Temporal and spatial changes of the yellow river delta wetland based on multi-source data during 30 years

Estuary wetlands are important and vulnerable. In order to demonstrate the performance of the imaging data of Wide-band Imaging Spectrometer of Tiangong-2 in wetland classification and detect the changes of the Yellow River Delta wetland, we used object-oriented classification, landscape center of gravity transfer model and landscape index to depict the temporal and spatial changes of the Yellow River Delta wetland in the past 30 years from 1986 to 2016. Landsat 5 TM data in 1986 and imaging data of Wide-band Imaging Spectrometer of Tiangong-2 in 2016, as well as Landsat 8 OLI in 2016, were utilized. The imaging data of Wide-band Imaging Spectrometer of Tiangong-2 was fused with Landsat image by Gram-Schmidt spectral sharpening algorithm for analysis. It shows that: (1) After fusion with the higher resolution image, Tiangong-2 multi-spectral data is helpful for wetland study. (2) The natural wetlands decreased from 2404.24 km in 1986 to 1666.47 km in the past 30 years. Human-made wetlands increased from 42.41 km in 1986 to 836.58 km in 2016. (3) During the past 30 years, the gravity centers of natural wetlands, human-made wetlands and non-wetlands have been shifting towards the sea respectively. The shifting distance of human-made wetlands was larger. (4) The wetland landscape index indicated that the landscape pattern dominated by natural wetlands tended to be dominated by non-wetlands.