Abstract: Based on the 1989, 2000, and 2009 Landsat TM/ETM⁺ images of Yellow River Delta, and in combination with GIS approach and validation-on-spot, this paper analyzed the dynamic evolution and its driving factors of natural wetlands in the Delta. Under the effects of water and salinity, the spatial distribution of the natural wetlands presented a regular change pattern. The annual change gradient and dynamic degree of the natural wetlands area was -0.3 and 3.1 in 1989-2000, and -1.8 and 5.1 in 2000-2009, respectively, indicating an accelerated change of the natural wetland area in 2000-2009. Many factors affected this change, of which, the water regime of Yellow River was the main driving factor. There existed definite correlations between parts of the natural wetlands. Human factors such as the construction of culture pond and the reclamation for paddy field contributed to the reduction of natural wetlands. The increasing construction land was the main reason for the reduction of bush-grass lands.

Key words: Forest evapotranspiration, Broad leaved Korean pine forest, Survey, Calculation