Point-Based Rainfall Intensity Information System in Mt. Merapi Area by X-Band Radar
Santosa Sandy Putra*1,*2,, Banata Wachid Ridwan*1, Kazuki Yamanoi*3, Makoto Shimomura*4, Sulistiyani*5, and Dicky Hadiyuwono*6
*1Balai Sabo, Ministry of Public Works and Housing
Balai Sabo, Sopalan, Maguwoharjo, Yogyakarta 55282, Indonesia
*2School of Geography, Faculty of Environment, University of Leeds, Leeds, United Kingdom
*3RIKEN Center for Computational Science, Kobe, Japan
*4Sakurajima Volcano Research Center, Kyoto University, Kagoshima, Japan
*5Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi, Ministry of Energy and Mineral Resources, Yogyakarta, Indonesia
*6Department of Civil and Environmental Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia
An X-band radar was installed in 2014 at Merapi Museum, Yogyakarta, Indonesia, to monitor pyroclastic and rainfall events around Mt. Merapi. This research aims to perform a reliability analysis of the point extracted rainfall data from the aforementioned newly installed radar to improve the performance of the warning system in the future. The radar data was compared with the monitored rain gauge data from Balai Sabo and the IMERG satellite data from NASA and JAXA (The Integrated Multi-satellitE Retrievals for GPM), which had not been done before. All of the rainfall data was compared on an hourly interval. The comparisons were conducted based on 11 locations that correspond to the ground rainfall measurement stations. The locations of the rain gauges are spread around Mt. Merapi area. The point rainfall information was extracted from the radar data grid and the satellite data grid, which were compared with the rain gauge data. The data were then calibrated and adjusted up to the optimum state. Based on January 2017–March 2018 data, it was obtained that the optimum state has a NSF value of 0.41 and R2 value of 0.56. As a result, it was determined that the radar can capture around 79% of the hourly rainfall occurrence around Mt. Merapi area during the chosen calibration period, in comparison with the rain gauge data. The radar was also able to capture nearby 40–50% of the heavy rainfall events that pose risks of lahar. In contrast, the radar data performance in detecting drizzling and light rain types were quite precise (55% of cases), although the satellite data could detect slightly better (60% of cases). These results indicate that the radar sensitivity in detecting the extreme rainfall events must receive higher priority in future developments, especially for applications to the existing Mt. Merapi lahar early warning systems.
-  F. Lavigne et al., “Instrumental lahar monitoring at Merapi Volcano, Central Java, Indonesia,” J. Volcanol. Geotherm. Res., Vol.100, Nos.1-4, pp. 457-478, 2000.
-  S. S. Putra, C. Hassan, and S. Hariyadi, “Hot pyroclastic deposit as lahar resistor: a case study of Gendol River after the Mt. Merapi 2010 eruption,” Monitoring, Simulation, Prevention and Remediation of Dense and Debris Flows IV, pp. 97-109, 2012.
-  R. Putratama, “Peresmian Operasional Radar Cuaca Di Stasiun Meteorologi Klas III Frans Seda, Maumere, NTT,” Berita Badan Meteorologi, Klimatologi, dan Geofisika, 2017. http://www.bmkg.go.id/berita/?p=6958&lang=ID [accessed May 18, 2018]
-  M. D. Yamanaka et al., “HARIMAU Radar-Profiler Network over the Indonesian Maritime Continent: A GEOSS Early Achievement for Hydrological Cycle and Disaster Prevention,” J. Disaster Res., Vol.3, No.1, pp. 78-88, 2008.
-  S. P. C., T. Nakatani, and R. Misumi, “Hydrological Simulation of Small River Basins in Northern Kyushu, Japan, During the Extreme Rainfall Event of July 5–6, 2017,” J. Disaster Res., Vol.13, No.2, pp. 396-409, 2018.
-  Y. Yonese, A. Kawamura, H. Amaguchi, and A. Tonotsuka, “Study on the precision of 1-minute X-Band MP radar rainfall data in a small urban watershed,” Int. J. Sustain. Dev. Plan., Vol.13, No.4, pp. 614-625, 2018.
-  Y. Sugihara, S. Imagama, N. Matsunaga, and Y. Hisada, “Numerical Experiments on Spatially Averaged Precipitation in Heavy Rainfall Event Using the WRF Model,” J. Disaster Res., Vol.10, No.3, pp. 436-447, 2015.
-  L. J. Cobar, D. Legono, and K. Miyamoto, “Modeling of Information Flow for Early Warning in Mount Merapi Area, Indonesia,” J. Disaster Res., Vol.11, No.1, pp. 60-71, 2016.
-  BMKG and BIG, “Citra Radar Cuaca Mozaic Indonesia Terkini - Yogyakarta,” Badan Meteorologi, Klimatologi, dan Geofisika in cooperation with Badan Informasi Geospasial, 2018. https://www.bmkg.go.id/cuaca/citra-radar.bmkg [accessed May 21, 2018]
-  Evan and Golbez, “Indonesia provinces blank,” Wikimedia Commons, 2009. https://commons.wikimedia.org/wiki/File:Indonesia_provinces_blank.png [accessed May 21, 2018]
-  Y. Gonda, D. Legono, B. Sukatja, and U. B. Santosa, “Debris flows and flash floods in the Putih River after the 2010 eruption of Mt. Merapi, Indonesia,” Int. J. Eros. Control Eng., Vol.7, No.2, pp. 63-68, 2014.
-  E. de Bélizal et al., “Rain-triggered lahars following the 2010 eruption of Merapi volcano, Indonesia: A major risk,” J. Volcanol. Geotherm. Res., Vol.261, pp. 330-347, 2013.
-  H. Uyeda, “Mesoscale Precipitation Systems Along the Meiyu/Baiu Front and Future Expectation for Research Radar and Weather Radar Network,” J. Disaster Res., Vol.3, No.1, pp. 61-68, 2008.
-  M. Maki et al., “Preliminary Results of Weather Radar Observations of Sakurajima Volcanic Smoke,” J. Disaster Res., Vol.11, No.1, pp. 15-30, 2016.
-  M. Syarifuddin, S. Oishi, D. Legono, R. I. Hapsari, and M. Iguchi, “Integrating X-MP radar data to estimate rainfall induced debris flow in the Merapi volcanic area,” Adv. Water Resour., Vol.110, pp. 249-262, 2017.
-  FURUNO, “FURUNO’s meteorological monitoring and analysing system,” Furuno System Solution, 2014. http://www.furuno.com/en/systems/meteorological-monitoring/ [accessed May 21, 2018]
-  S. Oishi, M. Iida, M. Muranishi, M. Ogawa, R. I. Hapsari, and M. Iguchi, “Mechanism of Volcanic Tephra Falling Detected by X-Band Multi-Parameter Radar,” J. Disaster Res., Vol.11, No.1, pp. 43-52, 2016.
-  G. Huffman, “GPM IMERG Final Precipitation L3 Half Hourly 0.1 degree x 0.1 degree V05,” Greenbelt, MD, Goddard Earth Sciences Data and Information Services Center (GES DISC), 2018.
-  G. Skofronick-Jackson et al., “The Global Precipitation Measurement (GPM) Mission for Science and Society,” Bull. Am. Meteorol. Soc., Vol.98, No.8, pp. 1679-1695, 2017.
-  S. S. Putra and B. Neilzon, “River bed stabilization structures placement determination based on satelite data,” The 5th HATHI Int. Seminar on Water Resilience in a Changing World, 2016, p. 894, 2016.
-  S. P. C. et al., “Accuracy of Quantitative Precipitation Estimation Using Operational Weather Radars: A Case Study of Heavy Rainfall on 9–10 September 2015 in the East Kanto Region, Japan,” J. Disaster Res., Vol.11, No.5, pp. 1003-1016, 2016.
-  M. L. M. Scheel, M. Rohrer, C. Huggel, D. Santos Villar, E. Silvestre, and G. J. Huffman, “Evaluation of TRMM Multi-satellite Precipitation Analysis (TMPA) performance in the Central Andes region and its dependency on spatial and temporal resolution,” Hydrology and Earth System Sciences Discussions, Vol.7, No.5. pp. 8545-8586, 2010.