835 research outputs found

    Estimate of Heavy Metals in Soil Using Combined Geochemistry and Field Spectroscopy in Miyi Mining Area

    Get PDF
    Heavy metal-contaminated soil and water is a major environmental issue in the mining areas. However, as the heavy metals migrate frequently, the traditional method of estimating the soil’s heavy metal content by field sampling and laboratory chemical analysis followed by interpolation is time-consuming and expensive. This chapter intends to use field hyperspectra to estimate the heavy metals in the soil in Bai-ma, De-sheng and YuanBaoshan mining areas, Miyi County, Sichuan Province. By analyzing the spectra of soil, the spectral features derived from the spectra of the soils can be found to build the models between these features and the contents of Mn and Co in the soil by using the linear regression method. The spectral features of Mn are 2142 and 2296 nm. The spectral features of Co are 1918, 1922 and 2205 nm. With these feature spectra, the best models to estimate the heavy metals in the study area can be built according to the maximal determination coefficients (R2). The determination coefficients (R2) of the models of retrieving Mn and Co in the soil are 0.645 and 0.8, respectively. The model significant indexes of Mn and Co are 2.04507E-05 and 7.73E-06. These results show that it is feasible to predict contaminated heavy metals in the soils during mining activities for soil remediation and ecological restoration by using the rapid and cost-effective field spectroscopy

    Calibration of DART Radiative Transfer Model with Satellite Images for Simulating Albedo and Thermal Irradiance Images and 3D Radiative Budget of Urban Environment

    Get PDF
    Remote sensing is increasingly used for managing urban environment. In this context, the H2020 project URBANFLUXES aims to improve our knowledge on urban anthropogenic heat fluxes, with the specific study of three cities: London, Basel and Heraklion. Usually, one expects to derive directly 2 major urban parameters from remote sensing: the albedo and thermal irradiance. However, the determination of these two parameters is seriously hampered by complexity of urban architecture. For example, urban reflectance and brightness temperature are far from isotropic and are spatially heterogeneous. Hence, radiative transfer models that consider the complexity of urban architecture when simulating remote sensing signals are essential tools. Even for these sophisticated models, there is a major constraint for an operational use of remote sensing: the complex 3D distribution of optical properties and temperatures in urban environments. Here, the work is conducted with the DART (Discrete Anisotropic Radiative Transfer) model. It is a comprehensive physically based 3D radiative transfer model that simulates optical signals at the entrance of imaging spectro-radiometers and LiDAR scanners on board of satellites and airplanes, as well as the 3D radiative budget, of urban and natural landscapes for any experimental (atmosphere, topography,…) and instrumental (sensor altitude, spatial resolution, UV to thermal infrared,…) configuration. Paul Sabatier University distributes free licenses for research activities. This paper presents the calibration of DART model with high spatial resolution satellite images (Landsat 8, Sentinel 2, etc.) that are acquired in the visible (VIS) / near infrared (NIR) domain and in the thermal infrared (TIR) domain. Here, the work is conducted with an atmospherically corrected Landsat 8 image and Bale city, with its urban database. The calibration approach in the VIS/IR domain encompasses 5 steps for computing the 2D distribution (image) of urban albedo at satellite spatial resolution. (1) DART simulation of satellite image at very high spatial resolution (e.g., 50cm) per satellite spectral band. Atmosphere conditions are specific to the satellite image acquisition. (2) Spatial resampling of DART image at the coarser spatial resolution of the available satellite image, per spectral band. (3) Iterative derivation of the urban surfaces (roofs, walls, streets, vegetation,…) optical properties as derived from pixel-wise comparison of DART and satellite images, independently per spectral band. (4) Computation of the band albedo image of the city, per spectral band. (5) Computation of the image of the city albedo and VIS/NIR exitance, as an integral over all satellite spectral bands. In order to get a time series of albedo and VIS/NIR exitance, even in the absence of satellite images, ECMWF information about local irradiance and atmosphere conditions are used. A similar approach is used for calculating the city thermal exitance using satellite images acquired in the thermal infrared domain. Finally, DART simulations that are conducted with the optical properties derived from remote sensing images give also the 3D radiative budget of the city at any date including the date of the satellite image acquisition

    The data concept behind the data: From metadata models and labelling schemes towards a generic spectral library

    Get PDF
    Spectral libraries play a major role in imaging spectroscopy. They are commonly used to store end-member and spectrally pure material spectra, which are primarily used for mapping or unmixing purposes. However, the development of spectral libraries is time consuming and usually sensor and site dependent. Spectral libraries are therefore often developed, used and tailored only for a specific case study and only for one sensor. Multi-sensor and multi-site use of spectral libraries is difficult and requires technical effort for adaptation, transformation, and data harmonization steps. Especially the huge amount of urban material specifications and its spectral variations hamper the setup of a complete spectral library consisting of all available urban material spectra. By a combined use of different urban spectral libraries, besides the improvement of spectral inter- and intra-class variability, missing material spectra could be considered with respect to a multi-sensor/ -site use. Publicly available spectral libraries mostly lack the metadata information that is essential for describing spectra acquisition and sampling background, and can serve to some extent as a measure of quality and reliability of the spectra and the entire library itself. In the GenLib project, a concept for a generic, multi-site and multi-sensor usable spectral library for image spectra on the urban focus was developed. This presentation will introduce a 1) unified, easy-to-understand hierarchical labeling scheme combined with 2) a comprehensive metadata concept that is 3) implemented in the SPECCHIO spectral information system to promote the setup and usability of a generic urban spectral library (GUSL). The labelling scheme was developed to ensure the translation of individual spectral libraries with their own labelling schemes and their usually varying level of details into the GUSL framework. It is based on a modified version of the EAGLE classification concept by combining land use, land cover, land characteristics and spectral characteristics. The metadata concept consists of 59 mandatory and optional attributes that are intended to specify the spatial context, spectral library information, references, accessibility, calibration, preprocessing steps, and spectra specific information describing library spectra implemented in the GUSL. It was developed on the basis of existing metadata concepts and was subject of an expert survey. The metadata concept and the labelling scheme are implemented in the spectral information system SPECCHIO, which is used for sharing and holding GUSL spectra. It allows easy implementation of spectra as well as their specification with the proposed metadata information to extend the GUSL. Therefore, the proposed data model represents a first fundamental step towards a generic usable and continuously expandable spectral library for urban areas. The metadata concept and the labelling scheme also build the basis for the necessary adaptation and transformation steps of the GUSL in order to use it entirely or in excerpts for further multi-site and multi-sensor applications

    Soil threats in Europe

    Get PDF
    Although there is a large body of knowledge available on soil threats in Europe, this knowledge is fragmented and incomplete, in particular regarding the complexity and functioning of soil systems and their interaction with human activities. The main aim of RECARE is to develop effective prevention, remediation and restoration measures using an innovative trans-disciplinary approach, actively integrating and advancing knowledge of stakeholders and scientists in 17 Case Studies, covering a range of soil threats in different bio-physical and socio-economic environments across Europe. Existing national and EU policies will be reviewed and compared to identify potential incoherence, contradictions and synergies. Policy messages will be formulated based on the Case Study results and their integration at European level. A comprehensive dissemination and communication strategy, including the development of a web-based Dissemination and Communication Hub, will accompany the other activities to ensure that project results are disseminated to a variety of stakeholders at the right time and in the appropriate formats to stimulate renewed care for European soils.JRC.H.5-Land Resources Managemen

    Remote Sensing of Biophysical Parameters

    Get PDF
    Vegetation plays an essential role in the study of the environment through plant respiration and photosynthesis. Therefore, the assessment of the current vegetation status is critical to modeling terrestrial ecosystems and energy cycles. Canopy structure (LAI, fCover, plant height, biomass, leaf angle distribution) and biochemical parameters (leaf pigmentation and water content) have been employed to assess vegetation status and its dynamics at scales ranging from kilometric to decametric spatial resolutions thanks to methods based on remote sensing (RS) data.Optical RS retrieval methods are based on the radiative transfer processes of sunlight in vegetation, determining the amount of radiation that is measured by passive sensors in the visible and infrared channels. The increased availability of active RS (radar and LiDAR) data has fostered their use in many applications for the analysis of land surface properties and processes, thanks to their insensitivity to weather conditions and the ability to exploit rich structural and texture information. Optical and radar data fusion and multi-sensor integration approaches are pressing topics, which could fully exploit the information conveyed by both the optical and microwave parts of the electromagnetic spectrum.This Special Issue reprint reviews the state of the art in biophysical parameters retrieval and its usage in a wide variety of applications (e.g., ecology, carbon cycle, agriculture, forestry and food security)

    An overview of monitoring methods for assessing the performance of nature-based solutions against natural hazards

    Get PDF
    To bring to fruition the capability of nature-based solutions (NBS) in mitigating hydro-meteorological risks (HMRs) and facilitate their widespread uptake require a consolidated knowledge-base related to their monitoring methods, efficiency, functioning and the ecosystem services they provide. We attempt to fill this knowledge gap by reviewing and compiling the existing scientific literature on methods, including ground-based measurements (e.g. gauging stations, wireless sensor network) and remote sensing observations (e.g. from topographic LiDAR, multispectral and radar sensors) that have been used and/or can be relevant to monitor the performance of NBS against five HMRs: floods, droughts, heatwaves, landslides, and storm surges and coastal erosion. These can allow the mapping of the risks and impacts of the specific hydro-meteorological events. We found that the selection and application of monitoring methods mostly rely on the particular NBS being monitored, resource availability (e.g. time, budget, space) and type of HMRs. No standalone method currently exists that can allow monitoring the performance of NBS in its broadest view. However, equipments, tools and technologies developed for other purposes, such as for ground-based measurements and atmospheric observations, can be applied to accurately monitor the performance of NBS to mitigate HMRs. We also focused on the capabilities of passive and active remote sensing, pointing out their associated opportunities and difficulties for NBS monitoring application. We conclude that the advancement in airborne and satellite-based remote sensing technology has signified a leap in the systematic monitoring of NBS performance, as well as provided a robust way for the spatial and temporal comparison of NBS intervention versus its absence. This improved performance measurement can support the evaluation of existing uncertainty and scepticism in selecting NBS over the artificially built concrete structures or grey approaches by addressing the questions of performance precariousness. Remote sensing technical developments, however, take time to shift toward a state of operational readiness for monitoring the progress of NBS in place (e.g. green NBS growth rate, their changes and effectiveness through time). More research is required to develop a holistic approach, which could routinely and continually monitor the performance of NBS over a large scale of intervention. This performance evaluation could increase the ecological and socio-economic benefits of NBS, and also create high levels of their acceptance and confidence by overcoming potential scepticism of NBS implementations

    Effects of Mineral Elements on the Environment

    Get PDF
    Medical mineralogy and geochemistry constitute an important field, yet little attention has been paid to it by scientists, administrators, or the public. The aims of this book are: (a) to focus on a selection of current challenges and research opportunities and (b) to encourage knowledge transfer between geochemists and mineralogists whose work concerns medical problems and medical scientists who study problems surrounding biominerals and geomaterials. This book covers a variety of novel approaches, tools and techniques, and scenarios of contamination in water and wastewater, and is a key resource for policymakers and environmental scientists working hard to address environmental pollutants. The key features are: state-of-the-art techniques for the assessment and remediation of heavy metals, presenting the interdisciplinary impacts of heavy metals, including those on human health, ecosystems and water quality, and including various contamination indices, such as contamination factor, geoaccumulation index, enrichment factor, pollution index and ecological risk index

    APPLICATION OF GEOPHYSICAL AND GEOCHEMICAL METHODS FOR SOIL CHARACTERISATION IN SUSTAINABLE PRECISION AGRICULTURE IN SELECTED FARMS

    Get PDF
    All soils have potential for high yield for specific crops. Nigerian soils have potential for medium to high yield, but poor farming practices including the misuse of chemical fertilizers result in a number of constraints such as soil salinity, degradation and declining fertility, which militate against high crop yields. Nigeria, currently battling with food insecurity because population growth is not commensurate with agricultural production. Thus, there is need for urgent intervention in the agricultural sector. The aim of this study was to integrate geophysical and geochemical methods for sustainable precision agriculture in two farm sites of Covenant University and Landmark University, Nigeria. In this study, electrical resistivity, geochemical and satellite imagery methods were used for soil characterisation in farm sites at Covenant University, Ota, Southwest and Landmark University, Omu-Aran, North-central Nigeria between June, 2018 and January, 2019. The electrical resistivity data were processed using RES2DINV and Win-Resist software. Geochemical analysis of soil samples from the sites was conducted using ICP-MS in ACME laboratory, Canada. Monthly MERRA satellite data was used to determine the soil temperature and soil moisture content while soil salinity was estimated from Landsat-8 satellite imagery. The study showed that electrical resistivity of the topsoil in Covenant University farm ranged from 120 -500 Ωm, while that of Landmark University farm ranged from 345-527 Ωm. The soil types delineated at the Covenant University farm were clayey sand and lateritic clay; sand/lateritic gravelly sand was delineated at Landmark University farm. Potentially toxic elements were detected in the soil samples of both sites; arsenic (As), chromium (Cr), lead (Pb) and copper (Cu) exceeded FAO/WHO recommended standard limits in Covenant University farm. The pollution indices of Co, Cr, Ni, Pb and Mn in the Covenant University farm were within low to high contamination, while As was within medium to high contamination. In Landmark University farm, the pollution indices of Pb, Cu, Zn, Co and Cd ranged from low to medium, while As has pollution index within low to high contamination. Results showed elevated concentrations of As in all samples. Ca-Mg, P-Mg, Fe-Al, Ca-K, Mg-K and Na-K paired nutrients were positively correlated at 5% level of significance in both farmlands, indicating similar increase in both farmlands. Also, the geospatial maps revealed zones of high and low accumulation of essential macro nutrients within the farmlands. Landmark University farmland indicated higher soil salinity than Covenant University farm land. Soil temperature (ST) data at Covenant University farm ranged from 296 - 314 K, while ST at Landmark University farm ranged from 289 - 317 K. Soil moisture content data for both farms ranged from 23 – 113 3 3 mmand 10 - 110 3 3 mmin Covenant and Landmark University farms, respectively. The sandy gravelly soil of Landmark University farm is suitable for the planting of root and tuber crops such as carrot, yam, potatoes, turmeric and beets. Cabbage, leafy vegetables and lemon grass can be grown successfully in Covenant University farm. The ecological risk assessment of toxic metals, showed that arsenic may present a moderate to very high biological risk to both plants and animals that feed on the soil of both farm lands. The site-specific information of the farm sites has been provided. This study provides database that can serve as useful guide in soil management decision making for better yiel
    corecore