| The mineral resources are one of the basic sources for human’s production and living, and they play a large role in our daily life. However, the exploitation of the mines, especially the mines with heavy metals and sulfur, will also bring environmental problems if not handled properly. The crops, streams and soils in the mines will be contaminated by the heavy metals. So it is necessary to study the heavy metals contents of the plants, streams and soils in the mines. The mining areas in Wansheng District of Chongqing city is selected as study area, and the spectral data of three crops, water and soil samples was collected by ASD Field Pro III in March and August, 2012. And heavy metals contents of water and soil samples were analyzed in the lab using the ICP-MS(Inductively Coupled Plasma source Mass Spectrometer). This thesis intends to estimate the dust content and heavy metals content of crops qualitatively and evaluate the heavy metal contents in the water and soil quantitatively to acquire the environmental change information of mining areas in Wansheng Dirstrict, and can provide theory for the prevention and control to the environmental pollution. The results of this thesis are shown below:(1)In the study area main crops include eggplant, pumpkin and sweet potato on August, so the reflectance data of these three crops are used to estimate the dust content on the leaf blades. And with the dust content increase, the absorption peak on 1000 nm and 1200 nm changes and the whole reflectance decreases. After analyzing the results, we find that the overall reflectivity and the absorption peak of the pumpkin leaves are lowest, and then after by the eggplant leaves, the sweet potato leaves are the highest. And these results may indicate that the dust catching ability of the pumpkin leaves is stronger than eggplant leaves, and the sweet potato leaves’ is the weakest. After analyzing the spectra of samples, the dust contents of the eggplant leaves of the Yu Tian Bao Mine, the pumpkin leaves and sweet potato leaves of Yan Shi Tai Mine and all the three crops’ leaves of the Xin Tian Wan Mine are high. And these may indirectly explain that the dust content of Xin Tian Wan Mine is lowest, and Yu Tian Bao and Yan Shi Tai Mines are a little higher.(2)After analyzing the spectral data of water, the spectral features of Al, Cu, Cr in the water are found: 550 nm, 670 nm, 830 nm, 1000 nm, 1200 nm. And the regression models of these three heavy metals are built using the stepwise regression analysis method. Through these models, we can get the distribution maps of Al, Cu, Cr in the streams of the study area. The results indicate that the contents of the three heavy metals in the South-north are of great difference, and because the diversity contents in the mining areas in the south, the Al content in Qijiang river continues to increase, while the Cu and Cr contents begin to decrease.(3)The spectral features of As, Cd and Zn in the soils are found through analyzing the spectra of soils, and the spectral features are: 2320 nm, 1750 nm, 2260 nm, 2210 nm, 920 nm and 480 nm. And the regression models of the three heavy metals are built via stepwise regression analysis method. We find that As and Cd contents of two periods are similar, however, the Cd content is of great difference.In summary, this thesis analyzes the spectral data of crops, water and soil of the study area, and the dust contents and heavy metals contents of crops are qualitatively got, the heavy metals contents of water and soil are quantificationally acquired. And the final predicted results are consistent with measured results, which indicate that it is possible to analyze the environment of mining areas from crops, streams and soil using spectral method and can provide theory for environmental pollution prevention. |
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