Semantic calibration of digital terrain analysis scale

DTA has not been field tested to the extent that traditional field metrics of topography have been. Human assessment of topography synthesizes multiple parameters at multiple scales to characterize a landscape, based on field experience. In order to capture the analysis scale used by field scientists, this study introduces a method for calibrating the analysis scale of DTA to field assessments.

Drainage Index Grid (conterminous U.S.)

This raster contains the natural, inherent, soil wetness of the lower 48 states, as determined by the ordinally based Natural Soil Drainage Index (DI). The DI is intended to reflect the amount of water that a soil can supply to growing plants under natural conditions. It ranges from 0 for the very driest soils and exposed bedrock, to …Continue reading “Drainage Index Grid (conterminous U.S.)”

Productivity Index Grid (conterminous U.S.)

This raster describes the inherent, soil productivity of the lower 48 states, as determined by the ordinally based Natural Soil Productivity Index (PI). The PI uses family-level Soil Taxonomy information, i.e., interpretations of taxonomic features or properties that tend to be associated with naturally low or high soil productivity, to rank soils from 0 (least productive) to 19 (most …Continue reading “Productivity Index Grid (conterminous U.S.)”

Is It ‘Deduction’ or ‘Induction’, My Dear Watson?

Sherlock Holmes often talks about ‘deductive reasoning’ but was he really using deduction or induction? Although by definition these two approaches appear to be opposites, in practice, the differences between the two can be subtle. A simplified contrast between deductive and inductive reasoning is that deduction is reasoning from the top down and induction is …Continue reading “Is It ‘Deduction’ or ‘Induction’, My Dear Watson?”

Relief Analysis Toolbox

The central purpose of this toolbox is to provide ArcGIS users a convenient way to calculate hillslope position from elevation grids. However, the Relief Analysis Toolbox also includes some other ArcGIS models that may be of interest to anyone working with landscape and landform segmentation. The main features of this toolbox are: hillslope position (calibrated to …Continue reading “Relief Analysis Toolbox”

Is It a Scientific Theory or Hypothesis?

This is a common question addressing a popular misconception about how science classifies the knowledge that it has accumulated. The levels of hypothesis to theory to law often get interpreted as classes of confidence. However, this is not really right. The missing piece here is spatial scale! It isn’t easy to draw the line for …Continue reading “Is It a Scientific Theory or Hypothesis?”

The Scientific Method: Does Anybody Really Use It?

It can be hard to match what we learned about the scientific method in school with the scientific literature being published. There are a variety of reasons for this, but generally it is an issue of what is practical (especially within the time frames that sources of funding expect results). Because the classic description of …Continue reading “The Scientific Method: Does Anybody Really Use It?”

What is Science?

For my first blog post, it makes sense to start with the basics. And one of the most fundamental concepts for a researcher to establish is the definition of science. As a starting point, let’s begin with the definition from the Oxford dictionary (which is very similar to definitions found elsewhere): def. Science – the intellectual and …Continue reading “What is Science?”