铅及其复合污染对灰化苔草胁迫的光谱响应研究

发布时间：2018-03-21 08:24

本文选题：灰化苔草　切入点：铅污染　出处：《江西师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着工业化、城镇化进程的加快和社会经济的飞速发展,我国土壤和水体重金属污染问题日益严重,并已严重危害到人类的健康和生态环境的可持续发展。本文以鄱阳湖自然湿地优势植物灰化苔草和重金属污染物Pb为研究对象,在南矶山湿地建立野外实验田,监测灰化苔草在整个培养期内(包括苗期、伸长期和成熟期),不同Pb和Pb、Cu、Zn复合浓度下光谱参数(包括蓝谷位置与深度、绿峰位置与峰值、红谷位置与深度、红边位置、红边峰值、红边斜率、红边归一化植被指数(NDVI705)、近红外反射坪反射率平均值(R750-1250))的变化,研究灰化苔草对Pb及其复合污染的高光谱响应,结果表明:1、单一Pb污染的试验浓度为0、500、1000、1500、2000 mg/kg:(1)在单一Pb试验浓度范围内,灰化苔草在整个培养期内未出现枯亡现象,即其对Pb的耐性上限超过2000 mg/kg;(2)随着添加Pb浓度的升高,灰化苔草叶片Pb含量与土壤有效态Pb含量均逐渐升高;并且灰化苔草叶片SPAD值(代表叶绿素的相对含量)呈现明显降低的趋势;(3)灰化苔草叶片在Pb胁迫下敏感光谱波段与特征参数为:550 nm附近的绿峰峰值,495 nm附近的蓝谷深度,675 nm附近的红谷深度,725 nm附近的红边峰值和红边斜率,750~1250 nm范围内的R750-1250;灰化苔草在整个培养期内,蓝谷深度、红谷深度、红边峰值、红边斜率、NDVI705和R750-1250均与叶片Pb含量之间保持负的相关性,绿峰峰值与叶片Pb含量保持正相关性;(4)灰化苔草在整个培养期内,蓝谷深度、红谷深度、红边峰值、红边斜率、NDVI705和R750-1250与叶片SPAD值的变化规律相对一致,即随着时间的推移,都呈现逐渐降低的趋势;(5)通过分析灰化苔草叶片光谱参数在整个培养期内的变化过程,发现Pb污染下灰化苔草最佳监测生育期为灰化苔草的伸长期。2、PbCu复合污染的试验范围浓度为0、Pb400/Cu100、Pb400/Cu200、Pb600/Cu200、Pb800/Cu100 mg/kg:(1)随着添加Pb、Cu浓度的增加,灰化苔草叶片和土壤有效态Pb、Cu含量总体上呈现上升的趋势;(2)Pb浓度的升高对叶片和土壤有效态Cu含量的影响不大,故Cu的胁迫作用占据PbCu复合污染的主导地位;(3)在整个培养期内,叶片和土壤重金属含量、叶片叶绿素含量、各项光谱参数随添加Pb、Cu浓度的变化而变化的规律不明显,规律性不强。3、PbZn复合污染的试验范围浓度为0、Pb400/Zn400、Pb600/Zn600 mg/kg:(1)灰化苔草叶片和土壤有效态重金属含量随着Pb、Zn添加浓度的升高而升高,叶片SPAD值逐渐降低;(2)伸长期的光谱数据较其他生育期敏感,故为灰化苔草在PbZn复合胁迫的最佳监测生育期,其中红边峰值和红边斜率较其他光谱特征值更为敏感,可作为监测光谱特征参数。4、PbCu Zn复合污染的试验浓度为0、Pb200/Cu100/Zn200、Pb200/Cu200/Zn200、Pb200/Cu200Zn600、Pb400/Cu100/Zn800、Pb400/Cu200/Zn600、Pb600/Cu100/Zn600 mg/kg,结果表明所有监测光谱指标随添加浓度的变化而变化的规律不明显,与叶片和土壤有效态重金属含量之间均无显著相关关系。
[Abstract]:With the rapid development of industrialization, urbanization and social economy, soil and water pollution problem of heavy metals in China is becoming increasingly serious, and has serious harm to the sustainable development of human health and ecological environment. This paper takes Poyang Lake natural wetland dominant plants in grass and moss ashing of heavy metal pollutants in Pb as the research object, a field experiment in the field Nanjishan wetland monitoring, Carex cinerascens during the whole incubation period (including seedling stage, elongation stage and mature stage), Pb and Pb, Cu, Zn spectral parameters of composite concentration (including the location and depth of the blue valley, peak location and peak, Red Valley position and depth, the red edge position, the red edge peak. Red edge slope and red edge normalized difference vegetation index (NDVI705), near infrared reflectance (R750-1250) reflectivity average Ping) changes of Carex cinerascens spectrum of Pb and its composite high pollution response, the results showed that: 1, Pb single pollution The test concentration of 0500100015002000 mg/kg: (1) in a single Pb test concentration range, Carex cinerascens during the whole incubation period does not appear dead phenomenon, namely the Pb tolerance limit more than 2000 mg/kg; (2) with the increase of Pb concentration, Pb content in leaves and Carex ashing soil available Pb content gradually. Increased; and Carex cinerascens leaf SPAD values (relative content of representative chlorophyll) showed decreasing trend; (3) in the leaves of Carex cinerascens under Pb stress sensitive spectral bands and characteristic parameters: green peak near 550 nm, 495 nm of bluevale depth near the Red Valley, near the depth of 675 nm, red the edge of the peak and red edge slope near 725 nm, 750~1250 nm in the range of R750-1250; Carex cinerascens during the whole incubation period, blue valley depth, Red Valley depth, red edge peak, red edge slope, negative phase between NDVI705 and R750-1250 were associated with leaf Pb content The correlation of the green peak and leaf Pb content to maintain positive correlation; (4) Carex cinerascens during the whole incubation period, blue valley depth, Red Valley depth, red edge peak, red edge slope, the change regularity of NDVI705 and R750-1250 and the leaf SPAD value is relatively consistent with the passage of time, gradually reduced trend; (5) by ashing Carex leaf spectral parameters analysis during the whole culture period of the change process, found that Pb pollution monitoring period for the best ashing sedge Carex cinerascens elongation test range.2, PbCu compound pollution concentration was 0 Pb400/, Cu100, Pb400/Cu200, Pb600/Cu200, Pb800/Cu100, mg/kg: (1) with the addition of Pb and the increase of Cu concentration, ashing leaves and soil available Carex Pb, Cu content showed a rising trend; (2) the increase of Pb concentration has little effect on leaf and soil available Cu content, stress the Cu occupy PbCu compound pollution The dominant position; (3) during the whole incubation period, leaves and soil heavy metal content, the chlorophyll content and the spectral parameters with the addition of Pb, the change of Cu concentration and the variation is not obvious, the regularity is not strong.3, the test range combined pollution concentration of 0 PbZn, Pb400/ Zn400, Pb600/Zn600 mg/kg: (1) Carex cinerascens leaves and soil available heavy metal content with Pb, Zn increased concentration increased, leaf SPAD value decreased gradually; (2) spectral data at the elongation stage than other stages sensitive, so as the best monitoring growth period of Carex cinerascens in PbZn composite stress, the red edge peak and red edge slope is other spectral characteristics is more sensitive, can be used to monitor the parameters of spectrum characteristics of.4 PbCu Zn compound pollution test concentration was 0, Pb200/Cu100/Zn200, Pb200/Cu200/Zn200, Pb200/Cu200Zn600, Pb400/Cu100/Zn800, Pb400/Cu200/Zn600, Pb600/Cu100/Zn600, Mg /kg, the results showed that all monitoring Spectral indicators did not change significantly with the change of the concentration, but had no significant correlation with the available heavy metals in leaves and soil.

【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X503.23

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