Saturday, 31 December 2011

Maps, Maps and a Few More Maps.....

Apologises for being on the quiet side with regards to blogging - I hope you all had a lovely Christmas and that the revision is going well (sorry to have to remind you all!).

Considering that I haven't really written anything of great relevance this past term for AS students and A2 students also need to be able to use the geographical skills introduced at AS, I thought I would start off with going over some of the basics. Hopefully this will be of use to AS students in preparation for your skills exam, you will just have to bear with the possibly frequent references to Poole and its 'exciting' new bridge - so what better place to start then maps, especially as the map at the back of AIB looks like an invitation to construct a Choropleth map!

Maps with located symbols

= Located proportional symbols are drawn on maps to show location and number/size of variable

- Symbols are drawn proportional in size to the size of the variable
- These maps might be used for showing the size of the biggest towns in a region. Often bars or circles are drawn to a suitable scale to illustrate comparative size, and placed upon the map to show the position of the towns, for example.
- Proportional bars are often favoured over proportional circles as they are easier to draw, read and scale. However, if the range in the data (difference between largest value and smallest value) is very big then proportional circles should be used as they offer greater efficiency in presenting large ranges. When complex data sets are used, proportional symbols can be divided (with circles, using proportionally sized pie charts).
- Used to show a limited number of points/areas and should not be used for illustrating spread of distribution

Maps showing movement

- These maps show movement by using flow lines, desire lines or trip lines

Flow lines = indicate a line of movement with its thickness representing the volume of movement and direction the line of flow
Flow lines
e.g. Flow line could be used to represent traffic flow in Poole and show where congestion becomes an issue as, as more traffic joins the route the line would get thicker and as the traffic leaves the route the flow line would get thinner.
Desire lines
Desire lines = shows strength of desire to move with lines of proportional thickness. They are very similar to flow lines except they generalise movement, showing movement only directly from A to B whilst flow lines follow the exact path of movement.
- often used to show the number of people travelling from each part of the catchment area of a central point
Trip lines = simplest map for showing movement, shows journeys from a starting point to a central point
- typically used to map school catchment areas or comparing the 'sphere of influence' of towns etc.

Maps showing distributions

- Distributions can be represented using choropleth maps, isoline maps or dot maps

Dot maps = used to represent spatial distribution where values and location are known by placing dots of equal size on a map.
- scales can be used, so one dot could represent 10 people or 100 people and a appropriate scale is chosen to ensure the map does not become too crowded
- clusters on the map will give an idea of trends in the data BUT can be tricky to read and are not very precise as dots blur  into one, therefore nothing but basic trends and anomalies can be gained from the map
- issues are also presented with where excatly to place the dots
- however, dot maps do have the advantage that they show actually numbers so actual totals can be calculated (by adding up the dots!) - something that cannot be done with choropleth maps as they represent densitites rather than totals
- limitations include the difficulty of counting large numbers of dots in order to get a precise value and the need to have a large amount of initial information before drawing the map

Isoline maps = lines that join places with an equal value for a variable, seperating places with a higher value from those with a lower value
- ideal for showing gradual spatial change as avoids abrupt changes generated by boundary lines on choropleth maps; hence why temperature, velocity and relief are mapped in this way as they are continuous , without abrupt changes at any point (like population density, for example). There are plenty of examples of isolines, like isovels (water velocity), isobars (pressure), isotherms (temperature), isohyets (rainfall) and contour lines (height) - I am sure AS students have drawn a few isovels themselves over the last term!
- when isolines are drawn close together they represent a steep gradient in the values being plotted, when they are drawn far apart they represent a gentle gradient
- isolines can never cross each other as it implies that the point where they cross has two values
- however, a large amount of data is required for accurate drawing, so in reality many points are interpolated (drawn between two known points to represent the probable point where the line being plotted moght be assumed to occur) and they are unsuitable for showing discontinuous distributions

Choropleth maps = shows spatial distributions, using shadings of different densities to represent different densitites of the variable
- darker colours indicate higher numbers, although ideally different shades of the same colour should be used
- it is good practice to avoid leaving any areas unshaded - unless they actually have no population at all
- usually desirable to show about four or five different groups - more makes map confusing and fewer does not show enough variation to be useful
- perhaps most commonly used to illustrate population density but can be used for other variables such as indicating differences in land use from recreational land or type of forest cover
- provides a good visual impression of spatial change and shows areas which have similar densities and those with very different densities; therefore allows areas to be compared and contrasted
Has its limitations though:
- suggests abrupt changes at boundaries of shaded units, which again does not really occur in reality
- choropleths, on their own, are not suitable for showing total values and so are often used in conjunction with proportional symbol overlays to solve this problem
- sometimes difficult to distinguish between the different shades
- variations within the map units are hidden, and for this reason smaller units are better than large ones

Goad map = detailed town centre plan which shows every builidng. They can be coloured coded into type of business etc to make it easier to spot land use trends
- looking at land use maps of Poole past and present may be a good idea to see how industry has developed over the years and the extent of urban sprawl etc. There are lots of maps on the A Vision of Britain Through Time website....

Well, hopefully that pretty much covers all the maps we need know about and the skills booklet (if you can find yours from last year!) has some examples of each and how to plot them etc. I think perhaps choropleths maps could come up in the A2 exam, considering we have that blank map at the back of the AIB and population densities in the table at the back, although proportional located symbols could also be an option with divided circles/bars as the table contains three housing options as percentages and various employment figures - I think I would rather a choropleth!

Hopefully, this is of some use for AS students too! I found that be able to read off, and highlight trends and anomalies, from all the maps and graphs was really important - quoting figures is crucial!!!

Next up I think I will do a review of graphical methods of presenting data, before moving on to sampling techniques and the dreaded, by many, stats tests!

Thursday, 15 December 2011

Evaluating the Usefulness of Websites Regarding Poole Regeneration

Poole Borough (the website referenced in AIB) ---> This website is produced by the local council and, as such, is very useful for information relating to regeneration in Poole. Containing all the information regarding processes taking place (summarised into a timeline) and moves by the council to regenerate the area, accompanied by key documents and publications available for download, this website is probably the first place you should visit if you want to find out more about the regeneration. The website is very detailed and accurate with good archives that are easy to navigate (with a seperate section for regeneration in Poole and also the Twin Sails Bridge) through with language easily understandable for a general audience, meaning it is suitable for use by a group of A Level Geography students wishing to find out more about the Twin Sails Bridge and other elements of the regeneration. Links to websites of all the companies involved in the construction of the bridges are provided, permitting further research into how/when the bridge is being/has been built. The reliability and accessibility of this source, agruably makes it one of the best factual websites to use, however, although opinions are expressed in some of the leaflets/booklets contained within, opinions from all angles regarding the re-development are not presented, with only those supporting the bridge and re-development published. Therefore, when looking for the opinions of locals, this website is not the best one to use.

Bournemouth Echo ---> This website of a local newspaper  provides frequent updates regarding progress being made with the Twin Sails Bridge and regeneration project, as with other newspaper websites like ThisIsDorset. The website contains good archives and search facilities, therefore making it easy to navigate your way around the information. As with any sources of information, it is good practice to validate statistics provided with other sources, meaning that often it is the amalgamation of sources that proves most useful and credible, rather than one single source. One benefit of this website over that of Poole Borough Council's is its more discursive nature/style of writing that permits presentation of opinions other than those of the council, with all readers having the ability to leave comments on articles, meaning opposition to such ideas are also presenting, providing one of the best sources of public opinions on developments.  This difference between this and a national news agency such as the BBC is that public opinions are not as frequently expressed, instead focusing on the facts/statistics and illustrating what is occuring through videos. Also the only items to appear are the major 'milestones' in the regeneration process, not those just of concern for local people meaning that, again, balancing the use of both news-related sources, is the only way to gain the full picture.

New Civil Engineer ---> This is one of the websites referenced at the back of the AIB for supplying the diagrams of the bridge (page 5 of AIB), therefore, it is a sensible assumption to make that this website could be of use for an A Level student wishing to find out more about this topic. However, restrictions are placed on what a student can access as you have to be a subscriber to read the vast majority of the content, meaning most typical Geography students won't be able to access the site. This issue is not limited to just this site, with a few other sites that focus on more specific, technical detials of the bridge and regeneration also having restrictions in place, meaning gathering of information is more challenging.

Design Council ---> Provides more specific articles regarding the regeneration from architects points of view. Different to some of the other sources as provides analysis and evaluation of the project, referring it back to three key points, scale of development, quality and sustainability. Compared to other websites it is perhaps not as easy to find specific information required as the vast majority is irrelevant to this topic but it does provide an invaluable perspective from specialists rather than public opinion whilst also suggesting an alternative regeneration proposal for Poole. Websites like this, which focus more on the specific details do however start to become less accessible to a general audience as a consequence of language used.

Poole People ---> This is the website of a new political party which aims to improve the governance of this borough. From the website, it is probably clear to see that they oppose the proposals and so this website provides some of the reasons as to why people oppose the regeneration project, via video format as well as text-based explanations. It is because of this that this website could be of some use to students researching Poole regeneration plans but its usefulness beyond supplying reasons for opposition is debatable.

Tourist Information ---> With regards to finding general information about Poole and its current tourist attraction, many of the tourist information-based websites, are not that useful, such as Bournemouth and Poole and Poole Tourism, as they don't provide many specifics regarding numbers of visitors etc. On the other hand they do demonstrate what already exists in Poole and the surrounding area, as well as a bit of local history. Despite this, in terms of utility for this project, they are perhaps the least useful sites to use.

Social Media ---> Increasingly used to express opinions and convey messages to people around the world. The council have created their own Facebook page for the Twin Sails Bridge to keep the public informed about developments and it is regularly updated with links to relevant articles etc. This is very accessible and used in conjunction with their website provides ongoing accurate information. There are other groups on Facebook set up by members of the public by those opposing the bridge building although, as with discusion forums (for example, this particular one expresses the opposition from the boating community to two lifting bridges), they do not seemed to be utlised that much. Their collective usefulness only extends as far as providing an insight into the opinions of local people, although they by no means represent always the general consensus.

YouTube ---> Visual analysis of the bridge can only really be gained from either visiting Poole itself or from videos and they are quite a few 'exciting' videos on YouTtube that you could watch of the bridge being built and lifting up etc. These allow opinions to be formed on whether this iconic bridge can really blend in with the surrounding natural environment and the visual impact of such a construction. Many of these videos are on afore-mentioned websites but having them all in one place is a lot easier!
Google Earth/Google Maps ---> This form of GIS is useful in that satellite images of the surrounding area can be used to help understand which areas are going to be redeveloped and comparing such areas with the location of important conservation areas. They also indicate road layout and so how builidng a bridge would help to solve issues with traffic congestion in the area. This resource is best combined with others, such as flood risk evaluations by the Environment Agency and regeneration plans outlined on Poole Borough website to provide a visual representation of information and provide greater spatial awareness of impacts. One of the biggest uses of such a resource is the guidance it provides when conducting a Risk Assessment in preparation for conducting fieldwork in an area as risks can be highlighted such as proximity to dangerous roads, suitable/safe areas for conducting a traffic survey and where is suitable for large groups of students to cross roads, for example.

Overall, websites as a whole provide one the best sources of accessible information regarding this topical and contemporary topic and whilst some are clearly more useful and reliable than others, it is the combination of the secondary data provided that proves most significant and useful, providing a means of validation and information covering all of the key research areas.