scholarly journals A history of the concept of time of concentration

2020 ◽  
Vol 24 (5) ◽  
pp. 2655-2670 ◽  
Author(s):  
Keith J. Beven
Keyword(s):  
Response Times ◽  
Rational Method ◽  
Unit Hydrograph ◽  
Surface Flows ◽  
Time Of Concentration ◽  
Water Particle ◽  
Subsurface Flows ◽  
History Of ◽  
The 1960S ◽  
Catchment Responses

Abstract. The concept of time of concentration in the analysis of catchment responses dates back over 150 years to the introduction of the rational method. Since then it has been used in a variety of ways in the formulation of both unit hydrograph and distributed catchment models. It is normally discussed in terms of the velocity of flow of a water particle from the furthest part of a catchment to the outlet. This is also the basis for the definition in the International Glossary of Hydrology. While conceptually simple, this definition is, however, wrong when applied to catchment responses where, in terms of how surface and subsurface flows produce hydrographs, it is more correct to discuss and teach the concept based on celerities and time to equilibrium. While this has been recognized since the 1960s, some recent papers and texts remain confused over the definition and use of the time of concentration concept. The paper sets out the history of its use and clarifies its relationship with time to equilibrium but suggests that both terms are not really useful in explaining hydrological responses. An Appendix is included that quantifies the differences between the definitions of response times for subsurface and surface flows under simple assumptions that might be useful in teaching.

scholarly journals A history of the concept of time of concentration

2020 ◽  
Author(s):  
Keith J. Beven
Keyword(s):  
Response Times ◽  
Rational Method ◽  
Unit Hydrograph ◽  
Surface Flows ◽  
Time Of Concentration ◽  
Use Of Time ◽  
Subsurface Flows ◽  
History Of ◽  
The 1960S ◽  
Catchment Responses

Abstract. The concept of time of concentration in the analysis of catchment responses dates back over 150 years to the introduction of the Rational Method. Since then it has been used in a variety of ways in the formulation of both unit hydrograph and distributed catchment models. It is normally discussed The concept of time of concentration in the analysis of catchment responses dates back over 150 years to the introduction of the Rational Method. Since then it has been used in a variety of ways in the formulation of both unit hydrograph and distributed catchment models. It is normally discussed in terms of the velocity of flow of a water particle from the furthest part of a catchment to the outlet. This is also the basis for the definition in the International Glossary of Hydrology. While conceptually simple, this definition is, however, wrong when applied to catchment responses where, in terms of how surface and subsurface flows produce hydrographs, it is more correct to discuss and teach the concept based on celerities and time to equilibrium. While this has been recognized since the 1960s, some recent papers and text remain confused over the definition and use of time of concentration. The paper sets out the history of its use and clarifies its relationship to time to equilibrium but suggests that both terms are not really useful in explaining hydrological responses. An appendix is included that quantifies the differences between the definitions of response times for subsurface and surface flows under simple assumptions that might be useful in teaching.

scholarly journals A Combination between Synthetic Unit Hydrograph (SCS) and Rational Method in a similar Conditions Water Shed

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Mona Fathi ◽  
Neveen B. Abelmageed ◽  
M. Hassan
Keyword(s):  
Rational Method ◽  
Rainfall Data ◽  
Return Periods ◽  
Unit Hydrograph ◽  
Engineering Applications ◽  
Watershed Characteristics ◽  
Time Of Concentration ◽  
Excess Water ◽  
The Difference ◽  
Peak Runoff

Studying watershed characteristics and choosing the most applicable methods to determine the amount of access rainfall that ran off is very important in many engineering applications, especially hydrology applications. That is to know the more suitable methods for protection against floods and to maximize benefits from the excess water. This study aims to establish a relation between the rational method and the SCS method. A subbasin in Wadi Dahab in Sinai, Egypt is investigated as a study area. To achieve the study aims, HEC-WMS software is chosen, which can analyze a watershed by using DEM and delineating basin. It calculates also important watershed parameters like area, runoff distances, and slope. The rainfall data is compiled and arranged. A statical analysis is executed to obtain the IDF curves. Hyfran-plus software is employed to locate the maximum depths for different return periods. Various values for the time of concentration are studied. It is concluded that the difference between the rational and SCS methods is great for the time of concentration till 2 hours, then it decreases obviously from 2 till 6 hours. Also, it is concluded that the difference between the two methods is bigger for the small return periods of 2 and 5 years for all values of the time of concentration. Employing the obtained equations, the peak runoff for one of the two methods (the rational and SCS methods) can be calculated knowing the time of concentration and the peak runoff for the second method.  

A note on John Hawkins (1761–1841) and the Hawkins archive

2000 ◽  
Vol 27 (2) ◽  
pp. 261-268
Author(s):  
R. J. CLEEVELY
Keyword(s):  
Major Part ◽  
Reference Lists ◽  
The West ◽  
History Of ◽  
The 1960S

A note dealing with the history of the Hawkins Papers, including the material relating to John Hawkins (1761–1841) presented to the West Sussex Record Office in the 1960s, recently transferred to the Cornwall County Record Office, Truro, in order to be consolidated with the major part of the Hawkins archive held there. Reference lists to the correspondence of Sibthorp-Hawkins, Hawkins-Sibthorp, and Hawkins to his mother mentioned in The Flora Graeca story (Lack, 1999) are provided.

A history of botanical collections in the Luangwa Valley, Zambia

1998 ◽  
Vol 25 (2) ◽  
pp. 283-291
Author(s):  
P.S.M. PHIRI ◽  
D.M. MOORE
Keyword(s):  
Eighteenth Century ◽  
Environmental Impact ◽  
Impact Assessment ◽  
Vascular Plants ◽  
Central Africa ◽  
Peak Activity ◽  
Historical Account ◽  
History Of ◽  
The 1960S ◽  
Made In

Central Africa remained botanically unknown to the outside world up to the end of the eighteenth century. This paper provides a historical account of plant explorations in the Luangwa Valley. The first plant specimens were collected in 1897 and the last serious botanical explorations were made in 1993. During this period there have been 58 plant collectors in the Luangwa Valley with peak activity recorded in the 1960s. In 1989 1,348 species of vascular plants were described in the Luangwa Valley. More botanical collecting is needed with a view to finding new plant taxa, and also to provide a satisfactory basis for applied disciplines such as ecology, phytogeography, conservation and environmental impact assessment.

Islands of Stability: Engaging Emergence from Cellular Automata to the Occupy Movement

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Andrew Pickering
Keyword(s):  
Decision Making ◽  
Cellular Automata ◽  
Black Box ◽  
Collective Decision ◽  
Collective Decision Making ◽  
Occupy Movement ◽  
History Of ◽  
The 1960S

"Instead of considering »being with« in terms of non-problematic, machine-like places, where reliable entities assemble in stable relationships, STS conjures up a world where the achievement of chancy stabilisations and synchronisations is local.We have to analyse how and where a certain regularity and predictability in the intersection of scientists and their instruments, say, or of human individuals and groups, is produced.The paper reviews models of emergence drawn from the history of cybernetics—the canonical »black box,« homeostats, and cellular automata—to enrich our imagination of the stabilisation process, and discusses the concept of »variety« as a way of clarifying its difficulty, with the antiuniversities of the 1960s and the Occupy movement as examples. Failures of »being with« are expectable. In conclusion, the paper reviews approaches to collective decision-making that reduce variety without imposing a neoliberal hierarchy. "

State-run celebration of Liberation Day in Czechoslovakia (based on audiovisual sources)

2019 ◽  
pp. 251-268
Author(s):  
Timur Gimadeev
Keyword(s):  
Political Development ◽  
Communist Regime ◽  
Political Regime ◽  
The Political ◽  
Historical Experience ◽  
History Of ◽  
Post War ◽  
The 1960S ◽  
The Military

The article deals with the history of celebrating the Liberation Day in Czechoslovakia organised by the state. Various aspects of the history of the holiday have been considered with the extensive use of audiovisual documents (materials from Czechoslovak newsreels and TV archives), which allowed for a detailed analysis of the propaganda representation of the holiday. As a result, it has been possible to identify the main stages of the historical evolution of the celebrations of Liberation Day, to discover the close interdependence between these stages and the country’s political development. The establishment of the holiday itself — its concept and the military parade as the main ritual — took place in the first post-war years, simultaneously with the consolidation of the Communist regime in Czechoslovakia. Later, until the end of the 1960s, the celebrations gradually evolved along the political regime, acquiring new ritual forms (ceremonial meetings, and “guards of memory”). In 1968, at the same time as there was an attempt to rethink the entire socialist regime and the historical experience connected with it, an attempt was made to reconstruct Liberation Day. However, political “normalisation” led to the normalisation of the celebration itself, which played an important role in legitimising the Soviet presence in the country. At this stage, the role of ceremonial meetings and “guards of memory” increased, while inventions released in time for 9 May appeared and “May TV” was specially produced. The fall of the Communist regime in 1989 led to the fall of the concept of Liberation Day on 9 May, resulting in changes of the title, date and paradigm of the holiday, which became Victory Day and has been since celebrated on 8 May.

Frontiers of Visibility

Transfers ◽  
2013 ◽  
Vol 3 (2) ◽  
pp. 24-46 ◽  
Author(s):  
Franziska Torma
Keyword(s):  
Twentieth Century ◽  
Current Understanding ◽  
Machine Age ◽  
History Of ◽  
Three Stages ◽  
The 1950S ◽  
The 1960S ◽  
Popular Images ◽  
Cinematic Technology

This article deals with the history of underwater film and the role that increased mobility plays in the exploration of nature. Drawing on research on the exploration of the ocean, it analyzes the production of popular images of the sea. The entry of humans into the depths of the oceans in the twentieth century did not revitalize myths of mermaids but rather retold oceanic myths in a modern fashion. Three stages stand out in this evolution of diving mobility. In the 1920s and 1930s, scenes of divers walking under water were the dominant motif. From the 1940s to the 1960s, use of autonomous diving equipment led to a modern incarnation of the “mermen“ myth. From the 1950s to the 1970s, cinematic technology was able to create visions of entire oceanic ecosystems. Underwater films contributed to the period of machine-age exploration in a very particular way: they made virtual voyages of the ocean possible and thus helped to shape the current understanding of the oceans as part of Planet Earth.

MINING THE ARCHIVES: A POTTERY SEQUENCE FOR BORNO, NIGERIA

2003 ◽  
Vol 1 (1) ◽  
pp. 39-76 ◽  
Author(s):  
Graham Connah ◽  
S.G.H. Daniels
Keyword(s):  
Large Body ◽  
Archaeological Research ◽  
Independent Data ◽  
Frankfurt Am Main ◽  
Archaeological Pottery ◽  
New Findings ◽  
History Of ◽  
1960S And 1970S ◽  
The 1960S ◽  
Johann Wolfgang Goethe

New archaeological research in Borno by the Johann-Wolfgang-Goethe-Universität, Frankfurt am Main, Germany, has included the analysis of pottery excavated from several sites during the 1990s. This important investigation made us search through our old files for a statistical analysis of pottery from the same region, which although completed in 1981 was never published. The material came from approximately one hundred surface collections and seven excavated sites, spread over a wide area, and resulted from fieldwork in the 1960s and 1970s. Although old, the analysis remains relevant because it provides a broad geographical context for the more recent work, as well as a large body of independent data with which the new findings can be compared. It also indicates variations in both time and space that have implications for the human history of the area, hinting at the ongoing potential of broadscale pottery analysis in this part of West Africa and having wider implications of relevance to the study of archaeological pottery elsewhere.

Отцейхгаузадомузеяизисториивоенно-историческогомузеяартиллерии,инженерныхвойскивойсксвязи

2019 ◽  
pp. 134-197
Author(s):  
V.E. . Sergei
Keyword(s):  
18Th Century ◽  
Military History ◽  
Peter The Great ◽  
General Field ◽  
Signal Corps ◽  
History Of ◽  
Set Up ◽  
The 1960S ◽  
Military Engineering ◽  
The Military

The article is dedicated to the history of the Military Historical Museum of Artillery, Engineering and Signal Corps. The author examines the main stages of the museums formation, starting with the foundation of the Arsenal, established in St. Petersburg at the orders of Peter the Great on August 29th 1703 for the safekeeping and preservation of memory, for eternal glory of unique arms and military trophies. In 1756, on the base of the Arsenals collection, the General Inspector of Artillery Count P.I. created the Memorial Hall, set up at the Arsenal, on St. Petersburgs Liteyny Avenue. By the end of the 18th century the collection included over 6,000 exhibits. In 1868 the Memorial Hall was transferred to the New Arsenal, at the Crownwork of the Petropavlovsky Fortress, and renamed the Artillery Museum (since 1903 the Artillery Historical Museum). A large part of the credit for the development and popularization of the collection must be given to the historian N.E. Brandenburg, the man rightly considered the founder of Russias military museums, who was the chief curator from 1872 to 1903. During the Civil and Great Patriotic Wars a significant part of the museums holdings were evacuated to Yaroslavl and Novosibirsk. Thanks to the undying devotion of the museums staff, it not only survived, but increased its collection. In the 1960s over 100,000 exhibits were transferred from the holdings of the Central Historical Museum of Military Engineering and the Military Signal Corps Museum. In 1991 the collection also received the entire Museum of General Field Marshal M.I. Kutuzov, transferred from the Polish town of Bolesawjec. The Military Historical Museum of Artillery, Engineering and Signal Coprs is now one of the largest museums of military history in the world. It holds an invaluable collection of artillery and ammunition, of firearms and cold steel arms, military engineering and signal technology, military banners, uniforms, a rich collection of paintings and graphic works, orders and medals, as well as extensive archives, all dedicated to the history of Russian artillery and the feats of our nations defenders.Статья посвящена истории создания ВоенноИсторического музея артиллерии, инженерных войск и войск связи. Автор рассматривает основные этапы становления музея, начиная с основания Арсенала, созданного в СанктПетербурге по приказу Петра I 29 августа 1703 года для хранения и сохранения памяти, во имя вечной славы уникального оружия и военных трофеев. В 1756 году на базе коллекции Арсенала генеральный инспектор артиллерии граф П. И. создал мемориальный зал, установленный при Арсенале, на Литейном проспекте СанктПетербурга. К концу 18 века коллекция насчитывала более 6000 экспонатов. В 1868 году Мемориальный зал был перенесен в Новый Арсенал, на венец Петропавловской крепости, и переименован в Артиллерийский музей (с 1903 года Артиллерийский Исторический музей). Большая заслуга в развитии и популяризации коллекции принадлежит историку Н.Е. Бранденбургу, человеку, по праву считавшемуся основателем российских военных музеев, который был главным хранителем с 1872 по 1903 год. В годы Гражданской и Великой Отечественной войн значительная часть фондов музея была эвакуирована в Ярославль и Новосибирск. Благодаря неусыпной преданности сотрудников музея, он не только сохранился, но и пополнил свою коллекцию. В 1960х годах более 100 000 экспонатов были переданы из фондов Центрального исторического военноинженерного музея и Музея войск связи. В 1991 году коллекцию также получил весь музей генералфельдмаршала М. И. Кутузова, переданный из польского города Болеславец. Военноисторический музей артиллерии, инженерных войск и войск связи в настоящее время является одним из крупнейших музеев военной истории в мире. Здесь хранится бесценная коллекция артиллерии и боеприпасов, огнестрельного и холодного оружия, военной техники и сигнальной техники, военных знамен, обмундирования, богатая коллекция живописных и графических работ, орденов и медалей, а также обширные архивы, посвященные истории русской артиллерии и подвигам защитников нашего народа.

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