Question

The double mass analysis is adopted to

• A. Estimate the missing rainfall data
• B. Obtain intensities of rainfall at various durations
• C. Check the consistency of data
• D. Obtain the amount of storage needed to maintain a demand pattern

Answer 1

The correct option is C Check the consistency of data

The trend of the rainfall records at a station may slightly change after some years due to a change in the environment (or exposure) of a station either due to coming of new building, hence, planting of trees or cutting of forest nearby, which affect the catch of the gauge due to change in the wind pattern or exposure. The consistency of records at the station is tested by a double mass curve by plotting the cumulative annual rainfall at a station against the the concurrent cumulative values of mean annual rainfall for a group of surrounding stations, for the number of year of record