Land use monitoring with Keyhole and Landsat MSS fusion images: case of south bank of Hangzhou Bay

Important early data for wetland land cover change monitoring can be provided by historical images．Historical remote sensing images with high spatial resolution and multi-spectral resolution were obtained after fusing Keyhole remote sensing images of Sept．20, 1980 with Landsat MSS remote sensing images of the same period, filling the gap of historical high-resolution remote sensing images for the south bank of Hangzhou Bay．These results would advance the time series of historical land use monitoring and improve accuracy of land use change monitoring of the south bank of Hangzhou Bay．Historical fusion images and four-scene Landsat remote sensing images from 1990−2020 were used to monitor and obtain land use types of the Hangzhou Bay．Combined with previous visual interpretation results, classification of land use at accuracy of > 90% was obtained．The temporal and spatial changes of land use from 1980−2020 were analyzed for area change, type transformation and average annual change rate．Reservoirs and ponds showed a degradation trend from 1980−1990, but cultivated land gradually expanded to coastal area．Expansion area of the city continued to increase from 1990−2020, showing a trend of expanding to the coast．Area of reservoirs and ponds increased significantly, artificial farms continued to expand to the coast．Urban development was the main factor affecting land use change．In future urban planning of Hangzhou Bay, ecological environment should be fully considered．Protection of natural wetlands should be strengthened, development scale of natural wetlands should be strictly controlled．For sustainable development, reasonable development and utilization with wetland protection should be considered．