摘要
研究土地利用时空变化及驱动力,对促进区域土地资源科学配置及生态环境改善具有重要意义。以沱江流域为研究区,基于Google Earth Engine云平台调用Sentinel-2影像并构建NDVI、NDBI和NDWI光谱分类指数,选取六类地类样本,测试随机森林、决策树,支持向量机三类监督分类器,通过精度评价确定最优分类器,利用ArcGIS制作沱江流域2016年、2018年、2021年土地利用现状图,运用空间叠加和转移矩阵分析沱江流域土地利用时空变化特征,并利用地理探测器对其进行单因子探测和交互作用探测。结果表明:(1)随机森林分类器分类效果最佳。2021年分类精度比较为:随机森林>决策树>支持向量机,分类的总体精度分别为91.13%、85.22%、79.49%。Kappa系数分别为0.88、0.80、0.72。(2)林地、建设用地及耕地构成了沱江流域土地利用类型的主体,占总面积的89.13%。2016-2021年林地面积大幅减少,建设用地面积和耕地面积增加。(3)从时空变化来看,土地类型转移以林地、耕地及建设用地的相互转换为主。沱江流域中下游林地与耕地转移最为显著,上游地区和中部地区建设用地显著扩张,大量林地与耕地为建设用地所取代,草地先减后增,在中南部及东部地区变化明显,水域和未利用地变化不明显。(4)2016-2018年、2018-2021年水体和林地及草地土地利用动态度由负变正,建设用地和未利用地土地利用动态度为正,耕地土地利用动态度为负。综合土地利用动态度均为正。(5)3期社会因子在土地利用变化中均有重要影响,2016年社会因子为主要影响因素,2018年、2021年自然因子影响较大。沱江流域土地利用变化是多种因子交互作用的结果。而高程与人均GDP的交互作用影响力最大。研究结果可为沱江流域土地利用规划提供参考依据。随机森林分类器分类精度最高,林地、建设用地及耕地为沱江流域土地利用类型主体,从时空变化来看,土地类型转移以林地、耕地及建设用地相互转换为主,社会因子与自然因子共同驱动着沱江流域土地利用时空变化。
Studying the temporal and spatial changes and driving forces of land use is of great significance,which can promote the scientific allocation of regional land resources and the improvement of ecological environment.Taking the Tuojiang River Basin as the research area,the Sentinel-2 image was based on the Google Earth Engine cloud platform and the NDVI,NDBI and NDWI spectral classification indexes were constructed.Six types of land samples were selected to test three supervised classifiers:random forest,decision tree and support vector machine.The optimal selector was determined by accuracy evaluation,and the thematic maps of current land use of Tuojiang River Basin in 2016,2018 and 2021 were made by ArcGIS.The spatial and temporal variation characteristics of land use in Tuojiang River Basin were analyzed by spatial superposition and transfer matrix,and the single factor detection and interaction detection were carried out by geographical detector.The results show that①random forest classifier has the best classification effect.In 2021,the classification accuracy was ranked as random forest>decision tree>support vector machine,and the overall classification accuracy of the three classifiers was 91.13%,85.22%,79.49%,respectively.The Kappa coefficients were 0.88,0.80 and 0.72,respectively;②the main body of land use types in the Tuojiang River Basin are constituted by forest land,construction land and cultivated land,accounting for 89.13%of the total area.From 2016 to 2021,the area of forest land decreased significantly,and the area of construction land and cultivated land increased;③from the perspective of spatial and temporal changes,the transfer of land types was dominated by the mutual conversion of forest land,cultivated land and construction land.The transfer of forest land and cultivated land between the middle and lower reaches of the Tuojiang River Basin was the most significant.The construction land in the upstream and central regions had expanded significantly.A large number of forest land and cultivated land had been replaced by construction land.The grassland had decreased at first and then increased.It had changed significantly in the central and southern and eastern regions,and the changes in water areas and unused land were not obvious;④from 2016 to 2018 and from 2018 to 2021,the dynamics of water bodies,forests and grassland were changed from negative to positive,while the dynamics of construction land and unused land changed to positive,and the dynamics of cultivated land changed to negative.The overall dynamics of land use were positive in 2016,2018 and 2021;⑤in the three periods,social factors were found to play an important impact on land use change,with social factors being the main influential factor in land use variation in 2016,and natural factors having a greater impact on land use variation in 2018 and 2021.The land use variation in the Tuojiang River basin is the result of the interaction of multiple factors.The interaction between elevation and per capital GDP has the greatest impacts.In general,the research results can provide a reference basis for land use planning in Tuojiang River basin.The random forest classifier achieved the highest classification accuracy.Forest land,construction land,and arable land are the dominant land use types in the Tuojiang River Basin.In terms of spatiotemporal changes,the transitions among forest land,arable land,and construction land are the primary land type shifts.Both socio-economic factors and natural factors jointly influence the spatiotemporal variations of land use in the Tuojiang River Basin.
作者
张彬
姚虹宇
赵语琪
安芙莹
王驰美
Zhang Bin;Yao Hongyu;Zhao Yuqi;An Fuying;Wang Chimei(School of Geography and Resource Science,Neijiang Normal University,Neijiang 641000,Sichuan,China)
出处
《绿色科技》
2025年第11期182-191,共10页
Journal of Green Science and Technology
基金
四川省社会科学重点研究基地“沱江流域高质量发展研究中心”资助项目(编号:TJGZL2021-11)
省级大学生创新创业项目(编号:X2022044)
成都师范学院省厅级平台科研项目(编号:NDZDS202505)。
关键词
土地利用
时空变化
驱动力分析
GEE
地理探测器
沱江流域
land use
temporal and spatial changes
driving force analysis
google earth engine
geo detector
Tuojiang River Basin
