基于地理探测器的广州市土地利用时序变化及影响因素

Time series change and influencing factors of land use in Guangzhou city based on geodetector

【目的】研究自然条件和社会经济要素对土地利用时序变化的影响,为城市用地结构有序调控和可持续发展提供科学认知及决策依据。【方法】以5年为时间间隔选取6期Landsat卫星遥感影像进行广州市1995—2020年土地利用分类,分析广州市土地利用结构、动态度、土地利用转移情况,并利用地理探测器探讨各因素在不同时期对土地利用变化的影响强度及其相互作用机制。【结果】(1)在长时序(1995—2020年)城市土地利用变化的情景下,地理探测器模型能够对不同时期的城市土地利用变化的因素进行解析,揭示其变化规律,具有良好的适用性;(2)1995—2020年,广州市建设用地呈现“稳定—缓慢增加—剧烈增加”的趋势,其转入面积主要来自于耕地和林地,而耕地呈现出“缓慢减少—稳定—大幅减少”的趋势;林地和草地整体呈现出单调减少的趋势,主要转出分别为建设用地和林地;水域面积表现为上下浮动,主要转化面积来自于耕地;未利用地表现为“大幅减少—缓慢减少”的状态,主要转化为建设用地;(3)1995—2020年内的不同时期,广州市土地利用变化驱动因素的影响强度存在差异,其中社会经济类因子对土地利用变化的影响强度高于自然地理类因子;(4)1995—2020年内的各时期,广州市土地利用变化交互因子的q值(解释度)均高于单因子,说明因子之间的交互作用均为双因子增强。【结论】人类活动对土地利用变化的影响在空间分布上存在显著差异,多因素叠加会加剧各用地类型之间的冲突,减少人类活动对环境的影响是实现可持续发展的重要途径。

【Objective】Land use is comprehensively affected by natural conditions and socio-economic factors,and the study of time series changes in land use is conducive to providing a scientific basis for the rational use of urban land resources.【Method】Landsat satellite remote sensing images of six periods were selected at five-year intervals for land use classification from 1995 to 2020,and the land use structure,dynamics and land use transfer in Guangzhou were analyzed.The influence intensity and interaction mechanism of various factors on land use change in different periods were discussed by using geographic detectors.【Result】(i)Under the scenario of long time series(1995-2020)urban land use change,geodetector model could analyze the factors of urban land use change in different periods and reveal its change rules.(ii)From 1995 to 2020,the construction land in Guangzhou showed a trend of‘stable-slow increase-sharp increase’,while the cultivated land showed a trend of‘slow decrease-stable-substantial decrease’,and the transferred area mainly came from cultivated land and forest land.The forest land and grassland showed a monotonous decreasing trend,mainly transferred out as construction land and forest land.The water area fluctuated up and down,mainly from cultivated land.Unused land was gradually reduced,mainly converted into construction land.(iii)In different periods from 1995 to 2020,the influence of driving factors of land use change in Guangzhou was different.Among them,the influence of socioeconomic factors on land use change was higher than that of physical geography.(iv)In different periods from 1995 to 2020,the q value of the interaction factor was higher than that of the single factor q value,which showed that the interaction between the factors was two-factor enhancement.【Conclusion】The impacts of human activities on land use change are obviously different in spatial distribution.The overlapping of multiple factors will aggravate the conflict of land use.Reducing the impact of human activities on the environment is an important way to achieve sustainable development.