Biodiversity Loss Index Calculator
Estimate the Biodiversity Loss Index for an area based on habitat loss, land use intensity, species richness, and human disturbance.
Formulas Used
The Biodiversity Loss Index (BLI) is calculated using a weighted formula combining habitat loss, land use intensity, species richness, and human disturbance.
- Normalized Habitat Loss Score:
\\[ H_{\text{norm}} = \frac{H}{100} \\]
Where \\( H \\) is the percentage of habitat loss.
- Land Use Intensity Score:
\\[ L_{\text{norm}} = L \\]
Where \\( L \\) is the land use intensity factor (0.2, 0.5, 0.8, or 1.0).
- Normalized Species Richness Score:
\\[ S_{\text{norm}} = \min\left(1, \frac{S}{200}\right) \\]
Where \\( S \\) is the number of species, capped at 200 for normalization.
- Human Disturbance Score:
\\[ D_{\text{norm}} = D \\]
Where \\( D \\) is the human disturbance factor (0–1).
- Raw Biodiversity Loss Score:
\\[ B_{\text{raw}} = w_1 H_{\text{norm}} + w_2 L_{\text{norm}} + w_3 S_{\text{norm}} + w_4 D_{\text{norm}} \\]
Where:
- \\( w_1 = 30 \\): Weight for habitat loss
- \\( w_2 = 25 \\): Weight for land use intensity
- \\( w_3 = 20 \\): Weight for species richness
- \\( w_4 = 25 \\): Weight for human disturbance
- Biodiversity Loss Index (BLI):
\\[ \text{BLI} = \max\left(0, \min\left(100, B_{\text{raw}}\right)\right) \\]
Normalizes the raw score to 0–100. Impact levels: Low (0–25), Moderate (25–50), High (50–75), Critical (75–100).
Example Calculations
Example 1: Agricultural Expansion
Inputs: Habitat Loss = 40%, Land Use Intensity = Moderate (0.5), Species Richness = 100, Human Disturbance = 0.6
Calculations:
- Normalized Habitat Loss: \\[ \frac{40}{100} = 0.4 \\]
- Land Use Intensity: \\[ 0.5 \\]
- Normalized Species Richness: \\[ \min\left(1, \frac{100}{200}\right) = 0.5 \\]
- Human Disturbance: \\[ 0.6 \\]
- Raw Biodiversity Loss Score: \\[ 30 \cdot 0.4 + 25 \cdot 0.5 + 20 \cdot 0.5 + 25 \cdot 0.6 = 12 + 12.5 + 10 + 15 = 49.5 \\]
- Biodiversity Loss Index: \\[ 49.5 \\]
- Impact Level: Moderate (25–50)
Result: Biodiversity Loss Index: 49.5 (Moderate)
Example 2: Urban Development
Inputs: Habitat Loss = 80%, Land Use Intensity = Very High (1.0), Species Richness = 50, Human Disturbance = 0.9
Calculations:
- Normalized Habitat Loss: \\[ \frac{80}{100} = 0.8 \\]
- Land Use Intensity: \\[ 1.0 \\]
- Normalized Species Richness: \\[ \min\left(1, \frac{50}{200}\right) = 0.25 \\]
- Human Disturbance: \\[ 0.9 \\]
- Raw Biodiversity Loss Score: \\[ 30 \cdot 0.8 + 25 \cdot 1.0 + 20 \cdot 0.25 + 25 \cdot 0.9 = 24 + 25 + 5 + 22.5 = 76.5 \\]
- Biodiversity Loss Index: \\[ 76.5 \\]
- Impact Level: Critical (75–100)
Result: Biodiversity Loss Index: 76.5 (Critical)
Example 3: Sustainable Forestry
Inputs: Habitat Loss = 10%, Land Use Intensity = Low (0.2), Species Richness = 200, Human Disturbance = 0.3
Calculations:
- Normalized Habitat Loss: \\[ \frac{10}{100} = 0.1 \\]
- Land Use Intensity: \\[ 0.2 \\]
- Normalized Species Richness: \\[ \min\left(1, \frac{200}{200}\right) = 1 \\]
- Human Disturbance: \\[ 0.3 \\]
- Raw Biodiversity Loss Score: \\[ 30 \cdot 0.1 + 25 \cdot 0.2 + 20 \cdot 1 + 25 \cdot 0.3 = 3 + 5 + 20 + 7.5 = 35.5 \\]
- Biodiversity Loss Index: \\[ 35.5 \\]
- Impact Level: Moderate (25–50)
Result: Biodiversity Loss Index: 35.5 (Moderate)
How to Use the Calculator
Follow these steps to estimate the Biodiversity Loss Index:
- Enter Habitat Loss: Input the percentage of habitat lost (0–100, e.g., 40). Use the decimal button (.) for precision.
- Select Land Use Intensity: Choose low (0.2), moderate (0.5), high (0.8), or very high (1.0) from the dropdown.
- Enter Species Richness: Input the number of species (1–1000, e.g., 100).
- Enter Human Disturbance: Input the human disturbance factor (0–1, e.g., 0.5). Use the decimal button for precision.
- Calculate: Click “Calculate Biodiversity Loss Index” to see the result.
- Interpret Result: The result shows a 0–100 index with an impact level (Low: 0–25, Moderate: 25–50, High: 50–75, Critical: 75–100). If you see “Please fill in all fields,” ensure all inputs are valid.
- Share or Embed: Use the share buttons to post results on social media, copy the result, or get an embed code.
Note: This is a simplified model. Actual biodiversity loss depends on additional factors like species interactions, climate change, and conservation efforts.