Friday, April 30, 2010

Map of the Week





















Being an advocate of mass transit, it is helpful to use existing successful transit networks across the globe as paradigms for implementation in America. This map shows the Chinese rail network, which is primarily focused on transporting goods from one of China's many seaports to the interior of the country.

Lab 6: Dot Mapping and Proportional Symbol Mapping

Part A-





This map illustrates the population density across the State of Idaho utilizing dot mapping techniques. The green area on the map is forest service land, and was not considered when di









Part B-





This map is similar in nature to the previous map, the only differences being the mapped area and the mapping type. This map utilized proportional symbol mapping and displayed city populations using proportionally sized symbols.

Wednesday, April 21, 2010

Map of the Week










Portland, Oregon has one of the most heralded transit systems in the United States today. Over 30 years ago, Portland implemented controversial policies that encouraged transit oriented development, and has since become a model for efficient transit use. Portland's transit system, dubbed Tri Met, operates radially from the core of Portland's downtown.

Lab 5: Using IDW and Kriging for Interpolation

Inverse-Distance Weighted






The map communicates precipitation amounts, in inches, across Idaho in a continuous, contour format. The interpolation method used for this map was the Inverse-Distance Weighted method.









Kriging Method







This map also communicates precipitation amounts, in inches, across Idaho in a continuous, contour format. The interpolation method used for this map, however, was the Inverse-Distance Weighted method.









Comparing the IDW method and the Kriging method from the map perspective, the IDW method appears to be more precise in its adherence to the control point values. This is reflected in the very specific shapes that the contour lines form. The Kriging method, however, appears to be much more generalized.

Comparing the IDW method and the Kriging method from the five evaluation criteria:
  • Honoring control point data: The IDW method appears to be more accurate, but neither method is extremely precise.
  • Correct at non-control points: Cross-validation of RMS values from each method reveal that the Kriging method yielded the lowest RMS value.
  • Ability to handle discontinuities: Both methods appeared to perform equally well in this criteria.
  • Execution time: The execution time was slightly higher for the Kriging method.
  • Ease of understanding: The Kriging method was more difficult to understand than the IDW method because of the selection of an appropriate semivariogram.