Flooding on the Somerset Levels. ArcGIS Online

Transcription

1 Flooding on the Somerset Levels ArcGIS Online

2 Using this resource This resource has been written to help teachers make use of the ArcGIS Online program. It provides; guidance on how to use the program s tools and functions ideas for activities that can be used to help students understand something about the causes and effects of the 2014 flooding on the /Somerset Levels. With this guidance and ideas, teachers can create their own resources with classroom activities. The program could be used either by demonstration or worked on independently by students. A resource such as this can never be finished there is always more than can be added. Teachers can add additional data and save the resource under a different file name. The use of other resources may also be needed to provide more comprehensive information. Access the resource Open the ArcGIS Online program. You first need to Sign up for a free ArcGIS Online account. Then in the search box (top right), type Somerset Levels (Search all content). This image should appear in the list of available resources. Open resource Click on the drop down arrow beside Open then on Open in ArcGIS Online.com Viewer. The Somerset Levels resource will then open. It will show a map and a Contents list. The Contents list shows the different maps and other data that has been loaded as separate layers. These layers of data can be switched on or off as needed by ticking in the boxes beside their names. Contents the data for the resource in layers The Basemap and starting point for the resource

3 Location of the Somerset Levels The map that opens is a Basemap showing the names of places and roads in the general area in which the Somerset Levels is located. This map is named Streets. You can see it at the bottom of the contents list. The base map icon in the Contents list The zoom tool You can Zoom out to see where this area is in the wider context of the country. You can Zoom in to see details within the area. Another way to zoom in is to hold down the Shift key and draw a box around the area you want to study in greater detail. To find the Somerset Levels location, tick the box named Somerset Levels outline in the Contents list. Tick a box to make a data layer appear The shaded area can be made transparent You can set the Transparency level of the area by clicking on the drop down arrow beside the words Somerset Levels. This will let you see through the shading to the map layer below. Size and dimensions of area Transparency slider Find out the size of the area. Do this by clicking on the Measure tool, choosing Area, then drawing around the Somerset Levels outline. The size of the area is then shown in the box. Measure tool Use the line measuring tool to find out the length and width of the area, north to south and east to west. Click on the ruler icon. Place the cursor on the map and click. Click then double click at the end of the line Area and other measuring tools

4 History Click on the History item in the Contents list. Some notes about the area are shown by flags that have been marked on the map. The dates go in this order: yellow, white, red, green. Click on the flags to read some brief notes about the history of the area and how people have created and manage the area. Information at these pinpoints shown as flags Click on a flag for an information popup box Rivers and drainage Click on the UK Water Features item in the Contents list. This shows all the rivers in the area. Click to show the World Topographic Map layer. You map also want to see the Somerset Levels outline at the same time Zoom in to the map and pan around until you can find the names of the rivers. Notice that there are straight blue lines a cross the map these are artificial channels that have been dug to take water away from the area. Find areas where there are dense networks of straight blue lines these are drainage ditches. Extract from the topographic map

5 Cross profiles You can draw a cross profile of the area by using a Web Application. Click on the Share icon. Click on Make a web application. Click on Elevation profile. Click on Preview. The cross profile tool should now appear. Share option Click to find the elevation profile web application Map Elevation profile box Measure tool Click on the Measure tool (towards the bottom right of the screen). Click on the map and draw a line across the Somerset Levels. The profile drawing appears in the Elevation Profile box. You can zoom in and pan around the area of the map to draw several profiles. Use the profile diagrams to help explain why this area is prone to flooding, e.g., close to sea level, flat, little gradient to help drain water away. To return to the main map resource, click on the x to remove the tab with the Profile Elevation application.

6 Land use Click to show the World Imagery layer. Zoom in until you can see details for each field. The satellite image shows simulated real colours, i.e. green is usually grass. You can face the imagery by using the Transparency tool. This will let you see the names of places and roads in the Basemap. Zoom in to show land use Use the satellite image you find out about land use in the area. Measure the areas for about 10 fields and work out an average size. What seems to be the main type of farming in the area? How does farming seem to be different in the south of the area, e.g. in the area to the south east of Bridgwater? What might be some reasons for these types of land use in this area? When finished, you can close down the satellite imagery layer untick the box. Conservation Put a tick in the box beside the Environmental map layer in the Contents. Click on the word Environmental. A set of four maps within this layer then appears. Different types of environmental map Open the maps showing Special areas of conservation and the Sites of special scientific interest. You see details of each of these areas by clicking on the drop down arrow beside each map layer s name. Then click on Show Table. You can see details on a spreadsheet by clicking on an area, then Table options, then Show selected records. Use the information to answer questions about conservation in the area. What kinds of conservation and sites of special scientific interest are in this area? About what percentage of the Somerset Levels is protected for conservation reasons? Can you think of any possible conflicts there might be between draining and protecting the land for farming? Show Table

7 Flooding Open the map layer showing UK Water Features uk rivers. In the Environmental map layer, click the Area of Outstanding Natural Beauty map layer. Name the areas and find out about the types of topography in each, i.e. are they flat, hilly, mountainous etc. You can access a Table with more information about each area. The Somerset Levels forms a river basin. Why is basin a suitable tem to use for this area? Data in a Table Click on an area to access its data in the Table

8 Villages under water Several villages have been in the news because they have been badly flooded. Two of these villages are at Muchelney and Moorland. It should be possible to find these villages by using the Search tool (Find address or place). Unfortunately, neither of them are listed in the program s database because they are too small. Click on the Flood villages item in the Contents list. The location of the villages are shown by marker pins. Click on the pins to find out more. Pinpoints that show the villages Click a pin to see information and photos Zoom in to show details of each village. You can look at several map layers to do this, e.g. the World Imagery layer. A village in closeup About how big are they in area? About how many houses are in each? What road access is there to them? What do the photos show about how much of the villages have been flooded? Click on the Railway flooding item in the Contents list. Find the location on the map. Describe what the photo shows. How will flooding affect places outside the Somerset Levels? Symbol to show the railway flood point

9 Additional activities When students become familiar with ArGIS Online s tools and functions, they could undertake other activities such as enquiries, planning simulations or role play. The types of activities depend very much on the creativity of the teacher and students. These are some ideas. Enquiry Would changing land use on the Mendip Hills help to reduce the risk of flooding in the Somerset Levels? Planning simulation Make a flood protection plan that could help stop a river from flooding a village (choose a specific location for this activity). Role play How could a group of experts work together to organize helping people in a village that is about to be flooded, e.g., police, army, civil engineer, transport operator etc. Student use of the tools Perhaps the best way to use ArcGIS is for students to make use of the tools and functions. They can, for example, mark their own points of interest, draw areas, use the measure tools, create and import raw data, draw graphs and many other activities. Students could be competent to use the program in these ways with regular use over several years using a phased approach to the work. Additional resources It will also be important to access other resources that are not shown in the ArcGIS resource. Full screen sized photos, for example, are best accessed directly from web sites. This is one amongst many sites for photos