Hydrological Characteristics of Kaligarang Watershed

This paper is a result of research concerning hydrological characteristic in the Garang Catchment Area. At present tha catchment area is often facing the problem of flooding in the dense populated area with cause a lot of loos in Semarang City. This research is aimed at studying hydrological harateristic in the Garang Catchment Area. Hydrological data are obtain from direct measurement at the stream gauging stations in the Garang Catchment Area and collected from Balai Hidrologi Office at Pusat Litbang Teknologi Sumber Daya Air in Bandung and from Hydrological Unit of Central Java Province. From this research were known the rainfall depth, their distribution and their return period; runoff coefficient; streamflow volume; dependable flow; flood discharge characteristi; and minimum discharge. From the some occuring flood indicates of the runoff coefficient is about 0.70. The water volume wasted to the sea is about 195 million m3/year. Yearly average of the dependable flow at stream gaunging stations: Garang – Pajangan is about 2.28 m3/sec; Garang – Patemon is about 0.92 m3/sec and Kreo – Pancur is about 1.26 m3/sec. Yearly mean of annual flood discharge at Garang – Pajangan is about 435 m3/sec. The maximum capacity of river channel is about 485 m3/sec. The flood discharge characteristic are as follows: time of travel of flood is generally one km/hour approximately, rising time is about 3 hours and time of recession is about 6 – 11 hours. The floods, they are generally occur at the night. Flush flood of 1022 m3/sec occured on January 26, 1990 is estimated on 50 year return period, with 15 year return period of rainfall. The range of minimum discharge is about 0.43 – 3.15 m3/sec. The maximum discharge is about 47.2 – 1118 times of the minimum discharge. Design of the dam in Kreo River at Jatibarang and Kripik River at Mundingan, also increasing of the reforestation area in the upstream catchment are an alternative to reduce the Garang River peak flood.

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Evaluation of flood risk as a step in determining the “Acceptable Risk” criteria. Case study: Dengkeng River, Klaten, Central Java

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/894/1/012045 ◽

2021 ◽

Vol 894 (1) ◽

pp. 012045

Author(s):

A Sarminingsih ◽

M Hadiwidodo

Keyword(s):

Control System ◽

Return Period ◽

Flood Risk ◽

Flood Control ◽

Public Works ◽

Acceptable Risk ◽

Performance Function ◽

Central Java ◽

Flood Discharge ◽

Potential Risks

Abstract The planning of a flood control system in Indonesia is based on the planning criteria issued by the Ministry of Public Works. Flood control planning is based on flood discharge with a specific return period depending on the order of the river and the number of protected populations. Flood events in areas where the flood control system has been planned continue to occur almost every year, meaning that the probability of being exceeded is not as planned. This study is intended to evaluate the criteria for the magnitude of the designed flood discharge in flood control planning that considers the acceptable risk. Potential risks are evaluated against system reliability. The probability of failure of the flood control system occurs if the resistance is smaller than the load expressed as a performance function. By knowing the performance function associated with the level of flood risk, then the flood discharge can be selected with the appropriate return period according to the acceptable risk.

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Benefits of Embungs in the Rawa Pening Catchment Area for Reducing Tuntang River Flood Discharge

E3S Web of Conferences ◽

10.1051/e3sconf/20187308029 ◽

2018 ◽

Vol 73 ◽

pp. 08029

Author(s):

Darsono Suseno ◽

S Suripin ◽

Budieny Hary ◽

Cholifatul Afifah Risdiana ◽

Pujiastuti Ratih ◽

...

Keyword(s):

Catchment Area ◽

Flood Control ◽

Water Source ◽

Raw Water ◽

Sediment Control ◽

Resources Management ◽

Control Sediment ◽

Central Java ◽

Flood Discharge ◽

River Flood

Rawa Pening is a natural lake as a source of water for Tuntang River which is used for hydropower, raw water source, main irrigation water source in Glapan weir located in Grobogan District, Central Java provinces. Rawa Pening will be developed as location of national and international ecotourism. An Optimal Water Resources Management is required with several studies. This study is the beginning of a series of studies planned to determine the potential of embungs and its utilization as flood control, sediment control of Rawa Pening and for reducing weeds growth.

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Design Flood Discharge of 50 Years in Garang River Using Nakasayu Synthetic Unit Hydrograph Method

Jurnal Teknik Sipil dan Perencanaan ◽

10.15294/jtsp.v22i2.26847 ◽

2020 ◽

Vol 22 (2) ◽

pp. 146-151

Author(s):

Nadya Kintantrie Maulana ◽

Yeri Sutopo

Keyword(s):

Return Period ◽

Water Structure ◽

Structure Design ◽

Unit Hydrograph ◽

Design Flood ◽

Careful Planning ◽

The Past ◽

Central Java ◽

Flood Discharge ◽

Synthetic Unit Hydrograph

Abstract: Various kinds of buildings in civil engineering require careful planning. For example, in the planning of a water building needed a method to calculate the design flood discharge before starting to plan the dimensions of the building to meet the effectiveness of the water structure. Design flood discharge can be determined using several hydrograph methods that have been used in water building planning in Indonesia. One of the popular hydrograph method used is the Nakayasu Synthetic Unit Hydrograph method. In this case, the design flood discharge is located in the Garang watershed, precisely in Semarang City, province of Central Java, using rainfall data for the past 16 years. Hydrological analysis is carried out first before determining the design flood discharge with a return period of 2, 5, 10, 25, and 50 years. The results of the design flood discharge using Nakayasu method respectively were 305,522 m3/s, 390,742 m3/s, 447,783 m3/s, 520,560 m3/s, and 574,912 m3/s.

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KAJIAN BANJIR BANDANG DI DESA SUKOLILO MELALUI TINJAUAN PETA SUNGAI

Jurnal Litbang Media Informasi Penelitian Pengembangan dan IPTEK ◽

10.33658/jl.v13i1.89 ◽

2017 ◽

Vol 13 (1) ◽

pp. 13-23

Author(s):

Hermain Teguh Prayitno

Keyword(s):

Sea Level ◽

Catchment Area ◽

Flash Flood ◽

Secondary Data ◽

High Water ◽

Water Volume ◽

Interesting Phenomenon ◽

Central Java ◽

Quantitative Descriptive ◽

Descriptive Method

ENGLISHFlash floods often occur in the Sukolilo sub district, Pati Regency Central Java, in particular at Sukolilo village. The high intensity of rainfall in the Sukolilo’s catchment area producing high water volume and flow leads to flash floods in the Sukolilo village one hour after the rainfall. It is an interesting phenomenon because the river located in the Sukolilo village experiences flash flood more frequent compared to other rivers in Sukolilo sub district. This research was conducted by comparing rivers in the Sukolilo sub district through quantitative descriptive method with secondary data. The result of this study showed that the morphology of Sukolilo River has the highest catchment area 300 meter above sea level (ASL) and has narrow downstream 20 ASL. According to the calculation, 3 rivers in the Sukolilo sub district has the potential to experience flash flood that are river located in Sukolilo Village, river located in Wegil Village and river located in the border of of Baleadi Village and Kedung Winong Village, consecutively. INDONESIABanjir bandang di Kecamatan Sukolilo Kabupaten Pati Jawa Tengah sering terjadi terutama di Desa Sukolilo. Debit air yang besar serta kecepatan aliran yang tinggi menyebabkan sungai meluap dan mengkhawatirkan warga yang tinggal di sekitar sungai. Hal tersebut disebabkan intensitas hujan yang sangat tinggi di daerah tangkap sungai Sukolilo yang turun satu jam sebelumnya. Kondisi banjir bandang ini menjadi fenomena tersendiri dikarenakan hanya sungai Sukolilo yang sering terjadi. Maka penelitian ini perlu dilakukan dengan cara membuat studi perbandingan sungai-sungai di wilayah Kecamatan Sukolilo melalui metode deskriptif kuantitatif dengan data sekunder. Hasil penelitian menunjukkan bentuk morfologi sungai Sukolilo memiliki daerah tangkap tertinggi 300 meter di atas permukaan laut (DPL) terluas dari sungai sekitarnya dan mengecil di daerah hilir 20 meter DPL. Urutan tertinggi dari rata-rata skor potensi bandang pertama yaitu Sungai Desa Sukolilo, kedua sungai Desa Wegil, dan ketiga sungai perbatasan antara Desa Baleadi dan Desa KedungWinong.

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Analysis Of Surface Runoff Potential At Medan Industrial Estate Use SCS Method

Reviews in Civil Engineering ◽

10.31002/rice.v2i1.658 ◽

2018 ◽

Vol 2 (1) ◽

Author(s):

Yudha Hanova

Keyword(s):

Return Period ◽

Surface Runoff ◽

Catchment Area ◽

Flood Mitigation ◽

Effective Rainfall ◽

Flood Discharge ◽

Industrial Estate ◽

Runoff Potential ◽

Alternative Solutions ◽

Scs Cn

Flood disaster at the region Medan Industrial Estate resulted the losses in infrastructure, farming, and residence. Flood discharge at Medan Industrial Estate are influenced by surface runoff from several catchment area in Medan Industrial Estate. Analysis of potential for surface runoff is expected to provide input and information to find alternative solutions appropriate flood mitigation. Discharge of surface runoff were analyzed using SCS method with the return period of 1, 2 and 5 Years. Rainfall data are obtained BMKG Stations of Maritim Belawan. Effective rainfall calculated using SCS-CN method on condition AMC III (wet conditions). The results of the analysis of the potential for surface runoff maximum for 1 year return period on DAS I, II, III, IV, V, and VI was 17.631 m3/s, 22.183 m3/s, 12.621 m3/s, 11.338 m3/s, 18.224 m3/st, dan 15.839 m3/s. To return period of 2 years was 31.234 m3/sec, 39.235 m3/s, 22.351 m3/det, 20.044 m3/det, 32.300 m3/det, dan 28.097 m3/det. For the return period of 5 years is 45.346 m3/s, 56.926 m3/s, 32.446 m3/s, 29.076 m3/s, 46.903 m3/s, dan 40.816 m3/s.

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Drainage System of Tegalsari Polder for Handling Flood and Tide in Tegal City Indonesia

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/955/1/012008 ◽

2022 ◽

Vol 955 (1) ◽

pp. 012008

Author(s):

M Yuswo ◽

S I Wahyudi ◽

Soedarsono ◽

F C Boogard ◽

E Boer

Keyword(s):

Catchment Area ◽

Field Data ◽

Drainage System ◽

Statistical Parameters ◽

Technical Data ◽

Central Java ◽

Flood Discharge ◽

Retention Basin ◽

Central Java Province ◽

Long Storage

Abstract Although in 2019 the local government of Tegal city Indonesia had constructed a retention basin at drainage system of Siwatu, Tegal Barat, Tegal city with a catchment area of 226 ha, the areas around the system still experienced flood and inundation. This study belonged to a descriptive qualitative research aimed to evaluate the performances of Siwatu drainage system and Tegalsari retention basin. Data of the study included field data and technical data from institutions. Based on the 15-year rainfall data (2014 – 2018) from Pemali - Comal PSDA Office, Central Java Province, Indonesia, the statistical parameters of Cs: 0.0027, Ck: 1.904, Sd: 15.91, Cv: 0.144 were obtained and so Gumbel method distribution was applied in the study, the return period rainfall of 10 years was 138 mm, the flood discharge for Qr.10 years was 9.63 m3/sec., the addition of long storage was 8×2,50×500 m, and the combination of pump addition was of 1 m3/sec. with the long storage of 8×2.00×500 m. By implementing one of the alternative choices, either flood or inundation could be resolved.

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Sewer System for Improving Flood Control in Tokyo: A Step towards a Return Period of 70 Years

Water Science & Technology ◽

10.2166/wst.1994.0677 ◽

1994 ◽

Vol 29 (1-2) ◽

pp. 303-310 ◽

Cited By ~ 1

Author(s):

Kazuyuki Higuchi ◽

Masahiro Maeda ◽

Yasuyuki Shintani

Keyword(s):

Return Period ◽

Flood Control ◽

Rainfall Intensity ◽

Runoff Coefficient ◽

Large Drop ◽

Construction Costs ◽

Sewer System ◽

Construction Period ◽

Metropolitan Government ◽

Under Construction

The Tokyo Metropolitan Government has planned future flood control for a rainfall intensity of 100 mm/hr, which corresponds to a return period of 70 years, and a runoff coefficient of 0.8. Considering that the realization of this plan requires a long construction period and high construction costs, the decision was made to proceed by stages. In the first stage, the improvement of the facilities will be based on a rainfall intensity of 75 mm/hr (presently 50 mm/hr), corresponding to a return period of 17 years, and a runoff coefficient of 0.8. In the next stage the facilities will be improved to accommodate a rainfall intensity of 100 mm/hr. In the Nakano and Suginami regions, which suffer frequently from flooding, the plan of improvement based on a rainfall intensity of 75 mm/hr is being implemented before other areas. This facility will be used as a storage sewer for the time being. The Wada-Yayoi Trunk Sewer, as a project of this plan, will have a diameter of 8 m and a 50 m earth cover. This trunk sewer will be constructed considering several constraints. To resolve these problems, hydraulic experiments as well as an inventory study have been carried out. A large drop shaft for the trunk sewer is under construction.

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NOTE ON THE FLOOD-DISCHARGE OF THE TANSA CATCHMENT-AREA.

Minutes of the Proceedings of the Institution of Civil Engineers ◽

10.1680/imotp.1895.19849 ◽

1895 ◽

Vol 119 (1895) ◽

pp. 280

Author(s):

W J B CLERKE

Keyword(s):

Catchment Area ◽

Flood Discharge

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ANALISIS TINGGI MUKA AIR BANJIR DAS BELAWAN DENGAN MENGGUNAKAN SOFTWARE HECRAS

Jurnal Teknik Sipil ◽

10.24815/jts.v7i1.8382 ◽

2018 ◽

Vol 7 (1) ◽

pp. 26-29

Author(s):

Asril Zevri

Keyword(s):

Water Level ◽

Cross Section ◽

Return Period ◽

Industrial Development ◽

Daily Rainfall ◽

Flood Water ◽

Flood Discharge ◽

Flood Level ◽

Maximum Daily Rainfall ◽

River Cross Section

Abstract: Belawan River Basin is one of the watershed, which currently change the land use because of the increasing population and industrial development. Rainfall with high intensity can cause rapid runoff, causing flood around the plains of the river cross section. The purpose of this research is to determine the flood water level of Belawan Watershed and flood discharge return period. Scope of activity in this research is analyzing daily rainfall Belawan watershed with the flood-discharge return period. Scope of activity in this research is analyzing maximum daily rainfall Belawan Watershed, and simulating flood water level with HECRAS. The result of the study shows that the potency of Belawan watershed flood water level is caused by flood discharge at 25 to 100 years especially in the middle to downstream of river cross section that is between 0.7 m and 3.3 m. Keywords: Flood Discharge, Flood Level, Belawan Watershed, Software HECRAS. Abstrak: Daerah Aliran Sungai Belawan adalah salah satu DAS yang pada saat ini mengalami perubahan tata guna lahan seiring bertambahnya jumlah penduduk dan perkembangan industri. Curah hujan yang tinggi dapat mengakibatkan limpasan sehingga menimbulkan tinggi muka air banjir di sekitar dataran penampang sungai. Tujuan dari penelitian ini adalah untuk mensimulasi tinggi muka air banjir DAS Belawan dengan debit banjir periode kala ulangnya. Lingkup kegiatan dalam penelitian ini yaitu menganalisa curah hujan harian maksimum rata-rata DAS Belawan dan menganalisa debit banjir kala ulang 2 sampai dengan 100 tahun, mensimulasi tinggi muka air banjir dengan HECRAS. Hasil studi menunjukan potensi tinggi muka air banjir DAS Belawan terjadi akibat debit banjir periode kala ulang 25 sampai dengan 100 tahun khususnya di bagian tengah sampai hilir penampang sungai yaitu berkisar antara 0.7 m sampai dengan 3.3 m. Kata kunci: Debit banjir, Tinggi Banjir, DAS Belawan, Software HECRAS.

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Using Hydrological Mapping to Evaluate the Effectiveness of the Bener Dam Development in Reducing Flood Risk in Purworejo Regency, Central Java

Forum Geografi ◽

10.23917/forgeo.v34i2.10980 ◽

2020 ◽

Vol 34 (2) ◽

Author(s):

Sudaryatno Sudaryatno ◽

Bagus Wiratmoko ◽

Winanda Winanda ◽

Shelly Yeni Saputri

Keyword(s):

Remote Sensing ◽

Rainy Season ◽

Catchment Area ◽

Local Community ◽

Remote Sensing Data ◽

Peak Discharge ◽

Economic Losses ◽

Dam Reservoir ◽

Central Java ◽

Concentration Time

The Bogowonto Hulu sub-watershed has high flooding potential, especially during the rainy season. This flooding causes physical, social, and economic losses for the local community and so the Bener Dam was built to reduce the volume of flooding in the area. This research aims to find out the effectiveness of the Bener Dam in overcoming the problem of flooding around the Bogowonto Hulu sub-watershed. The effectiveness of dams can be analysed by comparing the volume of the dam reservoir with the peak discharge amount generated. The value of peak discharge can be obtained using remote-sensing data and mathematical calculations following the rational method. Using this method, the estimated peak discharge value obtained for the watershed was 302.3 m3/s while the value of dam capacity was only 210 m3/s, giving 92.3 m3/s of flooding potential. It is necessary to reduce the potential for flooding by building an IR reservoir in the catchment area, so that rainwater is accommodated rather than being immediately depleted, and to reduce concentration time.

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