Image Library
ALOS-2/PALSAR-2 Observation Results of mudslides in Hiroshima city
Landslides induced by heavy rain occurred on August 20, 2014 in Hiroshima city, Hiroshima prefecture. Japan aerospace and exploration agency (JAXA) conducted the emergency observation on August 22, 24, and 26 with Phased Array Type L-band Aperture Rader-2 (PALSAR-2) onboard the Advanced Land Observing Satellite-2 "DAICHI-2" (ALOS-2). Figs. 1 show the observation area (red polygon) and satellite orbit (blue line).
Fig.1: Observation area (red polygon) and satellite orbit (blue line)
upper: Aug. 22, Left lower: Aug. 24, Right lower: Aug. 26
Fig. 2 shows color composite PALSAR-2 observation image with 3m spatial resolution and dual polarization mode on Aug. 26. Red rectangular represents the disaster areas.
Fig. 2: PALSAR-2 color composite image on Aug. 26 (Red: HH, Green: HV, Blue VV)
(Click to view enlarged image)
PALSAR-2 image obtained in Asaminami-ku is compared with the PALSAR on-board ALOS image with HH polarization (Fig. 3). Linear structures were picked up, and drawn in red line in Fig. 4. Additional linear structures were observed in PALSAR-2 image, and this may be due to a topographic change due to the landslide.
(Note: Bright linear structure is emerged at mountain ridge line in a SAR image, because of oblique observation.)
Fig. 3: PALSAR-2 (upper) and PALSAR (lower) image observed in Asaminami-ku.
(Click to view enlarged image)
Fig. 4: Linear structure were picked up from the Fig. 3 image, and drawn in red line.
Additional lineament structure observed with PALSAR-2 is drawn in orange line.
(Click to view enlarged image)
Lineament analysis was also applied for the Takamatuyama area in Asakita-ku (Fig. 5, 6)
Fig. 5: PALSAR-2 (upper) and PALSAR (lower) image
observed in Asakita-ku.
(Click to view enlarged image)
Fig. 6: Linear structure were picked up from
the Fig. 5 image, and drawn in red line.
Additional lineament structure observed with
PALSAR-2 is drawn in orange line.
(Click to view enlarged image)
JAXA EORC