It s calculated by finding the loss difference between gross precipitation and observed surface runoff. The shape of a hydrograph varies in each river basin and each individual. Make sure you can name specific locations and use facts and figures to prove to the examiner that you know your case study well. A storm hydrograph is a way of displaying how the discharge of a river can change over time in response to a rainfall event. Unit hydrograph of different durations two methods are available for this purpose i method of superposition, and ii the s curve i method of superposition if a d h unit hydrograph is available, and it is desired to develop a unit hydrograph of nd h, where n is an integer. The free revision website for students studying gcse and alevels. The river tees drains the eastern slopes of cross fell in the pennines and flows eastward to the north sea. Aqa rivers lesson 4 storm hydrographs teaching resources. Hydrographs show how the volume of water flowing at specific point in a river varies over time. The number of times such unit hydrograph addition required is given by ratio tit. In the above example, we learned to use the given dhr unit hydrograph to compute the discharge hydrograph for any nd hour rainfall, where n is an integer. Pages of resources to help you study the river, coastal and glacial landscapes of the uk. The term overland flow is used for nonchannelized flows of water. A storm hydrograph is a way of displaying how the discharge of a river.
Soft engineering management is a more natural approach to manage flooding, such as flood plain zoning. Generally, the less the lag time the quicker the river rises, the more flashy the graph and the more likely a flood. At key river gages, such as along navigable rivers, daily forecast hydrographs are. Revise for geography as edexcel specification b is for the edexcel geography as course. Physical factors affecting flood hydrograph geography tutor2u. More than one fifth of the world s population live in areas of water scarcity, where there isnt enough water to meet everybody s needs. The impact of the hydrological cycle on soil moisture budgets, storm hydrographs. A level geography revision scool, the revision website. The next important concept is that of s hydrograph.
We have the knowhow to help and get you through revision towards high grade results. Hard engineering management involves using artificial structures, such as dams and embankments. Case studies used in year 12 bold and underlined all of these cases studies are expected in the specification, and as such will normally form the basis of an answer for the top mark questions 8 to 15 marks all of the others are supportive examples where you. The lag time is the delay between the maximum rainfall amount and the peak discharge. The volume is measured in cubic metres m 3 and its per second so the units of discharge are cubic metres a second or m 3 s1. Hydrographs can record river flow on a daily, monthly, annual or individual storm event basis. Save a copy of the boscastle flood data spreadsheet find it at the web address in the header go into the geography section and use this to work through your chart. Storm hydrographs are graphs that show how a drainage basin responds to a period of rainfall. A hydrograph is a graph showing the rate of flow discharge versus time past a specific point in. Scool s curated content, written by teachers and experts, gives you the revision shortcut you crave. Alevel geography revision guides and question banks covering population, agriculture, coastal processes and all core alevel geography topics.
A hydrograph shows how the river level changes over time at a specific location. They record how much water passes through a river at a particular point in its course discharge. Discharge is the volume of water passing along a river s channel over a given period of time, usually expressed in cubic metres per second, or cumecs. Average several uhg s it is suggested that several unit hydrographs be derived and averaged. You will find geography quizzes for girls, quizzes for boys and quizzes for teenagers which are all free to access and also free to print out. Flood hydrographs are graphs that show how a drainage basin responds to a period of rainfall they are used to plan for flood situations and times of drought. The regime of a river is the way in which the discharge of the river changes over time or in the course of the year. Discharge the quantity of water that passes a given point on a stream or river.
Coincidentally, 1m 3 s1 is the same as 1 cumec so the discharge of a river is often measured in cumecs because its a bit easier to say. They are useful in planning for flood situations and times of drought as they show the discharge amount of water reaching channel via surface runoff, throughflow, and base flow that originated as precipitation. Note that you will lose points if you ask for hints or clues. You will need to research this using your text book and the internet. Kids geography quiz the questions have been specifically selected with children in mind making these free kids quizzes suitable for schools and family quizzes. Hydrographs are graphs that show river discharge over time. For higher geography learn how to interpret a hydrograph and explore the effects soilrock type, slope, vegetation and other factors have on hydrographs. River discharge storm hydrograph a level geography. Physical natural factors the river tees catchment is located in the north east of england. Gcse and a level revision scool, the revision website. Storm hydrographs show river discharge around the time of a storm event.
The phiindex is an assumed uniform and constant infiltration rate. A hydrograph may be used to show how the water flow in a drainage basin particularly river runoff responds to a period of rain. Aqa gcse geography 9 to 1 cool geography book chapter. In temperate climates, where seasonal change is evident, runoff levels can vary greatly. Flood hydrographs flood hydrographs can be used to predict flooding by showing how different levels of precipitation affect a river during a storm. Snowfall until snow melts, potential discharge for a river is held in storage. But what if our rainfall is not a multiple of d hour. The last item indicated on the hydrograph is the lag time, this is the amount of time between the peak amount of rainfall and the peak discharge in the river. A level geography pc hydrology and fluvial geomorphology. It is often not sufficient to simply average the ordinates of the unit hydrographs in order to obtain the final unit hydrograph. Lets take a look at these different flood hydrograph dynamics. Flooding occurs due to a sudden increase in the amount of water travelling down a river, and can occur for a number of reasons. There is a powerpoint to go along with it, which is animated and helps explain what each part of the hydrograph means.
Alevel revision s cool, the revision website jump to navigation. This is something i pieced together for a year ten class to introduce them to drawing flood hydrographs. Runoff will increase after soil field capacity is met which means water will reach the channel quicker. The rate of flow is typically expressed in cubic meters or cubic feet per second cms or cfs. We are a well trusted platform for millions of students and hundreds of schools. At the start of the booklet youll find some helpful resources. Gcse geography revision guides and question banks covering rivers, ecosystems, tourism and resources and all core gcse geography topics. Fill in all the gaps, then press check to check your answers. Forecast hydrographs are displayed when flooding is expected, otherwise the hydrograph for the past few days is provided, if the data are available. Discharge is normally measured at gauging stations that are situated at different points along the river.
This resource has been created through multiple resources from tes and colleagues i work with. Geography quiz questions with answers pub quiz questions hq. They show the river discharge that occurs as a result of precipitation from an earlier storm key terms on the hydrograph, illustrated below, are. It has three main rivers, the river tees, the river skerne and the river leven. Unit hydrographs learning objectives hydrograph anatomy components what is the unit hydrograph. The variation of river discharge due to precipitation, evaporation, temperature or drainage basin characteristics over a year. Geography notes hydrology, atmosphere, weathering, population and. Storm hydrographs and river discharge scool, the revision website. Free alevel revision guides and question banks covering biology, chemistry, physics, maths and much more. Factors affecting river regimes geography from ks3 to ib. It can also refer to a graph showing the volume of water reaching a particular outfall, or location in a sewerage network graphs are commonly used in the design of.
Storm hydrographs only cover a short period of time around a particular storm event hours and days rather than longer periods of time. Freshwater issues and conflicts the geographer online. The unit hydrographs must be of the same duration in order to be properly averaged. A numerical average of several unit hydrographs which are different shapes may. Hydrographs flashcards in a level and ib geography. The case studies and examples information will help you to take an organised approach to these important parts of paper 1 and paper 2.
Pubquizquestionshq provide free pub quiz questions on a range of subjects in downloadable, printable pdf format. The diagram shows two flood hydrographs for rivers a and b and how they responded to the same storm. A hydrograph shows how the river level changes over time. I cant take full credit as i have just pieced them together, it looks at what a storm hydrograph is, skills of analysis and creating a hydrograph using data for bostcastle. This can be editied at will, but it worked quite well in this format. Learn vocabulary, terms, and more with flashcards, games, and other study tools. A hydrograph is a graph showing the rate of flow versus time past a specific point in a river, channel, or conduit carrying flow. Scool provides revision guides, question banks, revision timetable and more. A flood hydrograph shows the amount of rainfall in an area and the discharge of a river. A levelgcse geography revision for river hydrographs. Use the hint button to get a free letter if an answer is giving you trouble.
Gcse geography s cool, the revision website jump to navigation. You need a specific example of where flood management strategies have been used. The s hydrograph can be obtained by arranging the 4 hr. Flood storm hydrograph the starting and finishing level show the base flow of a river. Use counting and time management to run a freezeria.
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