STUDY ON GAMMA AND TRIANGLE UNIT HYDROGRAPH UPPER CILIWUNG WATERSHED

• Main Author: FITRAH - NIM: 95015313, IHSANUL
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27938
• Institution: Institut Teknologi Bandung

<p align="justify">Flood is a natural phenomenon that occurs naturally. Floods that should be a place of river floods have turned into a place of human activity, consequently the flood changed its meaning becomes a disaster. Jakarta floods are one of the most endless disasters. There have been many efforts made in dealing with flood problems in Jakarta, ranging from physical effort and non-physical. One of the flood prevention efforts in Jakarta is to implement an early warning system. Implementation of early warning system in Jakarta, especially in Ciliwung watershed is by monitoring the water level at Katulampa Dam, where flood forecasting that will occur is done by calculating the flood propagation time in upstream. Hydrograph development of rainfall and discharge data can be an additional tools for flood early warning systems. The unit hydrograph is built using the "solver" toolbox available in Microsoft Excel. Hydrograph unit of gamma and triangle function is analyzed with two rainfall analysis, that is rainfall hour analysis of Cilember rainfall post that represent rainfall area and rainfall hour-time analysis of Cilember rain post area obtained from daily rainfall area. The hydrograph parameters to be unolverted for the gamma unit unit hydrograph are K, n, and A0, and the triangular unit hydrographs are Qp, Tp, and Tb. The flood event used simulation and optimization input is the event on 22-23 January 2015, 1-2 February 2015, 10-11 October 2016, and March 17, 2014. Simulation and optimization of flood event data for unit hydrograph gamma function yields an average value of K = 1.90; n = 1.50; A0 = 429.35. Simulation and optimization of flood event data for unit hydrograph of triangle function yields average value Qp = 107,16 m3/s, Tp = 0,00 hr; Tb = 7,85 hr. Hydrographic calibration of flood event unit on November 15, 2015 with Qp peak discharge of 139.92 m3/s. The calibration results show that the degree of error over peak discharge for unit hydrograph gamma function and triangle function respectively 3% dan13%. <p align="justify">