Study On The Evolution Characteristics And Driving Forces Of Wetlands In Nanchang

As one of the most important ecosystems on earth,wetlands play a huge role in the ecological environment.Studying the wetland landscape pattern can help us understand the law of the spatiotemporal evolution of wetland landscape more clearly,which is of great significance for protecting the ecological environment and promoting reasonable economic development.Nanchang is located in the subtropical monsoon region of my country,on the southwestern shore of the largest freshwater lake,Poyang Lake.It is a capital city with a large wetland area,and is typical of wetland research.With the advancement of policies such as "Ecological Civilization Construction" in Jiangxi Province and "Creation of Wetland Cities" in Nanchang,the research results of wetlands in Nanchang have become more and more abundant,and the issue of wetlands has received more attention.This paper is based on GIS and RS technology,using Landsat remote sensing images as data sources,by establishing a wetland classification system and interpreting signs,to achieve 20-year wetland data extraction in Nanchang,establishing a wetland information dataset in Nanchang,shifting from spatio-temporal dynamic characteristics and wetland types The matrix and the wetland landscape pattern analyze the characteristics of wetland evolution in Nanchang from three aspects,and explore the driving factors affecting the wetland evolution in Nanchang from both social and natural perspectives,with a view to providing data for wetland protection and development in Nanchang.This article mainly draws the following research conclusions:(1)There are abundant types of wetlands in Nanchang,with a wide area distribution,accounting for more than 20% of the total area of the study area.Lake wetlands have the largest area and are unevenly distributed in the study area.River wetlands are mainly attributed to the Gan River water system.Grass and mudflat wetlands are concentrated in relatively low-lying areas with high humidity.Artificial wetlands are scattered in low and close terrain.Water source location.(2)Over the past 20 years,the transformation of wetland landscape types in Nanchang has been complicated,and there is no trend of continuous increase or decrease.From 1999 to 2018,the wetland area of Nanchang increased by 805.9 hectares.Among them,the wetland area reached the largest in 2014,being 156177.51 hectares.The overall performance is that the area of lake wetlands decreases and the area of artificial wetlands increases,and that of river wetlands is relatively stable.Through dynamic calculation,it is known that the largest amount of wetland type conversion is from 2014 to 2018.(3)The calculation of the wetland landscape pattern index shows that the wetland landscape in Nanchang has poor connectivity and poor aggregation,which is not conducive to wetland protection and management.The specific manifestation is that the fragmentation degree of the wetland patch landscape level and the patch type level is intensified,the lake wetland tends to be scattered and the connectivity is poor,and the aggregation degree of grass wetland is not high and continues to develop into fragmentation.(4)The analysis of the driving force of wetland evolution in Nanchang shows that socioeconomic factors and natural factors are both important factors influencing the change of wetland landscape in Nanchang.