FENOMENA GELOMBANG PASANG BONO DI MUARA SUNGAI KAMPAR
ABSTRACT: When a river mouth
has a flat converging shape and when the tidal is relatively high, the river
may existence a tidal bore. A tidal bore found at Kampar River, called Bono, is
basically a positive surge may travel
long distances upstream about 60 km of the
mouth. The occurrence
of a bore
has a significant
impact on river systems. To
understand flow characteristic where
Bono exist, the
hydraulic analysis is
intended to recognize
the water phenomenon
throughout the observed Kampar
River under the averaged velocities and the tides. The hydraulic analysis is
carried out using HecRAS software. The hydraulic simulation gives information
about water surface profile, velocity, and flow through the channel. Water surface
fluctuations, resulting from
simulation, are overlied
wih field data. Bono
phenomenon can be
analog as undular hydraulics
jump in steady
state conditions, suggesting
high shear stresses
beneath the first
wave crest. Consequently bed
erosion and scour take place beneath the bore front while suspended matters may
be carried upwards in the following
wave motion. This
sediment transport may
affect changes of
river morphology; creates
some small islands in
the river and
bank erosion near
Muda Island and
mouth of Serkap
River. These sediment
deposits can be explored, however this sand mining should
be managed and arranged to maintain the existence of Tidal Bore Bono. Flow simulation using Hec
RAS model predicts flow
fluctuations at same places
where tidal bores
Bono impact also significantly on
ecosystems. Water Salinity
near Muda Island
is raised significantly
3 hours after
the highest Tidal
at Kampar Mouth, following
near Sei Serkap
an hour later.
However at Tanjung
Rengas, increasing of salinity
is not important.
Keywords: Tidal Bore, Bono,
River morphology, Salinity
Penulis: Bambang Yulistiyanto
Kode Jurnal: jptsipildd090005
