Create Thematic Maps based on your Data
A thematic map is an enhanced map according to a particular theme, which is widely used to represent one or more natural or social phenomena on the map. A thematic map uses colors, symbols, charts, and so on to represent a theme. Commonly used thematic maps include Unique Values Map, Ranges Map, Graph Map, Graduated Symbols Map, Dot Density Map, Label Map. and Custom Map.
For example, Ranges maps display data of a specific attribute according to ranges you set. These ranges are shaded with different colors, patterns, line styles, or symbols. In a ranges map, the thematic values are divided into several ranges according to a certain ranging method. A range is assigned to each feature based on the corresponding thematic value. The same styles, such as color, fill, and symbol, are applied to features of the same range. A ranges map must be based on a thematic variable of a numerical type. Ranges maps are usually used to represent volume or degree characteristics of continuously distributed phenomena, such as distribution of precipitation and distribution of soil erosion rate.
For online mapping, thematic maps can be created directly using APOI of GIS clients, or created by GIS server through calling back-end map services. Creating thematic maps through server side will have better performance; while creating thematic maps through client side can introduce state-of-the-art front end technologies, therefore realizing more splendid effects.
This chapter will guide you through thematic mapping based on REST map service through server side and client side.