In order to map the inundation area, flooding events are investigated using unique RGB composite imagery based on the MODIS surface reflectance data obtained from the Terra satellite, which is used to visualize and analyze these events. This study proposes using an RGB combination of MODIS band 6 (1.64 μm), band 5 (1.24 μm), and band 2 (0.86 μm) data from the visible and the near-infrared spectral ranges to map flood events. The flooding events that were investigated in this study occurred on October 25, 2015 along the Pampanga River in the Philippines. This estimate was indirectly compared with the results obtained from SENTINEL-1A Synthetic Aperture Radar (SAR) data. In addition, RGB imagery results using MODIS 6-5-2 bands were supported by the refractive index retrieval along the inundation area, and the derived technique is applied to the data from Himawari-8 satellite. This study shows that the RGB composite techniques using advanced sensors with more bands and higher spatio-temporal resolutions and supported by the refractive index retrieval method, are useful for estimating flood events.
Generally, soil moisture plays an important role in water cycle, water resources and other diverse applications over land.
Passive microwave remote sensors (e.g., ASCAT, AMSR-E, SMOS, and SMAP) have successfully used for estimating
the amount of soil moisture irrespective of their low temporal and special resolutions. In this study, we present a TVDI
(temperature-vegetation dryness index)-based soil moisture retrieval algorithm based on visible and infrared remote
sensors. The TERRA/MODIS products such LST (MOD11A2) and NDVI (MOD13A2) data were used. Far-East Asia
area including the Korean peninsula were investigated for the case study. In particular, we found the elevation
dependence on the soil moisture retrieval. We developed a correction method for this elevation effect. The proposed
TVDI-based soil moisture algorithm in visible and infrared bands were compared and validated with soil moisture
contents estimated from GCOM-W1/AMSR-2 observations in microwave bands.