Geomorphic Change Detection Software

Thresholding Alternatives

Background

Synopsis of Topic

Today we will introduce a variety of techniques for estimating errors and propagating errors. Once you have an uncertainty estimate for your DoD, how do you use this information to distinguish real change from noise? Typically some sort of threshold is established, such as a minimum level of detection or a confidence interval on a probability that change is real. Then there is the question of what to do with data below that threshold. Exclusion is the most common method, but subtraction and weighted sums are other possibilities. In this session, we cover these alternatives and show you how to interact with these in the GCD software.

Fig_2007-2006_PW2_threshold

Simple MinLoD

SimpleMinLoD_Slide

Propagated Error

Propagated_Slide

Probabilistic

Probabilistic_Slide

Why we’re Covering it

Thresholding is a key concept in developing estimates of net change and volumetric estimates of erosion and deposition.

Learning Outcomes Supported

This topic will help fulfill the following primary learning outcome(s) for the workshop:

  • A comprehensive overview of the theory underpinning geomorphic change detection
  • The fundamental background necessary to design effective repeat topographic monitoring campaigns and distinguish geomorphic changes from noise (with particular focus on restoration applications)
  • Hands-on instruction on use of the GCD software through group-led and self-paced exercises

Resources

Slides and/or Handouts

Exercise

Relevant or Cited Literature


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