基于景观结构的生态移民安置区生态风险评价——以宁夏红寺堡区为例

Ecological risk assessment of an ecological migrant resettlement region based on landscape structure: A case study of Hongsibu in Ningxia

以宁夏自治区红寺堡区为例,以1995年、2000年、2005、2010年和2015年5期遥感影像为数据源,综合运用景观格局指数、生态风险指数、空间分析法以及地理探测器等多种研究方法,研究了移民安置区生态风险时空特征。结果表明:1995—2015年研究区景观格局发生了较大的变化,草地面积减少了2.97×10~4hm^2,耕地、林地、建设用地分别增加了1.90×10~4hm^2,0.42×10~4hm^2和0.43×10~4hm^2;在研究期间景观整体斑块数不断增加,其景观整体破碎度随之变大;研究区生态风险主要以较低风险和中风险为主,其中建设用地、沙地和未利用地生态风险值较高,在研究期间生态风险平均值由0.166降低至0.154,研究区生态风险值呈降低趋势。通过地理探测器诊断得出景观斑块数、景观破碎度、景观优势度、景观损失度、斑块密度等因素是安置区生态风险的主要影响因素。

In this study, the Hongsibu district of the Ningxia autonomous region is used as an example, and remote sensing images from 1995, 2000, 2005, 2010 and 2015 were selected as data sources. Landscape pattern index, ecological risk index, spatial analysis, and geographic detector were used to study the temporal and spatial characteristics of the ecological migration resettlement area. The results showed that the landscape pattern of the study area changed greatly from 1995 to 2015, the area of grassland decreased by 2.97 x 104 hm2, and the cultivated land, forest land, and construction land increased by 1.90×10^4hm^2, 0.42×10^4hm^2, and 0.43×10^4hm^2, respectively. During the study period, the overall patch number of the landscape increased, and the overall fragmentation of the landscape increased accordingly. The ecological risk of the study area was dominated by low and medium risk. Among these, the ecological risk of the construction land, the sandy land, and the unused land were high; the average ecological risk decreased from 0.166 to 0.154, and the ecological risk value of the study area decreased. The geographical detectors showed that the landscape patch number, landscape fragmentation degree, landscape dominance degree, landscape loss degree, and patch density were the main influencing factors of ecological risk in the resettlement area.