Change Characteristics of Water Cover in the Sanjiang Plain Based on Multi-source Remote Sensing Images
In response to the problems of low temporal resolution and missing information in previous studies using Landsat TM images for wa-ter cover recognition,combined with the advantages of high spatial resolution of Landsat TM images and high temporal resolution of MODIS im-ages,by establishing the relationship between the water distribution proportion extracted from Landsat TM images and the MODIS bands and de-rived indicators,a water fractional coverage model(FCWM)was constructed to simulate the formation of water cover spatiotemporal se-quences,analyse the change characteristics of water fractional coverage in the Sanjiang Plain.The results showed that from 2002 to 2020,the water fractional coverage of the Sanjiang Plain showed a decreasing trend,with an average decrease of 23.63 percentage points in overall water fractional coverage.With higher precipitation in 2020 than in 2002,many areas with high,relatively high and medium water fractional coverage were downgraded to lower and low levels.