黑河流域叶面积指数_LAI_空间尺度转换

第28卷第6期2008年6月生态学报ACTA ECOLOG I C A SI N I C A V o.l 28,N o .6Jun .,2008基金项目:国家发展基础规划资助项目(973)(2006CB400502,2001CB309404),中国科学院/百人计划0择优支持资助项目(8-047401)收稿日期:2007-04-23;修订日期:2007-11-07

作者简介:张万昌(1966~),男,新疆人,教授,主要从事遥感与GIS 生态水文、水资源及全球变化研究.E-m a i :l zhang w c @tea .ac .cn

致谢:蒋建军博士、张东博士、赵登忠,方秀琴硕士、刘三超、徐全芝、乐通潮、韩杰、黄清华、余均辉等提供野外观测资料,在此一并致谢。

Founda tion ite m:The pro j ect w as fi nan ci all y supported by the Nati onal Key Devel op i ng Progra m for B as i c Sciences of C h i na (Grant nu m ber 2006CB400502&2001CB309404),the 100Tal en tY oung Researcher Pro j ect ofC h i nese A cade m y of S ci en ces (N o .8-047401)

Recei v ed da te :2007-04-23;A ccepted da te :2007-11-07

Biography:Z HANG W an-Chang ,Ph .D .,Professor ,ma i n l y engaged i n the study of Re m ote Sen si ng &G I S Hydro l ogy &W ater Resources and G l ob al Changes .E-m ai:l z hangw c @tea .ac .cn

黑河流域叶面积指数(LAI )空间尺度转换

张万昌1,钟 山2,胡少英2

(1.中国科学院大气物理研究所东亚区域气候-环境重点实验室,北京 100029;2.南京大学国际地球系统科学研究所,南京 210093)摘要:为有机地整合利用不同分辨率遥感数据获取的陆面过程以及其他相关的环境变量,尺度问题越来越受到人们的重视。选取黑河张掖绿洲区为实验研究区,利用ETM +影像反演的LA I 通过升尺度转换到900m 分辨率,对LA I 尺度转换过程中引起的误差进行了定量分析,尝试提出一种新的基于ND VI 像元分解的更有效的升尺度转换方法。研究发现非线性的升尺度算法引起的误差不超过10.5%,且误差大小与地表异质性程度正相关,而地表异质性是导致LA I 尺度转化误差的主要原因,严重时可能造成45%的偏差,但纯像元LA I 的计算不受尺度影响。提出的基于ND VI 像元分解的LA I 升尺度转换算法,分两步考虑了地表异质性问题,很好的实现了研究区30m 空间精度L A I 向900m 的尺度转换,该方法应用于干旱、半干旱的中国西北黑河流域NA S A 发布的M OD IS LA I 产品校正,取得了良好效果。

关键词:尺度;尺度转换;叶面积指数(LA I );L andsat ETM +;MO D IS

文章编号:1000-0933(2008)06-2495-09 中图分类号:Q142,Q944,Q948 文献标识码:A

Spatial scale transferri ng study on L eaf Area Index derived fro m re m otely sensed data i n the H ei he R iver Basi n ,Chi na

Z HANG W an -Chang 1,Z HONG Shan 2,HU Shao -Y i n g 2

1START R egiona lC enter for Te mpera te E astA si a,In stit u t e of A t mosph e ric Physics ,CAS,B e i jing 100029,Ch i na

2In ternationa l Instit u te for E art h Syste m Sc i ence ,N an ji ng Universit y,Nanjing 210093,Ch i na

Act a Eco l og ica Sini ca ,2008,28(6):2495~2503.

Abstract :I n order to effect i vel y i ntegr ate various land -surface processes and environ m ental variables retri eved by d ifferent spatial resol ution re motely sense d data ,sca ling issues i nduce d by tr ansferri ng f or one reso l uti on data to another have dra wn m ore and more atte ntions .T a k i ng the Zhangye O asis i n the H eihe R i ver Basi n of north w ester n Chi na as a study site ,using the LAI m ap deri ve d fro m the Landsat ET M +m i age and NA SA published MOD I S LAI product for the sa me day of the reg i on ,an experm i ental study for up scali ng the 30m spat i a l reso l ution LAI to 900m was c onducted to quantitat i vel y analyzes the error transfor m s i n the process of LA I up scali ng w ith the fi nal goal o f establishi ng a ne w a nd much effective up scaling sc he m e i n ter m s o f ND VI p i xel deco mposing tec hn i ques .It was found that l ess than 10.5%errors were cause d by the non-li nearity of al gorith m s utilized i n LA I up scali ng ,and its val ue is hi ghl y positively c orrelated w it h the terrai n heteroge neities ,terra i n heteroge neity is the predo m i nate causing for the errors i ntroduced i n LA I sca le transferri ng .The max m i um err or caused by terrai n heterogeneity can reach to a bout 45%,but no err or can be cause d for t he pure pixel LA I scale