Special Issue (Civil Engineering Infomatics) Paper
A SIMPLE VEGETATION CLASSIFICATION METHOD FOR ESTIMATING BIOMASS LEVEL IN RIPARIAN ZONE USING SATELLITE IMAGES
2023 Volume 79 Issue 22 Article ID: 22-22010
Details
2023 Volume 79 Issue 22 Article ID: 22-22010
The frequency of torrential rainfall has increased in recent years. Japanese rivers have steep slopes, short lengths, and small basin areas. Therefore, the risk of flooding is high, and understanding the river channel shape and cover as a basis for disaster prevention measures is essential. In terms of the environment, environmental maps of first-class rivers in Japan are prepared based on the census of riverside areas and are required to be updated once every five years. We believe that changes in biomass, which quantifies the amount of greenery, can be used as basic data for implementing various measures for both disaster prevention and the environment (e.g., changes in the runoff function focusing on roughness, changes in the amount of greenery in terms of CO2 absorption, etc.). In this study, we aimed at estimating the biomass of a first-class river in Japan and its long-term evolution (about 40 years) and devised a simple method to extract grasslands and forests from optical satellite images. Based on the results of this study, we proposed an excellent method for practical use by devising a method to extract green areas (herbaceous and tree) focusing on the quantization level of the data and the season.
