An international team from The Australian National University, Ecowise Environmental, the Government of the Republic of Kiribati, the French agency CIRAD and the Pacific Islands Applied Geoscience Commission has been studying the impacts of natural and human-induced changes on groundwater in the central Pacific nation of Kiribati since 1996.
The work was initiated by UNESCO International Hydrological Programme and supported by the Australian Centre for International Agricultural Research, the Government of France, the Australian Academy of Science, the Australian Research Council and the European Union Pacific Water Governance Programme. Their work is published in a special issue of the Aug. 2007 Vadose Zone Journal which followed an International Symposium on Groundwater Resources Assessment under the Pressures of Humanity and Climate Change held in Kyoto in April 2006 and coordinated by the Japanese Research Institute for Humanity and Nature.
Very limited land areas and extremely permeable coral soils in atolls reduce surface runoff to insignificant amounts and decrease the potential for surface storages of water. This means thin lenses of fresh groundwater floating over seawater are the major source of reliable freshwater for people in many atolls. The team found that both the quantity and salinity of atoll groundwater is extremely vulnerable to frequent ENSO-related droughts. Droughts can last as long as 4 years and occur with a frequency of one significant drought, coupled to La Niña events, every 6-7 years. In long droughts domestic water wells are often too salty too drink and some communities have to rely on large groundwater lenses or on coconuts.
Population growth due to natural increases, inward migration and urbanization mean that fresh groundwater sources are reaching their limit of sustainable supply in urban South Tarawa in Kiribati. Groundwater can become salty due to over-pumping or inappropriate methods of pumping. Long, horizontal infiltration pumping galleries or “skimming wells”, placed just beneath the groundwater table (the top layer of soil and rock that is saturated with water) provide the best method of skimming off lower salinity groundwater. The study team tested the impact of infiltration galleries on lowering the watertable and on salinity. The researchers also used the results to examine how the permeability of the coral sands varied across islands and found that surface contaminants could reach shallow fresh groundwater within an hour of being split on the soil surface.
The team proposed a number of strategies to help increase the resilience of small island communities to water–related climate and human changes. These included: providing a sound institutional basis for the management of water and sanitation; improving community participation in water and related land planning and management; increasing the capacity of villagers and local agencies to manage water and sanitation under variable climates; improving knowledge of available water resources and demand for them; improving water conservation and demand management and reducing leakages; increasing the use of rainwater by households and communities; protecting groundwater source areas from contamination; improving sanitation systems to minimize water use and groundwater pollution; and ensuring that water aid programs are long-term partnerships that foster local engagement and ownership of solutions.
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Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
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Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
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