1. What is Rainfall Intensity for Storms Frequency of 10 Years?

Rainfall Intensity for Storms Frequency of 10 Years is the ratio of the total amount of rain falling during a given period to the duration of the period, considering a 10-year return period storm event. It represents the expected maximum rainfall rate for storms that occur on average once every 10 years.

2. How Does the Calculator Work?

The calculator uses the rainfall intensity formula:

Where:

• \( i_{storm} \) — Rainfall Intensity for Storms Freq of 10 Years (m/s)
• \( K_{s10} \) — K Constant when Storm having Frequency of 10 Year (mm/hr)
• \( T_m \) — Time in Minutes (minutes)

Explanation: The formula calculates the rainfall intensity based on the empirical constant K and the duration of the storm event, with the time component adjusted by 20 minutes and raised to the power of 0.7.

3. Importance of Rainfall Intensity Calculation

Details: Accurate rainfall intensity calculation is crucial for hydraulic engineering, stormwater management system design, flood prediction, and infrastructure planning. It helps determine appropriate drainage capacities and flood protection measures for 10-year storm events.

4. Using the Calculator

Tips: Enter the K constant value in mm/hr and the time duration in minutes. Both values must be positive numbers. The K constant is an empirical value specific to the geographical location and should be obtained from regional rainfall data.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the 10-year frequency?
A: A 10-year frequency storm has a 10% probability of occurring in any given year. It represents a storm event that is expected to occur on average once every 10 years.

Q2: How is the K constant determined?
A: The K constant is an empirical value derived from historical rainfall data analysis for a specific region. It varies based on geographical location and climate patterns.

Q3: Why is time adjusted by adding 20 minutes?
A: The +20 minute adjustment accounts for the initial rainfall development phase and provides better correlation with observed rainfall intensity data.

Q4: What are typical applications of this calculation?
A: This calculation is used in designing stormwater drainage systems, culverts, retention ponds, and other hydraulic structures that need to handle 10-year storm events.

Q5: How does this differ from other storm frequencies?
A: Different storm frequencies (2-year, 5-year, 25-year, 100-year) have different K constants and represent different levels of storm severity and probability of occurrence.