@article{Ibebuchi2021,
  author    = {Ibebuchi, Chibuike Chiedozie},
  title     = {Circulation pattern controls of wet days and dry days in Free State, South Africa},
  series = {Meteorology and Atmospheric Physics},
  volume    = {133},
  journal   = {Meteorology and Atmospheric Physics},
  number    = {5},
  issn      = {1436-5065},
  doi       = {10.1007/s00703-021-00822-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268552},
  pages     = {1469-1480},
  year      = {2021},
  abstract  = {Atmospheric circulation is a vital process in the transport of heat, moisture, and pollutants around the globe. The variability of rainfall depends to some extent on the atmospheric circulation. This paper investigates synoptic situations in southern Africa that can be associated with wet days and dry days in Free State, South Africa, in addition to the underlying dynamics. Principal component analysis was applied to the T-mode matrix (variable is time series and observation is grid points at which the field was observed) of daily mean sea level pressure field from 1979 to 2018 in classifying the circulation patterns in southern Africa. 18 circulation types (CTs) were classified in the study region. From the linkage of the CTs to the observed rainfall data, from 11 stations in Free State, it was found that dominant austral winter and late austral autumn CTs have a higher probability of being associated with dry days in Free State. Dominant austral summer and late austral spring CTs were found to have a higher probability of being associated with wet days in Free State. Cyclonic/anti-cyclonic activity over the southwest Indian Ocean, explained to a good extent, the inter-seasonal variability of rainfall in Free State. The synoptic state associated with a stronger anti-cyclonic circulation at the western branch of the South Indian Ocean high-pressure, during austral summer, leading to enhanced low-level moisture transport by southeast winds was found to have the highest probability of being associated with above-average rainfall in most regions in Free State. On the other hand, the synoptic state associated with enhanced transport of cold dry air, by the extratropical westerlies, was found to have the highest probability of being associated with (winter) dryness in Free State.},
  language  = {en}
}
@article{FleuchausBlumWildeetal.2021,
  author    = {Fleuchaus, Paul and Blum, Philipp and Wilde, Martina and Terhorst, Birgit and Butscher, Christoph},
  title     = {Retrospective evaluation of landslide susceptibility maps and review of validation practice},
  series = {Environmental Earth Sciences},
  volume    = {80},
  journal   = {Environmental Earth Sciences},
  issn      = {1866-6280},
  doi       = {10.1007/s12665-021-09770-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308911},
  year      = {2021},
  abstract  = {Despite the widespread application of landslide susceptibility analyses, there is hardly any information about whether or not the occurrence of recent landslide events was correctly predicted by the relevant susceptibility maps. Hence, the objective of this study is to evaluate four landslide susceptibility maps retrospectively in a landslide-prone area of the Swabian Alb (Germany). The predictive performance of each susceptibility map is evaluated based on a landslide event triggered by heavy rainfalls in the year 2013. The retrospective evaluation revealed significant variations in the predictive accuracy of the analyzed studies. Both completely erroneous as well as very precise predictions were observed. These differences are less attributed to the applied statistical method and more to the quality and comprehensiveness of the used input data. Furthermore, a literature review of 50 peer-reviewed articles showed that most landslide susceptibility analyses achieve very high validation scores. 73\% of the analyzed studies achieved an area under curve (AUC) value of at least 80\%. These high validation scores, however, do not reflect the high uncertainty in statistical susceptibility analysis. Thus, the quality assessment of landslide susceptibility maps should not only comprise an index-based, quantitative validation, but also an additional qualitative plausibility check considering local geomorphological characteristics and local landslide mechanisms. Finally, the proposed retrospective evaluation approach cannot only help to assess the quality of susceptibility maps and demonstrate the reliability of such statistical methods, but also identify issues that will enable the susceptibility maps to be improved in the future.},
  language  = {en}
}