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Lesson 2Lesson 2All about GISAll about GIS

(which stands for (which stands for Geographic Information Geographic Information

Systems)Systems)

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What is GIS? What is GIS? Introduction: Paper maps only tell us where a place is. GIS uses digital maps and information to help us make decisions and solve problems Hardware: GIS runs on mainframe computers, PCs, small PDAs or even mobile phones to organise information and map the results of investigations.

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SoftwareSoftwareGIS software is a set of computer ‘tools’ for collecting, storing, processing and displaying sets of information linked to places on maps. There are different types of GIS ‘tools’: for instance, a GIS that analyses land use is different from a GIS that maps the quickest route to a fire.

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MapsMapsElectronic maps and images: An essential component of any GIS is some kind of map or image of an area. This can be a digital map, satellite image or aerial photograph.Many GIS will use a full range of map data and images as a base to link information against. The maps are produced either as raster or vector dataRaster mapsThese are images made by a series of coloured dots on a screen (pixels), just like high quality digital photographs, e.g aerial views are one sourceRaster maps can be thought of as ‘unintelligent’ as you can only obtain information that is visually represented on them.Raster maps take up a lot of computer storage space but can be very useful as background maps to other information.

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MapsMapsVector maps Each vector map feature is recorded using XY coordinates. These may be a single point (like a trig point), lines (such as roads) or polygons (such as buildings or woods).The referenced features of vector maps make it possible for a GIS to link information from spreadsheets and databases to the maps. Vector data is stored in themed layers such asRoads, water, settlement

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MapsMapsData:It is easier to make sense of complicated spreadsheets and databases when they are linked to maps in a GIS. It is estimated that over 80% of all data has some link to a geographic place.People:The vital ingredient! We need people who understand digital maps and databases and know how to use GIS to organise the data on maps. They can ask the right questions and produce new maps showing the results. This helps to plan the way we live and use our environment for the future.

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An example of An example of how it workshow it works

The Hole StoryThe Hole Story

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The Hole StoryThe Hole StoryThe vast networks of underground pipes supplying our water, electricity and gas are hidden from view, so how do we know where it’s safe to dig? Louise works for a water authority to maintain the company's network of water mains and sewers. She uses a GIS to create a complete overview of the pipeline which helps her to monitor its condition and performance.

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The Hole StoryThe Hole StoryTo minimise the risks involved in digging trenches, laying cables and other maintenance and building projects, utility companies must share their underground asset maps upon request with other organisations.A GIS is built up of lots of different layers of information which users can Switch on and off depending on their needs.

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The Hole StoryThe Hole StoryInformation can be shared between utilities via a secure website. The website uses a GIS to pinpoint the location of water mains, gas pipes, electricity cables and sewers as well as details of current and future work Allowing all the utilities to access this information means that all utilities can agree to carry out work at the same time.Digging up the road only once helps to minimise public disruption and saving time and money.

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One more One more exampleexample

It’s a breezeIt’s a breeze

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It’s a breezeIt’s a breezeWind farms can provide a source of alternative energy but finding the right location for the turbines can be difficult.Dave works for an energy company that is keen to investigate the use of wind turbines as an alternative way of generating power. He is asked to work on a project to identify suitable sites for a new wind farm. The location needs to balance environmental concerns with operational efficiency..

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It’s a breezeIt’s a breezeDave has followed the debate in the newspapers and knows that the effect of the turbines’ appearance on the landscape is a major concern. Many other factors, however, also need to be considered when choosing a site. These include wind speed, wind direction, distance from the existing electrical grid system, access to the site, size of the site and the shape and profile of the land.

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It’s a breezeIt’s a breezeBy inputting data from various sources regarding weather, civil and military airfields, telecommunications and environmental organisations, Dave begins to put together a case for the available site. He still needs to take into account the height and spacing of the turbines so that they can produce the required amount of electricity balanced against their visual impact

Anyone spy anything

wrong with this map?

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It’s a breezeIt’s a breezeDave adds height data and information to produce a 3D model giving a virtual view of the site as it would appear from different directions, distances and perspectives. This enables him to focus on particular locations to check the turbines’ impact on the view. The information Dave produces is used to support planning applications and to reassure local residents that the wind farm will cause minimal disruption.

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To find out if you could use a wind To find out if you could use a wind turbine on your houseturbine on your house

ASK YOUR PARENTS FIRSTThen go tohttp://www.segen.co.uk/eng/wind/windspeed.htmEnter business type – residential, your name etc and press LookupIf the answer is 5 or better still 5.5 m/s then your home is potentially a good place to put a small wind turbine!

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Now for the Now for the worksheet and worksheet and

to work towards to work towards your homeworkyour homework

http://mapzone.ordnancesurvey.chttp://mapzone.ordnancesurvey.co.uk/mapzone/giszone/english/o.uk/mapzone/giszone/english/

andandhttp://mapzone.ordnancesurvey.chttp://mapzone.ordnancesurvey.co.uk/mapzone/giszone/english/gio.uk/mapzone/giszone/english/gismissions/page1.htmsmissions/page1.htm

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Click on the ‘i’ by Lockerford to find Click on the ‘i’ by Lockerford to find ……Population - 2,000

A small village to the west of Melchester. It grew on the site of a ford that farmers used when bringing their cattle to Melchester market. Now seen as one of the most desirable and expensive places to live in the area. Lots of commuters choose to live there.Latest flood information:Casualties – 0Evacuations - 100 peopleEstimated insurance claims - £ 50,000

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1. Locker Valley Storage basins1. Locker Valley Storage basinsTotal Cost = £ 5.0 millionEarth-moving equipment will dig out two large basins connected to the river by drainage channels. At times of high water, flood gates are opened allowing water to drain away from the river into the basins The Locker Valley meadows are home to many wetland bird species that will be disturbed during construction. However, long term the wildlife will benefit.The people of Lockerby are likely to be upset by all the noise from the earth moving machinery.

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Having gathered the informationHaving gathered the information

You will need to put in a scoreBut you cannot really do that until you know about ALL the sitesHence the worksheet I hope you have open!

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2. Locker Brook Relief Channel2. Locker Brook Relief ChannelTotal Cost = £ 10.0 millionA large drainage channel connecting the Locker Brook to the River Falmer. At times of high water, a flood gate is opened which allows the floodwater to be safely diverted past west Melchester. No opposition whatsoever from local residents, although the nearby main road will need to be closed during construction. Some high quality farmland to the south-west of Melchester will also be lost.

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3. Melchester drain by pass3. Melchester drain by passTotal Cost = £ 12.0 millionA large underground tunnel offering a more direct escape route for floodwater from the River Falmer. At times of high water, the tunnel is opened diverting water from the meanders near the town centre. Little environmental impact but local residents concerned about possible damage to houses caused by tunnel excavation.

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4. Falmer Ring Dyke4. Falmer Ring DykeTotal Cost = £ 15.0 millionA massive ringed embankment around the Falmer Levels which would allow floodwaters from the River Falmer and the River Dank to be held back, protecting all of Melchester. Would cause significant damage to the environment during construction due to the amount of earth that would need to be moved. It is expected to fill only once every 200 years. People living in north Melchester are likely to be upset by the noise from all the earth moving machinery required.

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5 Swinford temporary basin 5 Swinford temporary basin Total Cost = £ 5.0 millionRemovable flood walls that can be mounted into place with relatively little warning. Effective with smaller floods but not high enough to cope with 100 year flood events such as that experienced in 2001. Little environmental impact. Local residents in Swinford are highly supportive of the proposal although the people of Melchester are concerned that it would merely divert floodwater downstream.

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6. Bend Flood Wall6. Bend Flood WallTotal Cost = £ 5.0 millionA permanent flood wall made from local stone built to protect the village of Bend. It would also allow access to Bend and Narrowbridge during times of flood when the main road is blocked. Effective with smaller floods but not high enough to cope with 100 year flood events such as that experienced in 2001. Local residents in Bend are highly supportive of the proposal although the Bridgefordshire Tourist Board is concerned that it will ruin the lovely scenic views.