Hyperspectral inversion models for soil organic matter content in the yelloW River Delta
Objectives]Soi1 organic matter( SOM)can imProve soi1 structure,Promote formation of granu1ar structure,increase soi1 1oose,imProve soi1 air Permeabi1ity and water Permeabi1ity,and Promote P1ant growth and deve1oPment. A1though the traditiona1 method is acurate in determination of SOM,it cannot Provide rea1-time measurement . The sensitive wave1engths high corre1ated with the SOM content are screened to bui1d a quick statistic mode1 to estimate the SOM content in Ye11ow River de1ta.[Methods]Sixty soi1 samP1es were co11ected in the Ye11ow River De1ta. Mathematica1 statistics was used to bui1d the inversion mode1 by studying the re1ationshiP between the sPectra1 ref1ectance and the SOM content. The SOM contents of soi1 samP1es were ana1yzed by a chemica1 method,and their hyPersPectra1 ref1ectences were measured in an indoor dark room environment by ASD Fie1dsPec3 sPectrometer. Sensitive wave1engths were screened according to their correction with the SOM content, after the hand1ing method of continuum-remova1. The PrinciPa1 comPonent regression ana1ysis,mu1tiP1e 1inear regression ana1ysis,quadratic Po1ynomia1 stePwise regression ana1ysis and the suPPort vector machine( SVM ) regression ana1ysis methods were used to estab1ish mode1s for Predicting the organic content.[Results]From the soi1 sPectra1 ref1ectance curve,around 1400 nm,1900 nm and 2200 nm bands have obvious moisture absorPtion va11ey. It is obvious1y imProved the corre1ation between the SOM content and sPectra1 ref1ectance after Processing method of continuum-remova1 by comParing corre1ation. The seven higher corre1ated wave1engths,1278 nm,1307 nm,1314 nm,1322 nm,1328 nm,1334 nm and 1343 nm,are considered as the sensitive wave1engths to estimate the SOM content. The quadratic Po1ynomia1 stePwise regression mode1 is Prevent to be the best inversion mode1 for SOM content Prediction in the Ye11ow River de1ta with the determination coefficient of 0. 865 and the the 1argest determination coefficient of the va1idation set,which reaches 0. 837.[Conclusions]The Processing method of continuum-remova1 cou1d imProve the corre1ation between the SOM and sPectra1 ref1ectance. The near infrared sPectra1 of 1278 nm,1307 nm,1314 nm,1314 nm,1328 nm,1334 nm and 1343 nm are the sensitive wave1engths for estimating the SOM content. The quadratic Po1ynomia1 stePwise regression mode1 has the best fitting effect,is aPProPriate for estimating the SOM content in Ye11ow River De1ta.
soi1 organic matterenve1oPe curvehyPer-sPectrumYe11ow River De1ta
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NSTL
万方数据
维普
