Fluktuasi Debit Harian Sungai Mamasa Sub Daerah Aliran Sungai Mamasa Daerah Aliran Sungai Saddang

Flow discharge is one indicator in assessing the quality of a watershed.
The hydrological function of the Mamasa sub-watershed cannot work
optimally every year due to frequent flooding in the Mamasa river basin.
The purpose of this study was to determine the daily discharge fluctuation
of the Mamasa river in the upstream part and the correlation between the
daily flow of the river and the rainfall. The research was conducted on a
river that passes through Sumarorong Subdistrict, Mamasa Regency,
which has a discharge measurement requirement. Measurement begins
by measuring the cross-sectional area of the river when it is not flooded.
Discharge measurements were carried out in three time phases, namely
morning, afternoon and evening for 10 consecutive days. Rainfall data is
obtained from secondary data. Calculation of the correlation between
rainfall and daily discharge using the Pearson method with Microsoft Excel
2007 software. The mamasa river flow discharge at 08.00 and 12.00
tended to be the same on each measurement day but was different at
16.00 which had increased. The highest daily discharge is 3704.07 m3 /
second / day while the lowest discharge is 1988.36 m3 / second / day
while the average daily discharge of Mamasa River is 852.67 m3 / second
with the amount of monthly rainfall 242.80 mm. The correlation between
rainfall and flow rate is negative with the determinant coefficient (R2) is
0.036. The fluctuation of the daily discharge of the Mamasa River has
increased in the afternoon, while the morning and afternoon tend to be
constant. The correlation of flow rate with rainfall that occurs in the
Mamasa river is at a negative number, which means that the flow rate that
occurs is not fully influenced by rainfall.
Key words: Fluctuation, discharge, Mamasa river, rainfall