The stability of upstream deposited tailings dams is dependent on maintaining a drawn down phreatic surface and unsaturated profile in its outer edge. However, it has been speculated that intense rainfall events could induce unexpected translation of pore air and water pressures into the tailings profile and thus compromise the effective stress in the unsaturated zone or result in a sudden rise in the phreatic surface. This phenomenon, known as the Lisse effect, has been observed and studied in hydrological sciences to explain the rapid delivery of antecedent hillslope groundwater during storm events. However, the phenomenon has not been comprehensively applied to evaluating tailings dam slope stability. In this paper, the outcomes of controlled observations of the phenomenon in column and analytical experiments, are assembled and evaluated in terms of the surface water application volumes and rate, the properties of the porous media and the resultant nature of pore pressure and phreatic surface responses. In addition, application of applied theories to evaluate the rapid transmission of pore pressures through a profile in response to an advancing wetting front, leads to the development of a methodology that could be applied to tailings materials of a range of hydraulic conductivities and water retention characteristics. The theory is applied to a series of profiles of different tailings porous media, using varied water application rates. Resultant perturbations in phreatic surface elevation and changes to pore pressures in the unsaturated zone are used to evaluate changes in effective stress distribution in the unsaturated outer wedge and subsequent stability criteria. A possible evaluation algorithm for assessing stability criteria is suggested.
MULTIFILE
Music interventions are used for stress reduction in a variety of settings because of the positive effects of music listening on both physiological arousal (e.g., heart rate, blood pressure, and hormonal levels) and psychological stress experiences (e.g., restlessness, anxiety, and nervousness). To summarize the growing body of empirical research, two multilevel meta-analyses of 104 RCTs, containing 327 effect sizes and 9,617 participants, were performed to assess the strength of the effects of music interventions on both physiological and psychological stress-related outcomes, and to test the potential moderators of the intervention effects. Results showed that music interventions had an overall significant effect on stress reduction in both physiological (d = .380) and psychological (d = .545) outcomes. Further, moderator analyses showed that the type of outcome assessment moderated the effects of music interventions on stress-related outcomes. Larger effects were found on heart rate (d = .456), compared to blood pressure (d = .343) and hormone levels (d = .349). Implications for stress-reducing music interventions are discussed.
Urban planning will benefit from tools that can assess the vulnerabilityto thermal stress in urban dense cities. Detailed quick-scan heat stressmaps, as made in this study for Johannesburg, have proven valuable inthe decision-making process on this topic. It raised awareness on theurgent need to implement measures to tackle the effects of climatechange and urbanization. Awareness on heat stress has led to theimplementation of measures to mitigate the effects of climate change.As in other countries, nature-based solutions (e.g. green roofs and walls,swales, rain gardens, planting trees etc) are considered in urban areasin South Africa for various reasons. The awareness of the effect ofnature based solutions on heat stress is still low, which can be improvedby the use of heat stress maps. Some of these measures are alreadymapped on the open source web tool, Climate-scan(www.climatescan.nl) for international knowledge exchange aroundthe globe.
Worldwide, coral reefs are rapidly declining due to increased sea water temperatures and other environmental stresses (Figure 1). To counter the extinction of major coral reef building species on the island of Bonaire, the non-profit organization Reef Renewal Foundation Bonaire is restoring degraded reef sites using corals that are grown in local nurseries. In these nurseries, corals are propagated on artificial trees using fragmentation. After 6-8 months of growth in the nursery, the corals are transplanted to degraded reef sites around the island. Over the years more than 21.000 corals have been outplanted to reef restoration sites in this way. These corals show high survivorship under natural reef conditions but remain under threat by environmental disturbances, such as increased water temperatures, diseases, and competition with macroalgae. A promising intervention to increase reef persistence and resilience is to manipulate the coral-associated microbiome. At present, the composition of the microbiome in nursery-reared and outplanted corals on Bonaire is unknown. The aim of the current project is to identify and isolate naturally occurring beneficial bacteria that may stimulate the resilience of these corals. Our key objectives are: 1) to assess the presence of functionally beneficial bacteria in corals in nursery and restoration sites on Bonaire using metagenomic screening. 2) to design culture strategies to isolate these functionally beneficial bacteria. In the future, a selection of these beneficial bacteria can be applied to the corals to increase their resilience against environmental disturbances.
Due to the existing pressure for a more rational use of the water, many public managers and industries have to re-think/adapt their processes towards a more circular approach. Such pressure is even more critical in the Rio Doce region, Minas Gerais, due to the large environmental accident occurred in 2015. Cenibra (pulp mill) is an example of such industries due to the fact that it is situated in the river basin and that it has a water demanding process. The current proposal is meant as an academic and engineering study to propose possible solutions to decrease the total water consumption of the mill and, thus, decrease the total stress on the Rio Doce basin. The work will be divided in three working packages, namely: (i) evaluation (modelling) of the mill process and water balance (ii) application and operation of a pilot scale wastewater treatment plant (iii) analysis of the impacts caused by the improvement of the process. The second work package will also be conducted (in parallel) with a lab scale setup in The Netherlands to allow fast adjustments and broaden evaluation of the setup/process performance. The actions will focus on reducing the mill total water consumption in 20%.
Professionals van het Wetterskip, gemeenten, provincie en natuurorganisaties hebben de vraag gesteld hoe het watersysteem in Noordoost Fryslân duurzamer en toekomstbestendiger kan worden gemaakt. In dit RAAK Publiek project verricht hogeschool VHL samen met deze professionals en met kennispartners onderzoek naar dit vraagstuk. De ?houdbaarheidsdatum? van het traditionele waterbeheer lijkt bereikt. Traditioneel afwateren en ontwateren heeft geleid tot maaivelddaling in de veenweidegebieden, en daaraan gerelateerde CO2-uitstoot en uitspoeling van nutriënten in het grond- en oppervlaktewater. Gevolg is een verlies aan waterbergingscapaciteit en een achteruitgang van de waterkwaliteit. Bij zware regenval is het moeilijk om het water nog te bergen en af te voeren om wateroverlast te voorkomen. Bij droogte ontstaan veel sneller dan voorheen watertekorten. Ook staan daardoor veel unieke ecologische waarden in de veenweidegebieden onderzoek druk of zijn verdwenen. Klimaatveranderingen versterken deze problematiek. In het project wordt kennis ontwikkeld over een klimaatadaptief watersysteem in veengebieden en nieuwe vormen van waterbeheer, functies en functiecombinaties en de relatie met het meer toekomstbestendig maken van het watersysteem (flexibel waterpeil, berging in een natuurgebied, natte teelt, natuurvriendelijke oevers, etc.). Dit wordt gedaan door met elkaar en met andere actoren uit de regionale samenleving a) het watersysteem te onderzoeken en b) te experimenteren met innovatief waterbeheer in het gebied. De onderzoeksvraag is: In welke mate dragen nieuwe vormen van duurzaam, slim waterbeheer bij aan de toekomstbestendigheid van het watersysteem in Noordoost Fryslân? Het project levert voor de waterbeheerders, planologen, natuurbeheerders en andere betrokken professionals een digitaal handboek, bestaande uit een analyse van het watersysteem in het gebied, een klimaatstresstest, een gidsmodel voor het vasthouden en schoonhouden van water, beschreven innovatieve oplossingsrichtingen, een 3D animatie, een participatieve handreiking met ontwerprichtlijnen, beschreven ervaringen en enkele toekomstscenario?s voor het gebied. Dit alles wordt gekoppeld aan een veldwerkplaats en kennismanagementsysteem.
