Studi Fluktuasi Muka Air Waduk Akibat Curah Hujan Harian

Rainfall is one of the main hydrological factors affecting water level fluctuations in a reservoir. Changes in rainfall intensity can cause an increase ordecrease in the reservoir water volume, necessitating an analysis to understand thecorrelation between daily rainfall and reservoir water level fluctuations. This studyaims to analyze the effect of daily rainfall on the water level fluctuation of theBengkalis State Polytechnic Reservoir. The methodology involved collecting dailyrainfall, water level, and evaporation data through direct field observations anddocumentation from May 5 to June 28, 2026. Data were analyzed using simplelinear regression and Pearson correlation methods. The results show that reservoirwater levels fluctuated between 1.59 m and 1.84 m. The statistical analysis yieldeda simple linear regression equation of Y = 3.312801 - 0.09075X with a correlationcoefficient (r) of -0.10039, categorizing the relationship as very weak. Thecoefficient of determination (was 0.010078 (1.01%), indicating that daily rainfall accounts for only 1.01% of the water level fluctuation, while 98.99% is influenced by other hydrological factors such as evaporation, infiltration, surfacerunoff, and inflow/outflow dynamics. These findings suggest that daily rainfallalone is not the dominant factor driving water level variations in the reservoirduring the observation period.