Correct option is D
The
double mass curve technique is a graphical method used in hydrology to check the
consistency of rainfall records from a particular raingauge station over time. It is based on the principle that inconsistencies in data arise from changes in measurement conditions, such as relocation of the raingauge, changes in the surrounding environment, or changes in observational methods.
· In this technique, the cumulative rainfall of a suspect station is plotted against the cumulative rainfall of nearby stations or regional averages.
· If the data is consistent, the plot will form a straight line. Any deviation from the straight line indicates inconsistency in the rainfall record.
