基于遥感和InVEST模型的白龙江流域景观生物多样性时空格局研究

以甘肃白龙江流域为例,结合遥感、GIS技术和InVEST模型,从景观地理学角度选取区域生境质量、植物净初级生产力和景观状态指数为评价指标,构建区域景观尺度上生物多样性空间格局综合评估方法,并在栅格像元尺度上开展白龙江流域景观生物多样性时空变化特征分析。结果表明：白龙江流域景观生物多样性空间格局差异显著,其生物多样性高值区主要集中在自然保护区和林业管护区,低值区主要分布在舟曲-武都-文县的白龙江两岸及其以北区域、宕昌县岷江沿岸、高寒稀疏植被区和高山积雪-裸岩区。1990~2010年,流域景观生物多样性较为丰富,整体呈现不断增长的趋势,个别局部区域减弱,其增长区主要体现在生态工程实施区和林业管护区,减少区多分布在人类活动频繁的城乡农耕区和灾害多发区。

Spatiotemporal Change of Landscape Biodiversity Based on InVEST Model and Remote Sensing Technology in the Bailong River Watershed

Biodiversity is the material foundation and the environment guarantee that people are taken for their survival and development, and has four levels: molecular, species, ecosystem and landscape. The identification and understanding of the spatiotemporal variation of biodiversity in the landscape level are not just an important part of regional biodiversity monitoring and assessment, but also the first step in the formulation and implementation of the protection scheme. The Bailong River Watershed of the Gansu Province (BRWGP), one of the most abundant biodiversity regions in China, locating in the transitional ecotone along the Tibetan Plateau, Loess Plateau, and Qinba Mountains. The BRWGP served as a case to analyze the spatiotemporal heterogeneity of biodiversity. Based on the data integration analysis platforms of RS, GIS technology and InVEST 2.5.6, a comprehensive index system of biodiversity spatial patterns constructed with the incorporation of habitat quality, vegetation net primary productivity, and landscape state index by considering the difference of three assessment indicators intensity and influence degree. Meanwhile, AHP was used to determine the weights of index and GIS spatial technology apply to analyze the spatial distribution and differentiation of biodiversity under the landscape geography perspective. Our goal went to revise the biodiversity evaluation module of the InVEST model and demonstrate biodiversity spatial patterns on a grid cell. The results indicated that biodiversity was high and had obvious spatial pattern variations in the BRWGP. Areas with higher biodiversity mainly distribute in the national nature reserve and forest, while the relatively poor biodiversity areas distribute in the valleys of the BRWGP between Zhouqu-Wudu-Wenxian, the valley of Minjiang in Tanchang County, alpine mountain snow regions, and bare rock zones. Moderate biodiversity areas appeared in agroforestry ecosystem, shrub and grassland, which a vegetation cover, species richness and habitat quality were general. In 1990-2010, biodiversity was high and increasing, the area proportion of higher biodiversity (critical areas) increased from 16.74% to 26.02%. Meanwhile, the high growth area of biodiversity change was concentrated in the ecological engineering zone and forest districts (Such as these forest districts of Duoer, Axia, the Minshan Mountain, Baishuijiang Nature Reserve), while biodiversity reduction area locates in the region of human activities intensively and frequently, such as cultivated area, urban and rural areas.