近20a来巢湖流域生态服务价值空间分异机制的地理探测

Spatial differentiation of ecosystem service values and its geographical detection in Chaohu Basin during 1995-2017

生态系统服务功能是生态系统和生态过程形成和维持的自然环境条件及作用。基于1995-2017年遥感分类数据,对研究区按3 km×3 km幅度网格化2019个样方,利用空间统计和缓冲区等方法进行巢湖流域生态服务价值时空演变特征分析,应用地理探测器工具揭示生态服务价值空间分异的主导因子及因子交互作用机制,并提出生态服务价值空间优化策略。结果表明:①巢湖流域生态服务价值量由1995年的303.17亿元分别下降为2005年300.95亿元和2017年287.70亿元,近20a来减少约5.11%,年均下降率0.23%,其中合肥市区、巢湖南部和东部地区降速明显;②生态服务价值等级空间转移分析表明,巢湖流域低级别生态服务价值区域在扩展,中等及高级别区域在缩小。以巢湖为核心的缓冲区分析表明,20a来缓冲区核心环带内生态服务价值量下降18.55%,巢湖流域水环境保护核心区的生态系统功能变化值得关注;③地理探测分析表明,人为影响综合指数是生态服务价值空间分异的主导因子;地形、气象因素是重要影响因子;人为影响指数因子、自然因子及社会经济因子的交互协同增强效应共同影响了流域生态服务价值在空间上的分异效果。研究结果在一定程度上可为巢湖流域生态系统调控与优化提供理论依据。

Ecosystem service function refers to the natural environment condition and function in the formation and maintenance of the ecosystem and ecological process. In this study,landscape classification maps were acquired from Landsat TM/ETM +/OLI remote sensing images for years of 1995, 2005 and 2017 respectively in the Chaohu Basin. Based on township administrative units in the study area, and the study area was meshed into 2019 quadrates by a range of 3 km by 3 km, and the spatial-temporal evolution characteristics of the ecosystem service value(ESV) in the Chaohu Basin were analyzed by using spatial statistics and buffer zone tools. Finally, based on the geographical detector tool, the interaction mechanism of natural, humanistic and socio-economic factors of the temporal-spatial changes of the ESV in the Chaohu Basin was analyzed, and the strategies for the spatial optimization of ESV were proposed in the paper. The major results were shown as follows. Firstly, the ESV of the Chaohu Basin decreased from 30.317 billion yuan in 1995 to 30.095 billion yuan in 2005 and 28.770 billion yuan in 2017, respectively. During the last 20 years, the ESV decreased by 5.11%, with an average annual decline rate of 0.23%. Secondly, the analysis of spatial transfer of ESV in the Chaohu Basin showed that the region of low level ESV was expanding and the regions of medium and high level were shrinking. The buffer zone analysis with the Chaohu Lake as the core showed that when it is far from the Chaohu Lake, the decline trend of ESV decreases, and the ESV in the core buffer zone during the past almost 20 years decreased by 18.55%. The change of ecosystem function in the core area of water environment protection zone of the Chaohu Basin deserves attention. Thirdly, the analysis of geographical detection showed that the human active index(HAI) was the leading factor of spatial differentiation of ESV;the terrain and meteorological factors were the important factors;the interaction of human impact factors, natural factors and social and economic factors jointly affected the spatial differentiation characteristics of ESV in the Chaohu Basin. Under the background of ecological civilization construction, the results of spatial-temporal evolution characteristics and spatial differentiation driving research of ESV can provide theoretical basis for the regulation and optimization of ecosystem in the Chaohu Basin.