The researchers used satellite data to study changes in the Raoyanghe wetlands from 1975 to 2007. They found that the area of marsh wetlands decreased, turning into rice fields and bare land. The center of the marshes moved over time, closer to the river. Human activities, like farming and land development, were the main reasons for these changes. The depth of groundwater and economic activities also played a role in the decline of the wetlands. In summary, human actions are causing the Raoyanghe wetlands to shrink and change over time.