This study describes a statistical approach of watercourses hydrological regimes in flood, taking into account the latter duration
and return period
. The choice of Middle Cheliff watershed as study ...area is linked to disasters strong return period in the western region of Algeria. The Midlle Cheliff catchment basin, located in northwest Algeria, has particularly experienced severe floods over the last years. In view of the recurrence of these unusual events, the estimation and the predetermination of floods extreme quantiles are a strategic axis for prevention against floods in this region. The
curves are first of all locally determined, directly from a statistical analysis of flow continuously exceeded during a duration
(
) on different durations from available data of the study region. Then, these curves are compared to those obtained by application of different regional models VFS (Vandenesse, Florac and Soyans) in which two indices of the watershed characteristic flood are taken into account, a descriptive duration of the flood dynamics (
) and the instantaneous maximal annual flow of 10 year return period (
10). The final choice of the model is based on verification of certain criteria, such as: Nash and the root mean squared error (
). The closest regional models to the local ones are Florac’s for low duration and return periods, and Vandenesse’s for large return periods, for different durations. These results could be used to build regional
curves on ungauged or partially gauged Algerian basins.
Flood frequency data for different durations of floods are required in many practical hydrologic applications. The estimation of flood frequency as an integrated function of return period and flood ...duration can be accomplished by flood-duration-frequency modeling. This study introduces a new approach to regional flood-duration-frequency modeling that is based on statistical properties of combined flood–rainfall events. The approach integrates flood-duration-frequency (QDF) and rainfall depth-duration-frequency (DDF) models into one regional flood–rainfall duration-frequency model (QDDF). The proposed model has only one local parameter, which accounts for site-specific physiographic characteristics. Regional parameters of the model are determined from statistical properties of regional rainfall depth-duration-frequency curves. The main advantage of the proposed approach is that it relies on rainfall data, which are spatially and temporally more abundant than streamflow data, and usually also available in hydrologically ungaged areas. The regional QDDF model was applied to a set of small catchments from a hydro-climatologically homogeneous region in south-western Ontario, Canada. The performance of the model was compared to the performance of the conventional regional converging QDF model by means of a jack-knife procedure. The results showed that the proposed approach significantly outperformed the converging QDF model, leading to quantile estimates with three-times lower average BIAS and RMSE. The proposed QDDF model seems to be a promising alternative for the regional QDF modeling of floods in the study area.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
MANET can be affected by various kinds of attacks, as it has various mobile nodes which are decentralized and needs cooperation to transfer traffic. Any node can be malicious and can participate to ...result denial of Service (DOS) attacks. One such attack is flooding attack, which can have impact on QOS parameters of the network. In this paper we have shown variable flooding nodes that are flooding in network for different time intervals.NS2 is used to evaluate such malicious nodes and six different result is analyzed which shows drastic effect of such attack on QOS and throughput result also shows how packet delivery fraction is inversely proportion with bandwidth occupied by flood request
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Many hydrological engineering planning, design, and management problems require a detailed knowledge of flood event characteristics, such as flood peak, volume and duration. Flood frequency analysis ...often focuses on flood peak values, and hence, provides a limited assessment of flood events. This paper proposes the use of the Gumbel mixed model, the bivariate extreme value distribution model with Gumbel marginals, to analyze the joint probability distribution of correlated flood peaks and volumes, and the joint probability distribution of correlated flood volumes and durations. Based on the marginal distributions of these random variables, the joint distributions, the conditional probability functions, and the associated return periods are derived. The model is tested and validated using observed flood data from the Ashuapmushuan river basin in the province of Quebec, Canada. Results indicate that the model is suitable for representing the joint distributions of flood peaks and volumes, as well as flood volumes and durations.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Irish turloughs are hydrologically dynamic karst wetlands that are frequently used as marginal grazing land. We hypothesised that flood duration (FD) is a key driver of the spatial distribution of ...selected soil properties, and consequently turlough grazing practices. Six soil samples were collected during dry periods from eighteen turloughs between 2006 and 2008. Samples (
n
= 104) were analysed for pH, organic matter (OM) content, calcium carbonate content (CaCO
3
), sand/silt/clay content (INORG), total nitrogen (TN) and total phosphorus (TP). Data on flooding duration, flood frequency, grazing regime and vegetation type were collated for each soil sampling point. Multivariate and univariate statistical analyses were used to examine the relationships between soil properties, grazing regime and flooding variables. There was a positive association between CaCO
3
, FD and sedge-dominated communities, whereas INORG had a positive association with grazing and grassland. There was a strong positive association between TN, TP, OM and soil depth rather than FD, and OM was found to be an efficient predictor of TN. Extended FDs in ephemeral karst wetlands are likely to increase the extent and degree of calcium carbonate accumulation in soils, thus, reducing the grazing potential of land.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This study investigates the impact of climate change on the manageability of floods and droughts in the Ganges-Brahmaputra-Meghna basins using Flood Duration Curves (FDCs) and Drought Duration Curves ...(DDCs). Duration curves are drawn for monthly basin-averaged precipitation over each of the three basins and daily streamflow at their outlets for three periods: the observed (1980–2009), the near-future (2015–2039) and the far-future (2075–2099). Degree of difficulty of managing hydrological extremes is measured in terms of difficulty of smoothing hydrological variations which can be identified from the duration curves. Among three basins the manageability of the Meghna basin is expected to be more difficult due to increases of seasonal and annual variations of streamflow in the future. Significantly distinct persistence characteristics have been identified, which can be utilized for flood control, reservoir design and operation. The information contained in these curves has direct implications on policy making for future water resources development and water resources management both in flood and drought.
Naturally impounded lakes dammed by earth material like moraines and landslide deposits or glacier ice are capable of draining abruptly involving enormous amounts of water by overflow, seepage or ...drainage through pipes. Such kinds of outburst floods are among the largest floods by magnitude
and provide a serious hazard due to their frequently unexpected occurrence. A new model approach based on previously observed outburst flood hydrographs is presented here as previous attempts contain several limitations. Due to numerous influencing factors, physical-based modelling to forecast
the magnitude of future outburst floods is hindered by problems of achieving input data for case-studies to model. Black- box models that correlate lake volume with peak discharge of the outburst flood are frequently found to provide a good correlation, but cannot describe unsteady flood components
like rise and fall of the water level. Based on an intensive literature review, measured hydrographs of outburst floods from earth and ice-dammed lakes differentiated by drainage processes are compiled. After normalisation to reach a comparable style for the hydrographs of different flood
magnitudes and durations, mean values when peak discharge is reached are determined. In combination with regression equations for the peak discharge and flood duration based on drained lake volume, potential hydrographs of future outburst floods can be estimated. So far, the approach is limited
by low numbers of measured outburst flood events and missing correspondence of flood duration and drained volume for ice-dammed lakes. This approach could be improved by identification of more specific studies for the deduction of normalised hydrographs and regression equations.
Flooding problems in Jakarta cannot be handled comprehensively untill today. Various efforts in the short-term programs and long-term programs have been conducted but the results have not been ...satisfactory so that the flooding problems still threaten every year and the intensity of floods is likely to increase. The objective of this study is to find alternative flood controls, namely, the injection wells, which is cost efficient and resolves the problems effectively. Injection well applications, as new methods, for flood control in Jakarta seem to be a very attractive alternative in respect to both technical, social impact, as well as the financial aspects. In addition to flood control, at the same time, injection wells may prevent seawater intrusion.
Mathematical models were developed to represent the magnitudes of flooding problems, to predict the number of injection wells required, implementation schedule, as well as to estimate the investment cost for the application of injection wells. This modelling can be used to simulate the injection wells development plan with reference to the data that has been proven in successful experience, or based on the pilot scale project. Injection wells application for flood control in Jakarta is technically and financially very feasible, not only to cope with flood problems but also to control the sea water intrusion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to support disaster management activities related to flood situations, an automatic system for near-real time mapping of flood extent and duration using multi-sensor satellite data is ...developed. The system is based on four processing chains for the automatic derivation of the inundation extent from Sentinel-1 and TerraSAR-X radar as well as from optical Sentinel-2 and Landsat data. While the systematic acquisition plan of the Sentinel-1/2 and Landsat satellites allows a continuous monitoring of inundated areas at an interval of a few days, the TerraSAR-X processing chain has to be triggered on-demand over the disaster-affected areas. Beyond flood extent masks, flood duration products are generated to indicate the temporal stability and evolution of flood events. The flood monitoring system is demonstrated on a severe flood situation in Mozambique related to cyclone Idai in 2019.
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