针对传统的遥感影像解译速度缓慢、效率较低、人力物力需求量大等问题,基于谷歌地球引擎(Google Earth Engine,GEE)平台,利用Landsat TM/OLI遥感影像,采用分类回归树(Classification and Regression Tree,CART)方法,对1990~2016年北京市土地覆被/土地利用变化(LUCC, Land Use and Land Cover Change)开展了遥感解译研究,分析了北京市土地覆被/土地利用时空动态变化特征和耕地、人造地表面积变化的驱动机制。研究表明:①GEE在区域尺度遥感数据分析和处理等方面具有方便快捷的优势。②CART方法进行遥感分类精度较高,研究所得的6期土地覆被/利用数据产品与训练样本交叉验证的学习精度均在93%以上,方法可靠有效。2010年的分类产品与测试样本混淆矩阵的验证精度为88.67%,Kappa系数为0.86。2010年的分类产品与GlobeLand30-2010数据的空间一致性为74.0%,其中林地一致性高达84.28%;两套产品中,人造地表、草地和水体面积比重相差不足1%,各地类面积构成一致性较高。③北京市主要土地类型为耕地、林地和人造地表,面积比重为90%左右;1990~2016年期间人造地表和林地面积呈增加态势,耕地和水体呈萎缩态势,其中,人造地表面积增加1 371km2,增幅高达87%以上,耕地萎缩幅度近40%;1990~2016年北京市平原地区人造地表由圈层状的摊大饼扩张态势向遍地开花扩张态势转变;人造地表的扩张主要通过对耕地的侵占实现。人口快速增长、经济快速发展以及政策等社会经济发展因素驱动北京市土地覆被/土地利用的演化进程。
英文摘要:
Land-cover and land-use dynamics is a key component for global change,and it is a significant form of the impact of human activities on physical environment.Basing Google Earth Engine platform and Classification And Regression Tree method,selected seven types of cultivated land,forest,grassland,wetland, water body,artificial surface and bare land as classification system,the paper used Landsat 5TM and Landsat 8OLI images to interpret the land-cover and land-use since 1990of Beijing.Simultaneously,the paper analyzed and summarized the character of land-use changing and driving force.The results show that: (1)GEE has outstanding advantages in remote sensing data analysis and processing at regional scales. (2)The CART method has high accuracy of remote sensing classification,and the overall accuracy of validation of 6land cover products is above 93%.The spatial consistency of 2010products and GlobeLand30- 2010data showed that the spatial consistency ratios of woodland,water body and cultivated land were 84.28%,74.75% and 73.56%respectively.The spatial consistency of the distribution is 74.0%.(3)The main land types in Beijing were cultivated land,woodland and artificial surface,and the area accounted for about 90%.During the period from 1990to 2016,the artificial surface and woodland area increased,and the cultivated land and water were shrinking.The artificial surface area increase of 1 371km2,and cultivated land shrinkage 40%;On Beijing plain area,artificial surface by the circle ofspread pieexpansion trend to blossom everywhereexpansion trend;The expansion of the artificial surface is mainly achieved through the encroachment of cultivated land.We constructed a multidimensional stepwise linear equation model to analyze the driving force of land type change,indicated that rapid population growth,rapid economic development, government-related policies and other socio-economic development factors jointly drive the Beijing land-cover/land-use evolution process.