Abstract：At present，the main mode of remote sensing image analysis is to download the data，preprocess and extract the thematic information by using the algorithm model.The model has disadvantages of huge amount of data and low efficiency in large scale area.Based on the massive remote sensing image data and powerful computing and storage capabilities of Google Earth Engine platform，we use a linear regression trend analysis method programming to process MOD13Q1-NDVI data，and then analyze the change of vegetation coverage from 2001 to 2015 in beijing\|tianjin\|hebei.We use threshold method of processing DMSP/OLS data to extract urban land，and analysis of 2001 and 2013 urban expansion and degradation by using change detection method.The results show that:(1)The trend of vegetation change was mainly improved，and the area proportion of improvement was 63%，which was far greater than the proportion of degradation 22%.The region of vegetation improvement is mainly in the northwestern part of the study area，and the region with obvious degraded vegetation is the mainly in the Middle East(Beijing，Tianjin and other megacities).(2)From 2001 to 2010，the area of Beijing，Tianjin and Hebei changed little，with a ratio of 60%.[JP2]In 2013，the area decreased by 13 thousand Km2 compared with 2010，with a decrease of 5.97%.(3)90.45% of the urban areas remained unchanged，and the proportion of urban degradation areas(7.2%) was significantly higher than that of the expansion areas(2.3%).This paper makes full use of GEE platform to realize data processing quickly and efficiently，and solve Geosciences problems，so as to provide reference for related research.[JP]
张滔，唐宏. 基于Google Earth Engine的京津冀2001~2015年植被覆盖变化与城镇扩张研究[J]. 遥感技术与应用, 2018, 33(4): 593-599.
Zhang Tao，Tang Hong. Vegetation Cover Change and Urban Expansion in Beijing-Tianjin-Hebei during 2001~2015 based on Google Earth Engine. Remote Sensing Technology and Application, 2018, 33(4): 593-599.