Wetland is a unique ecosystem formed by the interaction of water and land on the earth. It is one of the most important living environments and the most biologically diverse landscapes in nature. It is resistant to floods, regulates runoff, replenishes groundwater, improves climate, controls pollution, beautifies the environment and maintains Regional ecological balance and other aspects have a role that cannot be replaced by other systems. Wetlands always provide a variety of services to human beings in obscurity. Human production and life are inseparable from wetlands.

The wetland developed in different parts of the basin has different ecological service functions:

◆Independent wetland is a habitat for waterfowl foraging and nesting. It provides land and wetland species habitats, buffers floods, and is beneficial to the absorption, transformation and deposition of sediments and nutrients. It has landscaping aesthetic significance.

◆ In addition to the above-mentioned functions, the lakeside wetland also has the functions of removing sediments and nutrients from the water bodies in the basin, and is also a hatching area for fish hatching.

◆ In addition to the independent wetland service function, the riverside wetland also has sediment control, stable river bank and flood drainage function.

◆The estuary and offshore and coastal wetlands, in addition to the service functions of independent wetlands, can also provide fish, crustacean habitats and spawning areas, and provide marine fish.

Nutrients to prevent the erosion of storm surges.

◆ Island wetlands provide sandy habitats to prevent erosion of high-energy waves and have aesthetic significance.

◆ Peat swamps, especially oligotrophic peat bogs, also have a special function, namely antisepsis and preservation. The bodies of humans and animals buried in the peat layer can be preserved for hundreds or even thousands of years. Trees that have been buried in peat for thousands of years can still be made into furniture.

Wetlands that develop in different parts of the basin (Zhao Xuemin, 2005)