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[en] In Belgium, river floods are among the most frequent natural disasters and they may cause important changes on travel demand. In this regard, we propose to set up a large scale scenario using MATSim for guarantying an accurate assessment of the river floods impact on the transportation systems. In terms of inputs, agent-based models require a base year population. In this context, a synthetic population with a respective set of attributes is generated as a key input. Afterwards, agents are assigned activity chains through an activity-based generation process. Finally, the synthetic population and the transportation network are integrated into the dynamic traffic assignment simulator, i.e. MATSim. With respect to data, households travel surveys are the main inputs for synthesizing the populations. Besides, a steady-state inundation map is integrated within MATSim for simulating river floods. To our knowledge, very few studies have focused on how river floods affect transportation systems. In this regard, this research will undoubtedly provide new insights in term of methodology and traffic pattern analysis under disruptions, especially with regard to spatial scale effects. The results indicate that at the municipality level, it is possible to capture the effects of disruptions on travel behavior. In this context, further disaggregation is needed in future studies for identifying to what extent results are sensitive to disaggregation. In addition, results also suggest that the target sub-population exposed to flood risk should be isolated from the rest of the travel demand to reach have more sensitive effects. (Author)
[en] This study is focusing on constructing the flood risk index in the Johor river basin. The application of statistical methods such as factor analysis (FA), statistical process control (SPC) and artificial neural network (ANN) had revealed the most efficient flood risk index. The result in FA was water level has correlation coefficient of 0.738 and the most practicable variable to be used for the warning alert system. The upper control limits (UCL) for the water level in the river basin Johor is 4.423 m and the risk index for the water level has been set by this method consisting of 0-100.The accuracy of prediction has been evaluated by using ANN and the accuracy of the test result was R"2 = 0.96408 with RMSE= 2.5736. The future prediction for UCL in Johor river basin has been predicted and the value was 3.75 m. This model can shows the current and future prediction for flood risk index in the Johor river basin and can help local authorities for flood control and prevention of the state of Johor. (author)
[en] Dam reservoirs with significant water volumes (storage coefficients exceeding 8-10%) cause diminishing of the maximum flow downstream, especially due to the aleatory variation of the initial water level in the reservoir. Depending on the flow reduction in the dam, a methodology for determining the flow for the whole water course downstream is proposed, taking into account various potential combinations for flood generation in the catchment area. Differences between potential damages caused by floods in case of natural conditions versus those occurring in case of engineered zones result in important public financial benefits, amounting up to around 30% of the investments required for dam construction. For instance, in the case of hydropower lake Dragan on the Crisul Repede River the damages diminished down to about 50% for downstream watercourse. (authors)
[en] Safe operating procedures developed by TransAlta Utilities for dealing with flooding, resulting from upstream dam failures or extreme rainfalls, were presented. Several operating curves developed by Monenco AGRA were described, among them the No Overtopping Curve (NOC), the Safe Filling Curve (SFC), the No Spill Curve (NSC) and the Guaranteed Fill Curve (GFC). The concept of an operational comfort zone was developed and defined. A flood action plan for all operating staff was created as a guide in case of a flooding incident. Staging of a flood action plan workshop was described. Dam break scenarios pertinent to the Bow River were developed for subsequent incorporation into a Flood Action Plan Manual. Evaluation of the technical presentations made during workshops were found them to have been effective in providing operating staff with a better understanding of the procedures that they would perform in an emergency. 8 figs
[en] Within the 'Progetto Finalizzato' Soil Conservation, subproject 'River Dynamics' the sample basin of Spigone torrent which is located in the province of Parma, main basin Parma torrent, secondary basin Baganza torrent, has been individualized. Some searches meant for verifying the link existing between the basin morphometric dimensions and those ones characterizing the floods waves have been carried out. This in view of acquiring mere confirms on the close interconnection between geology and hydrology of the basin within the wide scenery of floods forecasting in real time and of critical examination of the main methods employed for the definition of 'hydrogeological risk'. In particular, the collected data confirmed the limits of the rational method and the dependence of the floods propagation time on the peak flow
[en] The extreme floods of the past decade at the river Rhine (1993 and 1995), at the river Odra (1997) and at the River Elbe (2002) caused serious damages and confirmed again the urgency of exact and reliable flood forecasting systems as tools for decision support in order to reduce flood damages. The Federal Institute of Hydrology (BfG) is developing suitable operational water level forecast models for the River Rhine (WAVOS Rhein), for the River Odra (WAVOS Oder), and for the River Elbe (ELBA and WAVOS Elbe). These forecast systems are continuously used by the Federal Waterways and Shipping Administration on a daily basis for low water forecasting to support inland navigation. In case of floods the systems are used by four Federal State Flood Centres for flood forecasting several times per day. In this paper the operational WAVOS water level forecasting system is described and for the three river basins examples of the forecasting results of the last floods are given. With the growing demand for prolonging the forecasting period, increasing the accuracy and spatial density of forecasts, the tasks for future improvements of the models are shown.(Author)
[en] Climate change may result in increased variability in rainfall intensity in the future, leading to more frequent flooding and a substantial loss of lives and properties. To mitigate the impact from flooding events, flood control facilities need to be designed and operated more efficiently, which requires a better understanding of the relationship between climate change and flood events. This study proposed a framework combining the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) and the Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models to assess the impact of climate change on flood events. HEC-HMS is one of the most commonly used hydrologic models in the USA, and CMIP5 provides the latest climate data for potential future climate scenarios. The proposed approach is applied to the Nippersink Creek watershed, which shows that 10-, 25-, 50-, and 100-year precipitations for the low, medium, and high emission scenarios are all greater than the historic observations. The corresponding 10-, 25-, 50-, and 100-year floods are remarkably higher than in the historic observations for the three climate scenarios. The high emission scenario results in dramatically increased flood risks in the future. The case study demonstrates that the framework combining HEC-HMS and CMIP5 is easy to use and efficient for assessing climate change impacts on flood events. It is a valuable tool when complicated and distributed hydrologic modeling is not an option because of time or monetary constraints.
[en] A hydrological characteristic -based methodology for dividing flood seasons into sub-seasons is proposed to make full use of a reservoir’s flood control storage during the flood season via multi-stage flood-limited water levels. The proposed framework is mainly composed of three parts: the selection of indices depicting flood seasonality, the establishment of segmentation methods that can address clustering problems with high-dimensional time series and unknown numbers of clusters, and multi-scheme comparison and rationality analysis. The reasonability and validity of the proposed framework is illustrated through an empirical case study of China’s Panjiakou Reservoir basin. The results indicated that the dynamic fuzzy c-means method with clustering validity function provided more objective and quantitative divisions than other methods, including the Fisher optimal partition. The flood season of the Panjiakou Reservoir basin (June 1–September 30) is divided into three sub-seasons according to the principle of optimal clustering: a pre-flood season (June 1–July 10), a main flood season (July 11–August 20), and a post-flood season(August 21–September 30).