Double mass curve technique is used for checking the -

Correct option is A

· Double Mass Curve Technique:
· It is a graphical method used to assess the consistency of a hydrological record (e.g., rainfall or streamflow data) over time.
· Deviations in the curve indicate inconsistencies caused by changes in observation methods, instrumentation, or environmental factors.
· Procedure:
· Plot cumulative data of the target station against the average cumulative data of nearby stations.
· Check for linearity; deviations indicate inconsistency.