Spectral inversion models for prediction of total chromium content in subtropical soil

Abstract

With the high requirements and long test cycle of traditional testing method of soil heavy metal, this paper tries to es-tablish the quantitative prediction model between soil hyperspectral and soil chromium content( tested by ICP-MS) to realize thIeprediction of soil chromium element quickly and accurately. The paper studied the hyperspectral response characteristics of re dsoil, with 135 soil samples in Fuzhou city. After monitoring the hypersectral reflection of soil samples with ASD (analytica lspectral device) and total chromium contents with ICP-MS, the paper gained the spectral reflection data between 350 and 2 500 nm and soil total chromium contents. Then the paper treated the hyperspectral reflection data with 6 mathematic changes such as reciprocal logarithmic change, differentials and continuum removal in advance. The next step was to calculate the correlation co-fficient of soil chromium and the above spectral information, and select the sensitive spectral bands according to the highest cor-elation coefficient. Finally, six kinds of models were selected to build the soil total chromium content model, and the final opti-al mathematic model between soil chromium and hyperspectral information was significantly determined. Results showed that 520--30, 1 440-- 450, 2 010-- 020, and 2 230-- 240 nm were the main sensitive bands to soil total chromium, y= 120. 68Ce (-7.037x)was the optimal soil total chromium predicting model( in the model, the correlation coefficient R and the RIME of total chromium were 0. 68 and 0. 19 Cμ1(-,) and the inspection correlation coefficient R and the RMSE were 0. 84 μ ?xg-('1) nd 1. 26 Iμ ?xg-(1 )respectively). The model can be used to rapidly monitor soil total chromium with hyperspectral reflection in Fuzhou. area.