基于地貌分区的陕西省区域生态风险时空演变

Spatiotemporal changes of regional ecological risks in Shaanxi Province based on geomorphologic regionalization

论文采用"概率-损失"二维风险模型解构陕西省区域生态风险,基于地貌分区视角识别多源风险类型的同时以景观格局与生态系统服务价值为关联要素合成潜在生态损失,在此基础上分析了陕西省2000-2015年单一风险要素及区域生态风险的时空分异,并基于地貌分区视角结合重心模型探讨了生态风险的时空迁移。结果如下:①2000、2015年陕西省多源危险度分别为0.3837、0.4558,上升18.79%,大致呈现南北高、中间低的空间格局,沿南北轴线呈现"W型"展布;潜在生态损失分别为0.5537、0.6270,上升13.24%,除高原南部与秦岭东部山区外,生态损失均呈现高值;区域生态风险分别为0.2429、0.2865,上升17.95%,空间上呈现"三高夹两低"的分布格局。②从时序变化来看,秦巴山地保持较低风险且风险变化率较小;黄土高原与风沙过渡区变化率处于中等,后者面临较高风险;汉江盆地风险最高,该区域与关中平原分别为风险变化率的首位与次位。从生态风险重心变化趋势看,黄土高原与风沙过渡区重心均向西南移动,关中平原与秦岭山地重心东移趋势明显,汉江盆地与大巴山地重心跃向东南。

Land surface elements such as land use/land cover are in constant change and dynamic balance,driving the changes of global ecological processes and forming the regional differentiation of landscape, which cause many ecological risks under multi-source stresses. Based on a probability-loss risk model, a multiple hazards and potential ecological damage approach was used to construct a regional ecological risk evaluation system of Shaanxi Province. After identifying multiple hazard types from the perspective of geomorphologic regionalization, potential ecological damages were synthesized by taking landscape pattern and ecosystem services value losses as related factors. The spatial and temporal differentiation of individual risk factors and regional ecological risks in Shaanxi Province between 2000 and 2015 were analyzed. Meanwhile, the spatial and temporal changes of ecological risks were demonstrated from the perspective of geomorphologic regionalization and risk gravity model. Several conclusions were drawn from this analysis: 1) In 2000 and 2015, the multiple hazards index values of Shaanxi Province were 0.3837 and 0.4558, respectively, with an increase of 18.79%.Multiple hazards presented the spatial pattern of high in the north and south and low in the middle, with a Wshaped distribution along the north-south axis. Potential ecological damages were 0.5537 and 0.6270, up by13.24%. Except for the southern part of the Loess Plateau and the eastern part of the Qinling Mountains,potential ecological damages were high. The regional ecological risks were 0.2429 and 0.2865, rising by17.95%, and presented a spatial distribution pattern of "three high value areas sandwiched by two low value areas". 2) The ecological risks of the Qinling-Daba Mountains were low and the change rate of risks was small.The change rate of risks of the Loess Plateau and the sandification transitional zone was moderate, and the latter was facing a high risk. The Hanjiang Basin had the highest risks and the Hanjiang Basin and Guanzhong Plain took the first and second places in the change rate of risks, respectively. The risk gravity centers of the Loess Plateau and the sandification transitional zone both moved to the southwest, the risk gravity centers of the Guanzhong Plain and the Qinling Mountains moved significantly to the east, and the risk gravity centers of the Hanjiang Basin and the Daba Mountains jumped to the southeast.