Forest change detection using Tiangong-1 and Landsat 7 earth observation data

Abstract

Tropical forest plays an important role in sustainable development, biodiversity conservation, and offers many environmental benefits, including essential ecosystem services such as climate change mitigation and adaptation. Deforestation is one of the main problems in tropical area. In this paper, we used hyperspectral data from Tiangong-1 space station platform and historical Landsat 7 ETM+ data to map forest coverage and detect forest changes in the tropical forests of Xishuangbanna, Yunnan province, China. First, pure forest pixels were extracted according to the characteristic in the histogram of red band. Then spectral similarity was calculated for each pixel with these pure forest pixels. This similarity index was used to generate forest coverage map. Then a forest change map was generated using these multi-temporal coverage maps. After evaluated with field survey data, the results showed that:(1) The hyperspectral data from Tiangong-1 can be used to map forest coverage effectively. The forest distribution pattern agreed well with ground survey data. (2) With the aid of historical forest coverage map, the forest changes can be detected. The deforestation and reforestation patches were characterized well. The recent reforestation stands in low canopy density level can also be detected.