scholarly journals ANALISA MODEL HIDROGRAF BANJIR KALI NGOTOK DENGAN METODE SCS, SNYDER DAN NAKAYASU

BANGUNAN ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 1
Author(s):  
Gilang Id'fi
Keyword(s):  
Land Use ◽  
Return Period ◽  
Flood Control ◽  
Unit Hydrograph ◽  
River Watershed ◽  
Flood Discharge ◽  
Thiessen Polygon ◽  
Average Rainfall ◽  
Synthetic Unit Hydrograph ◽  
Polygon Method

Abstrak:Permasalahan banjir seringkali melanda wilayah DAS Kali Ngotok setiap tahun. Masalah banjir pada umumnya disebabkan oleh perubahan tata guna lahan dan penurunan fungsi sungai yang ada di wilayah DAS Kali Ngotok serta sering terjadinya back water dari sungai-sungai yang bermuara di Kali Brantas pada saat mengalami debit maksimal. Untuk itu studi perbandingan debit puncak banjir perlu dilakukan karena belum adanya penelitian mengenai pengendalian banjir. Sehingga dilakukan penelitian mengenai analisis model hidrograf satuan sintetik. Metode hidrograf satuan sintetik yang digunakan adalah SCS, Snyder, dan Nakayasu. Data hujan yang digunakan adalah data hujan tahun 1998-2016 dari 14 stasiun hujan di wilayah DAS Kali Ngotok. Metode poligon Thiessen digunakan untuk mengetahui besaran hujan yang tersebar di wilayah DAS Kali Ngotok. Besaran hujan rata-rata yang turun di DAS Kali Ngotok dalam kurun waktu 1998-2016 sebesar 97.05 mm. Pada tahap pemodelan, pembagian sub catchment DAS dilakukan dengan membagi menjadi 5 sub DAS. Hasil pemodelan dengan metode SCS, Snyder, dan Nakayasu menunjukkan besaran debit untuk kala ulang 2 tahun, 5 tahun, 10 tahun, 20 tahun, 25 tahun, 50 tahun, 100 tahun, dan 200 tahun yang bervariasi. Data AWLR yang mendekati hasil pemodelan adalah data tahun 2014. Hasil kalibrasi hidrograf untuk metode SCS dengan kala ulang 25 tahun sebesar 0.88, untuk metode Snyder dengan kala ulang 25 tahun sebesar 0.74, dan untuk metode Nakayasu dengan kala ulang 25 tahun sebesar 0.43. Dengan demikian model hidrograf SCS dengan kala ulang 25 tahun mendekati dengan model hidrograf lapangan berdasarkan data AWLR yang ada serta sesuai dengan hasil pengamatan pada saat survey penduduk.Kata-kata kunci: DAS, Kali Ngotok, SCS, Snyder, NakayasuAbstract: Flood problems often hit the Ngotok River watershed every year. The problem of flooding is generally caused by changes in land use and a decrease in river functions in the Ngotok River watershed area as well as frequent back water from rivers which empties into Brantas River when experiencing maximum discharge. For that reason a comparative study of peak flood discharge needs to be done because there is no research on flood control. So that research is conducted on the analysis of synthetic unit hydrograph models. The synthetic unit hydrograph method used is SCS, Snyder, and Nakayasu. Rainfall data used is data from 1998-2016 from 14 rain stations in the Ngotok River watershed. The Thiessen polygon method is used to determine the amount of rain scattered in the Ngotok River watershed. The average rainfall in the Ngotok River watershed in the period 1998-2016 was 97.05 mm. In the modeling phase, the sub catchment division of the watershed is carried out by dividing it into 5 sub catchments. The modeling results using the SCS, Snyder, and Nakayasu methods show the amount of discharge for the return period of 2 years, 5 years, 10 years, 20 years, 25 years, 50 years, 100 years, and 200 years which varies. AWLR data approaching the modeling results are 2014 data. The hydrograph calibration results for the SCS method with a 25 year return period are 0.88, for the Snyder method with a 25 year return period of 0.74, and for the Nakayasu method with a 25 year return period of 0.43. Thus the SCS hydrograph model with a 25 year return period approaches the field hydrograph model based on the AWLR data that exists and is in accordance with the observations during the population survey.Keywords: Watershed, Ngotok River, SCS, Snyder, Nakayasu

scholarly journals Hydrograph Study of Palu River Watershed

2020 ◽  
Vol 331 ◽  
pp. 04001
Author(s):  
Yassir Arafat ◽  
IG Tunas ◽  
Tuty Amaliah ◽  
Aswar Amiruddin
Keyword(s):  
Land Use ◽  
Unit Hydrograph ◽  
Alpha Coefficient ◽  
River Watershed ◽  
Watershed Land Use ◽  
Flood Discharge ◽  
Synthetic Unit Hydrograph ◽  
River Typology ◽  
Value Model ◽  
Basin Area

Hydrograph is a way of predicting the amount of flood discharge plans in a watershed. Each watershed has different drainage characteristics due to the topographic shape of the watershed, land use, river typology (length, number, and slope), height and duration of rainfall. This research was conducted in Palu River Basin, with a basin area of 3. 060,388 km2, mismatch analysis of watershed and synthetic unit hydrograph, rain and discharge analysis, hydrograph discharge design analysis using optimal synthetic unit hydrograph parameter model. From the results of research calculation of Synthetic Unit Hydrograph Nakayasu Method has big enough key compared with another method. By using hydrograph model of flood plan for Palu River Watershed with the approach of Synthetic Unit Hydrograph Nakayasu, hydrograph calculation of flood in Palu river watershed, obtained alpha coefficient equal to 0,651 and Tr coefficient 0,3 with cash value model 71,491%. with cash value model 71,491%.

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

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.

scholarly journals AN ANALYSIS OF DESIGN FLOOD DISCHARGE IN PARANGJOHO WATERSHED USING THE METHODS OF SYNTHETIC UNIT HYDROGRAPH (SUH) AND SOIL CONVERSATION SERVICE (SCS)

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Ridwan Abadi Akbar ◽  
Adwitya Bhaskara
Keyword(s):  
Flood Control ◽  
River Flow ◽  
Heavy Rain ◽  
Rainfall Data ◽  
Unit Hydrograph ◽  
Design Flood ◽  
Flood Discharge ◽  
River Region ◽  
Synthetic Unit Hydrograph ◽  
Prone Area

<p align="center"><strong>Abstract.</strong></p><p>Floods always come suddenly and unexpectedly, and lots of people living in the flood-prone area can be the victims. As happened on February 2, 2020, a number of rice fields, roads, and houses belonging to the residents in the Parangjoho watershed, Eromoko District, Wonogiri, with 9.8-km river length and 32.59-km<sup>2</sup> area, was flooded due to heavy rain for some time which flushed the Eromoko area, therefore, the river flow could not accommodate the volume of water that entered and overflowed. This was what motivated researchers to calculate the design flood discharge to be able to carry out the flood control.</p><p>The methods of calculating the design flood discharge in the Parangjoho watershed used the Nakayasu Synthetic Unit Hydrograph (SUH) Method and the Soil Conservation Service (SCS) Method, using the rainfall data from the Bengawan Solo Central River Region at Parangjoho Station. The rainfall data used were from 2000 to 2019.</p>

scholarly journals Analysis of Cross-Sectional Capacity of the Jambi River in the Muaro Jambi Temple About Various Times of Flooding Using HEC-RAS Software

2021 ◽  
Vol 004 (02) ◽  
pp. 127-140
Author(s):  
Putri Mayasari ◽  
Freddy Ilfan ◽  
Yasdi Yasdi ◽  
Rimba Rimba
Keyword(s):  
Water Level ◽  
Return Period ◽  
Unit Hydrograph ◽  
Cross Sectional ◽  
Tourist Attractions ◽  
Type Iii ◽  
Flood Discharge ◽  
Temple Complex ◽  
Pearson Type ◽  
Synthetic Unit Hydrograph

Jambi River is one of the rivers located in the Muaro Jambi Temple Complex Area, Muaro Jambi Regency, Jambi Province. Muaro Jambi Temple is one of the tourist attractions in Jambi Province. This study aims to find the capacity of Jambi River tested by planned flood discharge utilizing (synthetic unit hydrograph) HSS Nakayasu method for a return period of two, five, ten, twenty-five, fifty and hundred years. HEC-RAS software used to analyse the water level in the Jambi River towards the flood potential that causes the submerging of the Kedaton Temple building. This research used the log Pearson type III method to calculate the planned rain return period and used the Nakayasu synthetic unit method to calculate the planned flood discharge. The analysis showed that the Jambi River could not load the flood discharge in the five, ten, twenty-five, fifty, and one hundred years return period at several measurement points: river sta-1, river sta-2 and river sta-5. The floodwater level did not cause the Kedaton Temple building to be flooded from the simulation result

scholarly journals Application of Ecodrainage System in Reducing the Potential for Flooding in the District of Sampang

2017 ◽  
Vol 1 (2) ◽  
pp. 63-73
Author(s):  
Fauzan Andikha ◽  
Adhi Yuniarto
Keyword(s):  
Land Use ◽  
River Basin ◽  
Return Period ◽  
River Watershed ◽  
High Rainfall ◽  
Retention Ponds ◽  
Flood Discharge ◽  
Catchment Areas ◽  
The Creation

Kamoning River watershed is one of the watersheds in Sampang. Sampang City experienced flooding almost every year caused by the overflow of the River Kamoning. One of the causes of flooding in that city is the high rainfall and a lack of rainwater catchment areas in the upper and middle Kamoning River watershed. To overcome these problems, it is necessary to use a system of flood discharge reduction ecodrainage in the upstream and in the middle of Kamoning River watershed. This study used two scenarios of ecodrainage system: first is to change the land use in combination with the creation of retention ponds, the second scenario is to change the land use in combination with the creation of infiltration wells. From the analysis of large unknown, designed-flood discharge of 50 year-return period of Kamoning River basin is 289.361 m3/ sec. By using the first scenario, the designed-flood discharge can be reduced by 199.59 m3/s or 31.02%, while large designed-flood discharge can be reduced by 205.20 m3/s or 29.08% using second scenario. Efforts to reduce the discharge flood in Sampang can be effectively done by using the scenario 1.

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

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.

scholarly journals Analysis of urban flood using synthetic unit hydrograph (SUH) and flood mitigation strategies along way Halim River: a case study on Seroja street, Tanjung Senang District

2021 ◽  
Vol 331 ◽  
pp. 07015
Author(s):  
Dian Pratiwi ◽  
Arniza Fitri ◽  
Arlina Phelia ◽  
Nabila Annisa Amara Adma ◽  
Kastamto
Keyword(s):  
Mitigation Strategies ◽  
Flood Mitigation ◽  
Trigger Factor ◽  
Urban Flooding ◽  
Unit Hydrograph ◽  
Urban Flood ◽  
Flood Discharge ◽  
Absorption Area ◽  
Synthetic Unit Hydrograph

In the urban area, flooding becomes the most common disaster that has not been resolved until today. The utilization of river border area into housing and lack of absorption area becomes the trigger factor of urban flooding, as what is happening around Way Halim River on Seroja street. In this area, floods often happen during the rainy season, with the latest events recorded on January 21st, 2021. Analysis of flood intensities and discharges can be parameters for the decision-making of flood mitigation strategies. This study aims to analyze the flood discharges along Way Halim River, Seroja street by comparing the flood discharges resulting from three analysis methods of Synthetic Unit Hydrograph (SUH) including Gama I SUH, Nakayasu SUH, and Snyder SUH. Finally, suitable flood mitigation strategies were also proposed in this study based on the flood discharges and rain intensities. The results showed that Nakayasu SUH had the highest peak flood discharge than Snyder SUH and Gama I SUH. Based on the results of the investigation of land suitability; and analysis of rainfall intensities and flood discharges, the proposed flood mitigation in Seroja street is by installing biopore infiltration holes along Seroja street for storing water and reducing the risk of flooding in the area.

scholarly journals Increasing Effectiveness of The Urban Artificial Reservoir Trough Cross Section Improvement

2021 ◽  
Vol 945 (1) ◽  
pp. 012046
Author(s):  
Rizka Arbaningrum ◽  
Marelianda Al Dianty ◽  
Frederik Josef Putuhena ◽  
Rifki Priyambodo ◽  
Budianto Ontowirjo
Keyword(s):  
Land Use ◽  
Surface Area ◽  
Cross Section ◽  
Return Period ◽  
Rainfall Data ◽  
Flood Mitigation ◽  
Maximum Rainfall ◽  
Artificial Reservoir ◽  
Flood Discharge ◽  
Main Factor

Abstract Situ Ciledug is an artificial reservoir located at Tangerang Selatan, Indonesia. In 1950 known as one of the largest lakes with total area of 32.806 hectares. As time goes by, due to the construction of housing and land use around the area, the catcahment area was reduced about 19.3 hectares in 2013 and by the end of 2020 the surface area was become 16.2 hectares. Urbanization is the main factor that makes the area of Situ Ciledug’s narrower. The second impact was flooding, as a result, the flood inundates the cities around the reservoir. This study aims to increase the storage capacities by normalizing the reservoir using SWMM 5.1 software. Hydrological analysis was carried out in the first stage to find the maximum rainfall using a 100-year return period. Then result intensity of rainfall used to analyze the hyetograph as input for rainfall data in SWMM 5.1. The modeling uses a maximum of rainfall about 107 mm with a reservoir depth of 1.3 meters. The large inflow that enters the reservoir is 87.504 m3/second aand the volume is 30.145 m3/second. Therefore, it is necessary to normalize the reservoir by increasing the depth of the reservoir by 0.7 meters. Normalization is carried out to accommodate flood discharge as a solution to flood mitigation due to the overflow.

scholarly journals Analisis Debit Puncak Sungai Lubuk Banyau Kabupaten Bengkulu Utara Menggunakan Metode Hidrograf Satuan Sintetik

2020 ◽  
Vol 12 (2) ◽  
pp. 83-90
Author(s):  
Agam Sanjaya
Keyword(s):  
Return Period ◽  
Rainfall Intensity ◽  
Peak Discharge ◽  
Peak Time ◽  
Type I ◽  
Unit Hydrograph ◽  
Distribution Method ◽  
Pearson Type ◽  
Synthetic Unit Hydrograph ◽  
Log Normal

ANALISIS DEBIT PUNCAK SUNGAI LUBUK BANYAU KABUPATEN BENGKULU UTARA DENGAN MENGGUNAKANMETODE HIDROGRAF SATUAN SINTETIK Agam Sanjaya I1), Khairul Amri II2), Muhammad Fauzi III3) 1) 2) 3)Jurusan Teknik Sipil, Fakultas Teknik UNIB Jl. W.R. Supratman, Kandang Limun, Kota Bengkulu 38371, Telp. (0736)344087e-mail: [email protected], [email protected] , [email protected] aliran sungai (DAS) Sungai Lubuk banyau merupakan salah satu DAS yang berada di Bengkulu Utara. DAS Sungai Lubuk banyau mengalir dari daerah hulu yang terletak diwilayah Kabupaten Bengkulu utara. Tujuan dari penelitian ini adalah menganalisa debit puncak rencana akibat intensitas curah hujan pada DAS Lubuk Banyau dalam menganalisis hidrologi dengan menggunakan metode Hidograf Satuan Sintetik (HSS) Gama I, HSS Nakayasu dan HSS Snyder. Berdasarkan hasil perhitungan dari penelitian ini distribusi frekuensi terhadap tiga metode curah hujan, yaitu metode ditribusi Gumbel Tipe I, Log Pearson Tipe III dan Log Normal maka metode yang digunakan untuk perhitungan curah hujan rencana pada penelitian ini adalah Metode Gumbel Tipe I dengan periode ulang 2, 5, 10, 25, 50 dan 100 tahun, yaitu 181,164 mm, 275,356 mm, 337,709 mm, 416,518 mm, 474,974 mm dan 532,998 mm. Dari hasil analisis hidrologi pada penelitian diperoleh debit puncak pada DAS Lubuk Banyau untuk periode ulang 100 tahun dengan metode HSS Snyder adalah 1531,111 m3/detik dengan waktu puncak sebesar 5 jam merupakan debit puncak yang paling besar diantara HSS Gama I dan Nakayasu. untuk hasil debit puncak dengan metode HSS Gama I adalah 776,91m3/detik dengan waktu puncak sebesar 4 jam dan HSS Nakayasu 1023,87 dengan waktu puncak 2,46 jam. Maka didapatkan tinggi permukaan air pada DAS Lubuk Banyau yaitu 1,134 m.Kata kunci: hidrograf satuan sintetik, debit puncak, gama I, nakayasu, dan snyderAbstractWatershed Lubuk Banyau is one of the watersheds in North Bengkulu. The Lubuk River watershed flows from the upstream area located in the northern Bengkulu regency. The purpose of this study is to analyze the planned peak discharge due to rainfall intensity in the Lubuk Banyau watershed in analyzing hydrology using the Synthetic Unit Hydrograph (HSS) method of Gama I, HSS Nakayasu and HSS Snyder. Based on the results of calculations from this study the frequency distribution of three rainfall methods, namely the Gumbel Type I distribution method, Pearson Type III Log and Normal Log, the method used for calculating the planned rainfall in this study is the Gumbel Type I method with a return period of 2, 5, 10, 25, 50 and 100 years, namely 181,164 mm, 275,356 mm, 337,709 mm, 416,518 mm, 474,974 mm and 532,998 mm. From the results of the hydrological analysis in the study, the peak discharge in the Lubuk Banyau watershed for a 100-year return period with the Snyder HSS method was 1531,111 m3 / second with a peak time of 5 hours being the largest peak discharge between Gama I and Nakayasu HSS. for the peak discharge using the HSS Gama I method is 776.91m3 / sec with a peak time of 4 hours and Nakayasu HSS of 1023.87 with a peak time of 2.46 hours. Then the water level obtained at the Lubuk Banyau watershed is 1,134 m.Keywords: synthetic unit hydrograph, peak discharge gama I, nakayasu, and snyder.

scholarly journals ECODRAINAGE SYSTEM EVALUATION AND CONTROL OF FLOODS IN JOMBANG DISTRICT, EAST JAVA

2021 ◽  
Vol 1 (2) ◽  
pp. 83
Author(s):  
Sri Rahmawati ◽  
Anita Rahmawati ◽  
Azizah Rachmawati
Keyword(s):  
Land Use ◽  
Return Period ◽  
System Evaluation ◽  
Design Flood ◽  
Populated Area ◽  
Type Iii ◽  
Flood Discharge ◽  
Design Rainfall ◽  
And Control ◽  
Green Land

Jombang sub-district is the most densely populated sub-district because it is located in the middle of Jombang district and is also the center of government. Because it is a densely populated area, resulting in many changes in land use, green land for absorption has turned into a watertight area. The results of the analysis from this aspect indicate that several channels in Jombang District are not able to accommodate the design flood discharge. The calculation of the height of rain design in this study used the Log Person type III method with a return period of 5 years, which resulted in the design rainfall of 157 mm. The results of the analysis show that there are 8 channels out of 74 that are unable to accommodate the design flood discharge. After planning the infiltration wells, a different number was obtained for each road. For Jalan Sentot Prawirodirjo, there are 8 infiltration wells with a reduction power of 51.62%.

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