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In its 50 years of existence, the International Water Resources Association (IWRA) and its regionally and thematically diverse members have played a key role in producing and disseminating knowledg...

In the context of global warming and increasing human activities, the acceleration of the water cycle will increase the risk of basin drought. In this study, to analyze the spatial and temporal evolution characteristics of hydrological and meteorological droughts over the Hanjiang River Basin (HRB), the Standardized Precipitation Index (SPI) and Standardized Runoff Index (SRI) were selected and applied for the period 1961–2018. In addition, the cross-wavelet method was used to discuss the relationship between hydrological drought and meteorological droughts. The results and analysis indicated that: (1) the meteorological drought in the HRB showed a complex cyclical change trend of flood-drought-flood from 1961 to 2018. The basin drought began to intensify from the 1990s and eased in the 2010s. The characteristics of drought evolution in various regions are different based on scale. (2) During the past 58 years, the hydrological drought in the HRB has shown a significant trend of intensification, particularly in autumn. Also, the hydrological droughts had occurred frequently since the 1990s, and there were also regional differences in the evolution characteristics of drought in various regions. (3) Reservoir operation reduces the frequency of extreme hydrological drought events. The effect of reducing the duration and intensity of hydrological drought events by releasing water from the reservoir is most obvious at Huangjiagang Station, which is the nearest to Danjiangkou Reservoir. (4) The hydrological drought and meteorological drought in the HRB have the strongest correlation on the yearly scale. After 1990, severe human activities and climate change have not only reduced the correlation between hydrological drought and meteorological drought in the middle and lower reaches of the basin, but also reduced the lag time between them. Among them, the hydrological drought in the upper reaches of the basin lags behind the meteorological drought by 1 month, and the hydrological drought in the middle and lower reaches of the basin has changed from 2 months before 1990 to 1 month lagging after 1990. HIGHLIGHTS I discovered the evolution characteristics of meteorological and hydrological drought in the region.; I found the operating law of the reservoir has a greater impact on regional hydrology and drought.; I have identified the areas and times that are susceptible to drought.; I found the relationship between hydrological and meteorological drought.; I discovered the impact of human activities on the drought in the region.

Wastewater reuse is identified as strategic to help ameliorate scarcity in water-stressed regions around the world. However, to develop it, there is a need to better understand the social, institutional and technological contexts in which it takes place. This article develops a novel socio-technical framework to inform such an analysis and applies it to current wastewater reuse in Egypt. Our analysis highlights the different actors, management activities and practices that shape wastewater collection, transfer, treatment, discharge and/or reuse in different social, technological and environmental contexts in Egypt. It points out bottlenecks of current wastewater reuse policies and programmes.

Investigating long-term streamflow changes pattern and its response to climate and human factors is of crucial significance to understand the hydrological cycle under a changing environment. Caijiazhuang catchment located within Haihe River basin, north China was selected as the study area. To detect the trend and changes in streamflow, Mann–Kendall test was used. Elasticity and hydrological simulation methods were applied to assess the relative contribution of climate change and human activities on streamflow variability under three periods (baseline (1958–1977), impact I (1978–1997), and impact II (1998–2012)). The long-term hydro-climatic variables experienced substantial changes during the whole study period, and 1977 was the breaking year of streamflow change. Attribution analysis using the two methods showed consistent results: for impact I, climate change impacts explained 65% and 68% of streamflow reduction; however for impact II, it only represented 49% and 56% of streamflow reduction. This result indicated that human activities were intensifying over time. Various types of human activities presented significant effects on streamflow regimes including volumes and hydrographs. The findings of this paper could provide better insights of hydrological evolution and would thus assist water managers in sustainably managing and providing water use strategies under a changing environment.

China is planning to expand its coal power generation to meet its energy demand and support the economic development. The current level of water use for thermal power generation is 8% of total water use, China is a water-stressed country which is facing many new challenges including climate change and population growth. China’s future coal power industry will add further pressures on already stressed water resources. This raised the key question on how the limited water resources can be managed to meet the demand of planned coal power expansion. A great level of understanding on the present status of water use and forecasting future demand in coal power plant is very important to answer this question. However, knowledge gap, data availability and accessibility are the major challenge in this regard. This paper attempts to improve the knowledge of the water demand in the coal power generation plant in China by using a simple water use model. Furthermore, a method is proposed to forecast future water demand in coal power plant. The proposed method is applied for forecasting water demand in Shaanxi coal power bases in Northern China under four scenarios. The results showed that the future water demand for Shaanxi coal power base will increase by 102–161% compared to current use under different scenarios in order to increase the production capacity by 206%. Adopting the optimum level of current status of water use, it is possible to limit the increase in water demand by 102% or 47.119 million-m3. It is expected that the finding of the study would help decision-making processes in water resources management in Chinese coal power generation.

Water security is an integral aspect of the socio-economic development in China. Nevertheless, water resources are under persistent pressures because of the growing population, heavy irrigation, climate change effects and short-term policies. Traditional management approaches narrowly focus on increasing supply and reducing demand without considering the complex interactions and feedback loops that govern water resource behaviour. Whereas these approaches may provide quick fix solutions, they often lead to unanticipated, sometimes catastrophic, delayed outcomes. Therefore, water management needs to take a holistic approach that caters to the interdependent physical (e.g. water inflows, outflows) and behavioural (e.g. decision rules, perceptions) processes in the system. Unlike reductionist approaches, System Dynamics (SD) takes a system-level view for modelling and analysing the complex structure (cause–effect relationships, feedback loops, delays) that generates the systemic behaviour. Simulating the SD model allows assessing long-term system-wide impacts, exploring leverage points and communicating results to decision makers. In this paper, we follow an SD modelling approach to examine the future of water security in Yulin City. First, we present a conceptual model for integrating water supply and demand. Based on this, we build an SD model to simulate and analyse the dynamics of water resource over time. The model output is tested to ensure that it satisfactorily replicates the historical behaviour of the system. The model is used to quantitatively assess the effectiveness of various supply/demand management options. Three scenarios are designed and examined: business-as-usual, supply management, and demand management. Results show that current management regime cannot effectively meet the future water demand. Whereas supply acquisition provides short-term benefits, it cannot cope with the growing population. A combination of conservation measures and demand-management instruments is regarded the most effective strategy for balancing supply and demand.

The objective of this paper is to develop and present a GIS-based and software tool capable of data management, data visualisation, and data analysis. The developed software is proved to be a good tool in the initial assessment of the quality status of the Nile river water quality. In addition a Graphical User Interface (GUI) was fully designed and implemented to make the GIS tool very easy and handy for the decision maker. Spatial analysis and visualisation of water quality data can be easily presented through the interface. It is concluded that water quality along the main stem is much better than the quality along the two main branches, where more violations are observed.

Water sharing management is the major problem for water resources and irrigation management decision makers. However, irrigation systems are very complex and interconnected, posing significant difficulties in managing irrigation economically and environmentally. Therefore, it is imperative that innovative modelling approaches are employed to deal with the feedback loops inherent in these systems. Through the application of a system dynamics approach, a Network Simulation Model (NSM) was developed. The purpose of the NSM is to measure and identify the change in economic and environmental outputs of various allocations and demand scenarios. The aim of this study is to examine the use of two methods of auto calibration (single objective and multiobjective) over a variety of climatic and hydrological conditions. These methods have been compared and applied to three periods of calibration and validation using seven performance criteria. Results indicate that multiobjective method yields better identifiable parameters and an improved model structure