Storm Drainage Design Project - Scientific methods Assignment

Storm Drainage Design Project - Scientific methods - Assignment Example To understand more on the subject at hand, we first define what is a storm and a hydrograph. According to Wikipedia, a storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface, and strongly implying severe weather. It may be marked by strong wind, thunder and lightning (a thunderstorm), heavy precipitation, such as ice or wind transporting some substance through the atmosphere.1 Meanwhile a hydrograph is defined as "a representation of flow for a particular stream and is used to evaluate the watershed runoff volumes and the peak flow rates from a single storm or set of storms. This information is then used in the design of flood control facilities."2 A storm obviously has a fundamental effect on the course of rivers and other bodies of water and is part of the process known as the water cycle. The water cycle "..consists of four distinct stages: storage, evaporation, precipitation, and runoff. Water may be stored temporarily in the ground; i n oceans, lakes, and rivers; and in ice caps and glaciers. It evaporates from the earth's surface, condenses in clouds, falls back to the earth as precipitation, and eventually either runs into the seas or reevaporates into the atmosphere."3 Thus, we see the relationship between storm and runoff (which is flooding) in this cycle. Storm hydrographs are therefore "..graphs that show how a drainage basin responds to a period of rainfall. They are useful in planning for flood situations and times of drought as they show the discharge (amount of water reaching channel via surface run-off, through flow, and base flow) that originated as precipitation."4 The hydrograph in other words is simply a record of the flooding events in a river as an effect of rain and storm. II. Factors Influencing Hydrographs What are the factors that influence the appearance of storm hydrographs Since the hydrograph is a graphical representation of the flow versus time, any aspect that will affect flow will likewise affect the graph. Flow, being a unit of volume over time or velocity and area, implies that the parameters of area and velocity contribute to how the hydrograph is presented. The following are the factors as stated in Wikipedia : Soil Saturation is dependant on previous rainfall, or otherwise known as antecedent rainfall. The surroundings; Rural or Urban (Could be less impermeable surface, or the surface type could vary) Vegetation type (Deforestation and amount of interception) Steepness of surrounding land, or 'relief' land Drainage density (Number of tributaries) Geology (Rock Type; Impermeable=flashier hydrographs. Or Permeable) Season dependent; Very dry weather creates a crust on the river bed. Wet winters create increase in discharge. Soil Type (Clay, sand etc.) Clay would create a flashy hydrograph, but there could be a continuum between the two.5 As can be observed from the above factors, when the factors contribute to a faster flow, the resulting hydrograph is a "flashy" one. It means that peak flow is high and the time from the heaviest rainfall and the largest flow of the river is very small. It is noted that the term "flash" floods are similarly coined. Other factors mentioned above such as impermeable surf

Consumption and convergence Essay Example | Topics and Well Written Essays - 750 words

Consumption and convergence - Essay Example Consequently the concept now commands preponderance over format. The ensuing fusion of till now estranged media has finally made way for the virtual world that is far more interesting and tangible as compared to the utterly scattered version of reality offered by the analogous media. Murdock celebrates the advent of digitization by declaring that, â€Å"This age of analogue communications is now coming to an end. It is giving way to a new media landscape based on digital technologies (2008: 35).† Convergence is a natural and direct outcome of the homogenization of format made possible by digitization. Merriam-Webster dictionary defines ‘convergence’ as, â€Å"the merging of distinct technologies, industries or devices into a unified whole (2009).† Hitherto the concept of convergence had certain negative connotations associated with it because of the fear of a possible concentration of power and the annihilation of diversity. Yet, the fact is that convergence is a direct response to the needs and preferences of the contemporary consumer who thrives in a scenario where the line between work and entertainment is very think and the enhanced access facilitated by the compatibility of variegated portals is in high demand. It will get really feasible to grasp this idea by pragmatically comparing two recent instances of media convergence i.e. PS3 and Nintendo WII videogame consoles. On November 11, 2006, Sony Entertainment officially released its much anticipated Play Station 3 (PS3) video console in Japan. This was followed by a US release on November 17, 2006 and then in Europe on March 23, 2007. The PS3 was not being marketed as just a video game console but as a home multimedia system. This is because the PS3 is packed with various technologies that can readily be consumed through other platforms. The PS3 console is manufactured with an inbuilt BLUE RAY disc