Watershed processes and their effects on coasts are shaped by numerous interacting natural and societal factors. The knowledge of these factors and processes is often limited. This makes the field prone to politicisations with debates, research, and interventions being confined to a few selected factors. Debates on the causes of high river sediment loads and coastal sedimentation in Java have focussed on rainfed agriculture on peasants’ private lands, while other drivers have been neglected. This has undermined the effectiveness of watershed management. This paper links the sedimentation of the Segara Anakan lagoon on Java’s south coast with landscape characteristics and transformations in its catchment. Three-fourths of the lagoon have silted up since 1857/60. This is the result of a much broader range of drivers than commonly assumed to date. In addition to rainfed agriculture on peasants’ private lands, these drivers include coffee cultivation, timber extraction, plantation development, and in-migration in the late nineteenth and early twentieth century; erosion on contested state forest and plantation lands; state forest management practices; slope cuts to enlarge agricultural fields; agriculture in riparian zones; erosion from roads, trails, and settlements; river channel and floodplain modifications; and volcanic eruptions. The choice and expectations of societal responses aimed at reducing river sediment loads and coastal sedimentation hence need to be reconsidered, and related debates and research agendas must be broadened.
We detected Hepatitis E virus in serum samples of wild rabbits that were hunted in 1989 around the city of Greifswald, Germany. The recovery of one partial sequence and subsequent phylogenetic analysis indicates a close relationship to rabbit HEV sequences from France and suggests a long-established circulation of rabbit HEV in Europe. 相似文献
Tritium is an important environmental radionuclide whose reactivity with ligands and solids in aquatic systems is assumed to be limited. We studied the fractionation and sorption of tritium (added as tritiated water) in river water and seawater, and found that its distribution appears to be influenced by its affinity for organic matter. Tritium rapidly equilibrates with dissolved organic ligands that are retained by a reverse-phase C18 column, and with suspended sediment particles. Significantly, a measurable fraction of sorbed tritium associates with proteinaceous material that is potentially available to sediment-feeding organisms. These characteristics have not been reported previously and cannot be accounted for solely by isotopic exchange with hydrogen. Nevertheless, they are in qualitative agreement with available measurements of tritium in estuarine and coastal waters where its principal discharge is as tritiated water. Further research into the estuarine biogeochemical behaviour of tritium is required and radiological distribution coefficients and concentration factors that are assumed for this radionuclide may require reconsideration. 相似文献
Methane emission monitoring has become increasingly essential for diffusive area sources, especially for landfills, which contribute to a significant fraction of the total anthropogenic methane emission globally. Statutorily, methane emission rate from landfills in Germany shall be examined on a semiannual basis; however, an appropriate approach has yet to be developed and adopted for general use. In this study, a new method is proposed based on experimental results, which utilizes a TDLAS (Tunable Diode Laser Absorption Spectroscopy) instrument – GasFinder2.0® system and a dispersion model LASAT (Lagrangian Simulation of Aerosol Transport) as the measurement device and calculation model, respectively. Between April 2010 and December 2011, a research project was conducted at a pilot scale landfill in the south of Germany. Drawing on the extensive research into this pilot project, an effective strategy of measurement setup was determined. Methane concentration was measured with GasFinder2.0® system in the upstream and downstream sections of the project site, while wind and turbulence data were measured simultaneously by an ultrasonic anemometer. The average methane emission rate from the source can be calculated by using the results as input data in the dispersion model. With this method, site-specific measurement approaches can be designed for not only landfills, but also different diffusive area sources with less workload and lower cost compared to conventional FID (Flame Ionization Detector) method. 相似文献