1980-2018年银川市景观格局与生态安全分析

Analysis of the landscape pattern and ecological security of Yinchuan City from 1980 to 2018

基于银川市的土地利用数据,利用景观格局指数、转移矩阵、土地利用状态指数和生态安全度指数,进行长时序时空格局变化的动态分析,结果表明,1980-2018年银川市土地利用中建筑用地大幅增加,耕地整体上升,草地与未利用土地呈下降趋势,林地和水域保持稳定;银川市的土地斑块破碎化程度降低,建筑用地空间连通性越来越好,城市发展布局越来越合理化,最大斑块指数、散布与并列指数、香农多样性指数、景观形状指数和蔓延度指数能够很好地揭示银川市土地利用景观格局的空间变化特征;1980-2018年银川市土地利用频繁转移导致景观格局空间变化显著,主要表现为草地和未利用土地先转变为耕地,部分耕地再转变为建筑用地.建筑用地的分布最集中且分离度和破碎度不断降低,景观水平上整体景观的异质性、多样性及均匀度增加,多样性指数高的区域不断扩大,城市景观向规则和均衡化方向发展;银川市的整体景观格局生态安全度从1980年的0.657上升至2018年的0.766,城市的生态环境逐渐变好.

Based on land use data of Yinchuan City,landscape pattern index,the transfer matrix and the index of land use status were used,and the pattern of time and space dynamics analyzed,with the conclusions that the construction land increased dramatically,cultivated land rose overall,grassland and unused land were on the decline,woodland and water was stable from 1980-2018 in Yinchuan.The results showed that the fragmentation degree of land patches in Yinchuan had been reduced,the spatial connectivity of construction land was getting better and better,and the urban development layout of Yinchuan was becoming more and more reasonable.The largest patch index,intersperse and juxtaposition index,Shannon diversity index,landscape shape index and contagion index could well reveal the landscape pattern of Yinchuan;the frequent transfer of land use in from 1980 to 2018 resulted in significant spatial changes in landscape pattern,mainly manifested in that grassland and unused land were transformed into cultivated land,and part of cultivated land was transformed into construction land.The distribution of construction land was the most concentrated,and the degree of separation and fragmentation had been decreasing,the heterogeneity,diversity and evenness of the overall landscape were increasing,the areas with a high diversity index expanding,and the urban landscape developing in a regular and balanced direction.The ecological security degree of the overall landscape pattern of Yinchuan City increased from 0.657 in 1980 to 0.766 in 2018,and the ecological environment of the city gradually improved.