KONTROL DEBIT BANJIR BENDUNG DI KALI KUNING

Abstract

ABSTRACT
This study aims to determine design–flood discharge that occur in existing dam at Kali Kuning river
and calculate flood discharge at 4 control points Chek Dam Kuning, Yapah, Ngadirojo and
Dadapan Weir. The background of this study is flood disaster at Kalikuning river.The study iscarried
out by hydrology and hydraulic analysis. The analysis of hydrology which included: testing of
consistency data of rain fall, analysis of area averaged rain fall, design rain fall and testing of
goodness of fit by using Smirnov-Kolmogorof test and chi square test. The analysis of hydraulic
iscarried out by calculation the height ofthe design flood at each control pointusing Bundchu
formulation. The study results show that for 5th rain fall recorder, namely Kaliurang, Pakem,
Sorasan, Sopalan and Tanjungtirto using the Rational Method, Weduwen, and Hasperare obtained
the flood discharge for 100 year return period as follows (1) Chek dam Kuning 129.253 m3/sec, (2)
Yapah weir 226.697 m3/sec (3) Ngadirojo weir 262.062 m3/sec, (4) Dadapan weir 287.046 m3/sec.
By using Bundchu formulation are obtained the overflow depth as follows: (1) 1.254 m, (2) 2,526
m, (3) 2,163 m, (4) 3.157 m. The result explained that in Ngadirojo weir and Dadapan weirnotable
to accommodate High Run off design flood of Kali Kuning river, while in the others control points
are relatively safe.
Keywords: Flood discharge, high runoff, Kali Kuning river,