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1.
It is necessary to estimate heavy metal concentrations within soils for understanding heavy metal contaminations and for keeping the sustainable developments of ecosystems. This study, with the floodplain along Le’an River and its two branches in Jiangxi Province of China as a case study, aimed to explore the feasibility of estimating concentrations of heavy metal lead (Pb), copper (Cu) and zinc (Zn) within soils using laboratory-based hyperspectral data. Thirty soil samples were collected, and their hyperspectral data, soil organic matters and Pb, Cu and Zn concentrations were measured in the laboratory. The potential relations among hyperspectral data, soil organic matter and Pb, Cu and Zn concentrations were explored and further used to estimate Pb, Cu and Zn concentrations from hyperspectral data with soil organic matter as a bridge. The results showed that the ratio of the first-order derivatives of spectral absorbance at wavelengths 624 and 564 nm could explain 52% of the variation of soil organic matter; the soil organic matter could explain 59%, 51% and 50% of the variation of Pb, Cu and Zn concentrations with estimated standard errors of 1.41, 48.27 and 45.15 mg·kg?; and the absolute estimation errors were 8%–56%, 12%–118% and 2%–22%, and 50%, 67% and 100% of them were less than 25% for Pb, Cu and Zn concentration estimations. We concluded that the laboratory-based hyperspectral data hold potentials in estimating concentrations of heavy metal Pb, Cu and Zn in soils. More sampling points or other potential linear and non-linear regression methods should be used for improving the stabilities and accuracies of the estimation models.  相似文献   

2.
Soil nutrient maps based on intensive soil sampling are useful to adopt site-specific management practices. Geostatistical methods have been widely used to determine the spatial correlation and the range of spatial dependence at different sampling scales. If spatial dependence is detected, the modeled semivariograms can then be used to map the interested variable by kriging, an interpolation method that produces unbiased estimates with minimal estimation variance. The objectives of this paper were to examine and map the spatial distribution of the soil micronutrients Cu, Zn, Fe and Mn on an agricultural area in Kupwara, J&K, under temperate climatic conditions. The ordinary kriging was first used to determine the values for the non-sampled locations, and then the indicator approach was used to transform the micronutrient content values into binary values having the mean values of each nutrient as the threshold content. All four elements analyzed showed spatial dependence using the indicator semivariograms. The strength of spatial dependence was assessed using the values of nugget effect and range from the semivariogram, the fitted range values decreased in the order Zn > Cu > Mn > Fe. The spatial dependence of the combination of two or more of the studied micronutrients was also examined using indicator semivariograms. In opposition to spatial analysis of individual microelements, indicator semivariograms obtained for the binary coding of the variables showed a great nugget effect value or a low proportion of sill. The maps for each nutrient obtained using indicator kriging showed some similarity in the spatial distribution, suggesting the delimitation of uniform management areas.  相似文献   

3.
It is necessary to estimate heavy metal concentrations within soils for understanding heavy metal contaminations and for keeping the sustainable developments of ecosystems.This study,with the floodplain along Le’an River and its two branches in Jiangxi Province of China as a case study,aimed to explore the feasibility of estimating concentrations of heavy metal lead(Pb),copper(Cu) and zinc(Zn) within soils using laboratory-based hyperspectral data.Thirty soil samples were collected,and their hyperspectral data,soil organic matters and Pb,Cu and Zn concentrations were measured in the laboratory.The potential relations among hyperspectral data,soil organic matter and Pb,Cu and Zn concentrations were explored and further used to estimate Pb,Cu and Zn concentrations from hyperspectral data with soil organic matter as a bridge.The results showed that the ratio of the first-order derivatives of spectral absorbance at wavelengths 624 and 564 nm could explain 52% of the variation of soil organic matter;the soil organic matter could ex-plain 59%,51% and 50% of the variation of Pb,Cu and Zn concentrations with estimated standard errors of 1.41,48.27 and 45.15 mg·kg-1;and the absolute estimation errors were 8%-56%,12%-118% and 2%-22%,and 50%,67% and 100% of them were less than 25% for Pb,Cu and Zn concentration estimations.We concluded that the laboratory-based hyperspectral data hold potentials in esti-mating concentrations of heavy metal Pb,Cu and Zn in soils.More sampling points or other potential linear and non-linear regression methods should be used for improving the stabilities and accuracies of the estimation models.  相似文献   

4.
徐州市九里矿区土壤重金属插值分析及污染评价   总被引：1，自引：0，他引：1  
通过对徐州市九里矿区的表层土壤进行采样测定,进而对该矿区土壤重金属富集与污染状况进行了分析与评价。结果表明,该矿区表层土壤中5种重金属(Cd、Cu、Zn、Pb、Cr)含量均略高于中国土壤元素背景值,土壤中Cd富集程度较高,污染较严重;Cu、Zn、Pb、Cr富集程度较低,污染程度较轻。在GIS环境下利用空间数据插值方法对重金属的空间分布特征研究发现,该城区土壤重金属含量与该区的工矿活动和交通活动等密切相关。  相似文献   

5.
基于GIS的土壤重金属数据库构建及应用   总被引：2，自引：0，他引：2  
本文首先探讨了利用GIS技术构建上海市基本农田土壤重金属数据库的方法,该数据库集空间数据、采样点监测数据和元数据于一体,对于土壤重金属信息的管理、应用服务等具有重要的基础作用,是农产品安全生产环境认证和土壤环境长效管理的重要依据;接着,基于数据库进行了重金属元素的描述性统计、动态累积和Kriging插值分析;结果表明,除As外,其余重金属平均含量均高于该区域的背景值含量,尤其是Cd、Hg、Zn、Cu累积指数较高,是上海市农田土壤重金属污染的主要元素。  相似文献   

6.
An area of about 7500 km2 covering Cauvery delta has been studied from airphotos (1:60,000), Landsats (1:250,000) and survey of India topographic sheets (1:50,000) with a view to delineate various landforms, soils, land use, hydromorphic units, drainage, and flood intensity of the delta. The delta is composed of mainly ancient channels, delta p ains, fossil islands, levees, beach ridges, mangroves marshes and coastal dunes. The various soil types are clayey soils, silty soils, silty loams, sandy loams, coastal sands and alkaline clays. Paddy and sugarcane are dominant crops. The old channels are found to be zones of high ground water potential. The growth of delta seems to be from south to north with twelve abandoned meander lobes and three delta fronts with gradual influx of material into Bay of Bengal. The old rivet courses lying parallel to the present active Coleroon river in third stage of the growth of the delta seem to be severely affected by floods. Moderate to low growth is noticeable in the second stage of the of the delta. The oldest river course which debouched into Bay of Bengal near Adirama-patnam is less affected by floods. The delta plains, fossil islands, disturbed ridges and beach ridges are unaffected. Basing on landforms, soils, land use, hydrogeomorphology and flood intensity the land capability of the delta has been evaluated. About seven classes of land are interpreted.  相似文献   

7.
The present investigation has been designed to analyze the landform and soil relationship in a geologically complex terrain of Tirora tahsil of Gondia district, Maharashtra using remotely sensed data and GIS technique. The geomorphologic units of the study area were delineated through visual interpretation of IRS–ID LISS-III data based on the spatial variation of the image characteristics. Thirteen landform units have been identified in the tahsil. The slope varied from level to nearly level with an area of about 63.76% of the tahsil. Rest of the area ranged from very gentle to moderately steep slopes. During soil survey, soil profiles were studied for morphological features. Horizon-wise soil samples were collected from the representative soil profiles on each landform unit. The depth of soil varied from 25 to 160 cm and colour from dark brown to very dark grayish brown. The texture ranged from clay loam to clayey in accordance with higher and lower topographic positions respectively. Higher available water holding capacity (AWC 285 mm) is found in low-lying area and low to medium AWC (140 mm) is noticed in the soils developed at higher elevation. The soils reaction (pH) is strongly acidic in nature (pH 5.2) on dissected hills, linear ridge and moderately weathered pediments, whereas, the soils are moderately to slightly acidic in nature (pH 5.5 to 6.5) on hills, shallow weathered pediments, moderately weathered pediments, deeply weathered pediments, narrow valleys, and broad valley floors. Slightly alkaline condition (pH 7.6) was observed on foot slopes and aggraded valley fills. The electrical conductivity of the soils is found almost same in all landforms. The cation exchange capacity of the area varies from 10.5 to 51.5 cmol(p+)kg?1. The base saturation increases with decreasing elevation and slope. The four major soil orders viz, Entisols, Alfisols, Inceptisols and Vertisols are found in the study areas which are further classified into suborder and great group levels. The landform and soil relationship was analyzed to appraise the land resources in the tahsil. The study shows that the application of remotely sensed data and GIS are immensely helpful in land resources appraisal for their management on sustainable basis.  相似文献   

8.
The accumulation of heavy metals in the biosolid amended soils and the risk of their uptake into different plant parts is a topic of great concern. This study examines the accumulation of several heavy metals and nutrients in soybeans grown on biosolid applied soils and the use of remote sensing to monitor the metal uptake and plant stress. Field and greenhouse studies were conducted with soybeans grown on soils applied with biosolids at varying rates. The plant growth was monitored using Landsat TM imagery and handheld spectroradiometer in field and greenhouse studies, respectively. Soil and plant samples were collected and then analyzed for several elemental concentrations. The chemical concentrations in soils and roots increased significantly with increase in applied biosolid concentrations. Copper (Cu) and Molybdenum (Mo) accumulated significantly in the shoots of the metal-treated plants. Our spectral and Landsat TM image analysis revealed that the Normalized Difference Vegetative Index (NDVI) can be used to distinguish the metal stressed plants. The NDVI showed significant negative correlation with increase in soil Cu concentrations followed by other elements. This study suggests the use of remote sensing to monitor soybean stress patterns and thus indirectly assess soil chemical characteristics.  相似文献   

9.
Soil Resource Database at Village Level for Developmental Planning   总被引：1，自引：0，他引：1  
A study was carried out in village Mohammadabad, Nalgonda district, Andhra Pradesh to demonstrate the potential of high-resolution remote sensing data in generating soil resource database at village level that would facilitate natural resource developmental planning. For this study, detail soil resource database was generated by interpreting IRS Resourcesat-1 LISS-IV + Cartosat-1 merged data and by undertaking soil survey and soil analysis. This database was integrated with cadastral map and was analysed for preparation of an action plan for the village that included recommendation on suitable crops, soil and water conservation measures and distribution of soil health card to farmers. The study indicates that the LISS-IV + Cartosat-1 merged satellite data helps in mapping soils at phase level and in delineation of more number of pure soil mapping units i.e. consociations at 1:10.000 scale. The plot-wise resource potential and constraints reveals that significant inter and intra-field soil variability exists. Soil fertility assessment indicates that the soils of the village are low to medium in fertility (available NPK Content) and micronutrients like copper, manganese and iron content is above the critical level for optimum growth of crops while zinc content is less than the critical level.  相似文献   

10.
Secondary salinisation is the most harmful and extended phenomenon of the unfavourable effects of irrigation on the soil and environment. An attempt was made to study the impact of poor quality ground water on soils in terms of secondary salinisation and availability of soil nutrients in Faridkot district of Punjab of northern India. Based on physiographic analysis of IRS 1C LISS-III data and semi-detailed soil survey, the soil map was finalized on a 1:50,000 scale and digitized using Arc Info GIS. Georeferenced surface soil samples (0–0.15 m) from 231 sites were collected and analyzed for available phosphorus (P) and potassium (K). Interpolation by kriging produced digital spatial maps of available P and K. Ground water quality map was generated in GIS domain on the basis of EC (electrical conductivity) and RSC (residual sodium carbonate) of ground water samples collected from 374 georeferenced tube wells. Integration of soil and ground water quality maps enabled generating a map showing degree (high, moderate and low) and type (salinity, sodicity and both) of vulnerability to secondary salinization. Fine-textured soils have been found to be highly sensitive to secondary salinisation, whereas medium-textured soils as moderately sensitive to secondary salinisation. The resultant map was integrated with available P and K maps to show the combined influence of soil texture and ground water quality on available soil nutrients. The results show that available P and K in the soils of different physiographic units were found in the order of Ap1 < Ap2 < Ap3. The soils of all physiographic units had sizeable area having high content of P (>22.5 kg / ha) and medium available K (135–335 kg ha−1) in most of the test sites when irrigated with saline, sodic or poor quality water.  相似文献   

11.
In the present study, landforms and soils have been characterized in Borgaon Manju watershed of basaltic terrain located in Akola district, Maharashtra, Central India. Terrain characterization using Shuttle Radar Topography Mission (SRTM) elevation data (90 m) and IRS-P6 LISS IV data in conjunction with adequate field surveys shows nine distinct landforms. Soil resource inventory shows fourteen soil series in the study area. Soils formed on gently sloping (3–8 %) subdued plateau are very shallow (23 cm), moderately well drained, moderate (15–40 %) surface stoniness, severely eroded, clayey and slightly alkaline in reaction, whereas, the soils formed on level to nearly level (0–1 %) slope in the main valley are very deep (>150 cm), well drained, very slight (<3 %) surface stoniness, moderately eroded with clayey surface and moderately alkaline in reaction. Soils in the watershed are grouped into Lithic Ustorthents, Vertic Haplustepts, Calcic Haplustepts, Typic Haplustepts, Typic Haplusterts and Sodic Calciusterts. The study demonstrates that the analysis of SRTM elevation data and IRS P6–IV data in Geographic Information System (GIS) with adequate field surveys helps in characterization of landforms and soils in analysis of landscape-soil relationship.  相似文献   

12.
To understand the nature of land degradation and factors responsible for it, investigations were carried out in Etah district with an area of 4.45 lakh hectares. For identification of soil/land degradation problems, multidate Landsat, TM spectral bands and FCC were used. It is observed that salt-affected soils are sharply depicted by light and dark gray mixed tone on band 3, while they are not clear on band 4. Flood plain and waterlogged soils are clearly observed on band 4. Band 6 (10.3 – 12.5 µm) helps in separation of broad zones of coarse and fine-textured soils, active flood plain of rivers, and eroded and gullied lands. The confusion between coarse-textured droughty soils and salt-affected areas in TM FCC (2, 3, 4) could be eliminated by use of band-6 data in combination with FCC. For delineation of problematic areas, two approaches were followed viz. (i) physiographic approach, and (ii) direct approach. In the physiographic approach landscape map associated with image characteristics was prepared. Further the image interpretation units were interpreted for land degradation hazards. With this approach physiography and soil relationship and the degradation problems vis-a-vis soil units could be established and ameliorative measures as per soil condition can be suggested. In direct approach, the problematic areas as per predetermined key were demarcated. Out of 4.45 lakh ha of the area, 1.99 lakh ha is affected by various soil degradation problems, like droughty soils, flooding hazard and salinity and alkalinity which cover 22.1%, 50.0% and 27.9%, respectively. To study the distribution of a salt-affected lands, major physiographic boundaries were superimposed over the land degradation map prepared by direct approach. It is observed that 81.5% of the salt-affected areas lie in the old alluvial plain while 18.5% is in recent flood plain.  相似文献   

13.
During the Hapex-Sahel international investigation, portable radiometers (Barringer and Cimel) were used to study, in the optical domain, the relationship between soil mineralogical and granulometric compositions and radiometric indices: redness index, colour index and texture index. The results show that the granulometric distribution and the mineralogical composition have both important influence on these indices.In this Sahelian area, for soils having more than 1% of hematite, the redness index presents a high correlation with hematite content. For soils with less than 1% of hematite, the redness index depends on the size of the particles and their distribution at the surface.For eolian sandy and ferricrust soils, the colour and texture indices present good correlations, respectively, with iron oxide and kaolinite content. No such correlation is observed for ferruginous soils because of the complex interactions existing between iron oxides, kaolinite and the size of particles.  相似文献   

14.
土壤重金属污染灰色综合评价模型   总被引：1，自引：1，他引：0  
针对稀疏采样难以准确估测区域土壤重金属综合污染情况和迁移变化规律的问题,提出基于GIS的多属性决策组合赋权灰色综合评价模型。首先采用GIS技术揭示土壤重金属空间变异和污染分布格局;然后利用最大化熵理论集成主客观因素,架构优化组合赋权的土壤重金属污染灰色综合评价体系;最后以试验区土壤中8种(铜、锌、铅、镉、砷、铬、汞、镍)重金属的综合污染情况为例,检验该方法应用效果。结果表明:最优组合权重的灰色综合分析方法兼顾主观偏好和客观属性,其评价结果具有更高的可信度和风险辨识度,提高了综合评价的合理性与有效性,可为土壤重金属污染监测提供方案参考。  相似文献   

15.
The spatial distribution of some soil chemical properties and trace element contents of a plot affected by the Aznalcóllar mine spill were investigated using statistical and geostatistical methods to assess the extent of soil contamination. Total and EDTA-extractable soil trace element concentrations and total S content showed great variability and high coefficients of variation in the three examined depths. Soil in the plot was found to be significantly contaminated by As, Cd, Cu, Pb and Zn within a wide range of pH. Total trace element concentrations at all depths (0–60 cm) were much higher than background values of non-affected soil, indicating that despite the clean-up operations, the concentration of trace elements in the experimental plot was still high. The spatial distribution of the different variables was estimated by kriging to design contour maps. These maps allowed the identification of specific zones with high metal concentrations and low pH values corresponding to spots of residual sludge. Moreover, kriged maps showed distinct spatial distribution and hence different behaviour for the elements considered. This information may be applied to optimise remediation strategies in highly and moderately contaminated areas.  相似文献   

16.
基于GIS的县域土壤重金属生态风险评价   总被引：2，自引：0，他引：2  
为研究经济快速发展区农田土壤中重金属的含量及污染状况,本文以浙江省慈溪市为研究对象,研究土壤中铜、汞、镉、铅、砷、铬、锌七种重金属含量特征,并采用潜在生态危害指数法对其进行评价,并绘制生态风险危害指数分级图。结果表明:土壤中除汞元素含量较高外,其他各元素含量仅稍高于当地土壤背景值。七种元素的单因子污染指数Cfi值均属于中等的污染参数,综合污染指数Cd上限值已处于高污染指数的范围,但平均值为属于中等污染水平。从潜在生态风险评价结果来看,七种元素的单项潜在生态风险参数Eri的值也只有汞达到了强生态危害,七种元素综合潜在生态危害指数RI刚刚达到中等生态危害水平,说明该区农田土壤尚处于较低的生态风险状态。生态危害指数插值结果表明,慈溪市重金属元素的高风险区分布在中南部人类活动较为活跃、城乡工业较发达的区域,在今后的土地利用中,应高度重视人类活动对土壤重金属污染的影响。  相似文献   

17.
The aim of this work was to map Red Mediterranean soils, for which no previous mapping approach exists, using optical multispectral satellite remote sensing data. This case study explores the use of SPOT XS images over the viticultural Southern Rhone Valley, France, to map exposed vineyard soils. Field spectral measurements were used to distinguish Red Mediterranean soil surfaces during Spring 1999. A supervised maximum likelihood classification was applied to sparsely vegetated and unvegetated surfaces of two spring images from 1995 and 1997, drawing on the field training set and available soil data. Similar global spatial segmentation was obtained despite different soil surface states on these dates. Classification performances were higher than 84% in both images. Mean classification accuracies of Red Mediterranean soils at seven reference surfaces were 60% in 1995 and 70% in 1997. This suggests that the direct use of optical remote sensing data at medium resolution can be useful for mapping bare Red Mediterranean soils.  相似文献   

18.
The Quaternary geology of the Cambay basin is studied with the help of aerial photographs and spot checking in the field. Sub-aerial denudational, fluviatile, aeolian and marine processes have produced the Recent deposits that cover the Cambay basin. Black cotton soils, lateritic soils and sandy loams, flood plain deposits, levees, swamps, salt waste, barrier spits, sand hills, undulating sands and flat sands have been identified. The trend of the fluviatile and aeolin deposits are in the NE-SW direction and the marine deposits trend NW-SE. The morphostructural distribution studied on the basis of tonal contrasts and drainage pattern indicates a general NE-SW pattern of structural trend in the Cambay basin and is in confirmation with the Aravalli and the Cutch structural trends. The Cambay basin area is a compound landscape wherein a mantle of youthful material fails to hide the dominant features of the underlying landforms. An attempt is made to relate the different geomorphic aspects to the underlying landforms.  相似文献   

19.
In the present study, an attempt has been made to analyse IRS-ID LISS-III satellite data in conjunction with field observations for geomorphological mapping and pedo-geomorphological characterisation in Mohgaon area of Nagpur district, Maharashtra. Analysis of satellite data reveals distint geomorphological units viz., plateau top, isolated mounds, linear ridges, escarpments, plateau spurs, subdued plateau, rolling plains, pediments, narrow valleys and main valley floor. Soil profiles, studied on different identified landforms, showed variation in site and morphological charactaristics. Moderate soil erosion occurs on plateau top, isolated mouds, plateau spurs, rollinmg plains and pediments. Severe erosion was identified on escarpments and subdued plateau and narrow valleys suffer very slight erosional hazards. Moderately well drained soils were found on rolling plains, pediments, narrow valleys and main valley floor. Well drained soils were noticed on plateau top and plateau spurs. Very shallow soils were found on the plateau top and isolated mounds. Shallow soils are found in linear ridges, escarpments, plateau spurs and rolling plains. Moderately deep and deep soils are found on subdued plateau, pediments and main valley floor. The landform-soil relatioinship reveals that the soils on the plateau top and isolated mounds are very shallow, well drained, clay textured. The soils on the narrow valleys and main valley floor are deep, moderatly well drained, and clayey in texture. It also indicates that landform-soil processes are governed by physiographic position, drainage, slope and erosion conditions of the area. The present study reveals that the analysis of remotely sensed data in conjunction with field observations in GIS will be of immense help in geomorphology mapping, analysis of landform-soil relationships and generation of their geo-spatial database.  相似文献   

20.
Landform constitutes one of the important factors in establishing a firm relationship between soil development and pertinent morphological characteristics. Therefore, an understanding of the geomorphological processes helps to initiate studies in the characterisation of soil scapes. Landscape-soil relationships also assist in mapping soils rapidly and accurately. Remote sensing data products like aerial photographs and satelite imagery help in the recognition, delineation and satellite imagery help in the recognition, delineation and classification of landforms for genetical studies. Five sample areas selected from heterogeneous climatic environments distinctly reveal geomorphic-soil linkages. In the humid, highly weathered, sedimentary hilly terrain of Tripura, Udalfs, Ochrepts and Orthents are common while in the valleys Aqualfs, and Aquepts occur dominantly. In the arid and hilly terrain of Kutch, shallow Orthents and Orthids form the dominant soils but in the plains, deep Salorthids and Natrargids take a dominant place. The semihumid Malwa plateau and Nagpur consists of Ochrepts and Usterts.  相似文献   

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