scholarly journals Increase of flood water levels on the middle Danube

2015 ◽  
Vol 366 ◽  
pp. 145-146
Author(s):  
P. Pekarova ◽  
P. Miklanek ◽  
J. Pekar
Keyword(s):  
Water Levels ◽  
Flood Water

THE TRANSIENT EFFECTS OF FLOOD WATER ON A WARSHIP IN CALM WATER IMMEDIATELY FOLLOWING DAMAGE

2021 ◽  
Vol 152 (A4) ◽  
Author(s):  
G J Macfarlane ◽  
M R Renilson ◽  
T Turner
Keyword(s):  
Equilibrium Position ◽  
Upright Position ◽  
Water Levels ◽  
Transient Effects ◽  
Roll Damping ◽  
Transient Motion ◽  
Flood Water ◽  
Transient Behaviour ◽  
Calm Water ◽  
The Way

The safety of a ship which is damaged below the waterline will depend on the way water floods into the internal compartments. The water will cause the ship to take on an angle of heel and trim which will further affect the flooding into the compartments. The ship’s equilibrium position in calm water can be predicted using hydrostatic theory, however at present it is difficult to predict the transient behaviour between the initial upright position of the ship and its final equilibrium. In some cases, the transient motion may cause a capsize prior to a possible equilibrium position being reached. This paper describes an investigation of this phenomenon using a model of a warship with simplified, typical internal geometry. With the model initially stationary, a rapid damage event was generated, and the global motions measured, along with the water levels in some of the internal compartments, as functions of time. Immediately after the damage occurred the model rolled to starboard (towards the damage). It then rolled to port (away from the damage) before eventually returning to starboard and settling at its equilibrium value. In all the tests conducted the equilibrium heel angle was less than that reached during the initial roll to starboard. This implies that the roll damping, and the way in which the water floods into the model immediately following the damage, could both have a very important influence on the likelihood of survival.

Hydrological projections based on the coupled hydrological–hydraulic modeling in the complex river network region: a case study in the Taihu basin, China

2014 ◽  
Vol 6 (2) ◽  
pp. 386-399 ◽  
Author(s):  
Liu Liu ◽  
Zongxue Xu
Keyword(s):  
Land Cover ◽  
Regional Climate ◽  
Hydraulic Modeling ◽  
Water Levels ◽  
Future Climate ◽  
Baseline Scenario ◽  
Climate Scenarios ◽  
Flood Water ◽  
Taihu Basin ◽  
The Impact

Water resources in the Taihu basin, China, are not only facing the effects of a changing climate but also consequences of an intensive urbanization process with the abandonment of rural activities and the resulting changes in land use/land-cover. In the present work, the impact of climate change and urbanization on hydrological processes was assessed using an integrated modeling system, coupling the distributed hydrological model variable infiltration capacity and the hydraulic model ISIS, while future climate scenarios were projected using the regional climate model providing regional climate for impact studies. Results show a significant increasing trend of impervious surface area, while other types of land cover exhibit decreasing trends in 2021–2050. Furthermore, mean annual runoff under different future climate scenarios will increase, especially during flood seasons, consistent with the changes in precipitation and evapotranspiration for both spatial and temporal distribution. Maximum and mean flood water levels under two future scenarios will be higher than levels under the baseline scenario (1961–1990), and the return periods of storms resulting in the same flood water level will decrease significantly in comparison to the baseline scenario, implying more frequent occurrence of extreme floods in future. These results are significant to future flood control efforts and waterlog drainage planning in the Taihu basin.

scholarly journals Long-term dynamics of maximum flood water levels in the middle course of the Ob River

2019 ◽  
Vol 400 ◽  
pp. 012004
Author(s):  
V A Zemtsov ◽  
D A Vershinin ◽  
V V Khromykh ◽  
O V Khromykh
Keyword(s):  
Water Levels ◽  
Flood Water ◽  
Ob River

Achieving Flood Reduction with Natural Water Retention Measures in Agricultural Catchments in Ireland 

2021 ◽  
Author(s):  
Pia Laue ◽  
Paul Quinn ◽  
Mary Bourke ◽  
Darragh Murphy ◽  
Mark Wilkinson ◽  
...  
Keyword(s):  
Land Use ◽  
Natural Water ◽  
Water Retention ◽  
Water Storage ◽  
Sediment Traps ◽  
Water Levels ◽  
Storm Events ◽  
Peak Reduction ◽  
Flood Water ◽  
The Impact

<p>In recent decades, land-use and climate change have dramatically altered catchment runoff rates. For example, agriculture intensification has led to increased flood risks by decreasing  soil permeability and reducing channel-floodplain connectivity. Natural Water Retention Measures (NWRM) is an approach that has been adopted European-wide for the attenuation of peak floods and the provision of wider ecosystem services. A reduction in peak flow is achieved by increasing water storage potential in the landscape and by modifying natural flow pathways. In agricultural areas (~70% of Irish land use),  runoff attenuation features such as offline ponds, earthen bunds, sediment traps and leaky dams are frequently deployed natural retention measures.</p><p>Despite the growing evidence across Europe of their efficacy for flood peak reduction, water quality enhancement and biodiversity on the local scale, NWRM features have not been adopted in Ireland as a flood mitigation approach. In order to build a case that will help address this, this presentation will detail a NWRM demonstrate site in Ballygow, Co. Wexford.  The construction and instrumentation of a network of features developed at the field-scale (~1km<sup>2</sup>) is shown. This site is an intensive pasture, small-hold farm. We aim to quantify the effectiveness of these NWRM features to demonstrate their potential to attenuate flood peaks on agricultural areas using temporary storage, whilst minimising the impact on farming.</p><p>The constructed measures consist of a flood swale that connects the channel to the floodplain during high flows, an earthen bund, an offline pond with a sediment trap, that can retain the water from the channel and contributing field slopes, for <12 hours. On-site video footage and eyewitnesses confirm that the flood water flows along the field without draining back into the stream. At approximately 800m across the field, the water is retained temporarily, permitting water storage and the opportunity for suspended sediment to settle out of the water column. Flood water is returned to the channel via a perched 20 cm diameter pipe in the bund. Four automated water level recorders (In-Situ Rugged Troll 100) continuously monitor water levels in the stream and the offline pond at 5 min intervals. In addition, local rainfall (EML Event Logger) is monitored. These data are used to identify the hydrograph characteristics of several storm events and are used to determine the effectiveness of the NWRM structures for flood attenuation. The quantification of the effectiveness of NWRM features will use the observed time series combined with hydraulic and hydrological modelling. </p><p>The quantitative evidence provided by our findings will contribute to establishing vital evidence for the implementation of local and national NWRM schemes in Ireland.</p>

scholarly journals Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods

2015 ◽  
Vol 19 (1) ◽  
pp. 631-643 ◽  
Author(s):  
A. Md Ali ◽  
D. P. Solomatine ◽  
G. Di Baldassarre
Keyword(s):  
Low Cost ◽  
Water Levels ◽  
Test Model ◽  
Flood Inundation ◽  
Model Accuracy ◽  
Flood Water ◽  
Hydraulic Models ◽  
Topographic Data ◽  
Ground Survey ◽  
Different Sources

Abstract. Topographic data, such as digital elevation models (DEMs), are essential input in flood inundation modelling. DEMs can be derived from several sources either through remote sensing techniques (spaceborne or airborne imagery) or from traditional methods (ground survey). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle Radar Topography Mission (SRTM), the light detection and ranging (lidar), and topographic contour maps are some of the most commonly used sources of data for DEMs. These DEMs are characterized by different precision and accuracy. On the one hand, the spatial resolution of low-cost DEMs from satellite imagery, such as ASTER and SRTM, is rather coarse (around 30 to 90 m). On the other hand, the lidar technique is able to produce high-resolution DEMs (at around 1 m), but at a much higher cost. Lastly, contour mapping based on ground survey is time consuming, particularly for higher scales, and may not be possible for some remote areas. The use of these different sources of DEM obviously affects the results of flood inundation models. This paper shows and compares a number of 1-D hydraulic models developed using HEC-RAS as model code and the aforementioned sources of DEM as geometric input. To test model selection, the outcomes of the 1-D models were also compared, in terms of flood water levels, to the results of 2-D models (LISFLOOD-FP). The study was carried out on a reach of the Johor River, in Malaysia. The effect of the different sources of DEMs (and different resolutions) was investigated by considering the performance of the hydraulic models in simulating flood water levels as well as inundation maps. The outcomes of our study show that the use of different DEMs has serious implications to the results of hydraulic models. The outcomes also indicate that the loss of model accuracy due to re-sampling the highest resolution DEM (i.e. lidar 1 m) to lower resolution is much less than the loss of model accuracy due to the use of low-cost DEM that have not only a lower resolution, but also a lower quality. Lastly, to better explore the sensitivity of the 1-D hydraulic models to different DEMs, we performed an uncertainty analysis based on the GLUE methodology.

scholarly journals SIMULASI SUMUR RESAPAN BERDASARKAN ANALISIS PERBANDINGAN KETINGGIAN AIR BANJIR DI KELAPA GADING JAKARTA

2020 ◽  
Vol 3 (3) ◽  
pp. 797
Author(s):  
Lionel Felix ◽  
Gregorius Sandjaja Sentosa
Keyword(s):  
Surface Water ◽  
Rainfall Intensity ◽  
Shallow Groundwater ◽  
Extreme Rainfall ◽  
Water Levels ◽  
Extreme Conditions ◽  
Drainage Channel ◽  
Entire Volume ◽  
Flood Water ◽  
The Past

Flooding has been a problem for the past few decades in Jakarta. The flooding in early January 2020 was one of the worst floods since 2013. One of the most severely affected areas was Kelapa Gading. To find a solution, infiltration wells are used. Infiltration well is a simple conservation in the form of a container that is built in the soil that functions to accommodate, hold and absorb surface water into the soil to increase the amount and position of the ground water level. The analysis begins by calculating the rainfall intensity from the January 2020 rainfall data, proceeding with the calculation of rainwater discharge with USSCS rational method, and calculation of the volume of water entering and not entering the drainage channel. This analysis focuses on flood water levels due to extreme rainfall, to then design infiltration wells. Analysis using the program is done after getting the results of manual calculations. The results of this analysis conclude that millions of infiltration wells are needed to absorb entire volume of flood water. This is due to the shallow groundwater and extreme conditions of rainfall.  Banjir sudah menjadi masalah selama beberapa dekade terakhir di Jakarta. Banjir pada awal Januari 2020 adalah salah satu banjir terparah sejak tahun 2013. Salah satu daerah yang paling terdampak adalah Kelapa Gading. Untuk mencari solusi banjir, digunakan sumur resapan. Sumur resapan adalah konservasi sederhana berupa wadah yang dibangun ke dalam tanah yang berfungsi menampung, menahan dan meresapkan air ke dalam tanah untuk meningkatkan muka air tanah. Analisis dimulai dengan menghitung intensitas hujan dari data curah hujan Januari 2020, lalu dilanjutkan dengan perhitungan debit air hujan dengan metode rasional USSCS, dan perhitungan volume air yang masuk dan tidak masuk ke saluran drainase. Analisis ini berfokus pada ketinggian air banjir akibat curah hujan yang ekstrim, untuk kemudian mendesain sumur resapan. Analisis menggunakan program dilakukan setelah mendapatkan hasil dari perhitungan manual. Hasil analisis ini menyimpulkan bahwa dibutuhkan jutaan sumur resapan untuk menyerap seluruh volume air banjir. Hal ini dikarenakan kondisi muka air tanah yang dangkal dan tingginya curah hujan.

scholarly journals Modeling of Flooding of Settlements During the Spring Flood

2021 ◽  
pp. 63-72
Author(s):  
Anna Klikunova ◽  
Tatyana Dyakonova ◽  
Ekaterina Agafonnikova ◽  
Ilya Makoveev ◽  
Mariya Kornaukhova ◽  
...  
Keyword(s):  
Spatial Data ◽  
Negative Impact ◽  
Parallel Implementation ◽  
Residential Buildings ◽  
Water Levels ◽  
Water Dynamics ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Flood Water ◽  
River Bed

The problem of flooding of territories with flood waters for settlements of the Volgograd region is considered. A numerical model of flood water dynamics is constructed, taking into account the topography of the terrain. The simulation is based on two-dimensional shallow water equations. For computational experiments, a parallel implementation of the numerical scheme CSPH-TVD for NVIDIA graphics accelerators with CUDA technology is used. The digital model of the river-bed and floodplain relief is based on spatial data SRTM3 and SRTMGL, topographic maps of the area, longitudinal profiles of rivers. The water flow rates for the Buzuluk and Perevozinka rivers are determined and a hydrograph of the Volga hydroelectric power station is constructed for the given probabilities of exceeding the water level. Flood maps were obtained for the following localities: Novoannisky, Berezovka 1st, kh. Vyazovka. The maximum values of the depths for 1 %, 3 %, 5 %, 10 %, 25 % and 50 % of water security are presented. An analysis of the flood situation was carried out and appropriate engineering and protective measures for settlements were proposed. At maximum flood water levels, residential buildings of kh. Berezovka 1-I are not subject to flooding. In order to minimize the negative impact for the city of Novoanninsky, it is proposed to carry out timely clearing of the river-bed of the Perevozinka river from congestion. To protect from flooding ch. Vyazovka it is recommended to use diversion dyke.

Stereological Analyses of Hepatocyte Ultrastructure Monitor Arsenic Liver Burdens

1980 ◽  
Vol 38 ◽  
pp. 442-443
Author(s):  
E. M. B. Sorensen ◽  
R. R. Mitchell ◽  
L. L. Graham
Keyword(s):  
Drainage System ◽  
Water Levels ◽  
Ultrastructural Changes ◽  
Hepatocyte Ultrastructure ◽  
Lepomis Cyanellus ◽  
Large Numbers ◽  
Activation Data ◽  
Water Analyses ◽  
Municipal Lake ◽  
Green Sunfish

Endemic freshwater teleosts were collected from a portion of the Navosota River drainage system which had been inadvertently contaminated with arsenic wastes from a firm manufacturing arsenical pesticides and herbicides. At the time of collection these fish were exposed to a concentration of 13.6 ppm arsenic in the water; levels ranged from 1.0 to 20.0 ppm during the four-month period prior. Scale annuli counts and prior water analyses indicated that these fish had been exposed for a lifetime. Neutron activation data showed that Lepomis cyanellus (green sunfish) had accumulated from 6.1 to 64.2 ppm arsenic in the liver, which is the major detoxification organ in arsenic poisoning. Examination of livers for ultrastructural changes revealed the presence of electron dense bodies and large numbers of autophagic vacuoles (AV) and necrotic bodies (NB) (1), as previously observed in this same species following laboratory exposures to sodium arsenate (2). In addition, abnormal lysosomes (AL), necrotic areas (NA), proliferated rough endoplasmic reticulum (RER), and fibrous bodies (FB) were observed. In order to assess whether the extent of these cellular changes was related to the concentration of arsenic in the liver, stereological measurements of the volume and surface densities of changes were compared with levels of arsenic in the livers of fish from both Municipal Lake and an area known to contain no detectable level of arsenic.

Sign in / Sign up

Export Citation Format

Share Document