【摘要】 汉中市是国家级重点生态功能区、生物多样性保护关键区、南水北调中线工程核心水源涵养区和主要水源地,生态地位显著,对该区进行生态环境及风险研究意义重大。选取汉中市2007年、2011年和2017年3期遥感影像数据,综合运用景观生态学和地统计学基本原理与方法,利用RS和GIS空间信息技术,通过构建汉中市景观生态风险指数,对汉中市近十年景观生态风险时空变化特征进行了系统分析。结果表明:(1)研究区以林地和建设用地面积持续增加,耕地稳定减少为主要变化特征;林地和建设用地分别增加426.71,215.48 km~2,耕地减少539.33 km~2;(2)研究区林地优势度最为明显,研究期末达0.73;建设用地优势度增幅最快,10年增加了0.10;全区景观格局破碎化趋势明显;(3)研究区生态风险呈明显的倒"r"型分布。10年间,中高山区原有的集中连片低风险格局被打破;低山丘陵区生态修复工作成效显著,生态风险显著降低;(4)汉中市景观生态风险存在较强的空间正相关关系,但"高—高"和"低—低"风险聚集区分布范围逐渐缩小。更多还原

【Abstract】 Hanzhong City is a national key ecological function zone, a key area for biodiversity conservation, a core water source conservation area of the Middle Line of South-to-North Water Diversion Project and a major water source. The ecological status of Hanzhong City is prominent, so it is significant to evaluate the ecological environment and its risk of this area. Selecting remote sensing image data of Hanzhong City in 2007, 2011 and 2017, we use the basic principles and methods of landscape ecology and geostatistics, and using RS and GIS spatial information technology to construct landscape ecological risk index of Hanzhong City. The spatial and temporal variation characteristics of landscape ecological risk of Hanzhong City in the past ten years were systematically analyzed. The results showed that:(1) the areas of forest land and construction land in the study area increased continually, and the area of cultivated land was decereasing; the forest land and construction land increased by 426.71 and 215.48 km~2, respectively, and the cultivated land decreased by 539.33 km~2 for farmland;(2) the dominant degree of forest land in the study area was the most obvious, and the most rapid increase of the dominant degree was construction land; the fragmentation trend of the landscape pattern in the whole area was obvious;(3) the ecological risk of the study area showed an obvious inverted ‘r’ type distribution; in the past 10 years, the ecological risk of the original concentrated low-risk areas in the middle and high mountainous areas was intensified; the ecological restoration work in the low hilly areas was remarkable and the areas had low ecological risk;(4) there was a strong positive correlation between landscape ecological risk and the spaces in Hanzhong City, but the distribution ranges of ‘high-high’ risk clusters and ‘low-low’ risk clusters were gradually narrowing.更多还原