G.Hudson Mastering GIS

 Isarithmic mapping is another type of thematic mapping that results in continuous phenomena of a geographic area being displayed using various symbology methods. The continuous phenomena typically displayed can include precipitation, elevation or topography. As it is difficult to record values for every single point across any given area, isarithmic mapping utilizes data from control points (true point data or conceptual point data) and interpolates the data using one of many interpolation methods to calculate the various intermediate points, producing a continuous surface. The interpolated data can then be symbolized to present as smooth surface using continuous tone or a stepped surface using hypsometric tinting. Contours can also be created and displayed as a stand alone feature or in conjunction with hypsometric tinting. Using the contours along with hypsometric tinting is recommended, however, because it helps the map reader obtain a better understanding of the data being display

 Expanding on last week's lecture and assignment, module 5 focused on choropleth mapping, dot mapping and proportional symbol mapping. Choropleth mapping displays phenomena that are aggregated to areas and are the most common type of thematic map. Most cartographers choose to utilize choropleth mapping when they want to display data that is evenly distributed across an enumeration district, however, it is important to refrain from using raw data. The data should be normalized to avoid presenting false narratives.  Dot mapping is also a type of thematic mapping. A dot map displays the location of one or more geographic occurrence or phenomena. Quite often one dot can represent a multiple occurrences of phenomenon, at which time the location of the dot is places in a relative position. Dot maps are easy for the reader to understand and can show variations of large quantities, however, it can be difficult to accurately interpret density.  Proportional symbol mapping consists of, both,

 Data classification is important when presenting data. It breaks raw data down into a more palatable and understandable format for the reader. It can also provide insight on and highlight patterns that may not have previously been visible. As such, this week we learned about various data classification methods. In the first instance we were introduced to the various types of data. They include qualitative data, which differentiates types of things and focuses more on characteristics, and quantitative data, which speaks to amount or magnitude. Once we learned of the various types of data we moved on to ways that data can be expressed, specifically via classification. The methods included: Equal Interval - classes are equal in range.  Natural Breaks - classes based on naturally occurring breaks in the data. Quantile - classes contain an equal amount of data in each class. Standard deviation - based on the mean and classes are formed based on deviation from the mean. Optimal Classificati

This week's focus was land partitioning systems and cartographic design. Land partitioning systems can be broken into two categories, systematic and unsystematic. We were given a historic perspective of  both types of systems in the US and how they impact systems that are used today. The land partitioning systems were introduced to included Metes and Bounds, Long Lots, Spanish Land Grants, State Land Surveys, and the US Public Land Survey which is the most widely used land partitioning system in the USA today.   The cartographic design lesson introduced the 7 step map design process and elements required to produce a well designed map. To produce a well designed map, along with following the 7 step design process a cartographer has to be mindful of certain principles. Gestalt's design principles, inclusive of visual hierarchy, figure-ground relationship, contrast and balance, are all important.  Map of Ward 7 Public Schools Once we learned of the cartographic design principles,