Study On Landscape Ecological Quality In Poyang County Based On Land Use Change

At present,our government actively promotes the construction of new urbanization and ecological civilization.Poyang County,known as the "Lake City of China",is located in the geographical center of the "Poyang Lake Eco-economic Zone".Taking Poyang County as the research area,this thesis constructs a comprehensive evaluation system of landscape ecological quality from two aspects of stability and disturbance,evaluates the landscape ecological quality grade.At first,based on 0.5km Grid,Inverse Distance Weight Interpolation(IDW)and Spatial Autocorrelation Analysis were used to analyze the spatial and temporal characteristics of landscape ecological quality in Poyang County from 1995 to 2015.Then,the CA-Markov model was used to predict the land use pattern in Poyang County in 2025 and to analyze the spatial and temporal heterogeneity of landscape ecological quality.The main conclusions are as follows:(1)The proportion of cultivated land and woodland in the land use types of Poyang County is 72%,in which cultivated land is the largest,accounting for about 40% of the whole research area.The area of cultivated land is decreasing continuously,which is mainly converted into woodland and construction land;the area of construction land has been increasing,and the woodland shows the trend of "increase-decrease-increase";the water areas shows the trend of slow decrease;the unused land shows the trend of "decrease-increase-decrease",basically shifting to the water areas.(2)According to the selected 15 landscape pattern indices,analysis the land use landscape pattern spatial distribution characteristics in Poyang County:(1)On the level of landscape types,there are great differences and strong spatial heterogeneity among different types of land use landscape.(2)On the level of landscape,the landscape pattern of Poyang County shows the characteristics of diversity and equalization,and the structure is complex.Landscape patch shape of each land use type tends to be complex,showing complex distribution,better aggregation degree,better spatial connectivity,landscape fragmentation degree shows an increasing trend.(3)The overall landscape ecological quality of Poyang County showed a significant downward trend,and the spatial difference was obvious.The landscape ecological quality of the northeast low mountains and the southwest Poyang Lake waters gradually became more stable-instable-extremely instable to the center of the county.The spatial autocorrelation method analyzes the results as follows:(1)On the whole,the landscape ecological quality of Poyang County shows a positive spatial autocorrelation.(2)From the local point of view,the spatial distribution of Local Moran's I shows high-high clustering and low-low clustering.The spatial outliers(low-high and high-low clustering)are not obvious.The "hot spot" and "cold spot" areas of Poyang County are basically the same throughout the study period.The "hot spot"(high-high)mainly distributes in the northeastern low mountain forest and the southwestern Poyang Lake waters areas.The "cold spot"(low-low)districts are mainly distributed mainly distributed in the county as the center to continue to spread around the trend.(4)Compared with 2015,the landscape ecological quality of Poyang County in 2025 is predicted: the area of first-class stability and second-class stability continues to decline,while the third-class instability and fourth-class extremely instability show a significant increase.The main reason is that the urban center of Poyang County,such as Poyang Town,Tuanlin Town,and Sishilijie Town,Terrain is relatively flat,and the surrounding cultivated land and water areas are largely occupied for construction land;Lianhuashan Township,Jiantianjie Township,Houjiagang Township in the Northeast because of its high terrain and high vegetation coverage,and the southwest of the Yaquehu Township,Yinbaohu Township,Baishazhou Township,because of its close to the waters of Poyang Lake,and the Poyang Lake National Wetland Ecological Reserve also is located.So the landscape ecological quality has been stable.This shows that the landscape ecological quality of Poyang County in the future is still developing in accordance with the trend of previous years,with a significant reduction in the rate of decline in a slow decline.