Feasibility of Estimating Heavy Metal Contaminations in Floodplain Soils Using Laboratory-Based Hyperspectral Data~A Case Study Along Le＇an River, China

Itisnecessarytoestimateheavymetalconcentrationswithinsoilsforunderstandingheavymetalcontaminationsandforkeepingthesustainabledevelopmentsofecosystems.Thisstudy,withthefloodplainalongLe'anRiveranditstwobranchesinJiangxiProvinceofChinaasacasestudy,aimedtoexplorethefeasibilityofestimatingconcentrationsofheavymetallead(Pb),copper(Cu)andzinc(Zn)withinsoilsusinglaboratory-basedhyperspectraldata.Thirtysoilsampleswerecollected,andtheirhyperspectraldata,soilorganicmattersandPb,CuandZnconcentrationsweremeasuredinthelaboratory.Thepotentialrelationsamonghyperspectraldata,soilorganicmatterandPb,CuandZnconcentrationswereexploredandfurtherusedtoestimatePb,CuandZnconcentrationsfromhyperspectraldatawithsoilorganicmatterasabridge.Theresultsshowedthattheratioofthefirst-orderderivativesofspectralabsorbanceatwavelengths624and564nmcouldexplain52%ofthevariationofsoilorganicmatter;thesoilorganicmattercouldex-plain59%,51%and50%ofthevariationofPb,CuandZnconcentrationswithestimatedstandarderrorsof1.41,48.27and45.15mg·kg-1;andtheabsoluteestimationerrorswere8%-56%,12%-118%and2%-22%,and50%,67%and100%ofthemwerelessthan25%forPb,CuandZnconcentrationestimations.Weconcludedthatthelaboratory-basedhyperspectraldataholdpotentialsinesti-matingconcentrationsofheavymetalPb,CuandZninsoils.Moresamplingpointsorotherpotentiallinearandnon-linearregressionmethodsshouldbeusedforimprovingthestabilitiesandaccuraciesoftheestimationmodels.