龙口市污灌区农田重金属遥感监测研究

发布时间：2018-01-06 23:22

本文关键词：龙口市污灌区农田重金属遥感监测研究　出处：《山东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：土壤,在社会生产生活中扮演者不可或缺的重要角色,其质量直接决定了农作物的品质乃至人类健康。然而随着人口的爆发式增长及工业的迅速发展,越来越多的“三废”等有害物质通过多种途径在土壤中积累,造成土壤污染,进而影响生长在土地上的作物,其中使用污水对农田进行灌溉而导致农田重金属污染的事件时有发生。生活废水中含有较多的营养物质,可以在缓解灌溉用水不足的同时改善土壤肥力、促进作物生长,但工业废水的重金属等有害物质成分偏多,长期灌溉势必会引起重金属在土壤及作物体内的过度积累;而重金属在土壤中难以转化分解,危害性持久,因此如何快速高效地监测污灌区农田的重金属含量水平及做出合理的污染评价成为当前的研究热点。相比于传统监测手段,遥感技术以其实效性、非侵入性及覆盖范围广等特点,为农田重金属的监测与评价提供了新的解决思路。本文以山东省龙口市北部平原为研究区,在国家自然科学基金项目“基于地表参量的污水灌溉区农田生态安全遥感监测研究”(No.41371395),山东省自然科学基金项目“龙口矿区及周边海岸带遥感监测研究”(鲁勘字[2012]110号)、“山东省焦家金成矿区及周边矿区环境地质遥感调查研究”(鲁勘字[2013]141号)和“黄河三角洲高效生态经济区海咸水入侵调查与监控预警系统建设”(鲁勘字[2011]14号),以及山东省国土厅项目“山东省国土资源遥感波谱库建设项目”的共同支撑之下,采集72个土壤样品及42个玉米叶片样品进行光谱实验室测量,并化验重金属Cr、Cu、Ni、Pb、Zn、As、Cd和Hg的含量。对原始光谱进行了光谱变换,提取了一阶微分(RD1)、去包络线(CR)、标准正态变量(SNV)及多重散射校正(MSC)4种光谱指标,分别利用逐步回归和偏最小二乘回归等多种分析方法建立了土壤和玉米叶片重金属含量的高光谱估测模型;利用地统计技术及主成分分析法探究了8种重金属的空间分布特征及可能性来源;以内梅罗综合指数、污染负荷指数和潜在生态危害指数为参考指标,评价了研究区土壤污染状况及潜在危害程度;最后针对龙口市污灌区的农田污染现状提出了相应的防治建议与对策。主要研究结果如下:(1)土壤元素中Cr、Cu、Pb和Zn的建模效果最好;Cr的最佳光谱指标为SNV、Zn为去包络线,其余元素均为一阶微分数据;所有重金属中7种元素的逐步回归模型更优。玉米叶片中Zn、Cd和Hg的模型效果比较理想;除Cd元素外最佳建模指标同样为RD1光谱,且最佳模型中逐步回归模型数量高于其他方法。因此可以认为一阶微分数据可以有效地提高建模精度,而逐步回归法更适合本次研究。玉米叶片光谱对土壤重金属Pb和Cd的预测效果比较理想,R2均达到0.5以上,表明植物叶片光谱可以在一定程度上反映土壤的重金属污染状况。(2)土壤重金属除Cr与Ni外,其余元素的空间分布存在一定差异,但东北部工业区及中部人口密集区为主要的高值区域,说明重金属含量受人为活动扰动较大。玉米与土壤对应元素的空间分布特征并不相似,其中Cd的高值区位于研究区南部,而其余元素高值区出现在北部及东部的部分岛状区域。玉米叶片中的重金属含量受到化肥农药施用等随机干扰的可能性更大。(3)多种重金属间存在比较显著的相关关系,表明可能拥有相同的来源,主成分分析则进一步解析了各种来源。土壤重金属共辨识出3个主成分,主成分1代表自然源因子,主要包含Cr和Ni元素;主成分2代表交通及工业源因子,包含Cu和Zn元素;主成分3代表工农业源因子,主要包含Cd和Pb;As和Hg则是受到自然和工农业活动的双重影响。玉米叶片同样辨别出3种来源,As和Cd与化肥农药的施用有关,Cu和Zn多源于植物本身,用于叶绿素合成、光合与呼吸等生理活动,而Cr、Ni、Pb和Hg受工业活动影响。(4)内梅罗综合指数及污染负荷指数评价结果显示,研究区农田土壤主要处于中等污染水平,各别地区存在点源污染;而潜在生态危害指数评价结果表明,农田土壤的生态危害性不高,为轻微水平。评价结果空间化表达后显示,污染较严重的地区与土壤重金属的普遍高值区分布比较一致,集中分布于东北部和龙口港工业区及中部人口密集的城区。总体来说,龙口市污灌区农田重金属的污染程度并不严重,但已经出现明显富集的态势。针对研究区现状,本文在土壤修复、土壤环境监管、保护与立法及减少污水灌溉方面提出了几点对策建议,以期为该地区的农田生态环境改善提供一定的理论指导。
[Abstract]:The soil plays an indispensable role in social production and life of its quality directly determines the quality of crops and human health. However, with the rapid development of the explosive growth of population and industry, more and more of the "three wastes" and other harmful substances through a variety of ways in the accumulation of soil, cause soil pollution, thereby affecting the growth of in the land of the crops, including the use of sewage for irrigation of farmland caused heavy metal pollution incidents have occurred. More nutrients contained in domestic wastewater, can improve soil fertility in reducing irrigation water is not sufficient at the same time, promote crop growth, but the industrial wastewater of heavy metals and other harmful substances ingredients partial, long-term irrigation it will cause excessive accumulation of heavy metals as object in soil and heavy metals in the soil; and the difficult transformation of decomposition, harm of lasting, so how to fast High speed monitoring of sewage irrigation farmland and pollution evaluation of heavy metal contents to make reasonable become the focus of current research. Compared with the traditional monitoring method, remote sensing technology to its effectiveness, non intrusive features and wide coverage, which provides a new method for the monitoring and evaluation of heavy metals in farmland in Shandong province. The northern part of Longkou City plain as the study area, in the National Natural Science Fund Project "sewage irrigation farmland ecological security study on remote sensing monitoring of surface parameters based on" (No.41371395), Shandong Provincial Natural Science Fund Project "in Longkou mining area and the surrounding coastal zone based on remote sensing monitoring" (Lu Kan word [2012]110), "Shandong Province Jiao Jiajin research remote sensing investigation of environmental geology in mining area and the surrounding area" (Lu Kan [2013]141) and "the Yellow River delta efficient ecological economic zone of sea salt water intrusion investigation and monitoring alarm system The construction of "(Lu Kan word [2011]14), under the support and the Shandong Provincial Committee of Shandong province project" land resources remote sensing spectral library construction project ", 72 soil samples and 42 maize leaf samples for spectroscopy laboratory measurements, and testing the heavy metals Cr, Cu, Ni, Pb, Zn, As, content the Cd and Hg. The original spectra of spectral transform, extract the first derivative (RD1), to the envelope (CR), standard normal variate (SNV) and multiple scattering correction (MSC) 4 spectral index respectively using multiple stepwise regression and partial least squares regression analysis method is established for hyperspectral the estimation model of heavy metal content in soil and maize leaves; method to explore the distribution characteristics and possible source of 8 kinds of heavy metals spatial analysis using statistical techniques and principal components; within the Merrow index, pollution load index and potential ecological risk index as the reference index, evaluation The price of the soil pollution in the study area and potential hazards; finally, the corresponding suggestions and Countermeasures of prevention and control of pollution of farmland according to the present situation of Longkou City sewage irrigation area. The main results are as follows: (1) soil elements Cr, Cu, Pb and Zn, the best modeling effect; optimal spectral index of Cr is SNV, Zn to go the envelope, the remaining elements are first order differential data; stepwise regression model of all 7 elements in the heavy metal better. Maize leaf Zn, Cd and Hg model effect is ideal; except Cd the best model for the same RD1 spectral index, and the best model in the regression model is higher than that of other methods. Therefore, the number of you can think of first order differential data can effectively improve the modeling accuracy, and stepwise regression method is more suitable for this study. The prediction effect of maize leaf spectra of soil heavy metal Pb and Cd ideal, R2 reached more than 0.5, that of plant leaves Slice spectrum can reflect the status of soil heavy metal pollution in a certain extent. (2) soil heavy metals except Cr and Ni, there are some differences in the distribution of the remaining elements of the space, but the northeast industrial areas and densely populated areas in central high value area, that the content of heavy metals by human activities greatly. Maize and soil disturbance the spatial distribution of the corresponding elements are not similar, the Cd high value area located in the south of the study area, while the remaining elements of the high concentration area in the northern and eastern part of the island region. The heavy metal content in maize leaves by chemical fertilizer and pesticide application possibility of random interference more. (3) the relationship between comparison a significant variety of heavy metal, that may have the same source, principal component analysis is further analyzed. Various sources of soil heavy metals were identified 3 principal components, principal components representing 1 natural source factors, mainly Contains the Cr and Ni elements; principal component of 2 representative traffic and industrial sources of factors, including Cu and Zn elements; principal component 3 represents the industrial and agricultural sources factor, including Cd and Pb; As and Hg are affected by natural and industrial and agricultural activities. The same maize leaves identify 3 sources, As and Cd with the fertilizer and pesticides, Cu and Zn - from the plant itself, for the synthesis of chlorophyll, photosynthesis and respiration and other physiological activities, while Cr, Ni, Pb and Hg by industrial activities. (4) the evaluation results of Nemero index and pollution load index showed that the soil in the study area mainly in the middle level of pollution there are several regions, point source pollution; and the potential ecological risk index evaluation results showed that the soil ecological risk is not high, a slight spatial expression level. The evaluation results showed that the serious pollution of heavy metals in the soil area and the general distribution of high value area comparison , concentrated in the northeast and Longkou Port Industrial Zone and central densely populated urban areas. In general, the pollution degree of heavy metals in farmland sewage irrigation area of Longkou City is not serious, but there is an obvious enrichment trend. According to the status of the study area, the soil remediation, soil environmental regulation, put forward some countermeasures and suggestions on protection and the legislation and reduce sewage irrigation, in order to provide some theoretical guidance for the improvement of farmland ecological environment in this area.

【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X87

【参考文献】