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1.
分区分级统计图不但可以充分表达化学元素在地理空间中的宏观分布规律以及内在联系,而且具有直观性、概括性和综合性的特点。其缺点是只能反映区划单位之间的差别,不能反映同一区划单元内部的差异或局部上的差异,区划单位越大,反映元素在土壤中的分布状况越概略。编制这种图的条件有四个: 1.必须具备制图区域的基础图件。如土壤图、母质、母岩图、地形图、植被图、pH值图、土地利用图以及水系图等。 2.必须掌握影响元素含量的主要因素如土壤类型、成土母质母岩、植被、pH值、地形、土地利用方式和土壤质地等  相似文献   

2.
一、制图单元的划分 对三十四个统计单元土壤中各元素含量的分布特征,含量水平进行了研究。在获得各统计单元土壤中各元素的背景值后,着重讨论了土壤背景值含量与土壤成土母质、土壤类型、地貌等自然环境因素之间的关系。然后确定其制图单元。 (一)对石灰岩、第四系、页岩、砂岩、砂页岩、冲击母质发育的土壤中元素含量水平与成土母质之间的关系进行了差异显著性检验,结果表明:这六种成土母质发育的土壤中元素背景值含量有显著性差异。其中砂岩发育的土壤中元素Mn、V、Cr、Co、Ni、Cu、Zn、F、Cd的背景值含量均低于其它成土母质发育的土壤。石灰岩母质发育的土壤中Mn、Ni、Zn、  相似文献   

3.
本文拟对影响我国除台湾省以外的土壤微量元素背景值的因素用数量化理论Ⅰ进行分析,以期为确定土壤背景值制图统计单元,分析其区域变异规律提供依据。  相似文献   

4.
分区分级统计图的图斑界线是由制图的统计单元确定的,一般来说统计单元明确以后,级别间的界线并不难确定。如以土类、母质、母岩、地貌等指标为统计单元的土壤环境背景值的分区分级统计图界线就很容易确定。当然,在只考虑一个主要影响因子时才能如此划分级别界线。如果综合考虑影响因子时问题就不那么简单了。所以本文要阐述的就是利用多个影响因子如何综合确定分级界线的问题。  相似文献   

5.
在土壤元素背景值的调查研究中,除了要考虑合理布点采样外,还应保证各采样单元的样点数满足数理统计的需要。样品数太大,浪费人力、物力。而样品数太小,则难以获得能正确表达该统计单元的背景值。为获取一个统计单元的土壤元素背景值,究竟应该采取多大的样本才合适,这是需要认真考虑的问题。 关于样本大小的确定,统计学上有各种不同的方法。其中有些方法失之过严,不适于诸如中国土壤元素背景值等大规模面上调查工作应用。因此,必须选用一个适宜的、易行的方法来检验  相似文献   

6.
一、分级的一般原则 (一)符合统计学原则:分级数的确定要保持数据的客观分布特征。如正态分布、对数正态分布等。 (二)符合制图学原则:分级数控制着地图的精度,反映了数据的综合程度,随着分级的增加,图上数值估计的正确性也随之增加。反之,如果分级数减少,则对制图对象的区域分布特征  相似文献   

7.
在全国土壤元素背景值研究中,所有土壤样品均按A、B、C三个发生层次采样,这对于全国背景值的统计运算及统计单元间的比较,无可置疑,是正确的。但若深入研究区域性土壤元素背景值的形式、分异及其影响因素,实事证明按照土壤剖面的发生学特征,更详细地划分发生层次,逐层采样,不但更有利于准确划分A、B层的界限,而且对于揭示背景值分异的实质——在土壤发生过程中元素的表生地球化学行为的差异,也是完全必要的。本文以黄土高原五个主要土类(含亚类)为例,按照土壤发生层次,讨论土壤元素在剖面上的分布特征,探讨土壤元素背景值垂直分异与土壤剖面发生学特征的内在联系。  相似文献   

8.
黄山风景区土壤环境背景值基本特征及其影响因素分析   总被引:1,自引:0,他引:1  
一、黄山风景区土壤环境背景值基本特征 由表1可以看出,黄山土壤背景值有以下主要特征:①亲铁元素背景值较低。这显然是由于成土母岩以花岗岩系为主所致。②高F背景。黄山土壤中F高出世界平均含量近4倍。黄山土壤高F背景主要发生在花岗岩及花岗闪长岩为母岩的土壤中。 以下采用灰色系统理论中的灰色统计方法研究黄山土壤中各元素背景相对于安徽省背景值的情况。以安徽省元素背景值作为平均水平类,分别定义三个灰类(?)_1={高于平均水平指  相似文献   

9.
1.制图的基本内容与重点对于基岩来讲,岩石性质对土壤物质组成的影响最为明显,故对基岩的分类应以岩性为主要依据,图中的主要表现内容应为岩性.对松散沉积物来讲,其岩性、成因、形成时代对土壤的物理、化学性质均有影响,因此在分类时就应兼顾这三个方面的因素.图中的主要表  相似文献   

10.
广西土壤环境背景值应用开发初探   总被引:1,自引:0,他引:1  
1.背景值与污染评价为了查清广西某锡矿矿山开采对周围土壤环境污染的程度,曾进行了矿区土壤背景值的调查(表1).  相似文献   

11.
利用微机制作土壤环境研究中的趋势面等值线图   总被引:2,自引:0,他引:2  
介绍一种利用微机制作土壤环境元素含量趋势面等值线图的实用方法,其中包括地理背景底图,趋势面等值线图及两图的套绘技术。本法简便易操作勿需复杂的硬,软件支撑,利用普遍流行的常用软件,不但能进行趋势面分析及绘图中所需的坐标转换,耐用可解决图件套绘中的定位问题,对拥有微机和小型绘图仪的单位均可适用。  相似文献   

12.
黑龙江流域地处世界三大黑土区之一的中国东北平原,土壤腐殖质含量高,这些腐殖质随着地面径流进入水体,成为流域溶解性有机物(DOM)的自然本底(环境背景)。自然本底的存在导致流域水质有机污染综合指标不能真实反映流域的人为污染,流域背景区内高锰酸盐指数、化学需氧量背景值范围分别为3.0~11.7、14.3~40.5 mg/L。流域部分水质考核断面水质受到有机质背景值的影响。由于叠加人为污染,定量分析高锰酸盐指数、化学需氧量背景值范围存在很大难度。重金属元素相对稳定,相对于"六五"时期重金属背景值,目前水体中重金属含量普遍升高。结合水环境管理需求,背景值研究成果应用于水环境管理还需要进一步深入研究和实践。笔者在综述黑龙江流域水环境背景值研究基础上,总结目前存在的问题,提出水环境背景值研究建议,为科学客观评价流域水质提供参考。  相似文献   

13.
受工业活动影响,上海市典型工业区表层土壤氟中位值普遍高于"七五"背景值。针对工业企业场地土壤氟化物高值现象,目前仍缺乏相关的管理标准体系,且基于总量的评估分析方法已无法满足日益增长的精细化管理需求。详细梳理了国内外氟化物相关标准体系,并对上海市土壤氟限值进行了探讨。基于上海市典型工业场地特征参数计算得到的土壤氟化物筛选值高于上海市土壤"七五"背景值,与上海市工业场地调查得到的土壤氟化物高值基本持平;第一类、第二类用地的氟化物筛选建议值分别为1 980、10 000 mg/kg。与氟化物相比,水溶态氟化物是影响作物体内氟含量的重要因素,且在淋溶等作用下会对地下水安全构成威胁。考虑到水溶态氟化物的环境行为与风险,建议针对农田土壤开展水溶性氟化物含量限值研究。  相似文献   

14.
The Universal Soil Loss Equation (USLE) is an erosion model to estimate average soil loss that would generally result from splash, sheet, and rill erosion from agricultural plots. Recently, use of USLE has been extended as a useful tool predicting soil losses and planning control practices in agricultural watersheds by the effective integration of the GIS-based procedures to estimate the factor values in a grid cell basis. This study was performed in the Kazan Watershed located in the central Anatolia, Turkey, to predict soil erosion risk by the USLE/GIS methodology for planning conservation measures in the site. Rain erosivity (R), soil erodibility (K), and cover management factor (C) values of the model were calculated from erosivity map, soil map, and land use map of Turkey, respectively. R values were site-specifically corrected using DEM and climatic data. The topographical and hydrological effects on the soil loss were characterized by LS factor evaluated by the flow accumulation tool using DEM and watershed delineation techniques. From resulting soil loss map of the watershed, the magnitude of the soil erosion was estimated in terms of the different soil units and land uses and the most erosion-prone areas where irreversible soil losses occurred were reasonably located in the Kazan watershed. This could be very useful for deciding restoration practices to control the soil erosion of the sites to be severely influenced.  相似文献   

15.
Ecological regionalization according to the USDA Forest Service National Hierarchical Framework of Ecological Units was undertaken for the New England-New York region. A topdown, map-overlay approach was used to map sections and subsections. Where available, landscape level units (LTAs) were aggregated and evaluated to supplement the subsection mapping. A regional collaborative effort was undertaken to counterbalance the shortfalls of a purely mechanistic approach. As a result of this process, 17 section and 58 draft subsection units were delineated for the New England-New York region. The sub-regional units developed reflect the strong correspondence among climate, topography and geography at this scale. Geologic factors, due to their influence on landform and mineral availability, are also reflected in the ecological unit boundaries. Efforts to apply the multifactor model at the sub-regional level have been hampered by the lack of scale appropriate information on a number of factors particularly meso-scale climate and potential natural community composition and distribution. Further research and investigation are required before these criterion are adequately met.  相似文献   

16.
中国土壤中溴,碘的背景含量   总被引:1,自引:0,他引:1  
通过对全国八百余个表层土样的分析测试,获得了中国土壤中溴、碘背景含量的总体水平及在各土类中的含量,相对于地壳丰度,中国土壤中溴、碘普遍得到了富集,溴、碘含量分异变化较大,并具有明显的地域分异特征,影响中国土壤中溴、碘含量的主要因素是降水量、土壤吸附体的含量以及某些特殊母质。  相似文献   

17.
数理统计方法在岷沱江水环境背景值计算中的应用   总被引:1,自引:0,他引:1  
统计单元的划分,异常值的剔除,分布类型检验及背景值的表征是环境背景值计算中的四个关键环节,本文就其应用进行了较为系统地讨论。  相似文献   

18.
本文对自制管理样的定值及应用做了描述,样品采自新疆吐鲁番地区红、黄壤土,分析定值采用内检、外检方式,数据经统计检验处理,以多组均值求得总平均值作为元素的含量估计值,用±2S表示测量的单项不确定度.在土壤背景值研究等工作中应用的结果,各元素相对标准偏差(RSD)为:汞、镉大于 10%,铜、铅、锌、镍、氟均小于 10%。  相似文献   

19.
Ecological risk assessment of open coal mine area   总被引:2,自引:0,他引:2  
The coal mine areas in China have the serious conflicts between resources exploitation and ecology safety, therefore the coal mine ecological risk assessment is an important problem which relates to the sustainability of coal mines to regions and the whole country. In this study, open coal mine area serves as researching object, heavy metals, soil erosion and coast are screened out as risk resources, soil wireworm as the receiver of heavy metals risk, biotope ecosystem as the receiver of soil erosion and coast risk; ecological indexes are calculated with species background index, biological diversity index and natural degree index, ecological friability indexes are calculated with soil fertility index, plant coverage, plant species diversity index, soil wireworm index and maturity index, and the typical coal mine area assessment indexes system is established. In addition, the regional ecological risk assessment is conducted on the friable ecological system of Fuxin Haizhou open coal mine area. Examples are researched of Haizhou open coal mine, the coal mine risk distribution is established, and foundations are provided for the administrative decision-making.  相似文献   

20.
House dust has been identified as a major exposure medium for lead (Pb) in children. High levels of Pb in soil and house dust have been recorded at the Bunker Hill Superfund Site (BHSS) in northern Idaho, an historic mining and smelting district. Soil and dust remediation at the site was required; however, regional background soil and dust Pb levels had not been well characterized. The objective of this survey was to determine background house dust Pb levels and to compare those levels with concentrations, and dust and Pb loading rates measured at the BHSS. Soil and house dust samples were collected in five towns demographically similar to the BHSS but unaffected by the mining industry. The background concentrations and loading rates were significantly lower than those observed at the site. House age was a significant factor affecting background soil and house dust Pb concentrations and loading rates.  相似文献   

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