Unpacking water conflicts: a reinterpretation of coordination problems in China’s water-governance system

In China, water conflicts have been traditionally framed as the external costs of economic development and tackled with technocratic measures. This study examines water conflicts through the lens of water diversion, water allocation and water functional zoning. It reframes water conflicts as a result of coordination problems nested in complex inter-jurisdictional interactions. With a game-theoretic illustration, it identifies that individual and group heterogeneities are two challenges to effective coordination. It argues that China’s state-centric water institutions are tailored to optimize overall social utilities, yet they constrain coordination due to insufficient costs and benefits redistribution mechanisms at the local level.     

Lost in transition? The introduction of water users associations in Uzbekistan

A “policy as process” perspective is adopted to analyze the early period of water users associations (WUAs) in Uzbekistan (2000–2006). The article is based on extensive fieldwork (in 2005–2006) and analysis of policy and other relevant documents. It is shown that WUAs have a role and logic beyond water management and are used by the state as instruments with which to monitor and regulate “state-ordered” agricultural production. Through a state-centric policy process with room for local experimentation, the WUA was fit into the socio-political landscape of continued state control and the increased role of individualized risks and benefits.     

Water productivity and water footprint: misguided concepts or useful tools in water management and policy?

Water productivity (WP) and water footprint (WFP) are popular concepts in research and discourses on water management. Yet there are concerns about their theoretical validity and practical value. This paper shows that the water production function, the concept with a sound theoretical foundation, is the basis for WP. Total WFP is the reciprocal of WP. The practical value of WP and WFP depends on the context of water use and stress. Maximizing WP, not a panacea to all water problems, mainly suits arid rainfed areas. In other regions, economic and marginal WP for increasing overall production should take precedence in water management and policy decisions.     

Hierarchical MnO? nanostructures: synthesis and their application in water treatment

Hierarchical MnO? nanostructures were prepared through the reaction between KMnO? and oleic acid at room temperature in the surfactant-free microemulsion system. The obtained samples were characterized by powder X-ray diffraction, N? adsorption, scanning electron microscopy, and transmission electron microscopy. The results indicated that the flowerlike nanospheres were three-dimensional (3D) porous microstructures consisting of nanoplates. The surface area of the sample was 171.5 m(2)/g and the distribution of pore diameter lay within the range of 5-15 nm. The prepared hierarchically structured MnO? showed excellent adsorption capacity and rapid adsorption rate for methylene blue ions in water. The maximum adsorption capacity of methylene blue was as high as 273.9 mg/g and 97.5% of the dye was removed within initial 5 min of contact time. Compared with other adsorbents, the synthesized hierarchical MnO? nanostructures displayed a faster adsorption rate and higher adsorption capacity, which implied potential application for removing dye pollutants from waste water.     

Photocatalytic reduction of Cr(VI) in aqueous solution using TiO? nanoparticles prepared with various alcohols as solvent

TiO? nanoparticles were prepared with various linear alkyl chains of alcohols under a sol-gel process. The structure characterization and the photocatalytic reduction of hexavalent chromium of the TiO? nanoparticles were investigated. The phase transformation temperature, crystal aggregation and surface area of prepared TiO? samples were found to be strongly influenced by alcohol used. The phase transformation from anatase to rutile was retarded and the surface area was reduced for TiO? prepared with alcohols of longer alkyl chain. TiO? nanoparticles prepared with methanol or ethanol exhibited higher photocatalytic reduction activity of hexavalent chromium possibly due to greater and more positively charged surface area.     

Hydropeaking in small hydropower in Norway—Compliance with license conditions?

Hydropeaking involves rapid changes in water flow, causing negative effects on aquatic organisms. To reduce these effects, hydropower licenses contain restrictions on hydropeaking. The owners of a hydropower plant are obliged to follow the requirements in the license. This study was conducted to understand the effect of environmental policies in small hydro licenses. We studied the occurrence of hydropeaking by analysing 256 high‐head, small Norwegian hydropower plants in relation to a set of characteristics that define each plant. We selected plants that were online during 2005–2014 and chose 2015 as a year for hourly production patterns. We counted the number of starts, that is, the moment when the hydro facility starts to produce energy, as an indicator of hydropeaking. Among the analysed plants, 75.8% had restrictions to practice hydropeaking. Production typically showed daily, weekly, and annual cycles though shapes varied depending on turbine type and location. The number of starts was independent on having or not having a license to practice hydropeaking. The average duration of periods with production and the average production in these periods were higher for plants without restrictions. The number of starts varied widely among plants. The number of starts was lower for installed Pelton turbines than for Francis and Kaplan turbines, which was in agreement with the characteristics of the turbines. Overall, these results show that hydropeaking restrictions given in the licenses are rarely followed. The high number of starts may be explained by failure in the grid system, improper maintenance, and financial interests. Their relative importance should be subject to further investigation.     

How would the Rogun Dam affect water and energy scarcity in Central Asia?

The construction of the Rogun Dam in the Amu Darya Basin to increase upstream energy generation creates potential trade-offs with existing downstream irrigation, due to the different timing of energy and irrigation water demands. The present analysis, based on a hydro-economic optimization model, shows that cooperative basin-wide maximization of benefits would lead to large increases in upstream hydropower production and only minor changes in downstream irrigation benefits. However, if upstream stations, including Rogun, are managed unilaterally to maximize energy production, hydropower benefits might more than double while irrigation benefits greatly decrease, thereby substantially reducing overall basin benefits.     

Why doesn’t every family practice rainwater harvesting? Factors that affect the decision to adopt rainwater harvesting as a household water security strategy in central Uganda

ABSTRACT

This article investigates the reasons householders do, and don’t, adopt domestic rainwater harvesting (DRWH). Using a mixed-methods research approach, we collected data in three districts in central Uganda. Factors that emerged as important with respect to uptake of DWRH to address water shortage, especially at the household scale, include the work of intermediary organizations, finance mechanisms, life course dynamics and land tenure.     

To what end? Drip irrigation and the water–energy–food nexus in Morocco

This article draws on three case studies of drip irrigation adoption in Morocco to consider the water–energy–food nexus concept from a bottom-up perspective. Findings indicate that small farmers' adoption of drip irrigation is conditional, that water and energy efficiency does not necessarily reduce overall consumption, and that adoption of drip irrigation (and policies supporting it) can create winners and losers. The article concludes that, although the water–energy–food WEF nexus concept may offer useful insights, its use in policy formulation should be tempered with caution. Technical options that appear beneficial at the conceptual level can have unintended consequences in practice, and policies focused on issues of scarcity and efficiency may exacerbate other dimensions of poverty and inequality.     

Particle counting as a tool to predict filterability in membrane bioreactors activated sludge?

Activated sludge quality is one of the major factors influencing flux decline in membrane bioreactors (MBRS). Sludge filterability is a recognized parameter to characterize the physical properties of activated sludge. Decrease in filterability is linked to a higher number of submicron particles. In our present research we studied whether particle counting techniques can be used to indicate deflocculation of the sludge suspended fraction to submicron particles, causing the aforementioned filterability decrease. A total number of 105 activated sludge samples were collected in four full scale municipal MBRS. Samples were tested for filterability and particle counting in the range 2-100 microm. In 88% of the membrane tank samples the filterability varied between good and poor, characterized by the deltaR20, being 0 < deltaR20 < 1. Filterability varied following the season of the year, stability of the MBR operation and recirculation ratio. The membrane tank filterability can be improved by applying low recirculation ratio between MBR tanks. The applied particle counting methodology generated reproducible and reliable results in the range 10-100 microm. Results show that differences in filterability cannot be explained by variations in particle size distribution in the range 10-100 microm. However, measurable deflocculation might be masked by the large numbers of particles present. Therefore, we cannot exclude the suspended particles as a possible source of submicron particles that are subsequently responsible for MBR sludge filterability deterioration.     

Use of a stable carbon isotope to assess the efficiency of a drinking water treatment method with CO?

CO? gas with a special isotopic signature (δ13C = -35.2‰ vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water-supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of δ13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO? gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method's overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage.     

Hydrosolidarity and beyond: can ethics and equity find a place in today's water resource management?

The notion of hydrosolidarity has permeated international discourses on water management, but it has received little comprehensive review. This paper traces the intellectual origins of hydrosolidarity and it explores how the concept has been applied by water scholars, organizations and in global water venues, like World Water Forums. Evolving conceptions and meanings of hydrosolidarity are presented and its kinship to related, sometimes oppositional terms, untangled. In particular, it explores how hydrosolidarity has evolved to serve as a socio-ethical annex to integrated water resources management. The paper concludes by examining some critiques and addressing the potential of hydrosolidarity in water management.     

Will the energy industry drain the water used for agricultural irrigation in the Yellow River basin?

This article employs the case of the Yellow River basin to advance understanding of the water–energy–food nexus by demonstrating how the country’s energy and agriculture sectors are competing for limited water supplies and by quantifying the future water demands in the two sectors. The results show that in 2030 the water demands for food and energy are likely to increase by less than 4 km³ and 1 km³, respectively, in the Yellow River basin. The analysis suggests that agricultural water savings and inter-basin water transfers are the main ways to ensure sufficient water flows through the basin to fulfil demand for both sectors while preserving the natural ecosystems.     

Let’s bring in the floods: de-poldering in the Netherlands as a strategy for long-term delta survival?

Controlled flooding, while heavily contested, is being experimented with in the Dutch delta as a new and ecologically oriented strategy to deal with floods, in contrast to the conventional flood prevention paradigm. The Noordwaard project (2012–15) represents an exemplary case. At the expense of agricultural practices, land is set aside occasionally to accommodate river floods, while restored flood and tidal dynamics aim to benefit nature development. It is argued that although controlled flooding aims to restore historical land and water dynamics in the area, the role of sedimentation processes has remained largely unaddressed in relation to shaping long-term delta futures.     

Landscape-scale modeling of water quality in Lake Superior and Lake Michigan watersheds: How useful are forest-based indicators?

The Great Lakes watersheds have an important influence on the water quality of the nearshore environment, therefore, watershed characteristics can be used to predict what will be observed in the streams. We used novel landscape information describing the forest cover change, along with forest census data and established land cover data to predict total phosphorus and turbidity in Great Lakes streams. In Lake Superior, we modeled increased phosphorus as a function of the increase in the proportion of persisting forest, forest disturbed during 2000–2009, and agricultural land, and we modeled increased turbidity as a function of the increase in the proportion of persisting forest, forest disturbed during 2000–2009, agricultural land, and urban land. In Lake Michigan, we modeled increased phosphorus as a function of ecoregion, decrease in the proportion of forest disturbed during 1984–1999 and watershed storage, and increase in the proportion of urban land, and we modeled increased turbidity as a function of ecoregion, increase in the proportion of forest disturbed during 2000–2009, and decrease in the proportion softwood forest. We used these relationships to identify priority areas for restoration in the Lake Superior basin in the southwestern watersheds, and in west central and southwest watersheds of the Lake Michigan basin. We then used the models to estimate water quality in watersheds without observed instream data to prioritize those areas for management. Prioritizing watersheds will aid effective management of the Great Lakes watershed and result in efficient use of restoration funds, which will lead to improved nearshore water quality.     

Patterns of long-term dynamics of aquatic communities and water quality parameters in the Great Lakes: Are they synchronized?

Long time series data can provide insights into dynamics of large lakes. We use the USEPA-GLNPO biological monitoring dataset (phytoplankton, benthos, zooplankton and water quality), collected from 1996 through 2016, to identify whether there is evidence of concordant linear or non-linear trends in community composition, density/biomass/biovolume and major environmental parameters. We show changes in biotic assemblages and water quality variables, particularly in Lakes Michigan and Huron. These include changes in phytoplankton biovolume and zooplankton biomass, increasing invasive Dreissena abundance and decreasing densities of other benthos. Biotic changes are accompanied by pronounced changes in water quality and nutrient ratios. Species change-points, identified using threshold indicator taxon analysis, are often less abrupt, but there are clear shifts in a large proportion of species in each assemblage. The concordance of breakpoints among assemblages or lack thereof provides valuable insight into potential drivers of ecosystem change.     

Source apportionment of river water pollution in a typical agricultural city of Anhui Province,eastern China using multivariate statistical techniques with APCS– MLR

The deterioration of the surface water environment has become a serious challenge for water resources management due to increasing anthropogenic disturbance. Water resources protection requires control of potential pollution sources. In this study, 99 water samples were collected from a river in a typical agricultural city of Anhui Province in eastern China, and these samples were analyzed in terms of pH, electrical conductivity, and the concentrations of F^-, Cl^-, SO₄^2-, Na⁺, K⁺, Mg²⁺, Ca²⁺, As, Cr, Cu, Zn, and Pb. Cluster analysis, co-occurrence network analysis, and principal component analysis/factor analysis were conducted to qualitatively identify the potential sources of river water pollution in the study area. An absolute principal component score-multiple linear regression receptor model was used to quantitatively evaluate the contribution of each source to water quality parameters. The results showed that all observed water quality indices met the quality criteria specified in the Chinese drinking water standards, except for pH, ρ(F^-), ρ(SO₄^2-), and ρ(As). The heat map showed that the frequent recharge of pollutants from the tributaries during the wet season was the main reason for the deterioration of water quality. Five sources of river water pollution were identified, and their contribution ratios in a descending order were as follows: the geogenic process (24%) > agricultural activities (21%) > poultry farming sources (17%) > domestic pollution (9%) > transportation pollution (5%). Therefore, controlling pollution from agricultural activities, strengthening the regulation of livestock farming, and improving the sewage network are the recommended strategies for improving the quality of surface water resources in this area.     

Nexus meets crisis: a review of conflict,natural resources and the humanitarian response in Darfur with reference to the water–energy–food nexus

Darfur has been widely used as a case study by both those arguing for causality between environmental scarcity and war and those disputing it. This article challenges that approach by drawing on debates taking place within Darfur, reflecting on both the conflict and the humanitarian response. It argues that reviewing Darfur on its own terms makes a stronger basis to identify transferable lessons for interventions elsewhere. It considers water, food and energy, and finds that supporting governance is an essential theme for promoting economic recovery and laying a foundation for a well-managed water–energy–food nexus.     

Can Fluctuating Asymmetry in Adult Burrowing Mayflies (Hexagenia rigida,Ephemeroptera) be used as a Measure of Contaminant Stress?

Fluctuating asymmetry (FA) in bilateral organisms may provide an early warning for detrimental effects of environmental stress in organisms well before populations are affected. Adult Hexagenia rigida were collected (17 June to 1 July 1996) at 6 sites around Lake Erie, representing areas with high (Monroe, MI; Colchester, ON; Middle Sister Island, ON) and low (Windsor, ON; Kingsville, ON; Catawba, OH) exposure to PCB contaminants. Balsam Lake, ON served as a reference site. Initially 27 structures were examined on the left and right sides of 30 males from both the most contaminated (Monroe) and least contaminated (Balsam Lake) sites using image analysis. Traits were autocorrelated; therefore, 7 independent traits were identified using principal component analysis. It was anticipated that there would be greater variation (i.e., greater FA) in organisms collected from sites known to exhibit high PCB body burdens than in organisms having low levels of contaminants. However, there were no significant differences in FA for male or female adults of H. rigida among the sites for the morphometric traits measured. There were significant differences in FA for two traits in H. rigida males among years (1991, 1994 to 96) at Windsor, but trends were not consistent. Although measurement error was low (1 to 6 %), results suggest that contaminant effects may be difficult to detect in the field because either the stress (PCBs) in the field was not strong enough to elicit a response by Hexagenia or PCB body burdens did not alter development in the insects.