基于土地利用/覆盖的甘肃省景观生态风险时空变化特征

甘肃省景观类型丰富多样，在中国西部地区的生态安全中起关键性作用，也为当地发展提供着重要的物质基础和生态服务。由于气候变化和人类不合理活动的影响，甘肃省部分地区生态环境的安全与稳定遭到严峻挑战。本研究基于欧洲航空局全球土地利用/覆盖数据（CCI-LC），利用动态度、转移矩阵方法分析了2005-2019年甘肃省土地利用/覆盖变化特征；通过构建景观生态风险指数并运用空间自相关分析法分析了景观生态风险的空间分布特征。结果显示：1)2005-2019年间，裸地面积减少最多，变化率1.88%，耕地次之，变化率2.31%；草地面积增加最多，变化率1.83%，建设用地次之，变化率191.08%。2）所有土地利用/覆盖类型中，建设用地的动态度最高且在整个研究时期内变化速率都保持在较高水平，综合动态度最大的时期为2010-2019年。3）土地利用/覆盖转移矩阵主要表现为耕地、林地、草地、裸地之间的转入与转出以及其他土地类型向建设用地的转入。4)2019年整体的生态风险值较2005年明显上升。其中低风险区和较低风险区面积最多，转化最频繁；中等风险区、较高风险区和高风险区面积虽然较少，但都存在不同程度的增长。...

Characteristics of temporal and spatial variation in landscape ecological risk in Gansu Province based on land use and cover

Gansu Province has rich and diverse landscape types， which play a key role in the ecological security of Western China， and also provide important material bases and ecological services for local development. Due to the impact of climate change and unsustainable human activities， the security and stability of the ecological environment in some areas of Gansu Province has become severely challenged. Based on the climate change initiative-land cover （CCI-LC） data of European Aviation Administration， this study analyzes the characteristics of land use and cover change in Gansu Province from 2005 to 2019， using a ‘dynamic degree and transfer matrix’ methodology. By constructing the landscape ecological risk index and using the spatial autocorrelation analysis method， this study analyzes the spatial distribution characteristics of landscape ecological risk. It was found that： 1） From 2005 to 2019， the area of bare land decreased the most， with a change over the 15-year study period of 1.88%， followed by cultivated land， with a decrease of 2.31%； grassland area increased the most， with a five-year change （an annual increase） of 1.83%， followed by construction land， with an increase of 191.08%. 2） Among all land use and cover categories， the extent of change for construction land was the highest， and the rate of change remained at a consistently high level throughout the study period. The period with the highest overall extent of change was 2010-2019. 3） The land use/cover transfer matrix was mainly comprised of the transfer in and transfer out of cultivated land， forest land， grassland and bare land， as well as the transfer in of other land types to construction land. 4） The overall ecological risk value in 2019 was significantly higher than in 2005. Among the risk categories， the ‘low-risk’ category had the largest area， and the most frequent occurrence of transformation. Areas designated ‘medium risk’ and ‘high risk’ were comparatively small， they all have exhibited different degrees of growth. 5） From 2005 to 2019， Moran’s I remained at a high level. This index was positively correlated with the spatial distribution of landscape ecological risk and had a strong aggregation effect. The purpose of this study is to provide a scientific basis for land use planning and ecological risk control in Northwest China.