31.3.1 - φ-index (Phi Index)
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Practice Questions
Test your understanding with targeted questions
What does the φ-index represent?
💡 Hint: Think about how rainfall and runoff relate to each other.
Calculate the φ-index if total rainfall is 80 mm and direct runoff is 20 mm over a 2-hour storm.
💡 Hint: Use the formula φ = (P - Q) / t.
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Interactive Quizzes
Quick quizzes to reinforce your learning
What does the φ-index measure?
💡 Hint: Think about what you're measuring during a storm event.
The φ-index assumes which of the following?
💡 Hint: Consider the definitions provided in class.
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Challenge Problems
Push your limits with advanced challenges
Over a course of a 6-hour storm, 200 mm of rainfall occurred, with 80 mm directly running off into a stream. Calculate the φ-index and discuss the implication of initial loss neglect.
💡 Hint: Review your calculations carefully, especially the assumptions.
Analyze and critique the φ-index from a sustainability perspective in urban environments prone to heavy rains. What might be some long-term implications?
💡 Hint: Reflect on both environmental sustainability and practical applications.
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