Attempt of Expansion Detection of Bamboo Forest in Kochi City by Classification Tree Using Existing Bamboo Location Data and Sentinel-2 Satellite Imagery

Abstract

The distribution area of bamboo forests was databased using aerial photos as basic data for the management and effective utilization of bamboo forests. However, bamboo forests are expected to expand over the year, and a method to continuously monitor their expansion is required. Therefore, using Sentinel-2 satellite images, the classification tree (overall accuracy: 95%) was created using satellite image in the shortwave infrared band (spatial resolution: 20 m), which is reported to be effective for extracting bamboo forest. By applying this tree to satellite images taken in 2018 and 2021 and comparing the bamboo extraction results, we attempted to identify locations that bamboo forests might expand, and the expansion was confirmed in 61% of the sites surveyed. This result showed the usefulness of a simple method using a single band of satellite image to monitor the expansion of bamboo forests.