Differences in NDVI and iTVDI Among Various Land Cover Types in Kanto region, Japan

Abstract

The differences in the improved Temperature Vegetation Dryness Index (iTVDI) and the Normalized Difference Vegetation Index (NDVI) between eleven land cover types in northwestern part of the Kanto region of Japan were analyzed using Landsat5 TM data and a vegetation map. The results showed that there were significant differences in iTVDI and NDVI values among the land cover types. The NDVI values were highest in the forest regions including evergreen forest, deciduous forest and mixed forest, while the iTVDI values were relatively lower in comparison to other land cover types, except for water. The iTVDI values of the grassland, cropland and orchard were higher while their NDVI values were not very low. And the iTVDI value of the paddy field was much higher than that of the water. In order to identify the reason, these land cover types were further classified into two classes respectively, the paddy field was classified into water-covered and not water-covered, and the other land cover types were classified into the full-covered and partialcovered. Consequently, the iTVDI values of the water-covered region of the paddy field and the well-vegetated region of the other three types were reduced. These results suggest that different land cover types cause the differences of iTVDI values and NDVI values due to the different fraction of vegetation cover and transpiration rates.