scholarly journals Effect of the Hydraulic Characteristics of a Stream Channel and its Surroundings on the Runoff Hydrograph

10.14311/923 ◽  
2008 ◽  
Vol 48 (1) ◽  
Author(s):  
V. Matoušek
Keyword(s):  
Urban Areas ◽  
High Capacity ◽  
High Water ◽  
Throughput Capacity ◽  
Hydraulic Characteristics ◽  
Flood Wave ◽  
Stream Channel ◽  
Storage Reservoirs ◽  
Smooth Channel ◽  
Rainfall Flood

The course and magnitude of a rainfall flood depends primarily on the intensity and duration of the rainfall event, on the morphological parameters of the watershed (e.g. its slope and shape), and on how to watershed has been exploited. A flood wave develops in the stream channel that drains the watershed, and it transforms while passing along the channel. This is particularly the case if the water spreads into floodplains and/or storage reservoirs while passing through the channel. This paper addresses an additional effect that has a significant influence on the magnitude and course of the flood wave but has not previously been addressed adequately, namely the effect of the hydraulic parameters of the stream channel itself on the transformation of a flood wave. The paper explains theoretically and shows on a practical example that a smooth channel with a high capacity significantly increases the magnitude and speed of a flood wave.Many flood events are unnecessarily severe just because the watershed is drained by a hydraulically inappropriate channel. The channel is large and smooth and therefore it gathers most of the flowing water during the flood event, producing high water velocity in the channel. As a result, the large and smooth channel accelerates the runoff from the watershed and constrains the spread of water into the floodplain. A high and steep flood wave is developed in the channel, and this floods areas with a limited water-throughput capacity (e.g. urban areas in the vicinity of hydraulic structures) downstream the channel. This paper offers a methodology for evaluating the ability of a channel to convey a flood wave safely and for recognizing whether a regulated channel should be subjected to restoration due to its inability to convey flood waves safely. 

scholarly journals Analysis for Underwater Sound on Natural River Habitat

2018 ◽  
Vol 40 ◽  
pp. 02047
Author(s):  
Jung-Eun Gu ◽  
Sang Hwa Jung ◽  
Joongu Kang ◽  
Hyoseop Woo
Keyword(s):  
Underwater Acoustics ◽  
Fish Habitat ◽  
Habitat Type ◽  
High Water ◽  
Physical Structure ◽  
Physical Habitat ◽  
Hydraulic Characteristics ◽  
Underwater Sound ◽  
Underwater Acoustic ◽  
Sound Environment

A riffle-pool structure is a representative physical structure of bed in rivers. The change in the physical parameter of the habitat could lead to changes in the sound environment of rivers, which are expressed by underwater acoustics. This change in underwater sound affects fish habitat. In this study, the changes of underwater acoustics were analyzed according to the change of pool-riffle sequence in a natural river. And the correlation between underwater acoustics and hydraulic characteristics was investigated. The survey for underwater acoustics was performed in the Namdae stream where is in Gangwon province. This stream belongs to the Han River basin and the river length is 39.01 km and the catchment area is 127.56 km2. The Namdae stream is a river that accounts for more than 70% of salmon returning to South Korea. The spawning salmon will return to this area around November after growing in the Bering Sea. It is important to manage the fish habitat in this river so there is a lot of research on the enhancement of fish habitat. Hydraulic characteristics were changed by the river bed structure. In this study, we investigated the relationship between underwater acoustic characteristics and hydraulic factors such as riverbed material, flow rate and water depth of each habitat type at 12 sites. The characteristics of underwater acoustic differed relative to different hydraulic factors of the two habitats, which is riffle and pool. The sound pressure level of riffles was relatively higher than that of the pools due to bed materials, shallow depth and high water velocity of riffles. In the future, it is considered that the underwater sound can be utilized as a parameter to evaluate the physical habitat environment of the river.

Food and Chemistry Toxicology: Safety of Locally-Sold Food (Nutritional Distribution of Select Fruits and Vegetables in an Urban Food Desert)

2018 ◽  
Vol 2 (08) ◽  
Author(s):  
Kayla Dean ◽  
Nripendra Bose ◽  
Saleigh Derico ◽  
Felicia Jefferson
Keyword(s):  
Urban Areas ◽  
Inductively Coupled Plasma ◽  
Toxic Elements ◽  
Fruits And Vegetables ◽  
High Water ◽  
Food Stores ◽  
Water Abundance ◽  
Inductively Coupled ◽  
Community Area ◽  
Cadmium And Lead

There has been an increase of heavy metals in agricultural soil. The potentially harmful metals in the soil may come from the bedrock, waste deposits, agricultural inputs and urban emissions. Moreover, contaminated food is considered the main source by which humans are exposed to toxic elements. Fruits and vegetables are regarded as containing a low percentage of toxic compounds due to their high water abundance. However, dried fruits, which are often sold in areas where the abundance of fresh fruits and vegetables is low, may contain more toxic elements. Within considering all of the factors the trace metals induce on humans via the consumption of plants, one is able to analyze then disproportionate availability of toxin less foods in certain areas. Reasons that people do not consume fruits and vegetables that are not toxic are complex. This disproportionate representation is evident mainly in urban areas. Studies have shown that urban African Americans who shopped at their local neighborhood small- food stores consumed fewer fresh fruits and vegetables than their higher income peers who were able to shop in suburban supermarkets. Environmental barriers have been found the main cause for the limited availability of fresh fruits and vegetables. This research project will engage whether or not there is a disproportionate availability of toxin less foods in West End Atlanta community area by utilizing the Inductively Coupled Plasma Optic Emission Spectroscopy (ICP-OES), which will analyze the trace metal contents of arsenic, cadmium and lead in apples, bananas, and potatoes.

Stacker Modules Used in a High-Capacity Robotics System for High Throughput Screening Compound Replication

1999 ◽  
Vol 4 (6) ◽  
pp. 373-379 ◽  
Author(s):  
Mark Beggs ◽  
Herman Blok ◽  
Jan Mertens
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
High Capacity ◽  
Robotic System ◽  
Throughput Capacity ◽  
Process Automation ◽  
Technology Process ◽  
Human Operators ◽  
Automation Project ◽  
Logistics Control

High throughput screening is now established as a key component of the pharmaceutical lead identification process in many pharmaceutical companies. Over recent years, thanks to advances in assay technology, process automation, and logistics control, the throughput capacity of HTS groups has increased significantly. It is now entirely possible to screen corporate compound collections against an individual pharmacological target within a timescale of several weeks. Despite these improvements, many HTS groups find that their capacity is limited by the rate at which they can provide test compounds in a "screen-ready" format. This limitation is usually imposed by the capacity and productivity of the single-armed robotic systems utilized. We have recently constructed a robotic system aimed at overcoming this particular problem. This system uses purpose-built microplate stacker units that provide high-capacity microplate storage and, importantly, provide an easy and fast interface between the robotic system and the human operators. This paper describes this automation project and the benefits that have resulted from its deployment.

scholarly journals Evaluation of potential dam break flood risks of the cascade dams Mexa and Bougous (El Taref, Algeria)

2017 ◽  
Vol 33 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Hamza Bouchehed ◽  
Mustapha K. Mihoubi ◽  
Oussama Derdous ◽  
Lakhdar Djemili
Keyword(s):  
Storage Capacity ◽  
Human Life ◽  
Significant Loss ◽  
Dam Break ◽  
Hydraulic Characteristics ◽  
Flood Wave ◽  
Potential Threat ◽  
Arrival Times ◽  
Sediment Yields ◽  
Simulation Results

Abstract The implementation of Bougous dam at 5 km upstream of Mexa dam permits to compensate the storage capacity and to reduce sediment yields in the later, however, these advantages must be associated to the fact that the presence of two large dams in the region poses in case of a dam break event a potential threat to human life and property. Indeed, in this study a numerical simulation of the dam break wave propagation resulting from the failure of the two dams was performed using the two-dimensional hydrodynamic model Telemac-2D, in order to estimate the impacts on constructions located in the downstream valley. The simulation results exported to GIS platform allowed the elaboration of cartographic materials depicting the hydraulic characteristics of the flood wave and its arrival times at key locations, which constitute very useful information for the authorities to avoid significant loss in case of the failure of Bougous and Mexa dams.

scholarly journals Optimization of Green Space Planning to Improve Ecosystem Services Efficiency: The Case of Chongqing Urban Areas

2021 ◽  
Vol 18 (16) ◽  
pp. 8441
Author(s):  
Shuiyu Yan ◽  
Jun Tang
Keyword(s):  
Ecosystem Services ◽  
Urban Areas ◽  
Green Space ◽  
High Capacity ◽  
Careful Consideration ◽  
Green Spaces ◽  
Ecological Processes ◽  
Space Planning ◽  
Buffer Analysis ◽  
Gis Software

This paper applied landscape indexes to evaluate the size, form, and structure of green spaces in the mountainous city of Chongqing and found that green spaces benefit from certain advantages in size, but the network suffered from low heterogeneity and limited interconnectivity. To ensure the integrity and continuity of ecological processes and improve the efficiency of ecosystem services (ES), the authors used Geographic Information System (GIS) software to conduct adaptability evaluation and adjacent buffer analysis for the existing green spaces, wetlands, rivers, and other landscapes with relatively high capacity for ES. We designed a comprehensive map of potential areas for UGS expansion by superimposing the maps obtained from adaptability evaluation and buffer analysis. We also proposed some strategies that respect, consider, and evaluate aspects and special features of urban environment to optimize green space planning and improve ES efficiency, such as protection of important areas, development of green corridors, and careful consideration of ecological processes and complex functions in urban areas. Based on these strategies, the paper put forth suggestions for green space planning to improve ES efficiency that can function as foundation for subsequent green space planning.

scholarly journals Water resources and groundwater quality in North Peloponnesus (Greece)

2013 ◽  
Vol 7 (3) ◽  
pp. 340-353 ◽  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Water Resources ◽  
Water Supply ◽  
Urban Areas ◽  
Sea Water ◽  
Water Source ◽  
High Water ◽  
Comprehensive Management ◽  
Management Scheme

Groundwater plays an important role for urban and agricultural water supply in northern part of Peloponnesus. Despite increasing environmental awareness in this area, groundwater is a resource that is being stressed. Groundwater provides about 80% the total quantity of water supply. Distribution of water resources is nonhomogeneous in this region. In general the eastern part is semiarid, whereas the western part is supplied with abundant water. Surface water potential in North Peloponnesus estimated to be 0.9- 1.2x109 m3 y-1. Overexploitation of groundwater and the extensive agriculture has created environmental problems in some aquifers (sea water intrusion, nitrate pollution). Seawater intrusion occurs in some coastal aquifers, where negative water balance has been established. High percentage of the examined samples exceeded the maximum admissible nitrate concentration of 50 mg l-1, set by EU for drinking water. Groundwater in urban areas has been contaminated to varying degrees. The water quality is classified into Ca-HCO3 type (fresh water) and Na-HCO3 or Na-Cl type (brackish waters) in the coastal part, due to seawater intrusion. Some recommendations are made in order to safeguard high water quality and to develop new ways of providing water source in the study area. Moreover, an integrated and comprehensive management scheme should be applied, aiming at sustainability of water resources and based on surface water and groundwater exploitation, simultaneously.

scholarly journals New urban area flood model: a comparison with MIKE11-quasi2d

2005 ◽  
Vol 2 ◽  
pp. 279-284 ◽  
Author(s):  
A. Sole ◽  
G. Zuccaro
Keyword(s):  
Urban Areas ◽  
Explicit Scheme ◽  
The Other ◽  
Flood Wave ◽  
Piezometric Level ◽  
Simulated Event ◽  
The City ◽  
Water Overflow ◽  
Field Area ◽  
Urban Territory

Abstract. Recent hydrogeological events have increased both public interest and that of the Scientific Community in a more accurate study of flooding in urban areas. The present project proposes a new model which offers an optimal integration of two models, one for flood wave propagation in riverbeds and the other for flooding in urban areas. We consider it necessary to not only treat the modelling of the outflow in riverbeds and outside riverbeds.together but to integrate them thoroughly. We simulate the propagation in riverbed of the flood event with a model solving the equations of De Saint Venant with the explicit scheme at the finite differences by McCormack. The propagation outside the riverbed is simulated using an algorithm proposed by Braschi et al. (1990). This algorithm is based on a local discretization of the urban territory, divided in a series of "tanks" and "channels". Each tank is associated with an area of an extension related to the position of the other tanks and the quantity of buildings, modelled as insurmountable obstacles. The model facilitates the simultaneous performance of the two simulations: at each instant, the quantitiy of water overflow, depending on the piezometric level in every section, is calculated as a function of the dimensions of the weirs (the banks), assuming it passes through the critical state. Then, it is transferred to the tanks placed in the surroundings of the overflow points. Those points are the starting nodes for the propagation of the flood because they are connected to the network of tanks in which the surrounding land has been schematised. In this paper, we present a comparison of one of the most powerful models of inundation simulation in urban and no-urban areas. The field area is the city of Albenga (SV, Italy) and the simulated event is the inundation of the 1994 (return period of about 25 years).

scholarly journals Assessment of the effect of vegetation on the transition of the flood wave using hydraulic 2D models

2018 ◽  
Vol 44 ◽  
pp. 00195
Author(s):  
Krzysztof Wolski ◽  
Tomasz Tyminski ◽  
Pawel B. Dabek
Keyword(s):  
Numerical Models ◽  
High Water ◽  
Water Levels ◽  
Lidar Data ◽  
Direct Impact ◽  
Flood Wave ◽  
Mike Flood ◽  
Flood Model ◽  
Maximum Water ◽  
Flooded Area

In the paper an impact of vegetation accumulation on flood wave transition is presented. The research was conducted with use of the MIKE FLOOD model which combines elements of 1D and 2D numerical models. The study area included a 5.5 km long section of the Bystrzyca River near Wroclaw, Poland. A hydraulic model was constructed, on which the simulation of water transition with the probability of occurrence p = 1% and p = 0.2% was conducted. The simulation was carried out for current bank vegetation conditions determined on the basis of precise LIDAR data and for conditions with no vegetation. In this way, the direct impact of vegetation on flood wave transition was obtained. Acquired results, a decrease in maximum water levels and a reduction of flooded area, show that the hydraulic influence of vegetation on high water bed should not be underestimated.

scholarly journals Flood mitigation through riparian detention in response to climate variability - a case study in Taiwan

2018 ◽  
Vol 40 ◽  
pp. 06027
Author(s):  
Kwan Tun Lee ◽  
Pin-Chun Huang
Keyword(s):  
Climate Variability ◽  
Urban Areas ◽  
Flood Damage ◽  
Flood Mitigation ◽  
Main Stream ◽  
Flood Wave ◽  
Riparian Areas ◽  
Flood Prevention ◽  
Overbank Flow

Considering that urban areas may suffer more substantial losses than riparian farmlands during floods, diverting floodwater into riparian areas for temporal detention is expected to mitigate flood damage in downstream urban areas. In this study, an assessment has been conducted to evaluate the effect of flood mitigation through riparian detention in response to climate variability in the Tou-Chien Basin of Taiwan. A couple 1D-2D model was used to simulate the flood wave transporting in the main stream and the overbank flow inundating into the urban areas. Based on the numerical simulation results, flooding extent and inundated water depth corresponding to different return periods with current flood prevention infrastructures were detailed investigated. Various riparian detention strategies were proposed to alleviate severe losses in the downstream urban areas of the Tou-Chien Basin.

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