汾河流域生态敏感性综合评价及时空演变特征

Abstract

基于格网尺度，在定量构建景观生态风险敏感性、水土流失敏感性、生物多样性敏感性的基础上，对汾河流域综合生态敏感性进行评价，采用空间自相关分析与圈层分析方法，揭示其时空演变特征。结果表明：2000-2018年研究区重度、极度敏感区面积减少，生态环境得到改善，生态敏感性空间分异与流域地形分布具有一致性；生态敏感性具有显著的空间正相关关系，在空间上呈连片连带式分布，具有明显的聚集性特征，随着高高、低低聚集网格数量的减少，生态敏感性空间结构逐渐趋于离散化；结合圈层分布，可将西南象限9-13圈层的吕梁山区与东南象限9-13圈层的太岳山区识别为流域生态环境治理的重点区域，此类区域地形以山地丘陵为主，体现了地形因素对流域生态敏感性空间分布的影响；研究区生态敏感性变化是生态本底与人类胁迫共同作用的结果。;On the basis of quantifying landscape ecology risk sensitivity, soil erosion sensitivity, and biodiversity sensitivity in a grid scale format, this paper comprehensively evaluated the ecological sensitivity of the Fenhe River Basin. Methods such as spatial autocorrelation analysis and circle analysis were employed to display the characteristics of spatiotemporal variations in the Basin. According to the research findings, the Basin presented a reduction of severe and extremely sensitive areas and an improvement of the ecological environment from 2000 to 2018. The spatial differentiation of the ecological sensitivity was consistent with the terrain distribution of the Basin. The areas with higher comprehensive ecological sensitivity were mainly distributed in Luya Mountains Region and Yunzhong Mountains Region at the source of the Fenhe River Basin. The areas with lower ecological sensitivity were mainly distributed in Fenhe Reservoir and its surrounding areas, Taiyuan Basin in the middle reaches and Linfen Basin in the lower reaches. While the ecological sensitivity presented a significantly positive spatial correlation, showing a pattern of interconnecting areal and zonal distributions with obvious agglomeration characteristics. The low-low(LL) aggregation areas were mainly related to extreme and severe sensitive areas, while the high-high(HH) aggregation areas were mainly related to mild sensitive areas. With the decrease in the number of high-high and low-low aggregation grids, the spatial structure of the ecological sensitivity tended to be discretized. The range of distribution of circles in severe and extremely sensitive areas showed a trend of first enlargement and then narrowing, which showed that with the change of time, severe sensitive areas and extremely sensitive areas decreased and the ecological environment of the study area was improved. According to the distribution of quadrants, severe sensitive areas and extremely sensitive areas were mainly distributed in the southwest and southeast quadrants. According to the distribution of circles, Lüliang Mountains Region in the 9^th to the 13^th circles of the southwest quadrant and Taiyue Mountains Region in the 9^th to the 13^th circles of the southeast quadrant were identified as key areas for the ecological environment governance. The topography of this kind of region is mainly mountainous and hills, which reflects the influence of terrain factors on the spatial distribution of ecological sensitivity of the Basin. Variations of the ecological sensitivity in the study area are the result of the combined effect of ecological background and human stress. The natural background determines the ecological environment and human living conditions of the Basin, and human activities in turn can affect or even change the ecological environment of the Basin.