锡林郭勒盟不同类型植被的生长季变化  

The variability of growing season of different vegetation types in Xilingol League

作　　者：迟登凯 王宏[1] 李晓兵[1] 许凯凯[1] 喻峰[2] 

机构地区：[1]地表过程与资源生态国家重点实验室,北京师范大学资源学院,北京100875 [2]国土资源部信息中心,北京100812

出　　处：《草业科学》2016年第9期1825-1834,共10页Pratacultural Science

基　　金：国家自然科学基金项目(41471350);国家重点基础研究发展计划(2014CB138803);国家创新团队计划项目(41321001);教育部创新团队计划项目(IRT_15R06);地表过程与资源生态国家重点实验室项目

摘　　要：利用分辨率为1km×1km 1989-2008年长时间序列NOAA/AVHRR NDVI卫星产品数据以及锡林郭勒盟植被类型图,对时间序列影像进行Savitzky-Golay滤波后,提取了8种植被类型多年的归一化植被指数(NDVI)时序曲线,对NDVI时序曲线进行S-G滤波后,采用改进的动态阈值法分别估测各植被类型每年生长季的开始、结束时间及长度并进行线性拟合,讨论其变化情况。根据实测数据验证了温带丛生禾草典型草原遥感估测物候期的精确度。研究结果表明,各种植被类型生长季开始时间变化情况差别较大,除温带禾草、杂类草盐生草甸和温带落叶小叶疏林分别有4和1d·20a-1的轻微延迟以外,其它6种植被的生长季开始时间均有不同程度的提前趋势,不同植被类型生长季结束时间呈现出了差别较小的延迟趋势,生长季长度均延长,生长季结束时间对生长季长度的影响更大;估测的温带丛生禾草典型草原返青期与观测值变化趋势非常接近,分别提前了9和7d·20a-1,而两者的黄枯期则出现了相反的变化趋势。估测值与观测值的均方根误差(RMSE)分别是,生长季开始时间16.59d,结束时间14.40d。With the help of the time-series data of NOAA/AVHRR NDVI at 1-kilometer resolution from 1989 to 2008,and the vegetation chart of Xilingol League,this paper abstracted the NDVI time-series curves of eight types of vegetation after filtering the time-series images with the Savitzky-Golay method.After filtering the NDVI time-series curves with the S-G method,the paper estimated the annual beginning,end date and length of growing season of various vegetation using the improved dynamic threshold method,and performed the linear fitting.Finally,the accuracy of estimated phenophases and length of growing season of temperate needlegrass arid steppe was verified according to surveyed groud observations.The results indicated that there was significant difference among all vegetation types in beginning of growing season.Six vegetation types showed advanced trend of change in various degree,while temperate grass and forb holophytic meadow and temperate leaflet deciduous woodland showed delayed trend about 4and 1d·20a^-1,respectively.The end of growing season of all kinds of vegetation showed delayed trend in similar degree and the length of growing season of all kinds of vegetation extended.The end of growing season has greater impact on the length of growing season.Both surveyed and estimated values appeared similar trend of change which were 9and 7d·20a^-1 in advance,while end of growing season appeared converse.The RMSE between surveyed and estimated values was 16.59 dfor the bginning of growing and 14.40 dfor wilting date,respectively.

关 键 词：NOAA/AVHRR NDVI 遥感监测 Savitzky-Golay滤波 动态阈值法 

分 类 号：Q948.1[生物学—植物学]