ANALISIS BANJIR RANCANGAN DENGAN METODE INVERSELY ESTIMATED RAINFALL

Titiek, Mrs. (2008) ANALISIS BANJIR RANCANGAN DENGAN METODE INVERSELY ESTIMATED RAINFALL. ANALISIS BANJIR RANCANGAN DENGAN METODE INVERSELY ESTIMATED RAINFALL . pp. 1-13.

[img]
Preview
PDF - Published Version
96Kb

Abstract

ABSTRACT To avoid the paucity of rainfall data, development of flood estimation methods that rely on hydrograph data are required. Hydrograph data are the output of the catchment. It means that all the catchment behaviors are represented in the runoff data. The effect of temporal and the spatial variability of rainfall and the initial soil moisture condition has been represented in the runoff data. Hence, it’s necessary research about of design flood used on hydrograph. The research uses 16 flood events collected from Bojongloa sub-river basin and 10 data from Leuwigoong sub-river, which all included Cimanuk river basin in West Java. The filter separation autoregressive method is selected to separate the hydrograph to become baseflow and direct runoff components. The resulted direct runoff is then used for deriving the effective rainfall using inversely estimated rainfall (IER) method. The result of IER rainfall and IER pattern is used in design flood analysis using unit hydrograph IER method. And the observed rainfall are used as comparisons. The result show that design flood with hydrograph IER method is relatively similar with the observed rainfall. The result design flood with hydrograph IER method give accuracy between design flood the result of frequency analysis. Keywords : hydrograph, inversely estimated rainfalls, unit hydrograph ABSTRAK Data automatic rainfall recorder (ARR) untuk menurunkan agihan hujan pada kenyataan di lapangan masih sangat sedikit, disisi lain tersedia data hidrograf yang menggambarkan respon hujan yang memberi kontribusi pada aliran sehingga pengaruh yang timbul akibat variabilitas ruang dan waktu dari hujan serta kondisi initial soil moisture (ISM) sudah tercakup didalamnya. Dengan ketersediaan data hidrograf tersebut maka perlu dikembangkan suatu metode perkiraan banjir rancangan dengan menggunakan data hidrograf. Pada penelitian ini digunakan 16 data kasus banjir di Sub DAS Bojongloa dan 10 data kasus banjir di Sub DAS Leuwigoong, dimana keduanya masuk wilayah DAS Cimanuk. Pemisahan hidrograf banjir ke dalam komponen langsung (direct runoff) dan aliran dasar (baseflow) dengan filter separation autoregressive (AR) method. Perkiraan hujan efektif dari data hidrograf menggunakan metode inversely estimated rainfalls (IER). Perkiraan banjir rancangan dihitung dengan metode HS IER dan pola agihan IER. Kesalahan relatif yang ditinjau adalah kesalahan relatif antara banjir rancangan dengan HS tehadap banjir rancangan hasil analisis frekuensi. Hidrograf banjir rancangan untuk IER maupun ARR relatif berimpit, hal tersebut menunjukkan bahwa hidrograf banjir yang disebabkan oleh hujan IER menghasilkan hidrograf banjir yang sama dengan kondisi hidrograf banjir akibat hujan terukur. Dibandingkan dengan kondisi banjir aktual dari pengamatan debit maksimun tahunan maka prosentase relatif kesalahan cukup baik. Kata kunci : hidrograf, inversely estimated rainfall, hidrograf satuan

Item Type:Article
Subjects:T Technology > TA Engineering (General). Civil engineering (General)
Divisions:Faculty of Engineering > Department of Civil Engineering
Faculty of Engineering > Department of Civil Engineering
ID Code:25064
Deposited By:Mr Adi Widayat
Deposited On:30 Dec 2010 16:02
Last Modified:30 Dec 2010 16:02

Repository Staff Only: item control page