PENATAAN SISTEM SUNGAI SENGKARANG SEBAGAI SALAH SATU PENANGANAN ROB KOTA/ KABUPATEN PEKALONGAN
ABSTRACT: Tidal flood which’s
occured at Pekalongan City/District entered into settlement through a river
that empties into the sea, beach and drainage. This condition will be critical
when at the same time the highest tides and great flood. Tidal flood is
predicted to increase due to rising sea levels ranged from 4,46 to 4,60 mm/year
and there’s land subsidence about 3 cm/year. Tidal flood which’s enter into
settlements with the river one of them occurred at Sengkarang river system
(Sengkarang river, Meduri river and Bremi river). The occurrence of runoff in
rivers such as the capacity of the river current is smaller than the existing
discharge. To overcome this, the rivers will be evaluated its capacity to
discharge plans return period of 25 years (Q25) which is accompanied by tidal
conditions. Analysis is needed to evaluate the capacity of the river including
hydrological, tidal and hydraulic analysis. Hydrological analysis is used to
calculate the flood discharge plan with the HSS Gama 1 method. Tidal analysis
is used to determine the height of the sea surface elevation. Hydraulic
analysis is used to calculate the capacity and dimensions of the river using
HEC-RAS 4.1 software. HEC-RAS simulation performed with two scenarios. The
first scenario is the merge of the downstream of Meduri river and Bremi river
with Sengkarang river. The second scenario is the separate of the downstream of
Meduri river and Bremi river with Sengkarang river. Results from HEC-RAS
simulation with discharge plans Q25 and tidal conditions/HHWL for existing
cross-section of the river showed that hydraulically separated model is more
profitable than merge model because the water level in separated scenario is
lower than the merge scenario and estimated from sedimentation will better
because its estuary has been separated.
Penulis: Muhammad Firqotul
Ulum, Aji Perdana Wira Utama, Suripin, Sumbogo Pranoto
Kode Jurnal: jptsipildd150147
