广西海岸带土地利用时空格局及其驱动因子

明确广西海岸带土地动态变化趋势及其驱动因子,为优化该区土地利用结构和制定合理管控政策提供参考是全面、系统、合理地利用海岸带资源,进行生态文明建设的重要依据。基于多时相遥感数据,辅以随机森林分类、转移矩阵、景观格局指数和地理探测器等方法,系统分析了2010—2018年快速发展时期广西海岸带土地利用类型时空格演变规律与景观格局,并综合探讨了其演变的驱动因子。结果表明:(1)2010—2018年广西海岸带土地利用交错增减,变化显著。建设用地、林草地、人工湿地和自然湿地面积增加,建设用地年均增加101.89 km²,集聚特征突出,主要转入源为耕地; 耕地、其他用地和水体面积缩减,耕地年均缩减162.66 km²,分散特征明显,主要转出为林草地。(2)分时段土地利用动态度差异较大。2010—2014年其他用地和2010—2018年建设用地单一动态度最大,分别为-10.48%,8.80%; 2010—2018年水体单一动态度最小(-0.11%); 综合动态度逐段上升,2010—2018年达1.52%,属快速变化型; 林草地、耕地和建设用地间交替转化活跃。(3)土地利用景观格局呈斑块破碎化、多样化和均匀化演变趋势,景观的异质性和复杂性增强。(4)人文因子是土地利用变化的主导因子,平均贡献率为17.82%; 自然因子影响较小,平均贡献率仅9.72%。人文因子和自然因子协同作用加速了广西海岸带土地利用及景观格局变化。

Spatiotemporal Pattern and Driving Factors of Land Use in Guangxi Coastal Zone

The trend of land dynamic change and its driving factors in the coastal zone of Guangxi are clarified to provide reference for the optimization of land use structure and the formulation of reasonable management and control policies. It is an important basis for comprehensively and systematically utilizing coastal resources and carrying out ecological civilization construction. The spatiotemporal evolution of land use and its landscape pattern, driving factors in the coastal zone of Guangxi from 2010 to 2018 were analyzed by using the methods including random forest classification, transition matrix, landscape pattern index and geographic detector. The remote sensing data on multiple time scales were adopted. The results showed that:(1)between 2010 and 2018, the area of construction land, forestland and grassland, constructed wetland and natural wetland increased in the coastal zone of Guangxi; the annual increase of construction land was 101.89 km² with a feature of clustering, and it mainly derived from cultivated land; the area of cultivated land, other land and water area decreased; the average annual reduction of cultivated land was 162.66 km² with obvious dispersion characteristics, and mainly converted into forestland and grassland;(2)the land use dynamic index varied significantly in different periods; the single dynamic indexes of other land in 2010—2014 and construction land in 2010—2018 were the largest, which were -10.48% and 8.80%, respectively; the single dynamic index of water area was the smallest in 2010—2018(-0.11%); the comprehensive dynamic index increased gradually, which was up to 1.52% in 2010—2018; forestland and grassland, cultivated land and construction land had been exchanged actively;(3)the landscape pattern of land use showed a trend of fragmentation, diversification and homogenization; moreover, the heterogeneity and complexity were strengthened;(4)human activities with an average contribution rate of 17.82% were the dominating factor of land use change; natural factors had little influence, and the average contribution rate was only 9.72%; the synergistic effects of human activities and natural factors accelerated the changes of land use and landscape pattern in the coastal zone of Guangxi.