延安地区植被覆盖度时空变化及驱动力

Spatiotemporal Variation and Driving Forces of Vegetation Coverage in Yan′an Area

植被作为反映气候变化和人类活动的敏感因子,对维持生态环境安全和变化具有重要作用。以地处黄土高原脆弱区的延安市为研究区,采用地理探测器模型,研究延安地区自然、人文因子及其交互作用对植被时空覆盖变化的影响,分析影响因子促进植被生长的适宜范围或类型。结果表明:(1) 2000—2018年延安市平均植被覆盖呈现增加趋势,增速为0.89/10 a,生态环境得到有效改善,95.52%区域属于增加区域,其中在2000—2010年植被覆盖面积增速最快,低植被覆盖区主要位于延安市中心城区;(2)降水、气温因素对植被NDVI空间分布的影响力最大。自然、人文因子之间对植被NDVI的交互作用以非线性增强和双因子增强效应为主;(3)通过分析研究区内适合植被生长的各影响因子范围或类型,为进一步促进延安市植被恢复和生态保护提供科学依据。

As a sensitive factor reflecting climate change and human activities, vegetation plays an important role in maintaining the safety and changes of the ecological environment. Yan′an region which is located in the fragile region of the Loess Plateau is taken as the research area, and the geographical detector model was employed to study the impact of natural and human factors and their interactions on the spatiotemporal coverage change of vegetation in Yan′an. The appropriate range or type of impact factors was determined to promote vegetation growth. The results show that:(1) from 2000 to 2018, the average vegetation coverage in Yan′an exhibited the increasing trend with a growth rate of 0.89/decade, the ecological environment effectively improved;95.52% of the area belonged to the improvement area and the growth rate of vegetation coverage area had been the fastest between 2000 and 2010. Areas with low vegetation coverage mainly located in downtown of Yan′an;(2) precipitation and temperature exerted the strongest influence on the spatial distribution of vegetation NDVI;the interaction between natural and human factors on vegetation NDVI was dominated by nonlinear enhancement and double factor enhancement;(3) the analysis of the range or types of various influencing factors suitable for vegetation growth in the study area provided the scientific basis for further promoting vegetation restoration and ecological protection in Yan′an City.