8.5.1. Formula for Optimum Number of Gauges

Try these first

1. 1.

   What is the formula for calculating the optimum number of gauges?

   Hint

   Focus on where C and E appear in the formula.

2. 2.

   Define the coefficient of variation.

   Hint

   Think about how it relates to variability.

3. 3.

   What is the formula to calculate the optimum number of rain gauges?

   • N = C / E
   • N = C² / E²
   • N = C + E

   Hint

   Focus on the structure of the formula.

4. 4.

   True or false: A higher coefficient of variation means fewer rain gauges are needed.

   • True
   • False

   Hint

   Think about how variability affects accuracy.

5. 5.

   Determine the optimum number of rain gauges for a region with a coefficient of variation of 0.35 and an allowable error of 4%.

   Hint

   Make sure to square both C and E, then divide.

6. 6.

   Evaluate the relationship between gauge installation costs and precipitation variability. Provide a detailed strategy for a balanced approach.

   Hint

   Think about the balance between statistical data needs and practical costs.