切尔诺贝利核事故对区域景观格局及生境质量的影响

Impact of Chernobyl nuclear accident on regional landscape pattern and habitat quality

灾难地景观格局及生境质量演化特征研究对于评估灾难破坏力及其滞后性,揭示人类活动对自然环境的影响机制具有重要意义。基于Landsat系列遥感影像提取切尔诺贝利隔离区景观类型结构,借助景观指数和InVEST模型刻画研究区近49年来的景观格局和生境质量演化轨迹,使用CA-Markov模型模拟核事故对区域生态景观的影响。研究表明:(1)切尔诺贝利核事故改变了隔离区原有的景观结构,导致耕地、建设用地等人为景观数量大幅缩减,土地利用程度显著下降,但核事故未对隔离区当前的景观结构造成实质性负面影响;(2)切尔诺贝利核事故致使隔离区人为干扰减少,植被连通性和集聚度提升,景观格局总体向好发展;(3)隔离区的设立扭转了区内生境质量恶化趋势,由耕地形成的低生境质量区域迅速转变为草地、林地等高生境质量区域,区内生境质量极大改善;(4)切尔诺贝利核事故使得区内高生境质量区域占比提升34%,改变了原有以耕地、建设用地不断扩张为主线的景观演化轨迹和生境质量不断退化的发展趋势。

The study of the landscape pattern and the evolution characteristics of habitat quality in disaster areas is of great significance for assessing the destructive power of the disaster and its hysteresis,and revealing the impact mechanism of human activities on the natural environment.Extraction of landscape type structure of the Chernobyl Exclusion Zone based on Landsat series of remote sensing image.Using landscape index and InVEST model to describe the landscape pattern and habitat quality changes in the study area in the past 49 years.Using CA-Markov model to simulate the impact of nuclear accident on regional landscape and ecological environment.The results showed that:(1)the Chernobyl nuclear accident changed the original landscape structure in the exclusion zone,resulting in a significant reduction in the number of artificial landscapes such as cultivated land and construction land.The intensity of land use has declined significantly,but the nuclear accident did not cause a substantial negative impact on the current landscape structure of the exclusion zone.(2)The Chernobyl nuclear accident resulted in the reduction of human interference in the exclusion zone,the increase of vegetation connectivity and concentration,and the overall development of the landscape pattern.(3)The establishment of the exclusion zone has reversed the deterioration of the habitat quality in the area.The low habitat quality area formed by the cultivated land has rapidly transformed into high habitat quality areas such as grassland and woodland,and the habitat quality in the area has been greatly improved.(4)The Chernobyl nuclear accident increased the proportion of high habitat quality areas in the region by 34%,changing the original landscape evolution trajectory based on the continuous expansion of cultivated land and construction land and the trend of habitat quality degradation.