基于GEE的2000—2019年间升金湖湿地不同季节地表温度时空变化及地表类型响应

Spatio-temporal variation of land surface temperature and land cover responses in different seasons in Shengjin Lake wetland during 2000—2019 based on Google Earth Engine

为更好地开展长江下游湿地生态保护与恢复建设,以谷歌地球引擎(Google Earth Engine,GEE)云平台上2000—2019年不同季节升金湖区域Landsat影像为数据源,基于辐射传输方程法批量反演地表温度,综合分析了2000—2019年近20 a间升金湖湿地的地表温度时空变化及其与地表类型的响应关系。结果表明:①在空间上,不同温度等级的空间分布随季节变化具有明显差异:高温区域在春季相对分散,夏秋两季一般位于西北部,在冬季多处于南部;水域面积随季节变动,但其温度四季均属于极低温或低温;②在时间上,受林地和水域的影响,2000—2019年间升金湖湿地始终以占约70%~85%的中温区和低温区为主,各地表温度级别面积占比随季节、年份等时间趋势不同产生变化;③不同覆盖类型的地表温度存在季节性响应差异,基本以人造表面>耕地>林地、滩涂>水体的形式呈现;④非城市化因素对天然湿地地表温度等级变化产生一定影响。研究结果对于升金湖湿地合理开发规划具有一定意义。

In order to better carry out the ecological protection and restoration of the wetland in the lower reaches of the Yangtze River,the authors selected the Landsat images of Shengjin Lake in different seasons from 2000 to 2019 as the research data with the support of Google Earth Engine(GEE)cloud platform.The land surface temperature(LST)was retrieved by a batch program using radiative transfer equation method.The spatio-temporal variation of LST and its responses to land cover in Shengjin Lake during the past 20 years were comprehensively analyzed.The results are as follows:①From the perspective of space,the spatial distribution of different temperature grades has shown obvious differences with the seasonal changes.The high-temperature region is dispersed in spring,generally located in the northwest in summer and autumn,and mostly in the south in winter.The area of the lake varies with the seasons,but its temperature belongs to very low or low temperature grade at all seasons.②From the perspective of time,in the past 20 years,affected by forest and water,the Shengjin Lake wetland has always been dominated by the medium and low temperature grades that account for a large proportion of 70%-85%or so.The area proportion of temperature grades varies with the time trend such as seasons and years.③There exist seasonal differences in the responses of LST to land cover.It is basically presented in the form of a descending order of artificial surface>cultivated land>forest and mudflat>water.④Non-urbanization factors have a certain impact on the surface temperature of natural wetland.The research results are certainly significant for the reasonable development of Shengjin Lake.