Abstract: Using Landsat TM/ETM+ remote sensing image as data source, based on GIS and RS technology, using annual change rate and lake change intensity index and other methods to quantitatively analyze the change trend and characteristics of Hongze lake in 1988—2017. By collecting the meteorological data and artificial conservation data of Hongze lake in 1988—2018, combined with the local actual situation, the main causes of area change were studied in depth. ①From 1988 to 2017, the natural lake surface of Hongze lake showed a trend of shrinking-stable-shrinking. In the past 30 years, it decreased 125.81 km², the relative shrinking rate was 9.88%, and the intensity change index （Q） was -0.34. In comparison, the third stage （2009—2017） decreased significantly, followed by the first stage （1988—2000）, and the second stage （2000—2009）, which was relatively stable, with Q of -0.61, -0.24 and -0.13, respectively. In terms of regional location, the change of Hongze lake area was mainly concentrated in the west of the lake area, followed by the northeast. ②Both temperature and precipitation factors are linearly related to the change of lake level, and the overall increase of temperature in 1988—2018 promotes the increase of evaporation; The change of precipitation also leads to the decrease oflake supply. ③From 1988 to 2017, the area of artificial aquaculture expanded 20 times, which directly led to the loss of 5.0% of the natural lake. ④During the change of lake stage, policy change and flood disaster are also the driving factors that affect the change of the natural lake surface of Hongze lake. From 1988 to 2017, the natural lake surface of Hongze lake basically showed a trend of gradual shrinking. Meteorological factors, policy changes and flood and waterlogging disasters caused the lake surface to shrink, but purse seine farming was the main reason for its change.

Key words: Hongze lake, natural area change, influence factor, culture in enclosure