Xui Yan, Sun Xiao Yin, Zhang Da Zhi, Shan Rui Feng, Liu Fei
Shandong Universities Key Laboratory of Nansihu Lake Wetland Ecological and Environmental Protection/College of Geography and Tourism, Qufu Normal University, Rizhao 276826, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2018 Feb;29(2):635-642. doi: 10.13287/j.1001-9332.201802.013.
Landscape pattern and its vulnerability have direct impacts on ecological environment in the basin. In order to protect the ecological security in Nansihu Lake basin, we analyzed the changes of landscape pattern based on seven sets of land use data (1980-2015), with landscape adaptability index (LAI) and landscape sensitivity index (LSI) being used to build the landscape vulnerability index (LVI). The spatial distribution and changes of LVI were analyzed. Results showed that the percentage of arable land areas decreased by 4.6% and construction land areas increased by 39.7% from 1980 to 2015. Other land use types showed fluctuating changes. The areas of forest land, grassland, and unused land decreased while water area increased. The arable land was the dominant land use type from 1980 to 2015 in this area. The degree of fragmentation of arable land and water area in the basin increased, whereas other land use types decreased. The fragmentation of whole basin decreased, but connectivity among landscape types enhanced. The irregularity and complexity of landscape pattern decreased, but diversity and evenness of landscape pattern displayed an increasing trend. With respect to LVI in different periods, the eastern part of the basin was higher than the western part, while the northern part was higher than the southern part. The spatial distribution of LVI was related to topography, layout of landscape types and change of land use. The LVI of Nansihu Lake basin showed a decline trend during 1980-2015. In the eastern part of the basin, higher level of LVI gradually dispersed and was replaced by lower level. In the northwest, the recovery of LVI was obvious. In the south and southwest parts, LVI was consistently low.
景观格局及其脆弱性对流域生态环境有着直接影响。为保护南四湖流域的生态安全，基于七组土地利用数据（1980 - 2015年）分析了景观格局变化，采用景观适应性指数（LAI）和景观敏感性指数（LSI）构建景观脆弱性指数（LVI），并分析了LVI的空间分布及变化情况。结果表明，1980年至2015年，耕地面积减少了4.6%，建设用地面积增加了39.7%，其他土地利用类型呈现波动变化，林地、草地和未利用地面积减少，水域面积增加。该区域1980年至2015年耕地是主要土地利用类型。流域内耕地和水域的破碎化程度增加，其他土地利用类型则降低，整个流域的破碎化程度降低，但景观类型间的连通性增强，景观格局的不规则性和复杂性降低，而景观格局的多样性和均匀度呈上升趋势。不同时期的LVI情况显示，流域东部高于西部，北部高于南部。LVI的空间分布与地形、景观类型布局及土地利用变化有关。1980 - 2015年南四湖流域LVI呈下降趋势，流域东部较高水平的LVI逐渐分散并被较低水平取代，西北部LVI恢复明显，南部和西南部LVI一直较低。
