reported in Western African freshwater. This study has produced an effective tool that can be used or adapted to monitor other riverine ecosystems in West Africa, potentially contributing to the preservation of water and biological resources. [ABSTRACT FROM AUTHOR]

This article explores continuities and changes in the damming of rivers in the global South. By the 2000s, the infrastructural promises of large dams seemed exhausted. Yet, currently dams are making a strong comeback with new justifications highlighting their capacity to produce low-carbon energy and climate-proofed waterscapes, while the harms they generate are being presented as fixable. Through cases from the Mekong (Laos and Cambodia), and the Grijalva (Mexico) River Basins, we problematize these claims. Despite changes in the aspirations and agencies that foster damming, obdurate dam materialities and the new profit-maximizing operation modes provoke violent continuities of infrastructural harms and hinder the repurposing of dams to serve climate combat. Neoliberalised dams even augment climate vulnerabilities, as the more volatile rivers increasingly exceed their ordering capacities. We also show how the new dam assemblages continue dispossessing riverine residents while divergently strengthening corporate and state powers and obscuring relations of responsibility. [ABSTRACT FROM AUTHOR]

This article explores how changing environmental conditions and practices connect with shifting forms and valuations of sociality in a Ngaju Dayak village in the radically transformed peatlands of southern Borneo. It proposes that the production of values and social relations is indivisible from the production of a livelihood through material means and dwelling in the local environment. The article describes how changing Ngaju orientations to social life and the riverscape have been interlinked with fluctuations in the local valuescape. The focus is on two distinct but overlapping forms of organising sociality and labour in the riverine environment, and how they have influenced and been influenced by the dialectically conjoined Ngaju values of solidarity and autonomy, and, more recently, by emerging economic value. It is argued that the valuation of sociality crucially reflects the changing valuation of land and nature and related politics of value within the local riverscape. Finally, the article shows that the radically transformed riverine environment sets limits on (imagining) environmental practices, forms of sociality, and how they are valued. [ABSTRACT FROM AUTHOR]

Representative samples of biota collected relative to environmental gradients are important for measuring present distributions and predicting shifts in distribution of taxa in response to climate change or reduced river connectivity. Based on river ecology theory and established measures of species diversity, we present a method to identify suitable river segments for sampling and monitoring changes in taxon diversity. Alpha and beta diversities of selected aquatic macroinvertebrates were assessed in seven South African rivers. Data were drawn from historical and field samples and represented longitudinal species patterns down longitudinal river axes. Representative sampling sites were identified using a logistic regression model to predict the probability of site pairs that were more than 50% similar as a function of up-/downstream distance. Alpha diversities peaked in the upper third of river lengths; beta diversities showed predictable exponential decay rates down river axes up to and excluding the start of estuarine conditions. Application of the model to a 370-km long river indicated that 14 sites should be selected for sampling to capture overall biodiversity patterns. Additional factors, such as confluences tributaries, which influence alpha diversity at sites, are identified and incorporated into site selection. [ABSTRACT FROM AUTHOR]

At present, Bangladesh is self-sufficient in water. However, this self-sufficiency is by no means assured. Bangladesh's supplies of water are under threat through a combination of population growth, climate change, and pollution, sometimes caused by mismanagement. This article looks at the state of surface and ground waters in Bangladesh. It discusses the growing demand for water, pollution of the water bodies, and encroachment on the riverbeds, and the way in which this has been dealt with by Bangladesh's authorities. It argues that if things remain business-as-usual, it will become difficult for Bangladesh to continue with its high growth rate over the long term. [ABSTRACT FROM AUTHOR]

This article shows how Bangladesh and India intentionally maintain the status quo for the Brahmaputra River at the transboundary level, using material and ideational resources. Results show that India wants to reduce its hegemonic vulnerabilities and Bangladesh aims to maintain its control over the Brahmaputra river, simultaneously building its technical and negotiation skills. We conclude that the underlying processes of maintaining the status quo can be comprehended as 'non-decision making'. The analysis presented will help policy actors to push towards a forward-looking climate change adaptation planning for the Brahmaputra River. [ABSTRACT FROM AUTHOR]

Estimates of the impact of climate change on Sardabrud River located downstream of Alam-Kuh glacier in northern Iran, ultimately draining into the Caspian Sea, are described. In this research, the GCMs' projection data with CMIP5 scenarios have been used to predict the situation of this River over the two next decades. Projected data using GCMs (EC-EARTH, GFDL-CM3, HadGEM2-ES, MIRO-C5 and MPI-ESM-MR) for the period of 2021–2040 are employed with a 35-year observation period of 1984–2014. For data downscaling the LARS-WG method on its version 6.0 was used. Identification of the lowest error indicates (including RMSE and R2) were used to find the model with the best fit to projections from the historical period; the EC-EARTH model was used to show the changes in the basin's flow to the Sardabrud River in the period 2021–2040. Results from a conceptual glacier-hydrologic model (GSM-SOCONT) for joint simulation of daily discharges of the glacier are described. Despite a predicted 6% decrease in precipitation, the results point to an increase of 10% in flows in the Sardabrud River, meaning there is definitive evidence of reduction of annual glacier mass due to increasing temperatures and the melting of the glacier, as caused by climate change. [ABSTRACT FROM AUTHOR]

The aim of this study is to reveal statistical characteristics and exceedance probability of discharge under the combined effect of climate change and human activities. The study is conducted in the Xiaoqing River in Jinan, China, based on data of discharge, land-use types and precipitation from the period 1970–2016. A multivariate joint probability distribution of the data is established to test the univariable, bivariable and trivariable change points. These are then used to calculate and analyse the risk probability of discharge exceeding the specific values under different conditions of precipitation and land-use type. The results show that the change point calculated by trivariate joint distribution can reduce the disturbance of the change point obtained with the univariable or bivariable approach and reflect the changes of various factors in the hydrological processes more objectively. When the land-use type is taken into consideration, the trivariate distribution can reflect the variation of hydrological processes more reasonably. [ABSTRACT FROM AUTHOR]

This investigation into trends in annual discharge of Canadian rivers focuses on long-term hydrometric stations having record lengths of at least 75 years. Eliminating stations with significant non-stationarities in mean annual discharge, and stations having evidence of a large diversion or a withdrawal, resulted in a final streamflow dataset of 113 Water Survey of Canada, WSC, hydrometric stations. In order to assist with the identification of potential factors contributing to a trend, at least one representative long-term climate station was selected for each long-term hydrometric station. A comprehensive trend assessment was completed on both annual discharge and precipitation (rainfall, snowfall, and total). Of the 113 long-term hydrometric stations, significant trend was identified at 21 sites: four associated with anthropogenic activities in the watershed, eight consistent with climate change (i.e. changes in annual rainfall, or annual snowfall or annual precipitation) and the remaining nine consistent with some combination of climate and anthropogenic activities. With respect to the climate stations, about 50% had a significant trend in total precipitation without a corresponding significant trend in annual discharge. The ratio of discharge stations with significant trend to climate stations with significant trend varied with ecoregion, from 0% to 40%. Factors contributing to this discrepancy include a possible compensating trend in evapotranspiration and a watershed that is relatively insensitive to small changes in precipitation. [ABSTRACT FROM AUTHOR]

Macroinvertebrates are widely used as bio-indicators in streams and rivers, and it is usually assumed that their community composition is primarily controlled by local environmental conditions. We examined the distribution of macroinvertebrates within the Guadalupe River basin (3256 km2) in Central Texas across physiographic gradients. Spatial analysis with variables that considers flow direction, connectivity and distances between sites (asymmetric eigenvector maps, AEM) detected distinctive communities in the lower reaches of the mainstem, in spring-influenced reaches, and in a tributary with intermittent reaches. Variation partitioning with redundancy analysis showed that large-scale factors, i.e. riverine network patterns (large-scale AEM variables), climatic variation and ecoregion explained a significant proportion (28%) of the variation in community composition within a river basin. The riverine network patterns were the most important factor, explaining 12% alone. Local environmental factors were significant, but completely confounded within these spatial patterns. We propose that there are distinctive macroinvertebrate communities depending on the location in the river network and this may apply to other (subtropical) rivers, which should be tested by future studies. We recommend spatial analysis that considers distances and connectivity within a river network as a powerful tool to recognize multiscale riverine network patterns, which can help to identify priority areas for conservation and to develop sound monitoring programs. [ABSTRACT FROM AUTHOR]

Governing and managing water sustainably is a critical issue globally. Given its rapid economic development and the effects of global climate change, China faces serious water challenges including water shortages and pollution. The Chinese government has long been considering governance reforms which will improve water and river management. Conscious of the negative effects of fragmented institutions and the lack of incentives to support environmentally-sustainable management, China has recently established and implemented the 'He-Zhang' system - a network of River Chiefs and River Keepers across the country and at all administrative levels. This paper outlines the origins, purpose and structure of the system; summarizes progress with its implementation; and identifies some of its future challenges. [ABSTRACT FROM AUTHOR]

Climate change is projected to affect the flow regime in urban waterways adversely. This study investigates the climate change impacts on the flow regime in the Lucas Creek catchment under three Representative Concentration Pathways (RCPs): RCP 2.6, RCP 4.5 and RCP 8.5. Flow Duration Curves (FDCs) and Indicators of Hydrological Alteration (IHA) methods are used to assess flow regime variations. Results of FDCs show a maximum rise of 370% in peak flow under RCP 4.5 however, low flow increases by 40%. Monthly streamflow increases up to 380% except for October and December. Similarly, the majority of the IHA parameters also show at least a 10% increase in their magnitudes under RCP 8.5. However, some parameters such as high pulse duration and rise rate decrease by 50% under RCP 4.5. The catchment would mainly suffer severe impact variations under RCP 4.5 and RCP 8.5 in the future. [ABSTRACT FROM AUTHOR]

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The impact of climate change on Arctic rivers is expected to be severe. There is therefore a need for greater understanding of Arctic river temperature processes. This study quantifies the spatio-temporal variability of water temperatures in the Kårsa River, Sweden. Water temperature was monitored over two summers within the main proglacial channel and within braids fed by different sources. Longitudinal and lateral temperature patterns were assessed in relation to prevailing hydro-meteorology. Temperature metrics in the main channel increased with distance downstream but were moderated by a large lake, while temperatures in the braids were dependent upon channel source. The high temperature standard deviation and inter-site differences within the braids highlight the importance of braided channels for creating thermal habitat heterogeneity. Temperatures were dependent on hydro-meteorological conditions, with sensitivity to air temperature maximized during cooler, rainy conditions. These results shed new light on Arctic river temperature patterns and their controlling processes. [ABSTRACT FROM PUBLISHER]

A modelling study was undertaken to quantify effects that the climate likely to prevail in the 2050s might have on water quality in two contrasting UK rivers. In so doing, it pinpointed the extent to which time series of climate model output, for some variables derived following bias correction, are fit for purpose when used as a basis for projecting future water quality. Working at daily time step, the method involved linking regional climate model (HadRM3-PPE) projections, Future Flows Hydrology (rainfall–runoff modelling) and the QUESTOR river network water quality model. In the River Thames, the number of days when temperature, dissolved oxygen, biochemical oxygen demand and phytoplankton exceeded undesirable values (>25°C, <6 mg L−1, >4 mg L−1and >0.03 mg L−1, respectively) was estimated to increase by 4.1–26.7 days per year. The changes do not reflect impacts of any possible change in land use or land management. In the River Ure, smaller increases in occurrence of undesirable water quality are likely to occur in the future (by 1.0–11.5 days per year) and some scenarios suggested no change. Results from 11 scenarios of the hydroclimatic inputs revealed considerable uncertainty around the levels of change, which prompted analysis of the sensitivity of the QUESTOR model to simulations of current climate and hydrology. Hydrological model errors were deemed of less significance than those associated with the derivation and downscaling of driving climatic variables (rainfall, air temperature and solar radiation). Errors associated with incomplete understanding of river water quality interactions with the aquatic ecosystem were found likely to be more substantial than those associated with hydrology, but less than those related to climate model inputs. These errors are largely a manifestation of uncertainty concerning the extent to which phytoplankton biomass is controlled by invertebrate grazers, particularly in mid-summer; and the degree to which this varies from year to year. The quality of data from climate models for generating flows and defining driving variables at the extremes of their distributions has been highlighted as the major source of uncertainty in water quality model outputs.EDITOR A. Castellarin; ASSOCIATE EDITOR X. Fang [ABSTRACT FROM AUTHOR]

Hydrological alteration plays a crucial role in regulating a hydro-ecological and socio-economic framework. Apart from climate change issue and its impact on flow alteration, human interventions have brought a new paradigm on hydrological regime. The Atreyee river (390 km long) of Indo-Bangladesh is highly affected by the construction of reservoir at Mohanpur of Bangladesh. The present paper concentrates on regulating flow through the reservoir construction and its possible impacts on downstream courses at different hierarchical scales such as alteration of the dynamics of peak flow, monthly flow, average flow, minimum flow, seasonal flow, instability of flow and diurnal flow. Result shows that (1) the discharge ratio of maximum discharge from the reservoir after construction has reduced 4.15–5.66 times in the Atreyee river. (2) After the construction of the reservoir, on an average 53% discharge has curtailed down. On a seasonal scale, total run-off reduction rates are 30.97%, 66.86% and 64.01% during pre-monsoon, monsoon and post-monsoon periods. (3) Post-reservoir condition peakiness of average and maximum monthly water flow has reduced and flow variation (calculated CV) has also reduced by 4.5 and 10 times, respectively. (4) Volume of base flow has attenuated by 18.26% (26.34–21.53 cumec). (5) Percentages of discharge reduction in reservoir after condition are 30.97%, 66.86% and 64.01%, respectively, during pre-monsoon, monsoon and post-monsoon seasons. (6) Modal discharge during pre-monsoon, monsoon and post-monsoon has reduced by 13.38%, 80.31% and 72.20%, respectively. (7) Diurnal range of flow, flow volume, instantaneous flow pulses and mean up and down-ramp rates have reduced in the post-reservoir period. (8) In the post-reservoir period, flow magnitude is so lowered that it cannot maintain the natural threshold limits of flow for sustaining normal environmental performances. [ABSTRACT FROM PUBLISHER]

A 1240-year-long record of reconstructed annual flows of the Colorado River at Lees Ferry is analysed using singular spectrum analysis and multi-taper method of spectral analysis. Spectral analysis of the 100-year-long recent record of annual flows of Colorado River in the measured and reconstructed forms shows similar oscillations in high- and low-frequency bands. Therefore, the oscillatory components and trends extracted from the reconstructed data are a good representative of inter-annual, multi-decadal, and multi-centennial variability of natural flow in the river. In Colorado River the length of flow data is 1240 years and multi-centennial and multi-decadal oscillatory components can be extracted at a high confidence level. In this research we attempt to find whether the changes in streamflow in the twentieth century are due to an external cause such as climate change or whether they are part of the natural variability of flow observed in the past. The results suggest that there is only a part of the linear trend, caused by climate change or man-made effects, and an important part of that is due to climate variability which is believed to be totally natural. The same line of climate variability is still acting on our planet, and it may have gained new aspects due to the change in atmospheric composition and circulation as a result of anthropogenic effects. This may cause serious limitations to the water sustainability and water availability on the earth. [ABSTRACT FROM PUBLISHER]

A new approach, the ‘Naturalness Status' (NS), is suggested to classify the hydrologic alteration of temporary rivers from natural conditions based on the Hydrological Status Tool (HS-Tool). The HS-Tool considers two metrics: the degree and the predictability of dry flow conditions for both natural flow and its alterations, at each water body in actual and natural conditions. The Soil and Water Assessment Tool (SWAT) model is simulating the river flow of Evrotas water bodies, Greece, under natural, actual and climate-impacted conditions. The majority of Evrotas water bodies (72%) experience good (low-impacted) NS for the examined period (1990–2010), despite their intermittent flow regime. Severe flow alteration is predicted for 57% of Evrotas water bodies (high-impacted NS), while selecting the KNMI-RACMO2 future climate projections scenario (2020–2060) as input into the SWAT model. Hydrologic extreme drought phenomena or anthropogenic pressures in water regime can be quantified by the NS. The method is intended to be used in basin decision-making analysis at fulfilling the Water Framework Directive goals. [ABSTRACT FROM PUBLISHER]

Climate change will accelerate the hydrological cycle, altering rainfall, and the magnitude and timing of runoff. The purpose of this paper is to assess the impacts of climate change on streamflow and sediment yield from the Gorganroud river basin in the North of Iran. To study the effects of climatic variations, the SWAT model was implemented to simulate the hydrological regime and the SUFI-2 algorithm was used for parameter optimization. The climate change scenarios were constructed using the outcomes of three general circulation models for three emission scenarios. The study results for 2040–2069 showed an increase in annual streamflow of 5.8%, 2.8% and 9.5% and an increase in sediment yield of 47.7%, 44.5% and 35.9% for the A1F1, A2 and B1 emission scenarios, respectively. This implies that the impact of climate change on sediment yield is greater than on streamflow. Monthly variations show that the increase in discharge and sediment yield is more pronounced in wet seasons and the decrease is more pronounced in summer (July–September). The results highlighted the strong impact of climate change and reflected the importance of incorporating such analysis into adaptive management.Editor Z.W. Kundzewicz Associate editor Not assigned [ABSTRACT FROM AUTHOR]

River water temperature regimes are expected to change along with climate over the next decades. This work focuses on three important salmon rivers of eastern Canada, two of which warm up most summers to temperatures higher than the Atlantic salmon lethal limit (>28°C). Water temperature was monitored at 53 sites on the three basins during 2–18 summers, with about half of these sites either known or potential thermal refugia for salmon. Site-specific statistical models predicting water temperature, based on 10 different climate scenarios, were developed in order to assess how many of these sites will remain cool enough to serve as refugia in the future (2046–2065). The results indicate that, while 19 of the 23 identified refugia will persist, important increases in the occurrence and duration of temperature events in excess of 24°C and 28°C, respectively, in the mainstems of the rivers, will lead to higher demands for thermal refugia in the salmonid populations.Editor Z.W. Kundzewicz; Associate editor T. Okruszko [ABSTRACT FROM AUTHOR]

The Hindu Kush Himalayas are called the water towers of Asia as they are the source of 10 major rivers and have the largest snow and ice deposits outside the two poles. Water emanating from the HKH provides food, energy and ecosystem services to up to 1.3 billion people. Climate change and socio-economic and demographic changes have put unprecedented pressure on these water resources, leading to uncertain supplies, increased demands and higher risks of extreme events like floods and droughts. The eight articles in this special issue highlight various dimensions of the Himalayan water resources by focusing on both physical and social science aspects of water management. [ABSTRACT FROM PUBLISHER]

Two river catchments, the Huangfuchuan and the Hailiutu, located in the same climate zone in the Erdos Plateau, China, have distinctly different flow regimes. This study systematically compared differences between the flow regimes of these two catchments using several statistical methods, and analysed the possible causes. The variations in yearly, monthly and daily mean discharges were found to be much greater in the Huangfuchuan catchment than in the Hailiutu catchment. Preliminary analysis indicated that these differences are not caused by changes in climate, but are instead attributable to differences in geology, geomorphology, hydrological processes and human interventions. In the Hailiutu catchment, the dominant groundwater contribution maintains stationary daily and monthly river discharges, while shifts in yearly mean discharges were closely associated with the expansion or reduction of crop area. In the Huangfuchuan catchment, the dominant direct rainfall–runoff process generates flashier daily and monthly river discharges, while the decrease of yearly mean discharges is caused mainly by the construction of check dams. These findings have significant implications for water resource management and the implementation of proper soil and water conservation measures in the middle reach of the Yellow River Basin of China. Editor Z.W. Kundzewicz; Associate editor Y. Gyasi-Agyei [ABSTRACT FROM AUTHOR]

The impacts of changes in water temperature and flow on selected water quality parameters, as one of the consequences of climate change, were studied in river catchments in the Czech Republic with little anthropogenic influence. The impact of climate change was manifested by an increase in stream temperature by 1.15°C over 28 years. The selected water quality parameters were dependent on flow, with up to 10-fold increases in the concentrations of ammonia, phosphorus and chlorophyll-aat minimum flow levels. In river catchments with point source pollution predominating, significant pollution with ammonia nitrogen was observed. The influence of increased water temperature compared to flow rates was generally less marked and, with the exception of chlorophyll-a, rather positive. For existing land management and utilization of these river catchments, extreme changes in flow rates will influence the water quality more substantially than the water temperature itself.Editor Z.W. Kundzewicz [ABSTRACT FROM AUTHOR]

A practical approach to separate the impact of the processes of climate change (CC) and human activities (HA) on streamflow is presented. A non-parametric Mann-Kendall-Sneyers test, combined with movingttest and Yamamoto methods, was used to recognize abrupt change points in the runoff time series to determine a baseline period. A new algorithm to separate CC and HA influence on streamflow was deduced based on the climate elasticity concept. Application to the Chao River, China, shows that CC imposed a positive impact on streamflow in this region (25%, on average), while HA exerted a continuous negative impact of –75% in the period after the 1950s. These results are of great use in understanding the variation of CC and HA impacts under different human development patterns.Editor Z.W. Kundzewicz; Associate editor H. Aksoy [ABSTRACT FROM AUTHOR]

Managing competing needs in water resource planning will become increasingly important due to the impacts of climate change on water availability. A holistic management approach is required to ensure sustainable and equitable allocation between consumptive and environmental water needs. While consumptive licences are currently metered in Victoria, there is little data about stock and domestic usage and its associated impact on streamfl ow. This project aimed to estimate the use of stock and domestic water in the Woori Yallock catchment from waterways, groundwater and dams. The project gathered data that will improve the confi dence of hydrological modelling underpinning stream fl ow management planning in and around Melbourne. [ABSTRACT FROM AUTHOR]

This article addresses the critical need for a better quantitative understanding of how water resources from the Hérault River catchment in France have been influenced by climate variability and the increasing pressure of human activity over the last 50 years. A method is proposed for assessing the relative impacts of climate and growing water demand on the decrease in discharge observed at various gauging stations in the periods 1961–1980 and 1981–2010. An annual water balance at the basin scale was calculated first, taking into account precipitation, actual evapotranspiration, water withdrawals and water discharge. Next, the evolution of the seasonal variability in hydroclimatic conditions and water withdrawals was studied. The catchment was then divided into zones according to the main geographical characteristics to investigate the heterogeneity of the climatic and human dynamics. This delimitation took into account the distribution of climate, topography, lithology, land cover and water uses, as well as the availability of discharge series. At the area scale, annual water balances were calculated to understand the internal changes that occurred in the catchment between both past periods. The decrease in runoff can be explained by the decrease in winter precipitation in the upstream areas and by the increase during summer in both water withdrawals and evapotranspiration in the downstream areas, mainly due to the increase in temperature. Thus, water stress increased in summer by 35%. This work is the first step of a larger research project to assess possible future changes in the capacity to satisfy water demand in the Hérault River catchment, using a model that combines hydrological processes and water demand.Editor Z.W. KundzewiczCitation Collet, L., Ruelland, D., Borrell-Estupina, V., and Servat, E., 2014. Assessing the long-term impact of climatic variability and human activities on the water resources of a meso-scale Mediterranean catchment. Hydrological Sciences Journal, 59 (8), 1457–1469. http://dx.doi.org/10.1080/02626667.2013.842073 [ABSTRACT FROM PUBLISHER]

Ecological flow needs (EFN) frameworks incorporate a range of ecologically-relevant hydrological variables based on prior knowledge of river regime characteristics. However, when applied in cold regions, these approaches have largely ignored the influence of winter ice cover and the spring freshet on hydrological regimes: key components of river systems in cold regions with important direct effects on water quality, aquatic habitat and ecology. Here, we combine a review of the published literature on cold-regions hydrology and hydro-ecology with available hydrometric information for sites across Canada, a major cold-region country, to explore phenomena unique to these systems. We identify several ecologically-relevant hydrological measures (i.e. annual ice on/off dates, ice-cover duration, spring freshet initiation, peak water level during river ice break-up), pairing these with established metrics for incorporation into an enhanced suite of indicators specifically designed for cold regions. This paper presents the Cold-regions Hydrological Indicators of Change (CHIC), which can provide the basis for the assessment of EFN and climate change assessments in cold-region river ecosystems.Editor Z.W. Kundzewicz; Guest editor M. AcremanCitation Peters, D.L., Monk, W.A., and Baird, D.J., 2014. Cold-regions Hydrological Indicators of Change (CHIC) for ecological flow needs assessment. Hydrological Sciences Journal, 59 (3–4), 502–516. [ABSTRACT FROM PUBLISHER]

Characteristics of hydroclimatic change in the upper reaches of the Minjiang River are analysed using data collected over the past 50 years. The effect of autocorrelation of time series on trend analysis is removed by adopting a pre-whitening technique. Long-term hydrometeorological trend and abrupt changes are analysed by the Mann-Kendall test. The results were validated by the linear trend and Spearman methods. Correlations between runoff change with air temperature and with precipitation were studied with the Pearson method. The results clearly show that average air temperature in the upper reaches of the river is increasing, and precipitation decreasing, with differences in spatio-temporal distribution. Runoff change has a clear positive correlation with precipitation. Meteorological change, especially in precipitation, is the key governing influence of runoff volume. The annual runoff decrease, especially the decrease of inflow in spring and autumn and earlier appearance and longer duration of the low-flow season, will impact greatly on irrigation and municipal water supply. Therefore, relevant measures and further study are necessary. EditorZ.W. Kundzewicz;Associate editorQ. Zhang CitationHuang, X.R., Zhao, J.W., Li, W.H., and Jiang, H.X., 2013. Impact of climatic change on streamflow in the upper reaches of the Minjiang River, China.Hydrological Sciences Journal, 59 (1), 154–164. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the sediment dynamics that takes place at different scales within the Middle and the Lower Parana River in the La Plata Basin. The aim of this study is to provide a multi-disciplinary and multi-scale approach for the prediction of river future morphology in the context of climate change, the intended use of which is the prognosis of river morphodynamics’ long-term impact on manmade structures and activities over or near the river. The study is based on three levels of mathematical modelling, with the output of wider-scale models providing the input conditions for more specific ones. Climate models give the input ensemble, i.e. future precipitation and temperature over La Plata Basin. The semi-distributed macroscale variable infiltration capacity hydrological model simulates the flow discharge time series that are applied to an own-developed 1D morphodynamic model. The 1D model simulates future rate of sediment transport and corresponding bed-level changes at watershed scale and provides the boundary conditions for a 2D model. Therefore, streamflow divagations at channel scale are simulated by means of the MIKE21C code developed by the Danish Hydraulic Institute. The analysis indicates a rather low sensitivity of the Parana River bed profile, i.e. 1D morphology, to the increase predicted in flow discharge, whereas the streamflow appreciably divagates. In particular, surpassing an upper bound in the most frequent discharge appears effective in driving the actual bifurcated morphology into a meandering-multithread configuration. [ABSTRACT FROM PUBLISHER]

Variable seasonal stream temperatures are a critical factor in maintaining aquatic invertebrate community patterns. We investigated whether the degree of predictability in a stream's water temperature profile provides insights into the structure and functional predictability of macroinvertebrate communities. Quarterly macroinvertebrate sampling over 11 months at five paired sites along the longitudinal axes of the Keurbooms River, Western Cape, and the Kowie/Bloukrans River, Eastern Cape, was undertaken in conjunction with collection of hourly water temperatures. Macroinvertebrate taxonomic turnover across seasons was higher for sites having lower water temperature predictability values than for sites with higher predictability, while temporal partitioning was greater at sites with greater temperature variability. Macroinvertebrate taxa responded in a predictable manner to changes in their environment. Specialist taxa preferred sites with greater temperature variability, and generalist taxa those with less temperature variability. Water temperature is an important abiotic driver of stream ecosystems, and should be expressed in terms of predictability metrics, as mean values do not adequately measure the components of water temperature that are important for biotic communities. Water temperature predictability provided an indication of the structure, functional predictability and seasonal turnover in macroinvertebrate communities. These findings have implications for streams experiencing temperature modifications due to the onset of climate change. [ABSTRACT FROM AUTHOR]

The SWAT (Soil and Water Assessment Tool) was used to evaluate the impacts of a climate scenario based on IPCC A1B emissions on flows in the Volta River basin in West Africa for 2021–2050 and 2071–2100, using 1983–2012 as the reference period. Overall, the simulation indicates increased variability and a decrease of up to 40% in river flow as a consequence of decreasing rainfall and increasing temperature. In particular, the analysis shows smaller absolute but greater relative changes in the hydrology of the northern (upper) part of the basin, particularly at the end of the century. [ABSTRACT FROM PUBLISHER]

The article offers information on various aspects of temporary streams in Canada. It mentions that the Prediction in Ungauged Basins (PUB) Zeroflow workshop was held in Alberta in 2011 that focused on reconstruction, analysis and management of temporary streams in ungauged basins. It states that the temporary streams include ephemeral, intermittent and episodic channels and are common in the semi-arid areas of North America. The workshop revealed that Canada has distinct physio-climatic regions that influence the nature of temporary streamflow regimes.

The water-short adjacent basins of the Huang (Yellow), Huai and Hai Rivers in North China contain most of China's farmland. This study evaluates water vulnerability there as a function of sensitivity to climate change, people per unit flow, water use-to-availability ratio, and per capita water use. Three scenarios for 2030 are considered: (1) climate change without socio-economic changes; (2) socio-economic changes without climate change; and (3) both climate and socio-economic changes. Results show increases in the already precarious vulnerability, especially in the Hai river basin. [ABSTRACT FROM AUTHOR]

This paper quantifies the impacts of climate variability and human activities on streamflow in the Chao River catchment near Beijing from 1986 to 1998. The year 1990 is found to be an inflection point for the impact of human activities. Streamflow is simulated for before and after 1990; monthly flow is simulated for the latter period. The contribution rate of climate to streamflow change in the catchment is found to be 17%; thus, the impact of human activities was far greater than that of climate variability over the entire period. [ABSTRACT FROM AUTHOR]

This paper investigates hydrological responses to climate change in the Luan River basin in North China. The average outputs of IPCC AR4 multi-models under different scenarios (SRES-A2, A1B and B1) are used to drive the SWAT model after calibration to simulate hydrological processes during 2011–2099. Results show increasing trends for precipitation, temperature and runoff under all scenarios, while compared to the baseline, the annual runoff decreases except for a slight increase during the 2080s under the A2 and A1B scenarios; meanwhile, the runoff in spring, autumn and winter decreases except for a slight increase during the 2080s under A2. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For most of the 20th century, the Nile River has been the source of political tensions and low-intensity conflicts among three of its major riparian countries (Ethiopia, Sudan and Egypt). However, since the late 1990s, the Nile basin countries-with the encouragement and support of the international community-have made some attempts to establish basin-wide cooperative institutions. This process of engagement and collaboration is presently under severe stress due to increasing demand and decreasing supply of water resources in the basin. This situation may be complicated further by the global climate change, which is anticipated to result in long-term changes in the volume and pattern of runoff in the Nile River system. Moreover, the emergence of China as a major player in the power politics of the Nile basin has facilitated a number of unilateral initiatives for large-scale water development projects. In this context, this paper critically examines the survival and sustainability of water cooperation endeavours in the Nile basin as the river faces challenges from the global climate change and shifting regional geo-politics. Citation Swain, A. (2011) Challenges for water sharing in the Nile basin: changing geo-politics and changing climate. Hydrol. Sci. J. 56(4), 687-702. [ABSTRACT FROM AUTHOR]

The article focuses on the desk-assessment quantifying archeological resource in the rivers of Northern Ireland. It notes that the country has significant riverine environment and past investigations of river area reveal archaeological structures and remains. However, it says that there are increasing risks to these remains, including urbanization, water abstraction and climate change. It tells that enhance river mamagement are now being addressed at the Centre for Maritime Archaeology (CMA).

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A characterization of the low-flow regimes of 175 eastern Canadian rivers based on multivariate analysis of hydrological indices (HIs) is presented. Principal component analysis (PCA) was used to identify eight highly informative and low-correlated HIs amongst 67 low-flow HIs reported in the literature, and to test their ability to describe regional characteristics and differences among low-flow regimes at the 175 stations. It was found that eight HIs can provide a regional description of the main low-flow characteristics almost equivalent to using all HIs related to low flows. The PCA also identified regional similarities and differences among the geographical and hydrological regions within the Province of Quebec, as well as between the Atlantic provinces of Canada. Multivariate analysis proved to be an efficient tool that can complement expert knowledge in the selection of criteria for instream flow assessments in eastern Canada, by quantitatively indicating indices carrying high information, and by ensuring low redundancy in the selected subset of variables (HIs). Citation Daigle, A.,St-Hilaire, A., Beveridge, D., Caissie, D. & Benyahya, L. (2011) Multivariate analysis of the low-flow regimes in eastern Canadian rivers. Hydrol. Sci. J. 56(1), 51-67. [ABSTRACT FROM AUTHOR]

The impact of climate change on hydrological processes and nutrient input is one of the major uncertainties in projecting future global warming. The Soil and Water Assessment Tool (SWAT) model is applied to simulate the effects of temperature on the hydrology and sediment and nutrient load in the lower Pearl River Basin, South China. Calibration and validation results for SWAT showed that the Yamen estuary is appropriate for simulating the impacts of temperature change on both hydrological processes and nutrient input. The possible temperature change scenarios were set at T-2, T-1.5, T-1, T-0.5, T+0.5, T+1, T+1.5, T+2, T+2.5, T+3°C compared to the current temperature, T°C. The results showed that the relative variation of discharge with temperature was slight. The sediment load at T+3°C is increased by 13.58% compared to that at T°C. Inorganic N and P inputs to the Yamen estuary showed an increasing trend with the temperature increase from T-2°C to T+3°C. Global warming can reduce the vegetation land cover by slowing plant growth, which will aggravate the water and soil loss. Temperature changes would have an effect on mineralization and nitrification by changing soil temperature and temperatures. The warming is projected to cause an increase of sediment and nutrient load into the estuary and accelerate eutrophication in the coastal area. Citation Li, Y., Chen, B.-M., Wang, Z.-G. & Peng, S.-L. (2011) Effects of temperature change on water discharge, and sediment and nutrient loading in the lower Pearl River basin based on SWAT modelling. Hydrol. Sci. J. 56(1), 68-83. [ABSTRACT FROM AUTHOR]

Australia's rivers are among the most variable in the world and this has been a major challenge in catchments such as the Murray-Darling Basin where management has focused on increasing agricultural production while reducing risks from fluctuating water availability. Pressure for development and over-optimistic assessments of available water have resulted in over-allocation and increasing ecological decline, which has been severely exacerbated by record-breaking drought. In recent years, governments have agreed to radical policies such as the National Water Initiative 2004 and allocated substantial funds in response. Implementation is in gridlock, however, as the socio-economic implications have become clearer. Most debate is focused on the draft Murray-Darling Basin Plan due for release in mid-2010 before finalization in 2011. It will be the first Basin-wide plan and is intended to deal with inequities across borders and risks such as climate change and drought. Climate change scenarios for 2030 foresee a range of potential surface water availability outcomes, ranging from a 7% increase to a 37% decrease, yet greater water scarcity is being experienced in the current (2002+) drought with inflows reduced by 70% or more in extreme years. Contradictory policies are hindering the more open adaptation required to manage a drier future. [ABSTRACT FROM AUTHOR]

Developing and implementing effective adaptation policies for freshwater and estuarine systems in Australia will be a significant challenge in a rapidly changing climate. The broad aims of climate change adaptation policies are to reduce vulnerability and increase the adaptive capacity and resilience of ecosystems to climate change impacts. There are a range of adaptation policy options relevant to aquatic systems, and many of these measures can be 'mainstreamed' or incorporated into existing conservation and resource management frameworks. This article evaluates adaptation policy options and the constraints on policy implementation for freshwater and estuarine ecosystems in the coastal floodplains of tropical Queensland. Many of these aquatic systems are in a degraded condition and are vulnerable to the compounded impacts of climate change and other stressors. The analysis suggests that statutory planning schemes, water resource planning and protected area frameworks provide limited scope to address the more severe threats to these systems from rising sea levels, extreme cyclones, floods and droughts. In many locations, the effectiveness of adaptation policies is constrained by existing land uses and competing demands from communities and industry sectors. To prevent further widespread loss of habitat may require the development and implementation of new policies that prioritise adaptation management for freshwater and estuarine ecosystems. [ABSTRACT FROM AUTHOR]

This paper examines the security of water resources in Phoenix, AZ, under different scenarios of climate change, consumption patterns, and reductions of available surface water. Phoenix constitutes a key site for examining the projected effects of climate change on water resources in the US West. Water providers in Phoenix rely on a mix of water sources to deliver to their customers. These include groundwater, water from the Salt and Verde River watersheds, water from the Colorado River, and effluent (water reuse). Water providers in Phoenix vary in terms of their access and rights to different sources of water for municipal delivery. As a result, providers differ in terms of their exposure to cut-backs in available water. To assess vulnerability to climate change and reduced water resources available for delivery, we consider two primary questions. (1) Based on current water provider portfolio mixes, what is the current relative security of each provider's mix of water sources? (2) Using three different climate change scenarios for the Western USA and projected growth-related demand increases, what patterns of water supply vulnerabilities are likely to manifest themselves in 2030? We map projected supply shortages and discuss implications for the vulnerability of people and places and mitigation strategies. [ABSTRACT FROM AUTHOR]

Autonomous adaptation in the water sector is assessed to derive lessons for more successful climate change adaptation from six empirical, consistently designed river management case studies based on projects of WWF. They show that when adaptation measures are considered in the context of common problems in water management, many practical ways of building resilience to climate change through mainstream programs are evident. The cases are mainly from developing countries - India, China, Mexico, Brazil, the lower Danube basin and Tanzania - where efforts to reduce environmental degradation and enhance livelihoods have directly helped to reduce vulnerability to natural hazards and climate change. The key lessons include: the benefits of concurrent measures for improving livelihoods and reducing physical vulnerability; the need to enhance and fund local institutions to mainstream adaptation programmes; and the value in implementing 'no and low regrets' measures despite uncertainties. [ABSTRACT FROM AUTHOR]

Most of the inland river basins in north-west China have experienced ecosystem degradation and even desertification in the last few decades. As a case study, we estimated the net primary productivity (NPP) of the Heihe river basin and analysed its difference between 2002 and 1998 by using the C-Fix, a Monteith type parametric NPP model. The data used include the normalized difference vegetation index (NDVI) derived from the 1-km SPOT/VEGETATION sensor and other environmental records. By obtaining the spatiotemporal patterns of NPP change as well as land use changes from higher resolution imagery in the basin, we identified its forcing factors in terms of climate change and human activities. We suggest that a decline in rainfall over the five years was one reason for NPP decrease in the basin. Other factors, such as irrational reclamation upstream and intensive development of irrigated farmland in the midstream play more important roles. They reinforce water competition between artificial and natural ecosystems over the whole basin. It is also found that human activities can produce very different NPP changes in a short time in mountainous regions. The NPP decreased in the east Qilian Mountains due to farmland reclamation and overgrazing but increased in the west, according to the ecosystem preserve project. [ABSTRACT FROM AUTHOR]

This paper outlines the use of geographical information systems for predicting the possible implications of future climate change (as suggested by General Circulation Models) on the archaeological resource of selected parts of two major British river systems, the Trent and Yorkshire Ouse. The effects of future climatic change on the historic environment are likely to come from both natural 'system' responses, such as increased bank erosion and valley floor sedimentation, as well as the human adaptive responses selected to manage the impacts of climate change. The models described in this paper allow predictions to be made and quantified about how selected natural and anthropogenic responses may impact upon the archaeological resource. Such approaches, which are relatively rapid to implement and low cost, provide an important management tool for guiding policy makers and heritage managers in the face of changing climates. [ABSTRACT FROM AUTHOR]

In the rivers of northern Italy, the presence of water is typically continuous all year long, although in the last five decades there has been a conspicuous increase in drought periods, mainly caused by human impacts and climate change. The aim of this study was to assess the impact of the length of the drought periods on macroinvertebrate assemblages. We collected invertebrates in four reaches of the Po river, characterised by different periods of absence of surface water. We found significant differences among the stations in invertebrate abundance and taxa richness, with a decrease in the more drought-affected stream reaches. Collector-gatherers significantly increased as the drought period lengthened, while the opposite occurred for scrapers and shredders. The areas with a discontinuous presence of water were mainly colonised by small, fast-growing, plurivoltine organisms. A main result of our study is that only a few taxa appear to be able to survive in reaches with intermittent flow, underlining the great ecological difference between perennial and naturally intermittent streams. Our results suggest that the recent increase of droughts will likely cause an impoverishment of benthic communities in prealpine rivers. [ABSTRACT FROM AUTHOR]

This paper presents a systematic review and correlation of river terraces identified in 44 river catchments in the North Island, New Zealand, to assess river behaviour over the last c. 30 000 yr. This provides a comprehensive foundation from which to assess controls on river dynamics over this critical period of landscape development from the last glacial through to the present interglacial. From this review, an integrated framework for elucidating fluvial responses to environmental change is proposed. Sensitivity of river systems to climate change is variable over this time-scale. Substantial sediment inputs to valley floors during the last glacial reduced sensitivity to subtle climatic shifts. Sensitivity increased during the Holocene, with terraces forming in response to episodes of storminess. Tectonics and volcanic activity may both override climatic forcing to cause either cutting or filling of the valley floor. [ABSTRACT FROM AUTHOR]

Based on monitoring data of 123 meteorological stations from 1960 to 2000 near or in the Yellow River Basin, the spatial and temporal distributions and their trends for pan evaporation (PE) are investigated in this study. The results indicate that, despite the annual mean air temperature over the Yellow River Basin has, on average, increased by 0.6° over the past 40 years, the rate of PE has steadily decreased, especially in summer and spring. Compared with the period of 1960s to 1970s, the rate of annual pan evaporation during 1980s to 1990s has decreased by 126mm or 7.0 percent Spatial distribution of the rate of change show that this kind of trend is general but not universal, PE has significantly decreased over the upper and lower reaches of the Yellow River, but increased to a small degree over the middle reaches. Further analyses show that the decrease of PE is mainly related to reductions in sunshine durations and solar irradiance, owing to more clouds and aerosols. [ABSTRACT FROM AUTHOR]