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This review paper focuses on the question of what will happen to the future water resource system of Grand Renaissance Dam of Ethiopia based on the projected hydrology of the Upper Blue Nile River basin. For this, the hydrological extremes, the baseline hydrological trends, and projected hydrological extremes of the Upper Blue Nile River basin were reviewed from various published and unpublished sources. Changes in the future hydrology of the Upper Blue Nile River basin due to climate change or any other natural or manmade modification of the river basin deserve concerted attention in the future water resources system of the Grand Renaissance Dam of Ethiopia, because the water resources of the dam mainly depend on the water potential nature of the Upper Blue Nile River basin. [ABSTRACT FROM AUTHOR]

Rapid climate change is impacting water resources in Afghanistan. The consequences are poorly known. Suitable mitigation and adaptation strategies have not been developed. Thus, this paper summarizes current status of knowledge in relation to Afghan water resources. More than 130 scientific articles, reports and data sources are synthesized to review the potential impacts of climate change on the cryosphere, streamflow, groundwater and hydrological extremes. The available information suggests that Afghanistan is currently witnessing significant increases in temperature, less so precipitation. There is evidence of shifts in the intra-annual distribution of streamflow, with reduced summer flows in non-glaciated basins and increased winter and spring streamflow. However, in the short-term there will be an increase in summer ice melt in glaciated basins, a "glacial subsidy", which sustains summer streamflow, despite reduced snow accumulation. The future prognosis for water resources is likely to be more serious when this glacier subsidy ends. [ABSTRACT FROM AUTHOR]

Evaporation is important basic information for irrigation decision making in water resources management. Developing countries usually use a small pan to observe surface evaporation, but the relationship between evaporation in different small pans is not sufficiently clear. In this paper, we use an extreme learning machine (ELM) model to predict and convert E20 (diameter 0.20 m) and E601 (diameter 0.62 m) pan data for 38 meteorological stations in southern China. Firstly, we obtained the best combination of meteorological parameters for forecasting E20 and E601, respectively, and we also found that the accuracy of the model can be significantly improved by adding pan data. Secondly, we found that during the conversion between E20 and E601, the model performance when using E601 data to predict the E20 evaporation is better than that when using E20 data to predict the E601 evaporation. Finally, the geographical factors were analysed, and the model performance was found to be relatively poor in the coastal area and the North–South junction. [ABSTRACT FROM AUTHOR]

Socio-hydrology has recently garnered attention as a promising research paradigm among hydrologists. In this paper, we argue that viewing the socio-hydrological systems as a network of causal factors can assist in these efforts by revealing emergent properties of socio-hydrological systems. These factors, which are neither actors nor affiliations but symbolic representations of miscellaneous phenomena, represent the key variables affecting socio-hydrological system behaviour. Despite being crucial for understanding system dynamics, these factors are not captured by most equations of coupled human–water coevolutionary models. To demonstrate our method, we use qualitative case study research to analyse the Jaguaribe Basin in Ceará State-Brazil as a network of factors, i.e. mental conceptions, and representations of water resource management experts. We show that most results are unsurprising, exhibiting expected causal relationships. However, there was at least one unexpected result, which showed that the variable "conflict" was the single most sensitive variable to systemic evolution. [ABSTRACT FROM AUTHOR]

Water stress prompts a durable reduction in water demand under some circumstances. This demand reduction has the potential to alter the benefits and costs of demand- and supply-side alternatives in water supply planning. This paper takes a socio-hydrological approach to assess the implications of this feedback, in the context of Las Vegas, Nevada. This application demonstrates feasibility first by developing and testing a novel model of water salience as a function of proximity to water supply thresholds, and then linking modules to account for feedback between subsystems. Lastly, by comparing this model to a water use scenario model to assess system performance under a range of future conditions and potential responses, this work illustrates the trade-offs between scenarios and the socio-hydrological approach. This model, while specific to Las Vegas, demonstrates a prototypical modeling framework capable of examining water supply–demand interactions by incorporating water stress-driven conservation. [ABSTRACT FROM AUTHOR]

Groundwater is exploited extensively, continuously and in a disorderly way in the North China Plain (NCP), which leads to severe problems of groundwater over-exploitation, making it the largest groundwater funnel zone in the world. Based on a comprehensive treatment of over-exploited groundwater in Shandong province, this paper analyses and forecasts the water demand, supply and savings in over-exploited areas, and puts forward a method to analyse the potential for groundwater exploitation control, which provides technical support for the comprehensive analysis of exploitation control in over-exploited areas. As a result, under a 50% guaranteed rate of water supply, the potential for groundwater exploitation control in Shandong province over-exploited areas in 2020 and 2030 is 408 × 106 and 638 × 106 m3, respectively. This study can serve as a useful reference for the comprehensive management of groundwater over-exploitation in NCP and other over-exploited areas around the world. [ABSTRACT FROM AUTHOR]

This paper describes the development of the first operational seasonal hydrological forecasting service for the UK, the Hydrological Outlook UK (HOUK). Since June 2013, this service has delivered monthly forecasts of streamflow and groundwater levels, with an emphasis on forecasting hydrological conditions over the next three months, accompanied by outlooks over longer time horizons. This system is based on three complementary approaches combined to produce the outlooks: (i) national-scale modelling of streamflow and groundwater levels based on dynamic seasonal rainfall forecasts, (ii) catchment-scale modelling where streamflow and groundwater level models are driven by historical meteorological forcings (i.e. the Ensemble Streamflow Prediction, ESP, approach), and (iii) a catchment-scale statistical method based on persistence and historical analogues. This paper provides the background to the Hydrological Outlook, describes the various component methods in detail and then considers the impact and usefulness of the product. As an example of a multi-method, operational seasonal hydrological forecasting system, it is hoped that this overview provides useful information and context for other forecasting initiatives around the world. [ABSTRACT FROM AUTHOR]

Developing a general framework to capture the complexities associated with the non-linear and adaptive nature of farmers facing water resources scarcity is a challenging problem. This paper integrates agent-based modelling (ABM) and a data mining method to develop a hybrid socio-hydrological framework to provide future insights for policy-makers. The data associated with the farmers' main characteristics were collected through field surveys and interviews. Afterwards, the association rule was employed to discover the main patterns representing the farmers' agricultural decisions. The discovered patterns were then used as the behavioural rules in ABM to simulate the agricultural activities. The proposed framework has been was applied to explore the interactions between agricultural activities and the main river feeding the Urmia-Lake, Iran. The outcomes indicate that farmers' acquisitive traits and belongings have significant impacts on their socio-hydrological interactions. The reported values of the efficiency criteria may support the satisfactory performance of the proposed framework. [ABSTRACT FROM AUTHOR]

Water from the alluvium of ephemeral rivers in Zimbabwe is increasingly being used. These alluvial aquifers are recharged annually from infiltrating floodwater. Nonetheless, the size of this water resource is not without limit and an understanding of the hydrological processes of an alluvial aquifer is required for its sustainable management. This paper presents the development of a water balance model, which estimates the water level in an alluvial aquifer recharged by surface flow and rainfall, while allowing for abstraction, evaporation and other losses. The model is coupled with a watershed model, which generates inflows from upland catchment areas and tributaries. Climate, hydrological, land cover and geomorphological data were collected as inputs to both models as well as observed flow and water levels for model calibration and validation. The sand river model was found to be good at simulating the observed water level and was most sensitive to porosity and seepage. [ABSTRACT FROM AUTHOR]

This paper interprets differences in flood hazard projections over Europe and identifies likely sources of discrepancy. Further, it discusses potential implications of these differences for flood risk reduction and adaptation to climate change. The discrepancy in flood hazard projections raises caution, especially among decision makers in charge of water resources management, flood risk reduction, and climate change adaptation at regional to local scales. Because it is naïve to expect availability of trustworthy quantitative projections of future flood hazard, in order to reduce flood risk one should focus attention on mapping of current and future risks and vulnerability hotspots and improve the situation there. Although an intercomparison of flood hazard projections is done in this paper and differences are identified and interpreted, it does not seems possible to recommend which large-scale studies may be considered most credible in particular areas of Europe. EDITOR D. Koutsoyiannis ASSOCIATE EDITOR not assigned [ABSTRACT FROM AUTHOR]

The calculation of runoff and infiltration parameters is a fundamental task for water budget estimation and water resources management. The "Kenessey method" allows these values to be calculated and its use is widespread among water scientists and practitioners. Due to language barriers and inefficient translation in past decades, the method has undergone some misinterpretations and is now far from its original usefulness and purpose. The use of the modified method can give unreal results for specific climatic zones. The purpose of this paper is to point out these methodological variations and to return to the original approach, improving it with modern technology. [ABSTRACT FROM AUTHOR]

This paper introduces a Special Issue ofHydrological Sciences Journalcontaining 10 research papers which present current applications of the Soil and Water Assessment Tool (SWAT) for water resources assessment. First, an overview of selected, recently published papers with application of SWAT is given. The papers address the following topics: nutrients and related best management practices (BMPs); sediments and related BMPs; impoundment and wetlands; irrigation; bioenergy crops; climate change impact; and land-use change impacts. Then, papers from this Special Issue are briefly described, covering the themes: surface runoff and sediments; nonpoint-source pollution; surface water and groundwater; impacts of climate and land-use change; and large-scale SWAT applications. The presented model applications of SWAT were conducted across a variety of spatial scales, physiographic regions and climatic zones. This collection of papers demonstrates that applications of SWAT for water resources assessment are growing in number and cover drainage basins in many regions worldwide.Editor M. Acreman; Associate editor Xi Chen [ABSTRACT FROM AUTHOR]

This is an invited essay by the Dooge Medallist of the 2017 International Hydrological Prize. The paper reflects a broad perspective on hydrology, as a result of the author’s long experience. It is suggested that transgressing the traditional hydrological perspective, by increasing the scale of research, as well as interdisciplinarization have been, and are likely to remain, key drivers of the development of hydrology. Gaps in knowledge and research challenges are reviewed, and the interlinked areas of stationarity, extremes and projections for the future are discussed. Finally, after reviewing the achievements of Jim Dooge, examples of others following in his footsteps are presented. [ABSTRACT FROM AUTHOR]

Water losses in the Sudd wetlands of South Sudan have significant effects on water resources available to Sudan and Egypt. These losses increased greatly after the dramatic rise of Lake Victoria in 1961-1964, but investigation into the cause and location of these increased losses has been hindered by the shortage of records after 1963 and their cessation after 1983. By linking flow records at key points within the Sudd with the distribution of vegetation before the rise, analysis of vegetation after the rise can throw light on the distribution of resulting losses and their causes. Although the increased flooding in the upper reaches of the Sudd has been noted, this paper draws attention to greatly increased inundation in the lower reaches, apparently from backwater flooding, which would affect any future proposal for the Jonglei Canal project. [ABSTRACT FROM AUTHOR]

A constrained total water-use policy has been implemented to maintain sustainable water supply in some water shortage areas. Managing a constrained water-use quota (T) in water allocation is a challenging goal. This paper proposes a new framework for water allocation under total water-use constraint by utilizing the concept of the Newsboy model, commonly used in operations management and applied economics, and applying it to the Dongjiang River Basin, South China. This framework considersTas a state variable of the objective function, rather than simply dealing with it as a constraint of multi-objective analysis. Using this framework, it is revealed how different schemes ofTplay out in water allocation, and water-use warning is provided for each sector and water governor in water resources management. [ABSTRACT FROM PUBLISHER]

Scientists and water users are concerned about the potential impact on water resources, particularly during low-flow periods, of freshwater withdrawals for hydraulic fracturing (fracking). Therefore, the objective of this paper is to assess the potential impact of hydraulic fracturing on water resources in the Muskingum watershed of Eastern Ohio, USA, especially due to the trend of increased withdrawals for hydraulic fracking during drought years. The Statistical Downscaling Model (SDSM) was used to generate 30 years of plausible future daily weather series in order to capture the possible dry periods. The data generated were incorporated in the Soil and Water Assessment Tool (SWAT) to examine the level of impact due to fracking at various scales. Analyses showed that water withdrawal due to hydraulic fracking had a noticeable impact, especially during low-flow periods. Clear changes in the 7-day minimum flows were detected among baseline, current and future scenarios when the worst-case scenario was implemented. The headwater streams in the sub-watersheds were highly affected, with significant decrease in 7-day low flows. The flow alteration in hydrologically-based (7Q10, i.e. 7-day 10-year low flow) or biologically-based (4B3 and 1B3) design flows due to hydraulic fracking increased with decrease in the drainage area, indicating that the relative impact may not be as great for higher order streams. Nevertheless, change in the annual mean flow was limited to 10%. [ABSTRACT FROM AUTHOR]

There is a lack of suitable methods for creating precipitation scenarios that can be used to realistically estimate peak discharges with very low probabilities. On the one hand, existing methods are methodically questionable when it comes to physical system boundaries. On the other hand, the spatio-temporal representativeness of precipitation patterns as system input is limited. In response, this paper proposes a method of deriving spatio-temporal precipitation patterns and presents a step towards making methodically correct estimations of infrequent floods by using a worst-case approach. A Monte Carlo approach allows for the generation of a wide range of different spatio-temporal distributions of an extreme precipitation event that can be tested with a rainfall–runoff model that generates a hydrograph for each of these distributions. Out of these numerous hydrographs and their corresponding peak discharges, the physically plausible spatio-temporal distributions that lead to the highest peak discharges are identified and can eventually be used for further investigations.Editor A. Castellarin; Associate editor E. Volpi [ABSTRACT FROM PUBLISHER]

Neuroemulation is the art and science of using a neural network model to replicate the external behaviour of some other model or component of a model. It is an independent activity that is distinct from neural network-based simulation. Neuroemulation has become a recognized and established sub-discipline in many spheres of study, but remains poorly defined in the field of water resources research. Its many potential benefits have not yet been adequately recognized or established. Lack of recognition can in part be attributed to difficulties involved in identifying, collating and synthesizing published studies on neuroemulation: query-based searching of a publications database fails to identify papers concerned with a field of study, for which no agreed conceptual and/or terminological framework as yet exists. Therefore, in this paper, we provide a first attempt at defining such a framework for use in water resources investigations. We identify eight key benefits offered by neuroemulation and exemplify current activities with relevant examples taken from published research in the field. The concluding section highlights a number of strategic research directions related to developing the identified potential of neuroemulator applications for water resources modelling. Editor D. Koutsoyiannis Citation Abrahart, R.J., Mount, N.J. and Shamseldin, A.Y., 2012. Neuroemulation: definition and key benefits for water resources research. Hydrological Sciences Journal, 57 (3), 407–423. [ABSTRACT FROM AUTHOR]

The dominant legal discourse in Australian water law and policy since 2004 has been about incorporating several definitions of Ecologically Sustainable Development (ESD) rules into freshwater management. The strategy selected to achieve this has been the Regional Water Allocation Plan (RWAP), which is based on hydrological and biological information about the impact of water use. Several aims of the ESD policy reflect the three pillars (environmental, economic, and social outcomes) common to the use of the term in international instruments, such as the 1987 UN Declaration; all ESD formulations in several state laws and the recent Federal Water Act 2007 look at the integration of the three pillars. The State Acts and the Federal Act insist on the adoption of the precautionary principle and achievement of intra- and inter-generational equity-a stunning reversal of previous policies, where the economic use and social aspects of water use were the primary concern. The ESD policy is not without its critics, especially from the farming communities, hard hit by new water plans that have reduced the amount of water able to be allocated by up to 52%. City dwellers have also been critical of water restrictions in urban areas and the higher cost for water supplied through desalination plants where the groundwater is severely depleted. The RWAP is the tool that must bear the brunt of these conflicts; at present, there are 190 such plans. This paper outlines a research agenda, but also makes preliminary comments on the types of conflicts that have existed, and the potential future conflict types. This is based on legal case analysis and some field work, reports of other authors, as well as observations and discussions with key informants in the several jurisdictions. It finds that there are conflicts between users, between the environment and users, as well as several conflicts related to processes used to consult the community, the science used to reduce allocations and the way the water reductions have been administered. The social capital of the community, the extent of the water allocation reductions and the level of trust in the science are key determinants of how many conflicts will exist in any given WAP region. The paper suggests a law reform that could reduce conflicts, i.e. that a duty to co-operate be added to state laws to require persons working on water plans to work cooperatively in the region and with others in the next water plan region. Such a duty would go some way to increasing the achievement of ESD and overcome the fragmentation and introspective approach of some of the early regional water plans. Citation McKay, J. M. (2011) Australian water allocation plans and the sustainability objective-conflicts and conflict-resolution measures. Hydrol. Sci. J. 56(4), 615-629. [ABSTRACT FROM AUTHOR]

Against the discussion on the rationale and scope for water demand and supply management in India, this paper provides a brief overview of the status and effectiveness, as well as the technical, institutional and financial requirements of six demand management options (i.e. water pricing, water markets, water rights, energy regulations, water saving technologies, and user and community organizations) and one supply management option (involving the implementation of the National River Linking Project, NRLP). The paper then develops a framework that captures the analytics of water demand management in terms of both the impact pathways of and operational linkages among the options and their underlying institutions. Using this framework, the paper outlines a strategy for water demand management that can exploit well the inherent synergies among the options, and also align them well with the underlying institutional structure and its environment. Similarly, based on an analysis of the NRLP, the paper also indicates the strategy for implementing the NRLP and thereby promoting water supply management within the financial, institutional and political constraints. The paper concludes with the policy implications for water demand and supply management in India. Citation Saleth, R. M. (2011) Water scarcity and climatic change in India: the need for water demand and supply management. Hydrol. Sci. J. 56(4), 671-686. [ABSTRACT FROM AUTHOR]

The problem of estimation of suspended load carried by a river is an important topic for many water resources projects. Conventional estimation methods are based on the assumption of exact observations. In practice, however, a major source of natural uncertainty is due to imprecise measurements and/or imprecise relationships between variables. In this paper, using the Multivariate Adaptive Regression Splines (MARS) technique, a novel fuzzy regression model for imprecise response and crisp explanatory variables is presented. The investigated fuzzy regression model is applied to forecast suspended load by discharge based on two real-world datasets. The accuracy of the proposed method is compared with two well-known parametric fuzzy regression models, namely, the fuzzy least-absolutes model and the fuzzy least-squares model. The comparison results reveal that the MARS-fuzzy regression model performs better than the other models in suspended load estimation for the particular datasets. This comparison is done based on four goodness-of-fit criteria: the criterion based on similarity measure, the criterion based on absolute errors and the two objective functions of the fuzzy least-absolutes model and the fuzzy least-squares model. The proposed model is general and can be used for modelling natural phenomena whose available observations are reported as imprecise rather than crisp.Editor D. Koutsoyiannis; Associate editor H. Aksoy [ABSTRACT FROM PUBLISHER]

Today, more than ever, there is a need to implement robust statistical methods to ensure the proper evaluation of water resources data to support decision makers in water resources planning and management. Graphing or mapping data for visualization is the easiest way to communicate trends, especially to a non-technical audience. This paper describes the use of an approach that combines the Mann-Kendall test, Sen slope test and principal component analysis to detect and map the monthly trends of piezometric time series and their magnitude in the period 1979–2008. The data were obtained in 23 shallow wells in the alluvial aquifers of the Elqui River basin in central Chile, an area characterized by scarce water resources and intense agricultural and mining activities. The results show significant downward trends at the majority of the wells. Because groundwater in these shallow wells is highly dependent on the water in the river and its tributaries, the reasons for these downward trends are mainly related to a decrease of streamflow observed in the Elqui River. The streamflow is derived from mountain snowmelt rather than from rainfall, which showed no flow trend during the same period. [ABSTRACT FROM AUTHOR]

The increasing level of competition in scientific publishing arguably has a greater negative impact on hydrologists from developing countries and specifically young scientists. This paper discusses the constraints they face and offers suggestions to authors and the hydrological community about how these may be mitigated. These include a lack of access to resources to assist with creating good publications, the difficulty of publishing research based on relatively scarce data, a common problem in many developing countries, and a lack of familiarity with the process of publishing scientific material together with limited access to mentorship from experienced authors. A key point is to ensure that the research question addressed has a broad interest beyond the local study area. However, the more limited hydrological knowledge and the water resources problems of developing countries represent opportunities for internationally relevant research, particularly within the nexus between hydrology and society, or between science and practice. Both of these are high on the international hydrological research agenda. EditorD. Koutsoyiannis [ABSTRACT FROM AUTHOR]

Many of the Japanese regions subject to seasonal snow cover are characterized by low elevations and relatively high winter temperatures. A small change in winter temperatures could render many of these areas susceptible to snow cover change and consequently affect water resources management. This paper describes a climatological approach combined with an AGCM output to identify the regions and main river basins most sensitive to snow cover change in the case of climate change in Japan. It was found that a 1°C rise in temperature during the winter season could increase the snow-free area of Japan by 6%. The snow cover of Tohoku region and Mogami and Agano river basins was found to be the most sensitive to climate change. The AGCM output for a future scenario presents a reduction in total snowfall and an earlier peak in snowmelt for all regions. EditorZ.W. Kundzewicz CitationChaffe, P.L.B, Takara, K, Yamashiki, Y, Apip, Luo, P., Silva, R.V., and Nakakita, E., 2013. Mapping of Japanese areas susceptible to snow cover change.Hydrological Sciences Journal, 58 (8), 1718–1728. [ABSTRACT FROM PUBLISHER]

This paper presents the results of a survey carried out in 2010 aimed at evaluating the type and quality of the groundwater resources of the Bangui region of the Central African Republic. This work is the first step towards the development of groundwater resources in the Central African Republic in order to find alternatives to direct pumping from the Ubangi River and provide the population of the suburbs with a safer drinking water supply from deep boreholes. By combining both geological and hydrogeochemical approaches, it appears that the geology of Bangui is favourable to the development of a secure and sustainable water supply from groundwater provided that the conditions of exploitation would be constrained by the local authorities. The deep Precambrian carbonate aquifers, known as the Bimbo and Fatima formations, are identified as target resources in view of the relatively good quality of their water from the chemical point of view, and the semi-confined structure of the aquifers that prevents the mixing with shallow aquifers that are already strongly affected by domestic and industrial pollution. The main difficulty in terms of exploitation is to appreciate the depth of the resource and the more or less fractured/palaeo-karstified type of the porosity. EditorZ.W. Kundzewicz CitationDjebebe-Ndjiguim, C.L., Huneau, F., Denis, A., Foto, E., Moloto-a-Kenguemba, G., Celle-Jeanton, H., Garel, E., Jaunat, J., Mabingui, J., and Le Coustumer, P., 2013. Characterization of the aquifers of the Bangui urban area, Central African Republic, as an alternative drinking water supply resource.Hydrological Sciences Journal, 58 (8), 1760–1778. [ABSTRACT FROM PUBLISHER]

Impacts on water resources produced by climate change can be exacerbated when occurring in regions already presenting low water resources levels and frequent droughts, and subject to imbalances between water demands and available resources. Within Europe, according to existing climate change scenarios, water resources will be severely affected in Spain. However, the detection of those effects is not simple, because the natural variability of the water cycle and the effects of water abstractions on flow discharges complicate the establishment of clear trends. Therefore, there is a need to improve the assessment of climate change impacts by using hydrological simulation models. This paper reviews water resources and their variability in Spain, the recent modelling studies on hydrological effects of climate change, expected impacts on water resources, the implications in river basins and the current policy actions. Editor Z.W. Kundzewicz Citation Estrela, T., Pérez-Martin, M.A., and Vargas, E., 2012. Impacts of climate change on water resources in Spain. Hydrological Sciences Journal, 57 (6), 1154–1167. [ABSTRACT FROM AUTHOR]

Among the processes most affected by global warming are the hydrological cycle and water resources. Regions where the majority of runoff consists of snowmelt are very sensitive to climate change. It is significant to express the relationship between climate change and snow hydrology and it is imperative to perform climate change impact studies on snow hydrology at global and regional scales. Climate change impacts on the mountainous Upper Euphrates Basin were investigated in this paper. First, historical data trend analysis of significant hydro-meteorological data is presented. Available future climate data are then explained, and, finally, future climate data are used in hydrological models, which are calibrated and validated using historical hydro-meteorological data, and future streamflow is projected for the period 2070–2100. The hydrological model outcomes indicate substantial runoff decreases in summer and spring season runoff, which will have significant consequences on water sectors in the Euphrates Basin. Citation Yilmaz, A.G. & Imteaz, M.A. (2011) Impact of climate change on runoff in the upper part of the Euphrates basin. Hydrol. Sci. J. 56(7), 1265–1279. [ABSTRACT FROM AUTHOR]

The increasing water demand is a concern affecting many regions in the Mediterranean Basin. To overcome this situation rim countries resorted during the last decades to a massive mobilization of their water resources, often resulting in excessive water exploitation. In such a context, understanding the effects of present recharge and aquifer salinization is crucial for correct water management. Understanding the present hydrogeological situation of coastal plains requires the knowledge of both their past morphologic conditions and their recent geological evolution. Within this framework, this paper presents a review of water related problems in the Mediterranean Basin. It suggests a conceptual model for groundwater resources in Mediterranean coastal plains, deriving from the present and past recharge processes. Special attention is paid to providing a better understanding of climate change impacts on water quantity and quality, and conservation of ecological diversity. Citation Re, V. & Zuppi, G. M. (2011) Influence of precipitation and deep saline groundwater on the hydrological systems of Mediterranean coastal plains: a general overview. Hydrol. Sci. J. 56(6), 966-980. [ABSTRACT FROM AUTHOR]

Statistical tests have been widely used for several decades to identify and test the significance of trends in runoff and other hydrological data. The Mann-Kendall (M-K) trend test is commonly used in trend analysis. The M-K test was originally proposed for random data. Several variations of the M-K test, as well as pre-processing of data for use with it, have been developed and used. The M-K test under the scaling hypothesis has been developed recently. The basic objective of the research presented in this paper is to investigate the trends in Malaysian monthly runoff data. Identification of trends in runoff data is useful for planning water resources projects. Existence of statistically significant trends would also lead to identification of possible effects of climate change. Monthly runoff data for Malaysian rivers from the past three decades are analysed, in both five-year segments and entire data sequences. The five-year segments are analysed to investigate the variability in trends from one segment to another in three steps: (1) the M-K tests are conducted under random and correlation assumptions; (2) the Hurst scaling parameter is estimated and tested for significance; and (3) the M-K test under the scaling hypothesis is conducted. Thus the tests cover both correlation and scaling. The results show that the number of significant segments in Malaysian runoff data would be the same as those found under the assumption that the river flow sequences are random. The results are also the same for entire sequences. Thus, monthly Malaysian runoff data do not have statistically significant trends. Hence there are no indications of climate change in Malaysian runoff data. Citation Rao, A. R., Azli, M. & Pae, L. J. (2011) Identification of trends in Malaysian monthly runoff under the scaling hypothesis. Hydrol. Sci. J. 56(6), 917-929. [ABSTRACT FROM AUTHOR]

The water resources of the Juba and Shabelle rivers in southern Somalia are important for irrigation and food production, but are influenced by seasonal floods. Prior to the outbreak of civil war in 1991, the Somali Ministry of Agriculture successfully operated a hydrometric network covering the Juba and the Shabelle, data from which provided input to a flow forecasting model. The war resulted in the neglect and abandonment of monitoring stations and an enforced cessation of data collection and management. In 2001 and 2002, part of the pre-war hydrometric network was reinstated and water levels were again recorded at some stations. This paper examines the implications of the 11-year hiatus in data collection, and the now much reduced monitoring network, for assessing and managing the surface water resources. The problems faced have relevance to other basins, within Africa and elsewhere, where there has been a similar decline in data collection. [ABSTRACT FROM AUTHOR]

Rainfall-runoff models usually present good results, but parameter calibration sometimes is tedious and subjective, and in many cases it depends on additional data surveys in the field. An alternative to the conceptual models is provided by empirical models, which relate input and output by means of an arbitrary mathematical function that bears no direct relationship to the physical characteristics of the rainfall-runoff process. This category includes the artificial neural networks (ANNs), whose implementation is the main focus of this paper. This study evaluated the capacity of ANNs to model with accuracy the monthly rainfall-runoff process. The case study was performed in the Jangada River basin, Parana, Brazil. The results of the three ANNs that produced the best results were compared to those of a conceptual model at monthly time scale, IPHMEN. The ANNs presented the best results with highest correlation coefficients and Nash-Sutcliffe statistics and the smallest difference of volume. Citation Machado, F., Mine, M., Kaviski, E. & Fill, H. (2011) Monthly rainfall-runoff modelling using artificial neural networks. Hydrol. Sci. J. 56(3), 349-361. [ABSTRACT FROM AUTHOR]

This paper analyses the temporal dynamics of soil water balance components in a representative recharge area of the Sierra de Gador (Almeria, southeastern Spain) in two hydrological years. Two approaches are used to estimate daily potential recharge (PR): Approach 1 based on deriving PR from the water balance as the difference between measurements of rainfall (P) and actual evapotranspiration (E) obtained by eddy covariance; and Approach 2 with PR obtained from the dynamic pattern of the soil moisture (θ) recorded at two depths in the site's thin soil (average 0.35 m thickess). For the hydrological year 2003/04, which was slightly drier than the 30-year average, E accounted for 64% of rainfall and occurred mainly in late spring and early summer. The PR estimated by Approach 1 was 181 ± 18 mm year-1 (36% of rainfall), suggesting an effective groundwater recharge in the study area. In the unusually dry hydrological year 2004/05, E was about 215 mm year-1, close to the annual rainfall input, and allowing very little (8 ± 12 mm year-1) PR according to Approach 1. Estimation of PR based on Approach 2 resulted in PR rates lower than those found by Approach 1, because Approach 2 does not take into account the recharge that occurs through preferential flow pathways (cracks, joints and fissures) which were not monitored with the θ probes. Moreover, using Approach 2, the PR estimates differed widely depending on the time scale considered: with daily mean θ data, PR estimation was lower, especially in late spring, while θ data at 30 min resolution yielded a more reliable prediction of the fraction of total PR resulting from the downward movement of soil water by gravity. Citation Canton, Y., Villagarcia, L., Moro, M. J., Serrano-Ortiz, P., Were, A., Alcala, F. J., Kowalski, A. S., Sole-Benet, A., Lazaro, R. & Domingo, F. (2010) Temporal dynamics of soil water balance components in a karst range in southeastern Spain: estimation of potential recharge. Hydrol. Sci. J. 55(5), 737-753. [ABSTRACT FROM AUTHOR]

In their opinion paper, Liu et al. highlight the insufficient development of methods such as integrated modelling tools to assess the water-energy-food (WEF) nexus system complexity. This can be attributed to the lack of research programmes addressing the WEF nexus, especially in the European Union. To enable the development of innovative research methods, we need educational and research programmes that explicitly focus on the WEF security nexus. These programmes should promote interdisciplinary approaches that incorporate hydrology as well as sciences related to energy and food security, and environmental governance. [ABSTRACT FROM AUTHOR]