@article{ArendtReinhardtImjelaSchulteetal.2021, author = {Arendt, Robert and Reinhardt-Imjela, Christian and Schulte, Achim and Faulstich, Leona and Ullmann, Tobias and Beck, Lorenz and Martinis, Sandro and Johannes, Petrina and Lengricht, Joachim}, title = {Natural pans as an important surface water resource in the Cuvelai Basin — Metrics for storage volume calculations and identification of potential augmentation sites}, series = {Water}, volume = {13}, journal = {Water}, number = {2}, issn = {2073-4441}, doi = {10.3390/w13020177}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223019}, year = {2021}, abstract = {Numerous ephemeral rivers and thousands of natural pans characterize the transboundary Iishana-System of the Cuvelai Basin between Namibia and Angola. After the rainy season, surface water stored in pans is often the only affordable water source for many people in rural areas. High inter- and intra-annual rainfall variations in this semiarid environment provoke years of extreme flood events and long periods of droughts. Thus, the issue of water availability is playing an increasingly important role in one of the most densely populated and fastest growing regions in southwestern Africa. Currently, there is no transnational approach to quantifying the potential storage and supply functions of the Iishana-System. To bridge these knowledge gaps and to increase the resilience of the local people's livelihood, suitable pans for expansion as intermediate storage were identified and their metrics determined. Therefore, a modified Blue Spot Analysis was performed, based on the high-resolution TanDEM-X digital elevation model. Further, surface area-volume ratio calculations were accomplished for finding suitable augmentation sites in a first step. The potential water storage volume of more than 190,000 pans was calculated at 1.9 km\(^3\). Over 2200 pans were identified for potential expansion to facilitate increased water supply and flood protection in the future.}, language = {en} } @article{Ibebuchi2022, author = {Ibebuchi, Chibuike Chiedozie}, title = {Patterns of atmospheric circulation in Western Europe linked to heavy rainfall in Germany: preliminary analysis into the 2021 heavy rainfall episode}, series = {Theoretical and Applied Climatology}, volume = {148}, journal = {Theoretical and Applied Climatology}, number = {1-2}, issn = {0177-798X}, doi = {10.1007/s00704-022-03945-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324100}, pages = {269-283}, year = {2022}, abstract = {The July 2021 heavy rainfall episode in parts of Western Europe caused devastating floods, specifically in Germany. This study examines circulation types (CTs) linked to extreme precipitation in Germany. It was investigated if the classified CTs can highlight the anomaly in synoptic patterns that contributed to the unusual July 2021 heavy rainfall in Germany. The North Atlantic Oscillation was found to be the major climatic mode related to the seasonal and inter-annual variations of most of the classified CTs. On average, wet (dry) conditions in large parts of Germany can be linked to westerly (northerly) moisture fluxes. During spring and summer seasons, the mid-latitude cyclone when located over the North Sea disrupts onshore moisture transport from the North Atlantic Ocean by westerlies driven by the North Atlantic subtropical anticyclone. The CT found to have the highest probability of being associated with above-average rainfall in large part of Germany features (i) enhancement and northward track of the cyclonic system over the Mediterranean; (ii) northward track of the North Atlantic anticyclone, further displacing poleward, the mid-latitude cyclone over the North Sea, enabling band of westerly moisture fluxes to penetrate Germany; (iii) cyclonic system over the Baltic Sea coupled with northeast fluxes of moisture to Germany; (iv) and unstable atmospheric conditions over Germany. In 2021, a spike was detected in the amplitude and frequency of occurrence of the aforementioned wet CT suggesting that in addition to the nearly stationary cut-off low over central Europe, during the July flood episode, anomalies in the CT contributed to the heavy rainfall event.}, language = {en} }