Geosfera Indonesia
Vol. 9 No. 1 (2024): GEOSFERA INDONESIA

Heavy Rain Episodes Identified by L-band InSAR and Limitations of Split-Spectrum Method in Indonesia

Naufal Setiawan (Department of Geomatic Engineering, Faculty of Mineral Technology, Universitas Pembangunan Nasional “Veteran” Yogyakarta, Indonesia)
Masato Furuya (Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan)



Article Info

Publish Date
07 Apr 2024

Abstract

Located in a tropical area with abundant precipitation, Indonesia is highly prone to heavy rain hazards, in particular landslides and floods. Thus, rainfall observation is vital. Nonetheless, the topography, the fund availability, as well as the archipelagic state of Indonesia may raise difficulties for in-situ observation, such as rain gauge and weather radar. Currently, the advance of radiometer satellites, such as the Global Precipitation Mission delivers rain estimation and has proven to show good association with in-situ observation on a monthly basis, not daily over the Indonesia area. Therefore, it is vital to have additional measurement methods. For the first time, we apply L-band Interferometric Synthetic Aperture Radar (InSAR) to observe heavy rain in Indonesia. From our three study cases, we successfully identified localized anomalies due to the dense water vapor during heavy rain in the InSAR images. The localized anomalies vary from 10.9 cm in West Java, 7.8 cm in East Kalimantan, and 7.7 cm in West Kalimantan. Furthermore, we utilize the split-spectrum method for our InSAR result; the high-water vapor occurrence in the troposphere associated with heavy rain should be identified in the non-dispersive term. Nevertheless, due to long temporal separation and thinner bandwidth, the split-spectrum method results display unsatisfactory results. We conclude that, while InSAR has the ability to identify heavy rain, having SSM to distinguish between non-dispersive and dispersive phases is not currently practical in Indonesia.

Copyrights © 2024






Journal Info

Abbrev

GEOSI

Publisher

Subject

Earth & Planetary Sciences Education Environmental Science

Description

Geosfera Indonesia is a journal publishes original research, review, and short communication (written by researchers, academicians, professional, and practitioners from all over the world) which utilizes geographic and environment approaches (human, physical landscape, nature-society and GIS) to ...