Regionaler Klimawandel Sachsen

Goal and Background

Since consequences of global climate change include even contradicting directions and trends in different regions and seasons, regional studies are a necessity to understand regional problems and risks. Extreme precipitation is a highly variable climate element in time and space with serious economic and ecological impacts. The analysis of changes in the Saxonian precipitation characteristics is one constituent in our understanding of global climate change and regional climate-related risk assessment.

Methods

Changes of regional precipitation patterns and their extremes were analysed based upon data from 21 stations in Saxony from 1934 to 2000. Eighteen stations delivered 50-year data sets (1951–2000) and three stations (Altmörbitz, Chemnitz, Neuhausen) delivered daily precipitation data over 67 years (1934–2000). Differentiated by season and half-year periods, trends were calculated for the relevant parameters by linear regression. The trend significance was determined by the non-parametric Mann-Kendall-trend test.

Results and Conclusion

In the summer half of the year, distinctively more dry conditions developed. Over the same period, the winter half of the year became more wet. Regarding trends of extreme precipitation, a strong dependency to the size of the choosen treshold value exists. During the summer, size and excess frequency of the 90^th and 95^th percentiles have increased, whereas they decreased in the winter. On the other hand, the half year trends of the 99^th percentile are predominantly positive. Particularly the trend towards more dry conditions in summer is of substantial relevance for the economy and water management.

Recommendations and Perspective

The additional analysis of further precipitation data sets, provided by the Saxonion Climate database, will advance the regional accuracy of the presented findings. In addition work on the adjustment of an extreme distribution to daily and monthly precipitation sums is needed, and an effect-related definition of dry periods needs to be developed.     

Klimawandel in Küstenzonen

The IPCC-TAR (2001) depicts the consequences of climate change on a global scale with a central focus on vulnerability and adaptation. The objective of this article is the important regional/local scale: First, sea-level rise, storm surges and related issues are perceived here, and second, decisions about precautionary measures, and coastal protection are mostly initialised on this scale. The Integrated Coastal Zone Management (ICZM) is described as an auspicious approach managing conflicts in coastal zones.     

Globaler Vertrag zur Regelung von POPs: Die Stockholm Konvention

The success of the negotiations on the POPs Convention after the failure of the negotiations over the climate protocol in The Hague in late November is an important result for international action to protect the earth from damage by chemicals. It shows the countries’ real commitment to find compromises for protection of the environment and human health and for the restoration of damaged ecosystems on our planet. It deserves to be highlighted that all participants — not only the industrialized countries but also developing countries as well as environmental organizations and the (chemical) industry — regard the conclusion of this convention as a success and that a broad basis for joint action has thus been created. The convention is a signal also because of its useful contents, which includes instruments for the total elimination of 12 POPs in the beginning and of further persistent organic pollutants at a later stage. The basis for a gradual reduction of the increasing pollution of the environment on a global scale is given by mechanisms for subjecting further POPs to the requirements of this Convention in the future.     

Die Fungizide Hexachlorbenzol und Pentachlornitrobenzol und ihre Stoffwechselwege

Die Kenntnis biochemischer Veränderungen von lipophilen körperfremden Stoffen ist hinsichtlich deren Elimination aus dem Organismus, sowie bei Überlegungen zur Voraussage toxischer, insbesondere carcinogener Wirkungen von vorrangiger Bedeutung     

Wolke und Nebel

Obwohl Wolken- und Nebelwasser einen Anteil von 10?3 an der Masse und einen Anteil von 10?6 am Volumen der Luft nie wesentlich übersteigen, ist ihre Anwesenheit von großer Bedeutung für die Chemie der Troposphäre sowie an vielen Orten für den Schadstoffeintrag aus der Atmosphäre. Wolke und Nebel können Quellen sekundärer Schadstoffe darstellen und beeinflussen Umwandlung, Transport und Senken von vielen luftgetragenen Spurenstoffen. Die Inhaltsstoffe von Wolken- und Nebelwasser sind die Folge physikalischer und chemischer Selektionsprozesse im Mehrphasensystem Luft, das durch die atmosphärischen Gase, feste und flüssige Partikel gegeben ist. Stoffspezifische Anreicherungsvorgänge in der wäßrigen Phase und gegenüber der Gasphase beschleunigte Reaktionen sind die wichtigsten Urachhen für die in Wolken- und Nebelwasser vorgefundenen hohen Schadstoffkonzentrationen. Einige der atmosphärischen Säurebildungsprozesse, darunter die Oxidation von SO2 zu Schwefelsäure, verlaufen weit effektiver in Tröpfchen. Die Säurekonzentrationen, die in Wasser von aufliegenden Wolken, insbesondere bei Strahlungsnebeln, beobachtet wurden, übersteigen jene des Niederschlags weit, in der Regel um mehr als eine Größenordnung. Der Schadstoffeintrag durch Deposition von Wasser aufliegender Wolken kann an manchen Orten—insbesondere in bewaldeten Mittelgebirgs- und Gebirgsregionen—den durch Niederschlag bedingten Eintrag übersteigen. Besondere Gegebenheiten bei der Exposition von Vegetation in aufliegenden Wolken und in Nebeln erhöhen das Wirkungspotential der Schadstoff-Fracht von Nebel und Wolke.