Embankment dams as a flash flood hazard protection measure

The possible mitigation of floods by dams and the risk to dams from floods are key problems. The Peo-ple's Republic of China is now leading world dam construction with great success and efficiency. This paper is devoted to relevant experiences from other countries, with a particular focus on lessons from accidents over the past two centuries and on new solutions. Accidents from floods are analyzed according to the dam's height, storage, dam material, and spillway data. Most of the huge accidents that have been reported occurred for embankments storing over 10 hm 3. New solutions appear promising for both dam safety and flood mitigation.

IRJET, 2020

Bank are built for the maintenance of water for water system and supply, and for ensuring individuals, land, and property from flooding. Failure of any embankment poses risk to people and property nearby and the services provided by the embankment. The review of importance of embankment in flood control identifies significant issues in the parametresation of the process in existing model and the data used for calibration. The paper reports the options for multipurpose use of embankments in miraj based on the field visits to the embankments site, collected data and information on failure and on service embankments during field visit, necessary data related to embankment construction practice obtained from available publication and newspaper information. Based on by and large current circumstance in miraj, the paper additionally propose an appropriate plan and development strategy for dikes to control and limit the degree of flood risks over the long haul and furthermore inferred that to accomplish reliable standard of the board of flood dikes, and furthermore increase this expectation to enhance their exhibition, require a superior comprehension and utilization of good practice and a scope of research activities. Key words: Flood control, embankment, flood sub grade drainage flood resistance, flood risk management. II. INTRODUCTION Embankment are constructed for the retention of water for irrigation and water supply, and the protection of people, land, and property from flooding. Flooding is one of the most serious problem in the India today. As indicated by the Indian, Atmospheric, Geophysical and Astronomical Services Administration flooding is described as an "irregular dynamic" ascent in the water level of stream. That may result in the overflowing by the water of the normal confines of the stream with the subsequent inundation of area which are not normally submerged. Flood are categorized according to its natural and artificial causes. Embankments are constructed for the retention of water for irrigation and supply, and the protection of people, land, and property from flooding. Disappointment of any bank presents dangers to individuals and property close by and the administrations gave by the dike. The ability to maintain assets, and provide an acceptable standard of service for water supply and flood defence therefore depends on understanding and predicting performance of the embankments under all conditions. Tools currently available for simulating embankment failure are not very accurate and can only be used for indicative assessments. Consequently, the prediction of flood risk from embankment breach may be similarly inaccurate. III. LITERATURE REVIEW M. A. A. Mohamed1 (2009) Embankments are developed the survey of breaking of banks right now critical issues in the for the maintenance of water for water system and supply, and for securing individuals, land, and property from flooding. Disappointment of any dike presents dangers to individuals and property close by and the administrations gave by the dike. parameterisation of the procedures in existing models and the information utilized for alignment. This paper depicts the advancement of another model the disappointment of a dike that can reenact break development, and thus ensuing dangers, more dependably than existing models. The model uses the standard standards of water power, silt transport and soil mechanics and acquaints another system with model the parallel development of the rupture dependent on a blend of constant disintegration and mass unsteadiness. The model can mimic the disappointment of various dikes, either homogeneous or composite, by overtopping or funneling, and incorporates a probabilistic dispersion for recreating bank condition and soil parameters. The model has been tried utilizing both exploratory and genuine disappointment information, with demonstrating results indicating sensible concurrence with watched esteems for a scope of various situations. Suvendu Roy2 (2012) Floods in India have been a typical yearly event. In 1954, National Floods Control Program (NFCP) was embraced a few measures to limit their decimation. However, Floods proceeded with its yearly appearance with fluctuating degrees of influencing power. Now and then, Embankment, a significant auxiliary measure for floods may make negative condition for flood and water logging condition for any floodplain. The present paper has been set up as a flood chance evaluation study for the intersection zone of the Kunur River and the Ajay River, identified with the present and nonappearance of dike along the Ajay River bank, which expanding bowl runoff and channel release,

A Dam is an abstraction or barrier built across a river or stream. At back Of the barrier, water gets collecting to form a pool of water that is termed as the upstream side of the dam. And the other one is the downstream part of the dam.

Journal of Failure Analysis and Prevention, 2011

Dams are artificial lakes created to reserve water for a particular purpose. Reports on failure of dams are common things nowadays. Effects of dam’s failure on man and environment are well known, which require preventive measures. This article presents a brief assessment of a dam in Nigeria and suggested necessary failure preventive measures. The dam site was visited (up and down streams), selected soil and geological properties of the dam were conducted with a particular attention to the release of water from the reservoir as seepage, or filling of the reservoir by silt from erosion. Hydrology and hydraulic data of the study area and spillway were obtained and analyzed. The study revealed that the soil is mainly sandy-loamy soil of averagely sand (73.99 ± 3.12), clay (8.53 ± 0.18), and silt (17.48 ± 1.88). Geological structure of the soil revealed that the study area is in basement complex. The reservoir capacity is 177,000,000 m3 with about 18.5-m hydraulic high, silting rate of 0.301% per year. Hydraulic conductivity, transmissivity, and specific discharge were found to be of high side of 9.31 × 10−4 m/s, 5.08 × 10−4 m2/s, and 98.25 m/year, respectively. It was concluded that the current problems of the dam are high silting rate and seepage, big trees on the embankment and beside the spillway. All these may lead to failure of the dam in the following ways: lack of water in the reservoir due to seepage and silting, eutrophication and non-potable of the water due to silting and collapse of the embankment due to the presence of big trees. It was suggested that necessary and urgent solutions such as removal of trees from embankment, desilting and seepage control must be provided for safety of lives and properties.

2010

2008

Journal of Student Research, 2020

Damage caused in the past times and left by rain which led to floods of water and affected human life. On the other hand the occurrence of scarcity of water after periods of rain, which led to the provision of quick solutions to avoid recurrence, such as constricted protection dam. In general dam is an engineering constriction that is built above a wadi or a low place, with the aim of reserving water. They are usually classified according to their forms, the materials used in their construction and the goals for which they were built. There are 2 types of dams that are determined in Oman according to the needs of the area to be applied which is: protection dam and Recharge Dams. The main objectives of this study are to conduct a feasibility study of design a protection dam for this area with most economically advantageous engineering solution protecting from flood in wadi um allakhma in wallyat SUR. to achieve this goal we will use many important method that's help as to provide a design for this dam like: using geological and hydrological data by analyzing rain and wadi station to run models and find the final design. In general by the initial data of this wadi, the total area of the catchment almost 400 km2 which the possibility of saving up to 25-30 million m2

2010

The flood hazard assessment in the downstream valley from a possible dam failure requires a comprehensive modelling of the breach formation, the outflow through the breach, and the routing of flood wave in the downstream valley. Several analytical and numerical methods have been proposed to simulate the entire process the most popular of which are those proposed by the Nat. Weather Service of USA. This paper presents an application of the above tools in a risk assessment study of a new embankment dam which is under construction in Crete (Greece). The hydrograph at selected cross-sections of the valley downstream the dam and the inundation area from the hypothetical dam failure were determined for three failure times. It was shown that the results are quite sensitive in relation to the time of failure adopted. Furthermore, other parameters influencing the peak outflow and the inundation area are explained and discussed.

Water Science and Technology

The aim of this study is to analyze the effects of a possible dam failure under various scenarios and to generate a flood hazard map for two consecutive dams located in a study area with a dense-residential region and a heavy-traffic highway. Two consecutive dams consist of Elmalı 2, a concrete-buttress dam and Elmalı 1, an earth-fill gravity dam in the upstream and downstream, respectively. Hydrologic Engineering Center-River Analysis System (HEC-RAS) was used to develop a dam failure model. Dam failure scenarios were examined regarding three main criteria: the Breach Formation Time (BFT), the Number of Failed Buttresses (NFB) of Elmalı 2, and the Reservoir Volume Ratio (RVR) of Elmalı 1. Accordingly, flood peak depth (Hp), peak flow rate (Qp), peak velocity (vp), and time to reach the peak (tp) are discussed. The results showed that BFT and NFB of Elmalı 2 were highly effective on these values, whereas RVR of Elmalı 1 had no significant effect. Moreover, the total area affected by...

The Journal of The University of Duhok, 2017

This research is the part 2 of hydrological study and analysis for proposed Sartik dam which located on the Lesser Zab River, the second largest tributary of Tigris River at 18 km northeast of Altun Kopri town, within Erbil governorate of Iraqi Kurdistan Region. In this part water demand from the dam is calculated, the dam power generating facility with an installed capacity amounting to 156 MW with a maximum discharge of 300 m 3 /sec. The characteristics of the dam reservoir were calculated, from reservoir sedimentation calculation the dead storage level and capacity was determined and was equal to (309 m.a.s.l., and 104,304,031 m 3) respectively. The monthly and annual water losses due to evaporation were calculated from daily recorded evaporation using an equation based on area, volume and elevation curve, and the annual losses were equal to (51,132.366 m 3), also the normal reservoir water level (NWL) was fixed at 325 m.a.s.l. which gives live storage capacity equal to (384,846,885), and flooded area equal to (34.184 km 2). The simulation model of the dam reservoir, prepared from the calculation of water inflow into the reservoir and water demand including evaporation losses. The inflow was taken for different types of water years, dry (deficit) years (1984, and 1999), average water years (1981, and 1995) inflow, and maximum (flood) water years (1969 and 1988) inflow. From the curves, it is clear that the reservoir starts full at month April and ends full at month March during one year taking into account that the maximum water storage in the reservoir is (489,150,916)m 3 and minimum storage is (104,304,031) m 3. The flood routing study was done using the (PMF, 1000, 100, 50, and 25) years return periods inflow hydrographs, and stage and volume curve by fixing the crest level of ogee spillway will at 320 m.a.s.l., choosing the number of gated spans equal to 7, the length of each span equal to 12m, and the initial water level of the reservoir was 325 m.a.s.l. The results of this routing will be used to determine the design parameters of the spillway and to determine the actual need of the emergency spillway.