STUDY OF SEDIMENT TRANSPORT PLTU 1 NTT ROPA, KABUPATEN ENDE

• Main Author: Ihsan Prabowo, Ginanjar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40156
• Institution: Institut Teknologi Bandung

This study aims to make a model of sediment transport that occurs in the area around PLTU 1 NTT and find out the bathymetry profile of the review location which is near to the estuary of Rea River. This is because, in a certain period in the PLTU 1 NTT area, especially around the intake mouth it experiences drought. So that there is need a study of sedimentation and bathymetry profiles that cause the drought. Modeling simulations are carried out using Mike 21 Flow Model software from DHI. Modeling calibration is done using field data in the form of water level elevations, currents, and sediment concentrations. The modeling simulation was carried out for one month in two scenarios, namely the dry season in July 2016 and the rainy season in December 2016. To review the bathymetric profile, tidal forecasting was carried out for 20 years using ERGTide software. Based on the modeling results, the average calibration error values of water level and current were 13.74% using the value of chezy number 30. As for sediment calibration obtained an error value of 0.44%. Sediment modeling results for each scenario were analyzed for sediment concentration values and rate of bed level changes. The average sediment concentration value per month in the river mouth area ranges from 2.6904 gr/m3 to 5.5607 gr/m3 with rate of bed level changes 0.0007 m/day. While the sediment concentration in the mouth intake area is only 0.000005 gr/m3. Increasing the value of sediment concentration occurs in the rainy season where the discharge from the river as a source of sediment increases. The results showed that the sediment movement from Rea River did not reach the area of PLTU 1 NTT. The sediment was concentrated in the mouth area of Rea River which caused changes in the coastline morphology due to sediment deposition. Further analysis is carried out on tidal elevations in front of the power plant area, especially in the mouth of intake area. From the results of forecasting for 20 years showed that the lowest tide elevation at the mouth of the intake was at the value of -114.62 cm below MSL, while for the sea level surface elevation of -89.21 cm below MSL. Therefore, the cause of dryness on mouth of intake is because the seabed elevation is above the lowest tide.