Conference Presentations by Adam Pamudji Rahardjo
MSD Workshop, 2017
Nasiri flash flood disaster was identified and studied. Mitigation effort has been done for reduc... more Nasiri flash flood disaster was identified and studied. Mitigation effort has been done for reducing disaster risk in the future. Some activities for that purpose were explained.
Papers by Adam Pamudji Rahardjo
Flash Flood Characteristics of Ciberang River, Its Impact and Mitigation
IOP conference series, Dec 1, 2021
Flash flood is a deadly natural disaster that develops at space and time scales caused by high ra... more Flash flood is a deadly natural disaster that develops at space and time scales caused by high rainfall intensities and frequently occurs. It occurs in mountainous regions with steep slope relief and often causes a loss of economy, society, and environment and threatens human lives. The Ciberang river is located at Lebak district, Banten Province, and has been experiencing a significant flash flood from December 31, 2019 to January 01, 2020, which contributed to various damages, including households nearby the river. In this study, the impact areas were identified with the HEC-RAS model and satellite image data. The impact area was damage on eight sub-districts, including agriculture (77.86 Ha), buildings (0.80 Ha), roads (2.5 km), and nine bridges. In addition, this study tried to build Sabo Dam upstream of Banjar Irigasi sub-districts to respond to the flash flood occurrence. The results have reduced the discharge to around 40 m3/s, and the travel time was delayed about 53 min. The results of this study help the community and decision-makers be ready for further flash flood disasters.
Analisis Hidraulika Pada Kasus Keruntuhan Bendungan Cipanas
Kajian Penyebaran Aliran Polutan Sungai Code
Code River is one of the rivers passing through Yogyakarta city, which is located in a strategic ... more Code River is one of the rivers passing through Yogyakarta city, which is located in a strategic area. The middle of river segments cross the densely populated urban areas, however some people considered the river to be an alternative place of waste disposal. This leads to degradation in the water quality of the Code River, therefore an analysis of pollutants flow distribution is needed. The research site is located along the Code River from the North Ringroad to South Ringroad, with approximately 10 km length. The method of analysis used is numerical simulation of pollutant transport, using one dimension model HEC-RAS software version 4.1. Simulation were run for the flow of February 14, 2012 and October 10, 2012 by entering the pollutant load concentration at segment points which are source of pollutants along the Code River. The parameters studied were BOD5 and DO. Based on the results of this research it can be concluded that the concentration values along the reach on February 14, 2012 the average BOD5 and DO respectively are in the range of 3,97 to 6,72 mg/l and 5,50 to 7,34 mg/l , while on the October 10, 2012 with a range of 6,80 to 16,07 mg/l and 9,41 to 34,94 mg/l. The largest sources of pollutants were originating from residential and tourism areas along the point RS 53-45 or the distance between 5,16 to 4,48 miles downstream, which were derived from thed drainage. The sewage comes from domestic, apartement, hotels and restaurants sewage. Most of DO concentration are eligible, because it exceeds the permissible minimum limit, while for BOD5 are not eligible because it exceeds the permissible maximum limit, therefore it can be concluded that pollution load from waste sorce site assessed have been polluting Code River. To get better results about Code River pollution, monitoring and evaluating the quality and quantity of waste sources at the monitoring points continuously based on time are required.
Model Simulasi Pengoperasian Waduk Bili-Bili Untuk Optimasi Kapasitas Suplai Air Irigasi Dan Air Baku DI Daerah Aliran Sungai Jeneberang Propinsi Sul- Sel
Symptoms of urban development in South Sulawesi has a trend to minimize the open green spaces and... more Symptoms of urban development in South Sulawesi has a trend to minimize the open green spaces and converted into shops, shopping centers, residential, hotel, recreational areas and industrial. While the potential water availability has decreased with the increasing population growth and industrial sectors. This study aims to know the potential water availability of Bili-Bili dam for water supply served by constructing reservoir operation pattern. Operation pattern Bili-Bili dam using simulation with Standard Operating Rule to get the best supply capacity and optimal release. The availability of water in the Jeneberang watershed were analyzed using model in HEC-HMS and Thomas- Fiering method to get the amount of water availability in future projections. Water demand calculated based on the standard from the Center for Irrigation Department of Public Works. The results showed on simulations with Standard Operating Rule, the optimal supply happens at the first planting schedule with target release scenario irrigated rice-rice-maize. At existing condition the irrigation water needs is 61,35 percent with target release of raw water 100 percent. On the 10-year and 20-year projections, the best results is 53.7 percent and 44.5 percent of irrigation water needs with target release raw water 100 percent
Penyusunan model numeris elemen hingga persamaan aliran turbulen K-epsilon dengan formulasi Petrov-Galerkin
Analisis Hidraulika Banjir Akibat Keruntuhan Bendungan(Studi Kasus Bendungan Lempake, Kota Samarinda)
Finding an Optimal Use of Tides for Leaching of Pond Waters in Channel Networks with Various Size and Simultaneous Opening Number of Gates, Case Study of Sei Teras Fishpond Irrigation Area, Central Kalimantan
IOP conference series, Nov 1, 2022
Sei Teras Village has been developing aquaculture since 2006 and has fresh and saltwater sources.... more Sei Teras Village has been developing aquaculture since 2006 and has fresh and saltwater sources. Recently, there has been a plan for upgrading the traditional extensive ponds to intensive ones. It is expected to cultivate vannamei shrimp, which delivers a better return. An average of 5-15% of the total water volume in the ponds is recommended to be replaced every day to keep the water quality within the range of the requirements. This study aims to find an alternative design and operation of pond gates for better use of tides for fishpond water leaching. Measurements were carried out for topography, tides, and current boundary conditions for calibration. The flow simulations on the fishpond irrigation network are modeled with two scenarios of pond water gate size and variations in the number of fishpond gates operated simultaneously using HEC-RAS software. Flow simulation is carried out to determine the process of entering and leaving water into ponds. The results of the simulations are evaluated based on their water replacement capacity and changes of discharge and water level at the control point. The initial results show that wider gate opening increases the capacity of water replacement and simultaneous opening operation gives the maximum result.
A Proposed Improvement of Belanti II Tidal Irrigation Scheme, Kalimantan, to Support Leaching of Acid Sulphate Soil Reclamation
IOP conference series, Dec 1, 2021
The reclamation process of acid sulphate soil of the Belanti II tidal irrigation scheme remains u... more The reclamation process of acid sulphate soil of the Belanti II tidal irrigation scheme remains unfinished. During ebb tide, the upstream acidic drainage water retains and settles in the irrigation canals. During high tide, the acidic water flows back into some parts of the agricultural land and reduces rice productivity. The measured pH is about 2.5 ~ 3.5 and the measured electric conductivity is about 0,25 ~ 0,35 mS/cm. Sedimentation in the middle to the end of the primary, secondary, and collector canals and tidal pond at the upstream end of the primary canal, preventing the leaching process of sulfuric acid soil. Primary canal normalization as an alternative solution to increase the capability of acidity leaching is proposed. Leaching the acidic soil of Belanti II irrigated area of 3.976 ha requires 500 m3/ha/day of freshwater, equivalent to 1.998.000 m3/day. The one-dimensional HEC RAS mathematical model is used to evaluate the hydraulics performance to support the leaching process. The hydraulic analysis was carried out using two tidal cycles on the existing channel and the normalized channel. Channel normalization has succeeded in reducing the water supply deficit to support the leaching process from 39% to 9%.
Analisis Kinerja Pengendalian Banjirsungai Jampue Kabupaten Barrupropinsi Sulawesi Selatan
Floodings are common problems that occur in most parts of Indonesia, especially in urban areas. J... more Floodings are common problems that occur in most parts of Indonesia, especially in urban areas. Jampue river is one of rivers in Barru regency that flow across the central of regency. Floods that occur every year causing damage of houses, public facilities, rice field, even cause fatalities. Flood that occurred on January 5, 2010 is an interesting case for research to find the flood control alternatives. The research simulate flood control alternatives, examine flood control alternatives and analyze the election of the most optimal of flood control alternatives. The research uses hydrology and hydraulic approach by performing the application of Hydrologic Engineering Center-River Analysis System (HEC- RAS) Version 4.0 and application of Decision Support System with Analytical Hierarchy Process (AHP) model to determine the sequence of flood control alternatives. Assessment of alternative combines the relative valuation of all respondents to the social criteria, economic criteria and environmental criteria with absolute assessment of the physical criteria of flood control alternatives of Jampue River. The results shows that the best alternative is normalization/NS with a value of (0,258), the combination of normalization and leeves/NSTS is second rank with a value of (0,224). The third rank is leeves/TS with a value of (0,205) and the retention ponds/KR with a value of (0,113) is the fourth rank. The fifth rank is combination of normalization and retention ponds/NSKR with a value of (0,106) and the last one is combination of leeves and retention ponds/TSKR with a value of (0,094).
Studi Pengaruh Variabilitas Spasial Dan Temporal Hujan Ekstrem Terhadap Ketelitian Hitungan Debit Banjir Rancangan Sebagai Peningkatan Upaya Penanggulangan Banjir DI Kali Lamong - Jawa Timur
Analisis Perencanaan Peringatan Dini Banjir di Sungai Konaweha
Pemodelan numerik persamaan boussinesq menggunakan metode elemen hingga dua langkah taylor-galerkin
Pemodelan Aliran Debris 1 Dimensi Dengan Metode Elemen Hingga Eulerian Dan Lagrangian
Debris flow is natural disasters that can cause not only loss of property but also of human lives... more Debris flow is natural disasters that can cause not only loss of property but also of human lives. This flow is very dangerous because it can destroy anything in its path. To avoid large losses from natural disasters, mitigation of natural disasters is needed. One of mitigation measure is an early warning system and it can be in the form of hazard maps and travel time table of debris flow. This hazard maps and the travel time table of debris flow inform the extent of the affected area, so that it gives early warning for evacuation to residents around the disaster site when indicators gives signals. Debris flow modeling can be conducted for developing the early warning tools. The development of 1D (one-dimensional) model of debris flow uses the Finite Element Method with Eulerian approach and Lagrangian approach. The result of both approaches are compared to determine which one is better in modeling debris flow. The numerical models then are applied to two initial conditions, the staircase-shaped and half-Gaussian form. In order to get better modeling results a smoothing method is used to improve the stability of the numerical model. For the Eulerian approach, it is obtained that the results looks like a diffusive wave propagation to upstream and downstream, but still skewed to downstream. While the Lagrangian approach shows that the flow propagates downstream. The comparison of two methods shows that the model with Lagrangian Galerkin approach is more presenting the debris flow than Eulerian approach 2 Step Taylor Galerkin (2STG).
Finite element modelling of river bed dynamics
Study of the Potential Time of Flood Early Warning in Kuala Krai, Kelantan
Universitas Gadjah Mada, 2018
An Alternative Algorithm for Simulating Flash Flood
IOP Conference Series: Earth and Environmental Science, 2021
Most of the approaches in numerical modeling techniques are based on the Eulerian coordinate syst... more Most of the approaches in numerical modeling techniques are based on the Eulerian coordinate system. This approach faces difficulty in simulating flash flood front propagation. This paper shows an alternative method that implements a numerical modeling technique based on the Lagrangian coordinate system to simulate the water of debris flow. As for the interaction with the riverbed, the simulation uses an Eulerian coordinate system. The method uses the conservative and momentum equations of water and sediment mixture in the Lagrangian form. Source terms represent deposition and erosion. The riverbed in the Eulerian coordinate system interacts with the flow of the mixture. At every step, the algorithm evaluates the relative position of moving nodes of the flow part to the fixed nodes of the riverbed. Computation of advancing velocity and depth uses the riverbed elevation, slope data, and the bed elevation change computation uses the erosion or deposition data of the flow on the moving...
Review on Co-factors Triggering Flash Flood Occurrences in Indonesian Small Catchments
IOP Conference Series: Earth and Environmental Science, 2021
Flash flood is defined as “a flood of short duration with a relatively high peak discharge,” whic... more Flash flood is defined as “a flood of short duration with a relatively high peak discharge,” which leaves little time to take action to reduce property damage and the risk to life. Flash floods occur not only because of heavy rainfall but some co-factors that can trigger it. This study aims to determine the co-factors that trigger the flash flood. Observations are carried out using a descriptive-qualitative approach of five small catchments in Indonesia, namely Bahorok Catchment (Langkat, North Sumatra), Kalijompo, and Kalipakis Catchment (Jember, East Java), Nasiri Catchment (Western Seram, Maluku), Wasior Catchment (Wondama Bay, West Papua). The dominant co-factors are related to rainfall IDF, morphological characteristics (slope, channel properties, flow pattern), geological conditions (rock, soil, structure, geohydrology), catchment conditions (vegetation, land use). Flash floods generally occur due to landslides in the upstream part of the river. Debris consisting of water, roc...
Identification of Flood-prone Areas using HEC-HMS and HEC-RAS, the Case of Ciberang River Basin, Lebak District of Banten Province
IOP Conference Series: Earth and Environmental Science, 2021
It is common practice that flood hydrograph simulations help to provide better flood prediction a... more It is common practice that flood hydrograph simulations help to provide better flood prediction and flood damage reduction planning. These efforts require information on flood-prone areas identification from the hydrological and hydraulic analysis results. Historically, the Ciberang River Basin has experienced floods. Those floods cause the loss of human life and damage some houses along the river’s channels, especially in Lebak District, Banten Province, Indonesia. The main objective of this study is to identify flood-prone areas based on the simulation result of a hydrologic and hydraulic model of catchment response due to several extreme rainfall events using HEC-HMS and HEC-RAS software. Rainfall and discharge data measured at the Ciberang-Sabagi water level gauge on 10 January 2013 were used to calibrate hydrological watershed parameters. The hydraulics channel routing is started from the planned location of the Sabo dam to the downstream control point. The next stage was the s...
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Conference Presentations by Adam Pamudji Rahardjo
Papers by Adam Pamudji Rahardjo