scholarly journals Peak Flows and Stormwater Networks Design—Current and Future Management of Urban Surface Watersheds

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 759 ◽  
Author(s):  
António Freire Diogo ◽  
José Antunes do Carmo

Stormwater urban drainage systems are typically designed in open channel flow. Pipe sewers must have enough capacity to transport maximum design flows for a given frequency of the project rainfall. The classic rational method or related procedures that are based on rational approaches are still currently used to a great extent, particularly for small urban drainage basins, and the pipes are frequently designed in uniform steady flow. Numerical integration of Saint-Venant equations for one-dimensional gradually varied unsteady flow allows the computation of waves’ progression along the pipes for given input surface hydrographs. This paper presents a comprehensive, systematic, simple, and original comparison between the peak flows that are achieved through simulation in unsteady flow using an implicit complete dynamic model, developed in the Laboratory of Hydraulics, Water Resources and Environment of Coimbra University, and those that are obtained with the classic rational method along urban drainage networks. Boundary conditions and some approximations typically considered in the methodologies are analyzed in detail. Classic rational approaches may underestimate the peak and design flows. Practical recommendations for the system design phase when rational approaches are used are also proposed. The need for indispensable requirements for suitable urbanization rules, intelligent management of surface runoff in urban basins, and control measures for the reduction of peak flows entering existing networks is confirmed and reinforced.

2014 ◽  
Vol 580-583 ◽  
pp. 1966-1970
Author(s):  
Xin Liu

After the completion of the hub on river, its scheduling unsteady flow generated an adverse impact on the downstream navigation. In this paper, according to the unsteady flow data of PingBan hub in Nanpanjiangjiang River in Guizhou province, researched unsteady flow spread characteristics and rule in hub downstream channel. Studies have shown that: unlike general water level changes in hub downstream, the waterlevel amplitude attenuation along is not obvious in researched reach; Clear the concept of unsteady flow additional velocity、additional slope,through this theory reveals the ship ascending rapids mechanism difficultly under unsteady flow condition. On this basis, proposed channel regulation methods and measures in hub downstream, which provided support for the hub downstream channel regulation.


Author(s):  
Y. Arockia Suganthi ◽  
Chitra K. ◽  
J. Magelin Mary

Dengue fever is a painful mosquito-borne infection caused by different types of virus in various localities of the world. There is no particular medicine or vaccine to treat person suffering from dengue fever. Dengue viruses are transmitted by the bite of female Aedes (Ae) mosquitoes. Dengue fever viruses are mainly transmitted by Aedes which can be active in tropical or subtropical climates. Aedes Aegypti is the key step to avoid infection transmission to save millions of people in all over the world. This paper provides a standard guideline in the planning of dengue prevention and control measures. At the same time gives the priorities including clinical management and hospitalized dengue patients have to address essentially.


1986 ◽  
Vol 18 (9) ◽  
pp. 197-205
Author(s):  
Lj Jeftié ◽  
L. J. Saliba

Increasing concern over the deterioration of the Mediterranean sea as a result of increasing pollution by untreated sewage and industrial wastes, agricultural pesticides and fertilizers and oil discharges, led to a series of meetings between 1970 and 1974, and finally to the UNEP-sponsored Mediterranean Action Plan, adopted by governments of the region in 1975 and ongoing since that time. The legal component of the Plan includes a framework Convention and four protocols; the environmental assessment component (the MED POL programme) consists of national pollution monitoring programmes, and research projects conducted by Mediterranean institutions; the environmental management component consists of the Blue Plan (a prospective study combining socio-economic development with environmental preservation) and the Priority Actions Programme (a series of sub-region sectoral projects in defined areas). The Plan has been financed by Mediterranean States since 1979, and is managed by UNEP with the cooperation of other competent UN Agencies. During the last ten years, activities undertaken have improved knowledge of the state of pollution of the Mediterranean sea, and facilitated joint regional action in the form of preventive and control measures.


1994 ◽  
Vol 29 (1-2) ◽  
pp. 53-61
Author(s):  
Ben Chie Yen

Urban drainage models utilize hydraulics of different levels. Developing or selecting a model appropriate to a particular project is not an easy task. Not knowing the hydraulic principles and numerical techniques used in an existing model, users often misuse and abuse the model. Hydraulically, the use of the Saint-Venant equations is not always necessary. In many cases the kinematic wave equation is inadequate because of the backwater effect, whereas in designing sewers, often Manning's formula is adequate. The flow travel time provides a guide in selecting the computational time step At, which in turn, together with flow unsteadiness, helps in the selection of steady or unsteady flow routing. Often the noninertia model is the appropriate model for unsteady flow routing, whereas delivery curves are very useful for stepwise steady nonuniform flow routing and for determination of channel capacity.


1999 ◽  
Vol 39 (9) ◽  
pp. 1-8 ◽  
Author(s):  
P. Harremoës ◽  
H. Madsen

Where is the balance between simplicity and complexity in model prediction of urban drainage structures? The calibration/verification approach to testing of model performance gives an exaggerated sense of certainty. Frequently, the model structure and the parameters are not identifiable by calibration/verification on the basis of the data series available, which generates elements of sheer guessing - unless the universality of the model is be based on induction, i.e. experience from the sum of all previous investigations. There is a need to deal more explicitly with uncertainty and to incorporate that in the design, operation and control of urban drainage structures.


1997 ◽  
Vol 36 (8-9) ◽  
pp. 57-63 ◽  
Author(s):  
Homayoun Motiee ◽  
Bernard Chocat ◽  
Olivier Blanpain

This paper presents a model for the hydraulic simulation of a drainage network using the storage concept. This model is easier to use than the complete Barre de Saint Venant equations and gives better results than the usual conceptual models, i.e. the Muskingum model, or than models obtained by the simplification of the Saint Venant equations (kinematic wave model and diffusion wave model).


2020 ◽  
Author(s):  
Qiangsheng Huang

BACKGROUND As of the end of February 2020, 2019-nCoV is currently well controlled in China. However, the virus is now spreading globally. OBJECTIVE This study aimed to evaluate the effectiveness of outbreak prevention and control measures in a region. METHODS A model is built for find the best fit for two sets of data (the number of daily new diagnosed, and the risk value of incoming immigration population). The parameters (offset and time window) in the model can be used as the evaluation of effectiveness of outbreak prevention and control. RESULTS Through study, it is found that the parameter offset and time window in the model can accurately reflect the prevention effectiveness. Some related data and public news confirm this result. And this method has advantages over the method using R0 in two aspects. CONCLUSIONS If the epidemic situation is well controlled, the virus is not terrible. Now the daily new diagnosed patients in most regions of China is quickly reduced to zero or close to zero. Chinese can do a good job in the face of huge epidemic pressure. Therefore, if other countries can do well in prevention and control, the epidemic in those places can also pass quickly.


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