**4.1 Data consistency and normality**

The data from the rainfall stations in the selected watershed area, including Kedungsangku, Senduro, and Ranupakis stations, were tested for consistency and the results showed that they are consistent. The same process was conducted on the rainfall data from the applied watershed, such as Dampit, Poncokusumo, Sengguruh, Tangkil, and Wagir stations, and the results also showed that the data are consistent.

The normality test was conducted on the discharge data using pdf analysis with the indicator for the normal distribution being the formation of a straight line when the data are plotted visually. The results showed that the discharge data at Automatic Water Level Record (AWLR) and Umbul Dam (observation CA) are not normally distributed and the same trend was also observed for the data from Sutami Dam (Simulation CA).
