Photogrammetric and laser altimetric reconstruction of water levels for extreme flood event analysis

2003 ◽  
Vol 18 (104) ◽  
pp. 293-307 ◽  
Author(s):  
Stuart N. Lane ◽  
Timothy D. James ◽  
Hamish Pritchard ◽  
Mark Saunders
2018 ◽  
Vol 4 (3) ◽  
pp. 215
Author(s):  
Muhamad Zulhilmi Abdul Latif

A devastating flood disaster occurred at Kuala Krai, Kelantan on December 2014. The flood disaster had given a significant destructive impact on the infrastructure and as a result, almost 1,600 homes were lost or destroyed. This extreme flood event killed 25 villages and forced 45,467 people in Kuala Krai, Kelantan to be evacuated from their homes. Continuous heavy rain for over three days from the 21st to the 23rd of December, 2014 was set a rainfall record of 1,295 mm, equivalent to the amount of rain usually seen in a span of 64 days. As a result, the water levels of three major rivers, the Sungai Galas in Dabong, the Sungai Lebir in Tualang and the Sungai Kelantan in Jambatan Gueillemard, rose above the dangerous water levels. It is essential to estimate the extent of flood inundation. The objective of this study is to simulate flood event in December 2014 by using HEC-HMS. The results show the peak discharges and inundations occurred approximately on the 25th December 2014; 18,575.7 m3/s to be almost similar magnitude as reported by DID 2014 Flood Report. These findings led to the conclusion that the HEC-HMS model is useful as a flood analysis tool.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.


Limnology ◽  
2021 ◽  
Vol 22 (2) ◽  
pp. 169-177
Author(s):  
Yo Miyake ◽  
Hiroto Makino ◽  
Kenta Fukusaki

2016 ◽  
Vol 15 (2) ◽  
pp. 196-208 ◽  
Author(s):  
Nicole M. Masters ◽  
Aaron Wiegand ◽  
Jasmin M. Thompson ◽  
Tara L. Vollmerhausen ◽  
Eva Hatje ◽  
...  

We investigated Escherichia coli populations in a metropolitan river after an extreme flood event. Between nine and 15 of the 23 selected sites along the river were sampled fortnightly over three rounds. In all, 307 E. coli were typed using the PhP typing method and were grouped into common (C) or single (S) biochemical phenotypes (BPTs). A representative from each of the 31 identified C-BPTs was tested for 58 virulence genes (VGs) associated with intestinal and extra-intestinal E. coli, resistance to 22 antibiotics, production of biofilm and cytotoxicity to Vero cells. The number of E. coli in the first sampling round was significantly (P < 0.01) higher than subsequent rounds, whereas the number of VGs was significantly (P < 0.05) higher in isolates from the last sampling round when compared to previous rounds. Comparison of the C-BPTs with an existing database from wastewater treatment plants (WWTPs) in the same catchment showed that 40.6% of the river isolates were identical to the WWTP isolates. The relatively high number of VGs and antibiotic resistance among the C-BPTs suggests possessing and retaining these genes may provide niche advantages for those naturalised and/or persistent E. coli populations which may pose a health risk to the community.


2017 ◽  
Author(s):  
Maurizio Mazzoleni ◽  
Vivian Juliette Cortes Arevalo ◽  
Uta Wehn ◽  
Leonardo Alfonso ◽  
Daniele Norbiato ◽  
...  

Abstract. Accurate flood predictions are essential to reduce the risk and damages over large urbanized areas. To improve prediction capabilities, hydrological measurements derived by traditional physical sensors are integrated in real-time within mathematic models. Recently, traditional sensors are complemented with low-cost social sensors. However, measurements derived by social sensors (i.e. crowdsourced observations) can be more spatially distributed but less accurate. In this study, we assess the usefulness for model performance of assimilating crowdsourced observations from a heterogeneous network of static physical, static social and dynamic social sensors. We assess potential effects on the model predictions to the extreme flood event occurred in the Bacchiglione catchment on May 2013. Flood predictions are estimated at the target point of Ponte degli Angeli (Vicenza), outlet of the Bacchiglione catchment, by means of a semi-distributed hydrological model. The contribution of the upstream sub-catchment is calculated using a conceptual hydrological model. The flow is propagated along the river reach using a hydraulic model. In both models, a Kalman filter is implemented to assimilate the real-time crowdsourced observations. We synthetically derived crowdsourced observations for either static social or dynamic social sensors because crowdsourced measures were not available. We consider three sets of experiments: (1) only physical sensors are available; (2) probability of receiving crowdsourced observations and (3) realistic scenario of citizen engagement based on population distribution. The results demonstrated the importance of integrating crowdsourced observations. Observations from upstream sub-catchments assimilated into the hydrological model ensures high model performance for high lead time values. Observations next to the outlet of the catchments provide good results for short lead times. Furthermore, citizen engagement level scenarios moved by a feeling of belonging to a community of friends indicated flood prediction improvements when such small communities are located upstream a particular target point. Effective communication and feedback is required between water authorities and citizens to ensure minimum engagement levels and to minimize the intrinsic low-variable accuracy of crowdsourced observations.


2021 ◽  
Author(s):  
Mohamedmaroof Shaikh ◽  
Sanjaykumar Yadav ◽  
Vivek Manekar

<p>Floods are among the severe weather disasters that cause catastrophic damage to surroundings and adversely impact populations. This study aims to create a one-dimensional (1D) hydraulic model using HEC-RAS for the Rel River in Banaskantha, Gujarat, India. The model has been developed for the extreme flood event of July 2017. A total of hundred cross-sections have been used as geometric data. The peak discharge of 3355 m<sup>3</sup>/s and the river slope has been applied as upstream and downstream boundary conditions. The model has been calibrated and validated using observed water depth at Railway bridge and Highway bridge. Critical cross-sections have been identified using the 1D hydraulic model. Eight out of the hundred cross-sections were safe for a flood discharge of 3355 m<sup>3</sup>/s. The villages at high flood risk are identified for this discharge. To mitigating floods, the construction of a retaining wall or levees is recommended to protect these villages. This study can help a disaster management strategy for the cities and town in the River’s vicinity.</p>


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 156 ◽  
Author(s):  
Barbara Mayr ◽  
Thomas Thaler ◽  
Johannes Hübl

International and national laws promote stakeholder collaboration and the inclusion of the community in flood risk management (FRM). Currently, relocation as a mitigation strategy against river floods in Central Europe is rarely applied. FRM needs sufficient preparation and engagement for successful implementation of household relocation. This case study deals with the extreme flood event in June 2016 at the Simbach torrent in Bavaria (Germany). The focus lies on the planning process of structural flood defense measures and the small-scale relocation of 11 households. The adaptive planning process started right after the damaging event and was executed in collaboration with authorities and stakeholders of various levels and disciplines while at the same time including the local citizens. Residents were informed early, and personal communication, as well as trust in actors, enhanced the acceptance of decisions. Although technical knowledge was shared and concerns discussed, resident participation in the planning process was restricted. However, the given pre-conditions were found beneficial. In addition, a compensation payment contributed to a successful process. Thus, the study illustrates a positive image of the implementation of the alleviation scheme. Furthermore, preliminary planning activities and precautionary behavior (e.g., natural hazard insurance) were noted as significant factors to enable effective integrated flood risk management (IFRM).


Ecosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Ratha Chea ◽  
Thomas K. Pool ◽  
Mathieu Chevalier ◽  
Pengbun Ngor ◽  
Nam So ◽  
...  

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