Lessons learned from the Big Floods, 1999–2013: The Bavarian Flood Action Programme 2020plus

Flood protection is an integral part of society's development. Meeting a growing vulnerability in the context of geopolitical and global changes, existing systems of natural hazard management must be reviewed on a regular basis. This is illustrated well by Bavaria's recent history. The lessons from the big floods in the period of 1999–2013 led to a fundamental modification of Bavaria's integral flood protection strategy. The concepts of flood risk management, resilience and dealing with extreme flood events which exceed standard structural design limits came to the fore. Management of flash floods and other floods, handling of potential retention areas, the inclusion of insurance, resettlement, and the burden of maintenance are further challenges which are briefly addressed in this paper.

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Structural design of floodways under extreme flood loading

International Journal of Disaster Resilience in the Built Environment ◽

10.1108/ijdrbe-10-2019-0072 ◽

2020 ◽

Vol 11 (4) ◽

pp. 535-555

Author(s):

Isaac Greene ◽

Weena Lokuge ◽

Warna Karunasena

Keyword(s):

Finite Element ◽

Design Process ◽

Structural Design ◽

Design Guidelines ◽

Flood Events ◽

Worst Case ◽

Content Type ◽

Design Charts ◽

Hydraulic Design ◽

Extreme Flood

Purpose Current methods for floodway design are predominately based on hydrological and hydraulic design principles. The purpose of this paper is to investigate a finite element methods approach for the inclusion of a simplified structural design method into floodway design procedures. Design/methodology/approach This research uses a three-dimensional finite element method to investigate numerically the different parameters, geometric configurations and loading combinations which cause floodway vulnerability during extreme flood events. The worst-case loading scenario is then used as the basis for design from which several structural design charts are deduced. These charts enable design bending moments and shear forces to be extracted and the cross-sectional area of steel and concrete to be designed in accordance with the relevant design codes for strength, serviceability and durability. Findings It was discovered that the analysed floodway structure is most vulnerable when impacted by a 4-tonne boulder, a 900 mm cut-off wall depth and with no downstream rock protection. Design charts were created, forming a simplified structural design process to strengthen the current hydraulic design approach provided in current floodway design guidelines. This developed procedure is demonstrated through application with an example floodway structural design. Originality/value The deduced structural design process will ensure floodway structures have adequate structural resilience, aiding in reduced maintenance and periods of unserviceability in the wake of extreme flood events.

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Ectomycorrhiza resilience and recovery to extreme flood events in Tuber aestivum and Quercus robur

Mycorrhiza ◽

10.1007/s00572-021-01035-4 ◽

2021 ◽

Author(s):

P. W. Thomas

Keyword(s):

Climate Change ◽

Seedling Growth ◽

Quercus Robur ◽

Root Systems ◽

Fruiting Bodies ◽

Flood Events ◽

Tuber Aestivum ◽

Soil Zone ◽

Extreme Flood ◽

The Impact

AbstractVery little is known about the impact of flooding and ground saturation on ectomycorrhizal fungi (EcM) and increasing flood events are expected with predicted climate change. To explore this, seedlings inoculated with the EcM species Tuber aestivum were exposed to a range of flood durations. Oak seedlings inoculated with T. aestivum were submerged for between 7 and 65 days. After a minimum of 114-day recovery, seedling growth measurements were recorded, and root systems were destructively sampled to measure the number of existing mycorrhizae in different zones. Number of mycorrhizae did not display correlation with seedling growth measurements. Seven days of submersion resulted in a significant reduction in mycorrhizae numbers and numbers reduced most drastically in the upper zones. Increases in duration of submersion further impacted mycorrhizae numbers in the lowest soil zone only. T. aestivum mycorrhizae can survive flood durations of at least 65 days. After flooding, mycorrhizae occur in higher numbers in the lowest soil zone, suggesting a mix of resilience and recovery. The results will aid in furthering our understanding of EcM but also may aid in conservation initiatives as well as providing insight for those whose livelihoods revolve around the collection of EcM fruiting bodies or cropping of the plant partners.

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