南沙区土地利用变化对生态系统服务价值的影响

从全球地表覆盖数据(GlobeLand30)中获取南沙区30 m空间分辨率的多光谱影像，采用土地利用变化动态度、土地利用转移矩阵和重心迁移模型测算了南沙区2010、2020年各类土地的时空变化；基于当量因子法，修正了社会经济因子调整系数和生物量因子调整系数，构建了南沙区生态系统服务价值评估模型，并探讨了在土地利用格局的变化下，南沙区生态系统服务价值的变化特征。研究结果表明:(1)2010—2020年，南沙区土地利用格局变化明显，除建设用地和湿地的面积得到增长外，其他各类用地面积均有不同程度的减少，其中耕地面积减少最多，建设用地面积增加最多。(2)在空间分布上，南沙区耕地、林地与草地的布局呈现明显的碎片化，而建设用地的扩张较为集聚。(3)2010—2020年，南沙区生态系统服务价值减少234.59亿元。建设用地占用城镇周边的耕地及围海填地是导致生态系统服务价值减少的重要因素，其中，围海填地导致水体和海域大面积减少，是造成生态系统服务价值减少的主要原因。值得注意的是，湿地面积的增加在一定程度上缓解了生态系统服务价值的降低。因此，为保障南沙区生态系统服务价值的稳定，应及时对湿地采取保护措施、控制建设用地的扩张规模、稳定林地及耕地的生态系统服务功能。

The Influence of Land Use Change on the Ecosystem Service Value in Nansha District

A 30 m spatial resolution multi-spectral image of Nansha District was obtained from the global land co-ver data (GlobeLand30), and the spatiotemporal variation of land use in Nansha District in 2010 and 2020 were calculated with land use change dynamic degree, transition matrix and the gravity center migration model. Based on the equivalent factor method, an evaluation model of ecosystem service value in Nansha District was constructed by revising the socioeconomic factor adjustment coefficient and biomass factor adjustment coefficient. The changing characteristics of ecosystem service value in Nansha District under the change of land use pattern was discussed. The results are as follows. The land use pattern in Nansha District changed significantly from 2010 to 2020. Except for the increase of construction land and wet land, other types of land decreased to different degrees. Among them, cultivated land suffered the largest reduction, but construction land underwent the largest increase. In terms of spatial distribution, cultivated land, forest land and grassland in Nansha District showed obvious fragmentation, but the expanded construction land was more concentrated. The total ecosystem service value in Nansha District from 2010 to 2020 decreased by 23.459 billion yuan. The diversion of cultivated land around the city for construction purpose and the reclamation of land from the sea were important factors in the reduction of the ecosystem service value. Among them, the reclamation of land from the sea led to a substantial reduction of the water body and the sea area, which was the main reason for the reduction of the ecosystem service value. However, it is worth noting that the increase in the wetland area alleviated the decrease in the ecosystem service value to a certain extent. In order to ensure the stability of the ecosystem service value in Nansha District, timely measures for protecting wetland should be taken, the scale of construction land expansion should be controlled, and the ecosystem service function of forest land and cultivated land should be stabilized.