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.