The Hyperspectral Response Of Carex Cinerascens To Cu Pollution

With the rapid development of society and economy of Jiangxi province, thescope and extent of heavy metal pollution has increased in the Poyang lake wetland.Heavy metal pollutants, with the characteristics of concealment, accumulation andnon-degradation, cause lasting threaten to the ecological system of Poyang lakewetland. Preventing and treating heavy metal pollution in the wetland will base onstrengthening pollution monitor of heavy metal in time. Hyperspectral remote sensingtechnology which have the higher spectral resolution was applied to the fine groundobjects identification. Heavy metal pollutants were absorbed by the roots of plants andtransferred to overground plant tissues. When heavy metal accumulated concentrationreached toxic levels in plant body, plant leaf tissues and cells internal structures wouldchanged. Taked the dominant plant (Carex cinerascens)and the main heavy metal Cupollutant in the Poyang lake wetland as the research objects in thesis, by means of potexperiments, monitored the spectral parameters change of Carex cinerascens underdifferent Cu concentrations, so as to studied Carex cinerascens hyperspectral responseunder Cu pollution, the results showed as follow.(1) In the test concentrations of Cu range, namely, in the range of0(reference),50,100,150,200and300mg/kg, the200mg/kg was the supreme tolerance concentrationfor Carex cinerascens. Sensitive concentration was the50mg/kg.(2) With the increased of added Cu concentration, Cu content in the leaf of Carexcinerascens obviously raised which increasd gradually from2.03mg/kg to109.60mg/kg, while SPAD value in the leaf of Carex cinerascens obviously reduced whichgradually decreased from34.31to29.57.(3)The sensitive spectral bands and characteristic parameters of the leaf Carexcinerascens responsed to Cu pollution were the Green Peak value at550nm, thedepth of Red Valley at675nm, the location of Red Edge, the peak value of Red Edgeand the Red Edge Slope within the scope from680nm to750nm, the NormalizedDifference Vegetation Index of Red Edge (NDVI705), the Near-Infrared reflectionlevel ground of average reflectance from750nm to1250nm (R750-1250nm). While,therelationship between the depth of Red Valley, peak value of Red Edge, Red EdgeSlope and R750-1250nmboth were the highly negative correlation, the correlationcoefficient separately were the-0.631、-0.975、-0.965and-0.952； (4) The changes between the leaf SPAD values and spectral characteristicparameters which included the depth of Red Valley, the location of Red Edge, thepeak value of Red Edge, the Red Edge Slope, NDVI705and R750-1250nmwere relativelyconsistent during growth of Carex cinerascens. SPAD values and parameters werelower at the beginning of growth, were slightly higher in the exuberant growth stageand were the lowest in the later growth stage. But the changes regulation of the GreenPeak value was contrary to the leaf SPAD value.(5) Through the experimental research which spectral parameter response to Cupollution in the changing growth stage of Carex cinerascens, the research results canbe summed up: the Carex cinerascens best monitoring growth stages were from thebeginning of growth to the exuberant growth, that’s from the first ten-day period ofApril to the first ten-day period of May in this experiment.