关键词: 洞庭湖, 洲滩地, 淹水天数, 湿地演替

Abstract:

The paper discussed flooded days and areas of beach wetlands in Dongting Lake.To identify the flooded days in a year in the beach wetland，daily data of water level in Dongting Lake during 1952~2000 were applied.Variations of different flooded days in a year and area of the beach wetland were identified by using data from TM satellite picture with assistance of correlation analysis and interpolation method.Reduction of flooded days in a year in the beach wetland in east Dongting Lake during 1990’s indicated that it had shown reverse succession.The area of beach wetland flooded more than 100 days in a year had reduced in south Dongting Lake；however，the area of beach wetland flooded less than 100 days had enlarged.These indicated that the positive succession is the essential case in south Dongting Lake.Enlarging of beach wetland of different flooded day in a year in west Dongting Lake indicated that it had taken the place for positive succession.Correspondingly，it was proposed that it is not suitable to plant in the low beach wetland of Dongting Lake，and reed production should be shifted gradually to the west and south parts of Dongting Lake.

Key words: Dongting Lake, beach wetland, flooded days, wetland succession