1. What is Biotic Index?

The Biotic Index is a water quality measurement that uses the presence and abundance of aquatic organisms to assess the health of a water body. It provides a numerical value that indicates the level of pollution or environmental stress.

2. How Does the Calculator Work?

The calculator uses the Biotic Index formula:

Where:

• \( n_i \) — Number of individuals of species i
• \( t_i \) — Tolerance value of species i
• \( N \) — Total number of individuals

Explanation: The formula calculates a weighted average of tolerance values, where species with higher pollution tolerance contribute more to the index.

3. Importance of Biotic Index

Details: Biotic Index is crucial for environmental monitoring and assessment. It helps identify polluted water bodies, track changes in water quality over time, and evaluate the effectiveness of pollution control measures.

4. Using the Calculator

Tips: Enter the number of species you want to include, then provide the number of individuals and tolerance value for each species. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What do different Biotic Index values indicate?
A: Lower values generally indicate cleaner water (0-3.5: excellent, 3.6-5.0: good, 5.1-6.5: fair, 6.6-10.0: poor water quality).

Q2: How are tolerance values determined?
A: Tolerance values are assigned based on scientific research that measures species' sensitivity to pollution and environmental stressors.

Q3: What types of organisms are typically used?
A: Benthic macroinvertebrates (insect larvae, crustaceans, mollusks) are commonly used as they are sensitive to water quality changes.

Q4: Are there limitations to Biotic Index?
A: The index may be affected by seasonal variations, habitat differences, and requires proper species identification for accurate results.

Q5: How often should Biotic Index measurements be taken?
A: Regular monitoring (seasonally or annually) is recommended to track changes and identify trends in water quality.