Mod8 - Isarithmic Mapping

Isarithmic Mapping

In this week's lab I learn about Isarithmic maps which are used to depict smooth, continuous phenomena across an area using different symbology. I also learned about the two different types of data that are best suited for this type of mapping, True Point data and Conceptual Point data. This lab also covered four different methods of data interpolation that are used to derive intermediate points to create the data set, these are: Inverse Distance Weight (IDW), Kriging, Splining, and Triangulation.

This lab assignment was based of the school provided data of precipitation over a 30 year cycle for Washington and the map was designed entirely in ArcMap.

The precipitation data for the State of Washington that was derived and interpolated using PRISM (Parameter-elevation Relationships on Independent Slopes Model) analytical model. This model uses point data and an underlying grid such as a Digital Elevation Model (DEM) to generate grid estimates of monthly or annual precipitation. The precipitation data set was created from the application of this method on point data collected from weather monitoring stations and the calculated climate elevation regression for each grid cell within the DEM. The created data set accounts for physio-graphic factors that may influence climate patterns.

The primary objective of this lab are:

• Define an Isarithmic Map, review different kinds of isarithmic maps
• Identify appropriate data types for Isarithmic mapping
• Recall different interpolation methods (Triangulation, kriging, Inverse Distance Weighted, PRISM)
• Recognize the different symbolization methods
• Implement continuous tone symbology
• Implement hypsometric symbology
• Describe the basics of and create contour lines
• Work with continuous raster data, and
• Employ hill-shade relief

Here's the map rendered:

Hypsometric May with Contour Lines

   The map above used Hypsometric Tint symbology to represent the data with manual classifications f the annual precipitation into 10 classes. A "stepped" or 3-D like surface is created to more easily visually interpret the precipitation differences across the State, with lower values represented by bright/light colors while darker colors represent higher values. 

  This is a fun and color lab.