Satellite Monitoring of Landside and Rapid Erosion in Southern Luzon: Contributors to Sediment Deposition in the Lingayen Gulf, Northwestern Luzon, Philippines
Methodology
Several satellite images were obtained. Table 1 shows the shows the summary of the images used. A regional geological interpretation was made on the 1993 TM image to determine the geological and geomorphological boundaries and the lineament zones. A photo geomorphological interpretation map of the Agno River Basin with special emphasis on identifying landslide concavities was also made (Fig. 1). A maximum likelihood classification was applied to the 1988 and 1993 TM images to identify open area, soil, weathered areas or barren ground areas before and after the July 1990 earthquake. Figure 2 shows the identified barren ground areas (color green) in the two dates. A photogeological interpretation was made on the 1972 to 1993 images to monitor the extent of flood deposits in the Agno River Basin.
Table 1 - Summary table for the datasets used
| Data |
Path/Row |
Acquisition Date |
| Landsat MSS |
125/49 |
18 November 1972 |
| Landsat MSS |
125/49 |
10 May 1976 |
| Landsat MSS |
125/49 |
21 February 1979 |
| Landsat TM |
116/49 |
31 January 1988 |
| Landsat TM |
116/49 |
03 December 1989 |
| Landsat TM |
116/49 |
02 April 1993 |
| JERS-1 OPS |
91/273, 274 |
06 November 1993 |
| JERS-1 SAR |
91/273, 274 |
07 May 1993 |
Figure 1-Photogeomorphological interpretation map of the Agno River Basin with special emphasis on identifying landslide concavities.
Figure 2 -The 1988 and 1993 Landsat TM images after application of the maximum likelihood classifier to show the extent of open areas, soil, weathered areas or barren ground areas before and the July 1990 earthquake. 'The identified barren ground areas are colored green.
