Answer in brief.
Explain the use and types of distributional maps.
Distribution maps are a form of thematic maps that are used to represent the distribution of particular geographic elements within a given region. It utilizes the statistical data of the chosen element to create a map which provides the user with a visual representation the particular variable’s distribution. A properly made distributional map makes it easy to visualize how a certain variable or element varies over a region. It can be used to represent qualitative data like vegetation or soil in a region or quantitative data like population density or average annual rainfall in a region. The following table gives a classification of the different distributional maps along with their advantages and disadvantages.
|Type||Methodology and usage||Advantages||Disadvantages|
|Dot Maps||Use dots to represent precalculated values of chosen variable.||Easy to read maps.||Improper methodology leads to human error in map Interpretation.|
|Dot used should b uniform in size corresponding to their index.||Proper mathodology provides clear precie pattern for study.||Dense Dot distribution can lead to improper results|
|Dot Placement is dependent on presence of natural and man-made features like rivers roads etc.||Multi colored dots on the same map allowqs proper study of related phenomena like rural population and agricultural production.|
|Mostly used for variables that are scattered throughout the chosen region of study.|
|Choropleth Maps||The date for different geographical variables is represented by either shades of the same color or by different colors.||Popular form of representation as it is easy to read and interpret.||Cannot be used for contnuous data as it is limited by administrative boundries. Thus variables like temperature and rainfalls cannot be represented by these maps.|
|Every sub-administrative region has one assigned value.|
|Data is divided in calsses after ascertaining the highest nd lowest values, with each class getting a particular shade.|
|The shade becomes darker with increasing value of the given variables.|
|Isopleth Maps||Isolines are line lines which join the places having the same date on a map like lines joining places having equal rainfall.||These maps are ideal for showing the gradual change in variables over space and or time. For eg, temperature,rainfall, altitude are best represented by these maps.||Bot suitable for showing variables that are unevenly distributed in a given region like forest cover or agricultural land.|
|The ranges are between two isolines are often colored to represent the data diversity which creates the isopleth maps.|