It begins as uncertainty in communication
Shannon entropy was introduced to measure how uncertain the next symbol in a message is. A concentrated distribution has low uncertainty; an even distribution has high uncertainty.
Entropy / Diversity / Model
Shannon Diversity Index
An interactive tool to understand the concept of biodiversity through the Shannon Diversity Index. Adjust species populations and observe how diversity and evenness change in real-time.
H'1.099
Evenness1.000
Total45
Shannon Index1.099
Uncertainty calculated from each species proportion pᵢ. It responds to both richness and evenness.
Evenness1.000
Max H'1.099
Active species3
Effective species3.00
pᵢ = nᵢ / NH' = -Σ pᵢ ln(pᵢ)J' = H' / ln(S)¹D = exp(H')
Contribution to H'
-pᵢ ln(pᵢ) by species
Composition
100 cells = the full sample
A33.3%
B33.3%
C33.3%
Terms by species
The values that compose the index
| Species | nᵢ | pᵢ | -pᵢ ln(pᵢ) |
|---|---|---|---|
| A | 15 | 0.333 | 0.366 |
| B | 15 | 0.333 | 0.366 |
| C | 15 | 0.333 | 0.366 |
Academic Context
From uncertainty in information to composition in ecosystems and cities.
Ecology uses it to read richness and evenness
In ecological communities, symbols become species and probabilities become relative abundances pᵢ. H' responds to both the number of species and how evenly individuals are distributed.
Today it travels as a measure of compositional balance
It appears in microbiome studies, conservation ecology, land-use analysis, urban functions, and cultural or industrial category mixes. The index describes uncertainty in a distribution, not area or spatial arrangement.
Reading note
H' is an entropy value, so it is not directly the number of species. For an intuitive diversity reading, convert it to the Hill number q=1: ¹D = exp(H'), the effective number of equally common species.
Shannon Diversity Index Calculator & Visualizer
Reading diversity as a distribution, not a formula.
Diversity Visualization / Information Theory / Urban Development
Based on the concept of entropy proposed by Claude Shannon, the father of information theory, the Shannon Diversity Index is now used in various fields such as ecology, environmental assessment, microbiology, sociology, economics, business, and urban development. This tool was created to facilitate visual and interactive understanding of the index.
The objective is to deepen understanding of existing applications and open up possibilities for further use in new fields.