Analisis aliran dan erosi tikungan Sungai Konaweha ruas Morosi

Abstract

Konaweha River crosses five districts namely East Kolaka Regency, South Konawe Regency, Konawe Regency, Kolaka Regency, and Kendari City. There are many infrastructures located on the river’s bank, one of which is road. The Morosi National Road connecting Kendari City and Morosi District, Konawe Regency which is located right on the the river’s bank is threatened with damage due to scouring. This research analyzes the flow and erosion in the bend of the Konaweha River Morosi Section. The study was conducted using hydrological and hydraulics analysis. Hydrological analysis aims to obtain 25-year return period design flood hydrograph. Hydrological analysis using daily measured rainfall data to determine the design rainfall and hourly GPM IMERG satellite rainfall data for determining the design rainfall distribution and Nakayasu Synthetic Unit Hydrograph to obtain unit hydrograph in the watershed. The peak discharge of the 25-year return period design flood hydrograph is 2916,16 m3/s. The design flood is used as input in hydraulic analysis. Hydraulic analysis was using Iber. Hydraulic analysis aims to obtain flow behavior in the form of flow velocity and a decrease in riverbed elevation as an indication of scouring on river bends. The results obtained flow velocity on the outer bend is greater than the inner bend. The decrease in riverbed elevation mostly occurs on the outer bend. So it can be concluded that the bend of the Konaweha River in Morosi Section has a great risk of erosion and landslides on river banks.