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1.
Mapping of the soil texture using geostatistical method (a case study of the Shahrekord plain, central Iran) 总被引:1,自引:0,他引:1
Yaser Safari Isa Esfandiarpour Boroujeni Ardavan Kamali Mohammad Hassan Salehi Mohsen Bagheri Bodaghabadi 《Arabian Journal of Geosciences》2013,6(9):3331-3339
Soil texture is a key variable that reflect a number of soil properties such as soil permeability, water holding capacity, nutrient storage and availability, and soil erosion. The main objective of this study was to produce the kriged maps of soils of the Shahrekord region, central Iran. One hundred four soil samples were collected on a 375-m2 sampling grid from the depths of 0–30, 30–60, and 60–100 centimeter, and their particle sizes were determined using hydrometer method. The results showed a moderately spatial correlation in the soil particles among sampling soil layers and across the study area. Moreover, increasing clay and therewith observation of heavier soil textures is evident from surface to subsurface layers of the soils in the studied area due to rainfall and/or irrigation agriculture. These findings indicated that study of the soil texture variation with depth can be used as a clue for site-specific management and precision agriculture. Moreover, we suggest further analysis by using other data layers like topographical parameters, land use, parent material, soil erosion, and any other information which might influence the spatial distribution of soil texture. 相似文献
2.
Priyabrata Santra Bhabani Sankar Das Debashish Chakravarty 《Environmental Earth Sciences》2012,65(7):2051-2061
Surface map of soil properties plays an important role in various applications in a watershed. Ordinary kriging (OK) and regression
kriging (RK) are conventionally used to prepare these surface maps but generally need large number of regularly girded soil
samples. In this context, REML-EBLUP (REsidual Maximum Likelihood estimation of semivariogram parameters followed by Empirical
Best Linear Unbiased Prediction) shown capable but not fully tested in a watershed scale. In this study, REML-EBLUP approach
was applied to prepare surface maps of several soil properties in a hilly watershed of Eastern India and the performance was
compared with conventionally used spatial interpolation methods: OK and RK. Evaluation of these three spatial interpolation
methods through root-mean-squared residuals (RMSR) and mean squared deviation ratio (MSDR) showed better performance of REML-EBLUP
over the other methods. Reduction in sample size through random selection of sampling points from full dataset also resulted
in better performance of REML-EBLUP over OK and RK approach. The detailed investigation on effect of sample number on performance
of spatial interpolation methods concluded that a minimum sampling density of 4/km2 may successfully be adopted for spatial prediction of soil properties in a watershed scale using the REML-EBLUP approach. 相似文献
3.
Spatial analysis and hazard assessment of mercury in soil around the coal-fired power plant: a case study from the city of Baoji, China 总被引:2,自引:0,他引:2
Based on systematic sampling of soil around the coal-fired power plant (CFPP), the content of Hg was determined, using atomic
fluorescence spectrometry. The result shows that the content of Hg in soil is different horizontally and vertically, ranges
from 0.137 to 2.105 mg/kg (the average value is 0.606 mg/kg) and is more than the average content of Hg in Shaanxi, Chinese
and world soil. In this study, spatial distribution and hazard assessment of mercury in soils around a CFPP were investigated
using statistics, geostatistics and geographic information system (GIS) techniques. Ordinary kriging was carried out to map
the spatial patterns of mercury and disjunctive kriging was used to quantify the probability of the Hg concentration higher
than the threshold. The maps show that the spatial variability of the Hg concentration in soils was apparent. These results
of this study could provide valuable information for risk assessment of environmental Hg pollution and decision support.
An erratum to this article can be found at 相似文献
4.
为了快速获取印度尼西亚苏门答腊岛元素分布的详细情况,根据苏门答腊岛的地形及景观特征,以水系沉积物和土壤为采样介质,实施了覆盖全岛的1:100万低密度地球化学填图。详细介绍了1:100万低密度地球化学填图的野外工作方法、测试的元素及分析技术,根据测试结果制作了苏门答腊岛69种元素地球化学图,计算和分析了苏门答腊岛地球化学背景的特征参数。总结了苏门答腊岛不同成因类型组合元素的分布特征及规律,圈定了16处地球化学综合异常。结合主因子综合异常特征以及区内典型矿床(点)空间分布、规模,对苏门答腊岛主成矿元素综合异常进行了甲、乙、丙分类,包括6个甲级综合异常、4个乙级综合异常和6个丙级综合异常,并优选3处具有较好找矿潜力的甲级综合异常进行异常解释和讨论,认为HS7综合异常具有寻找SEDEX型铅锌矿的潜力,HS8和HS11综合异常具有寻找浅成低温热液型金银矿和矽卡岩型铜铅锌矿床的潜力,为苏门答腊岛深入开展矿产勘查提供参考和依据。 相似文献
5.
本文介绍谢学锦先生快速进行区域地球化学填图的计划在西藏取得的成果。区域水化学填图可分析66个指标,效率高,成本低,见效快;同时水化学填图的空间定位和分辨率比采集土壤样品的填图会差一些。西藏地球化学填图成果呈现了一定的规律性,例如西藏66种元素的地球化学图中,有三分之二沿雅鲁藏布江缝合带出现异常带。西藏许多元素的分布受雅鲁藏布江缝合带影响,是因为特提斯洋原有的一些元素残留在雅鲁藏布江缝合带两侧。氧化钾、氧化钠沿雅鲁藏布江缝合地带出现含量高的异常带,可见特提斯洋中丰富的钾、钠成分残留在代表大洋封闭的雅鲁藏布江缝合带两侧。沿雅鲁藏布江缝合地带氧化钙出现含量低的异常带,可用特提斯洋中的碳汇作用来解释,即特提斯洋中的钙由于碳汇作用变成碳酸盐岩石,氧化钙出现含量低的异常。西藏的地球化学图对矿产勘查和生态环境研究也具有一定意义。 相似文献
6.
文章以浙江省平湖市为典型三角洲平原区,开展了多种尺度、不同采样方法的对比试验。结果表明,田块内土壤元素分布较为均匀,小范围内元素的空间分异性较小,而田块之间土壤元素含量差异性明显增加;Hg,Cd等典型污染元素空间分异性较强,而人为污染扰动较弱的元素的空间分布较为均一;不同采样方法取得的区域性资料,其统计值接近,空间分布模式也相似,但有些元素仍有较明显差异。因此,中大比例尺地球化学调查时,应根据调查研究的目标任务,充分考虑地块分布、土壤类型和土地利用方式,选择合理的采样点。土壤样品可采取多坑点采集、多子样组合的方式,以保证样品的代表性,同时减少分析测试工作量。 相似文献
7.
Catchment scale spatial variability of soil salt content in agricultural oasis,Northwest China 总被引:4,自引:0,他引:4
Soil salinization is a serious environmental problem in the world, especially in arid and semi-arid regions. Therefore, estimating
spatial variability of soil salinity plays an important role in environmental sciences. Aiming at the problem of soil salinization
inside an oasis, a case study was carried out at the Sangong River catchment in Xinjiang province, northwest China. Methods
of classical statistics, geostatistics, remote sensing (RS) and geographic information system (GIS) were applied to estimate
the spatial variability of soil salt content in the topsoil (0–20 cm) and its relationship with landscape structure at catchment
scale. The objective of this study was to provide a scientific basis to understand the heterogeneous of spatial distribution
of soil salt content at a large scale. The results revealed that (1) elevation of landform was a key factor for soil salt
content’s spatial variability, and soil salt content had a strong spatial autocorrelation, which was mainly induced by structural
factors. (2) Mapping of soil salt content by Kriging and comparing it with landscape maps showed that area of soil salinization
in old oasis was smaller than that in new oasis, and degree of soil salinization in old oasis was also lower than that in
the new one. Among all landscapes, cropland was mostly affected by salinity, with 38.8% of the cropland in new oasis moderately
affected by soil salinity, and 8.54% in old oasis. 相似文献
8.
Alireza Owji Isa Esfandiarpour Boroujeni Ardavan Kamali Seyed Javad Hosseinifard Mohsen Bagheri Bodaghabadi 《Arabian Journal of Geosciences》2014,7(4):1491-1499
Soil texture is an important physical soil property that may contribute to variations in many soil functions as well as nutrient storage and availability, water retention, and soil erosion. Although several methods for determining the texture classes of soil particles have been proposed, differences among hydrometer reading times have presented challenges in determining the precise soil texture classes. Therefore, this study was conducted to evaluate the effects of hydrometer reading time on the spatial variability of soil textures in the Rafsanjan area, southeast Iran. To accomplish this, 77 soil samples were collected on a 500-m square sampling grid from depths of 0–40, 40–80, and 80–120 cm, and their particle sizes were determined through analysis for 40 s, 2 h, 6.5 h, and 8 h using the Bouyoucos hydrometer method. The results showed a strong spatial correlation in the soil particles among sampling soil layers and across the study area. Moreover, the differences among hydrometer reading times did not have a significant impact on determination of coarse soil texture classes, although they did influence determination of the finer classes. Although the 8 h reading time provided the most accurate response with respect to mechanical analysis of a soil, after 6.5 h the hydrometer could also largely (more than 80.0 %, on average) achieve this goal. Additionally, the 2 h hydrometer reading time could also be useful for the initial assessment or general overview of the soil texture in a certain region; however, it is not recommended for precision agriculture or site-specific management. 相似文献
9.
Drastically disturbed soils caused by opencast mining can result in the severe loss of soil structure and increase in soil compactness. To assess the effects of mining activities on reconstructed soils and to track the changes in reclaimed soil properties, the variability of soil properties (soil particle distribution, penetration resistance (PR), pH, and total dissolved salt (TDS)) in the Shanxi Pingshuo Antaibao opencast coal-mine inner dump after dumping and before reclamation was analyzed using a geostatistics method, and the number of soil monitoring points after mined land reclamation was determined. Soil samples were equally collected at 78 sampling sites in the study area with an area of 0.44 km2. Soil particle distribution had moderate variability, except for silt content at the depth of 0–20 cm with a low variability and sand content at the depth of 20–40 cm with a high variability. The pH showed a low variability, and TDS had moderate variability at all depths. The variability of PR was high at the depth of 0–20 cm and moderate at the depth of 20–40 cm. There was no clear trend in the variance with increasing depth for the soil properties. Interpolation using kriging displayed a high heterogeneity of the reconstructed soil properties, and the spatial structure of the original landform was partially or completely destroyed. The root-mean-square error (RMSE) can be used to determine the number of sampling points for soil properties, and 40 is the ideal sampling number for the study site based on cross-validation. 相似文献
10.
广西典型岩溶区土壤水分含量空间自相关分析 总被引:2,自引:1,他引:1
以广西壮族自治区马山县为研究区,在野外调查、室内实验测试获取182个土壤水分含量数据的基础上,采用半方差函数和Moran’s I统计量对研究区域土壤水分含量的空间自相关关系、空间相关尺度和空间分布规律进行了研究。结果表明:(1)研究区域土壤水含量平均值为16.97%,受结构性因素和随机因素共同作用,土壤水分含量具有中等强度的空间异质性;(2)研究区域土壤水分含量Moran’s I指数为0.423,表明研究区内土壤水分含量存在空间自相关性,在0~21 km和31~34 km范围内土壤水分含量自相关性为正,在21.7~31 km和34~45 km范围内自相关性为负;(3)Lisa聚类图表明,土壤水分含量空间聚集区和空间孤立区相伴存在,其中“高—高”空间聚集主要分布在马山县东北部,“低—低”聚集区主要分布在东南部。“低—低”聚集区和“高—低”孤立区土壤水分含量缺乏风险大。 相似文献
11.
The Application of Artificial Neural Networks to Landslide Susceptibility Mapping at Janghung, Korea 总被引:13,自引:0,他引:13
The purpose of this study was to develop techniques for landslide susceptibility using artificial neural networks and then to apply these to the selected study area at Janghung in Korea. Landslide locations were identified from interpretation of satellite images and field survey data, and a spatial database of the topography, soil, forest, and land use. Thirteen landslide-related factors were extracted from the spatial database. These factors were then used with an artificial neural network to analyze landslide susceptibility. Each factor's weight was determined by the back-propagation training method. Five different training sets were applied to analyze and verify the effect of training. Then the landslide susceptibility indices were calculated using the back-propagation weights, and susceptibility maps were constructed from Geographic Information System (GIS) data for the five cases. Landslide locations were used to verify results of the landslide susceptibility maps and to compare them. The artificial neural network proved to be an effective tool for analyzing landslide susceptibility. 相似文献
12.
13.
R. J. Yao J. S. Yang P. Gao H. B. Shao G. M. Liu S. P. Yu 《Environmental Earth Sciences》2014,71(1):233-243
Soil salinity has been known to be problematic to land productivity and environment in the lower Yellow River Delta due to the presence of a shallow, saline water table and marine sediments. Spatial information on soil salinity has gained increasing importance for the demand of management and sustainable utilization of arable land in this area. Apparent electrical conductivity, as measured by electromagnetic induction instrument in a fairly quick manner, has succeeded in mapping soil salinity and many other soil physical and chemical properties from field to regional scales. This was done based on the correlation that existed between apparent electrical conductivity and many other soil properties. In this paper, four spatial prediction methods, i.e., local polynomial, inverse distance weighed, ordinary kriging and universal kriging, were employed to estimate field-scale apparent electrical conductivity with the aid of an electromagnetic induction instrument (type EM38). The spatial patterns estimated by the four methods using EM38 survey datasets of various sample sizes were compared with those generated by each method using the entire sample size. Spatial similarity was evaluated using difference index (DI) between the maps created using various sample sizes (i.e., target maps) and the maps generated with the entire sample size (i.e., the reference map). The results indicated that universal kriging had the best performance owing to the inclusion of residuals and spatial detrending in the kriging system. DI showed that spatial similarity between the target and reference maps of apparent electrical conductivity decreased with the reduction in sample size for each prediction method. Under the same reduction in sample size, the method retaining the most spatial similarity was universal kriging, followed by ordinary kriging, inverse distance weighed, and local polynomial. Approximately, 70 % of total survey data essentially met the need for retaining 90 % details of the reference map for universal kriging and ordinary kriging methods. This conclusion was that OK and UK were two most appropriate methods for spatial estimation of apparent electrical conductivity as they were robust with the reduction in sample size. 相似文献
14.
B. Shifteh Some’e F. Hassanpour A. Ezani S. R. Miremadi H. Tabari 《Environmental Earth Sciences》2011,64(7):1849-1864
Analysis of the spatial variability of soil properties is important to explain the site-specific ecosystems. Spatial patterns
of some soil properties such as soil texture, exchangeable sodium percentage (ESP), electrical conductivity (ECe), soil pH
and cation exchange capacity (CEC) were analyzed in salt and sodic affected soils in the south of the Ardabil province, in
the northwest of Iran, to identify their spatial distribution for performance of a site-specific management. Soil samples
were collected from 0 to 30, 30 to 60, 60 to 90, 90 to 120 and 120 to 150 cm soil depths at sampling sites. Data were investigated
both statistically and geostatistically on the basis of the semivariogram. The spatial distribution model and spatial dependence
level varied in the study area. Among the considered parameters, maximum and minimum spatial variability were observed in
EC and pH parameters, respectively. Soil properties showed moderate to strong spatial dependence, except for a few. ECe was
strongly spatially dependent in the total soil depth and clay was strongly spatially dependent at the first depth. Sand and
pH were moderately spatially dependent for three of the five depths. ESP was strongly spatially dependent and silt was moderate
in the total soil depths, except at 90–120 cm depth. Furthermore, CEC had strong spatial dependence for three of the five
depths. All geostatistical range values were >1,389 m in this study. It was concluded that the strong spatial dependency of
soil properties would lead to extrinsic factors such as bedrock, agricultural pollution, drainage and ground water level. 相似文献
15.
16.
Isabelle Cousin Arlène Besson Hocine Bourennane Catherine Pasquier Bernard Nicoullaud Dominique King Guy Richard 《Comptes Rendus Geoscience》2009,341(10-11):859-867
The aim of this article is to present a strategy to interpret the hydraulic functioning of a small field area by using measurements of the soil electrical resistivity. The spatial soil electrical resistivity was recorded at a high resolution on a 2 ha area by the MultiContinous Electrical Profiling (MuCEP) device at two dates. These apparent electrical resistivity measurements were firstly interpreted in terms of local electrical resistivity by 1D inverse modelling to estimate the real resistivity of the soil. These interpreted electrical resistivity data were then transformed into soil water content values and soil water potential values by the use of independent punctual data of water content and the use of the water retention curve determined by laboratory data. Our analysis has permitted us to describe the spatial variability and temporal evolution of the hydraulic functioning at high resolution from electrical resistivity data. The interpretation of the water content and matric potential maps demonstrated that some soil hydraulic processes, such as lateral overland flow, can occur in the studied zone. They would never have been detected by local measurements of soil characteristics or by the use of the soil map. 相似文献
17.
Site investigations that aim to sufficiently characterize a soil profile for foundation design, typically consist of a combination of in situ and laboratory tests. The number of tests and/or soil samples is generally determined by the budget and time considerations placed upon the investigation. Therefore, it is necessary to plan the locations of such tests to provide the most suitable information for use in design. This is considered the sampling strategy. However, the spatial variability of soil properties increases the complexity of this exercise. Results presented in this paper identify the errors associated with using soil properties from a single sample location on a pad foundation designed for settlement. Sample locations are distributed around the site to identify the most appropriate sample location and the relative benefits of taking soil samples closer to the center of the proposed footing. The variability of the underlying soil profile is also shown to a have a significant effect on the errors due to sampling location. Such effects have been shown in terms of the statistical properties of the soil profile. The performance of several common settlement relationships to design a foundation based on the results of a single sample location have also been examined. 相似文献
18.
This paper presents a critique of current methods of sampling and analyzing soils for metals in archaeological prospection. Commonly used methodologies in soil science are shown to be suitable for archaeological investigations, with a concomitant improvement in their resolution. Understanding the soil‐fraction location, concentration range, and spatial distribution of autochthonous (native) soil metals is shown to be a vital precursor to archaeological‐site investigations, as this is the background upon which anthropogenic deposition takes place. Nested sampling is suggested as the most cost‐effective method of investigating the spatial variability in the autochthonous metal concentrations. The use of the appropriate soil horizon (or sampling depth) and point sampling are critical in the preparation of a sampling regime. Simultaneous extraction is proposed as the most efficient method of identifying the location and eventual fate of autochthonous and anthropogenic metals, respectively. © 2004 Wiley Periodicals, Inc. 相似文献
19.
Filipa Tavares Wahren Maria Tarasiuk Andriy Mykhnovych Myron Kit Karl-Heinz Feger Kai Schwärzel 《Environmental Earth Sciences》2012,65(5):1501-1510
Integrated watershed models require spatially differentiated soil information. However, in many regions of the world the limited
availability of soil data hinders an appropriate simulation of hydro-ecological processes. Such circumstances lead to unsupported
statements, poor statistics, misrepresentations, and, ultimately, to bad resource management. The Western Bug catchment in
west Ukraine is an example of such a region. In the former Soviet Union, soil classification primarily focused on soils of
agricultural importance, whereas, forested, urban, industrial, and shallow soil territories were left underrepresented in
the classification and soil maps. Spatially differentiated soil texture data are required to predict soil hydraulic properties
using pedotransfer functions (PTFs), along with soil maps. Furthermore, the Ukrainian soil texture scheme does not match the
particle size classes commonly used with PTFs. To overcome these shortcomings, a fuzzy logic methodology was applied, based
on terrain and vegetation/land use analysis and soil sampling, to close the information gaps. For the application of PTFs,
a procedure was tested to estimate missing values of soil texture distribution. Applied methods were evaluated using recent
soil surveys, measured soil texture, and water retention properties, while having in consideration the limitations brought
by scarce soil data for integrated watershed modelling purposes. 相似文献
20.
An approach for assessing soil health: a practical guide for optimal ecological management 总被引:1,自引:0,他引:1
Yang Gao Yafeng Wang Guoming Zhang Jun Xia Liang Mao Zhenwu Tang Pei Zhou 《Environmental Earth Sciences》2012,65(1):153-159
How to integrate environmental geographic information and biodiversity data combined with management measures to effectively
assess soil health is still an unresolved problem. This paper suggests an approach for systematically estimating soil quality
and guiding ecological management. First, canonical correspondence analysis is used to predict the distributions of plant
species or microorganism communities, principle pollutants and environmental variables from which spatial and environmental
data are extracted by the geographic information system (GIS). Secondly, geostatistical methodologies are then used to estimate
and quantify the spatial distribution characteristic of the species and pollutants and to create maps of spatial uncertainty
and hazard assessment through ArcGis technology. Finally, redundancy analysis provides a suggestion about better management
strategy and environmental factor for improving soil health and biodiversity. The combination of these methods with “3S” techniques
as an assessment approach effectively meets the challenges for estimation and management in different soil environments. 相似文献