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All Journal Jurnal Teknik Sipil Dinamisia: Jurnal Pengabdian Kepada Masyarakat JURNAL SUMBER DAYA AIR International Journal of Science and Society (IJSOC)
Wijaya, Obaja Triputera
Universitas Katolik Parahyangan
Civil Engineering, Building, Construction & Architecture Engineering Materials Science & Nanotechnology Social Sciences Other

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Correction and Validation of Daily Rainfall Satellite Data in the Wae Mese Watershed, Labuan Bajo, West Manggarai Regency Yudarsi, Pankrasio Mario; Wicaksono, Albert; Wijaya, Obaja Triputera
International Journal of Science and Society Vol 7 No 1 (2025): International Journal of Science and Society (IJSOC)
Publisher : GoAcademica Research & Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.54783/ijsoc.v7i1.1385

Abstract

This study aims to analyze rainfall correction in the Wae Mese watershed, located in Labuan Bajo, focusing on improving the accuracy of rainfall data for flood modelling and watershed management planning. In this research, corrections are performed using an objective function that compares observed rainfall data with satellite-based rainfall data from GPM (Global Precipitation Measurement). The objective function is used to evaluate prediction errors and determine the most effective correction factor to enhance the reliability of satellite rainfall data. The research methodology includes the application of the objective function to measure differences between satellite-derived rainfall data and observed data, and applying corrections based on the analysis results. The findings show that rainfall data corrected using the objective function provides a more accurate representation of rainfall events, leading to more precise flood predictions for the watershed. This study highlights the importance of using the objective function in rainfall correction, which plays a key role in effective flood risk management and planning. These findings provide a better understanding of rainfall patterns in the Wae Mese watershed and support the use of corrected satellite-based rainfall data for hydrological modelling and future flood risk assessments.
Evaluasi Curah Hujan Berbasis Data Global pada DAS Wae Mese, Labuan Bajo Sabu, Maria Kalista Hadia; Yudianto, Doddi; Wijaya, Obaja Triputera
JURNAL SUMBER DAYA AIR Vol 21, No 1 (2025)
Publisher : Direktorat Bina Teknik Sumber Daya Air, Kementerian Pekerjaan Umum dan Perumahan Rakyat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32679/jsda.v21i1.906

Abstract

Accuracy of rainfall data is very important in hydrological analysis, especially in areas with limited data such as Labuan Bajo City, Indonesia. Global climate data generated from satellite observations and assimilation products, which are freely available, have great potential for use in data scarce areas. However, this data needs to be evaluated to measure its accuracy in rainfall estimates. This research aims to evaluate the accuracy of eight global rainfall data products, namely Global Precipitation Measurement (GPM), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks – Cloud Classification System (PERSIANN-CCS), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks - Climate Data Record (PERSIANN-CDR), Precipitation Data Integration and Retrieval - Now (PDIR-Now), European Reanalysis for the 5th Generation (ERA5), European Reanalysis for the 5th Generation Land (ERA5-LAND), and Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) at two temporal scales: monthly and 15-daily. Evaluation is carried out using an assessment matrix which includes Root Mean Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), correlation (r), and Relative Bias (RB). The evaluation results show that on a monthly scale, ERA5, PERSIANN, and GPM provide the best results, with ERA5 being the top. On a 15-daily scale, ERA5 also shows the best performance, followed by GPM and ERA5-LAND. These findings confirm that ERA5 is the main choice for monitoring rainfall in Labuan Bajo City, which is very important for water resource management in areas with limited direct observation data.
Evaluating PERSIANN-CDR and ERA5 Precipitation Products: Insights from Bandung Raya Putro, Danurendro Ramadhani; Wijaya, Obaja Triputera
Jurnal Teknik Sipil Vol 25, No 1 (2025): Vol 25, No 1 (2025): JURNAL TEKNIK SIPIL EDISI FEBRUARI 2025
Publisher : Fakultas Teknik Universitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/jts.v25i1.90158

Abstract

Accurate precipitation estimation is essential for hydrological studies, particularly in regions with complex climatic and topographical characteristics, such as Greater Bandung, Indonesia. This study evaluates the performance of two high-resolution global precipitation datasets (GPDs), ERA5 and PERSIANN-CDR, by comparing them against observations from 32 rainfall stations at daily and monthly scales. The evaluation employs a straightforward ranking-based system considering three objective functions: Root Mean Square Error (RMSE), bias (B), and Pearson correlation coefficient (R). The results reveal that ERA5 performs better than PERSIANN-CDR for daily precipitation, as indicated by higher ranking scores across the selected metrics. Interestingly, the opposite is true for monthly precipitation, where PERSIANN-CDR outperforms ERA5. However, while the ranking system offers a practical comparative framework, the objective function values for both datasets exhibit considerable deviations from ground observations. Daily RMSE values reach as high as 24.89 mm, and monthly RMSE peaks at 525.605 mm, alongside less satisfactory bias and correlation scores. These findings suggest that while the ranking system helps identify the more suitable GPD for specific temporal scales, neither dataset is immediately fit for hydrological applications without further refinement. Bias correction of the GPDs against ground-based observations is recommended to improve their reliability and usability in hydrological analyses. This study highlights the need for tailored adjustments to GPDs in regions with high climatic variability.
Landslide Treatment in the Al-Husainiyyah Junior High School Area using Cantilever-Geofoam Wall: Penanganan Longsor di Lingkungan SMP Al-Husainiyyah dengan Menggunakan Dinding Kantilever-Geofoam Lim, Aswin; Pratama, Ignatius Tommy; Widjaja, Budijanto; Tjahjanto, Helmy Hermawan; Tjondro, Johannes Adhijoso; Wijaya, Obaja Triputera; Ginting, Bobby Minola; Setiawan, Theresita Herni; Adianto, Yohanes Lim Dwi; Hidayat, Felix; Hartieni, Patricia; William, Octavianus; Aldrianita, Tabitha; Fadhil, Imam Ahmad
Dinamisia : Jurnal Pengabdian Kepada Masyarakat Vol. 8 No. 4 (2024): Dinamisia: Jurnal Pengabdian Kepada Masyarakat
Publisher : Universitas Lancang Kuning

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31849/dinamisia.v8i4.19519

Abstract

A landslide triggered by heavy rainfall occurred in the Al-Husainiyyah Junior High School area on April 26th, 2023. The landslide damaged the nearby access roads, the existing retaining wall, and a futsal court threatening the safety of the teachers and students in conducting the learning activities that especially require open areas. Thus, this community service aims to provide a cantilever wall design with geofoam as an innovative lightweight backfill material to reinforce the slope and repair the damaged structures. Field surveying and numerical analysis were then conducted to understand the current slope and soil conditions and to analyze the stability of the slope and retaining wall. The results show that a cantilever wall with a total height of 1.8 m supported by a strauss pile row with a diameter of 0.4 m, 4 m in length, and 2.5 m in spacing could increase the stability of the slope.
PREDIKSI DAMPAK PERUBAHAN TATAGUNA LAHAN TERHADAP DEBIT LIMPASAN, STUDI KASUS: GEREJA RANCASARI Wijaya, Obaja Triputera; Yudianto, Doddi; Fitriana, Finna; Sanjaya, Stephen
JURNAL SUMBER DAYA AIR Vol 20, No 2 (2024)
Publisher : Direktorat Bina Teknik Sumber Daya Air, Kementerian Pekerjaan Umum dan Perumahan Rakyat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32679/jsda.v20i2.900

Abstract

Flooding is one of the most frequent natural disasters in Indonesia. Based on data, as of 2024, there have been 137 cases of flooding incidents. One of the causes of flooding, particularly in urban areas, is due to land use change. This study examines the impact of land use changes on runoff discharge in a Church area in the Bandung City. Additionally, this study investigates the effect of the development of this area on flood water levels in the Riung channel, which serves as an outlet channel. In this study, modeling is conducted using the SWMM model. The study utilizes data from the BMKG Bandung and GPM satellite rainfall data from 2001 to 2022 for rainfall analysis. The results indicate that in the study area, the duration of extreme rainfall producing maximum discharge is rainfall lasting for 7 hours. As a result of the church development, runoff discharge increases by 26.3 – 34.4% across various return periods. For time to peak, there is no significant change in conditions before and after the area is developed. This is due to area is relatively small, resulting in a relatively shorter concentration time. Based on the hydraulic analysis, the Riung channel is still able to accommodate additional runoff generated due to development, leaving a freeboard height of 4.5 cm for a 10-year return period. However, based on observations, special attention is needed regarding the issue of sedimentation and trash, which often causes backflow in several segments of the trenches.Keywords:runoff, land use change, urban drainage, SWMM, Bandung
Co-Authors Albert Wicaksono Aldrianita, Tabitha Aswin Lim Bobby Minola Ginting Budijanto Widjaja Doddi Yudianto Fadhil, Imam Ahmad Felix Hidayat Fitriana, Finna Hartieni, Patricia Helmy Hermawan Tjahjanto Ignatius Tommy Pratama Johannes Adhijoso Tjondro Putro, Danurendro Ramadhani Sabu, Maria Kalista Hadia Sanjaya, Stephen Theresita Herni Setiawan William, Octavianus Yohanes Lim Dwi Adianto Yudarsi, Pankrasio Mario