共查询到20条相似文献，搜索用时 31 毫秒
1.
Giorgos Papadavid Dionysia Fasoula Michael Hadjimitsis P. Skevi Perdikou Diofantos G. Hadjimitsis 《Central European Journal of Geosciences》2013,5(1):1-11
In this paper, Leaf Area Index (LAI) and Crop Height (CH) are modeled to the most known spectral vegetation index — NDVI — using remotely sensed data. This approach has advantages compared to the classic approaches based on a theoretical background. A GER-1500 field spectro-radiometer was used in this study in order to retrieve the necessary spectrum data for estimating a spectral vegetation index (NDVI), for establishing a semiempirical relationship between black-eyed beans’ canopy factors and remotely sensed data. Such semi-empirical models can be used then for agricultural and environmental studies. A field campaign was undertaken with measurements of LAI and CH using the Sun-Scan canopy analyzer, acquired simultaneously with the spectroradiometric (GER1500) measurements between May and June of 2010. Field spectroscopy and remotely sensed imagery have been combined and used in order to retrieve and validate the results of this study. The results showed that there are strong statistical relationships between LAI or CH and NDVI which can be used for modeling crop canopy factors (LAI, CH) to remotely sensed data. The model for each case was verified by the factor of determination. Specifically, these models assist to avoid direct measurements of the LAI and CH for all the dates for which satellite images are available and support future users or future studies regarding crop canopy parameters. 相似文献
2.
Pavan Kumar Haroon Sajjad Bismay Ranjan Tripathy Raihan Ahmed Vinay Prasad Mandal 《Natural Hazards》2018,90(2):693-704
Dynamic and vigorous top soil is the source for healthy flora, fauna, and humans, and soil organic matters are the underpinning for healthy and productive soils. Organic components in the soil play significant role in stimulating soil productivity processes and vegetation development. This article deals with the scientific demand for estimating soil organic carbon (SOC) in forest using geospatial techniques. We assessed distribution of SOC using field and satellite data in Sariska Tiger Reserve located in the Aravalli Hill Range, India. This study utilized the visible and near-infrared reflectance data of Sentinel-2A satellite. Three predictor variables namely Normalized Difference Vegetation Index, Soil Adjusted Vegetation Index, and Renormalized Difference Vegetation Index were derived to examine the relationship between soil and SOC and to identify the biophysical characteristic of soil. Relationship between SOC (ground and predicted) and leaf area index (LAI) measured through satellite data was examined through regression analysis. Coefficient of correlation (R 2) was found to be 0.95 (p value < 0.05) for predicted SOC and satellite measured LAI. Thus, LAI can effectively be used for extracting SOC using remote sensing data. Soil organic carbon stock map generated through Kriging model for Landsat 8 OLI data demonstrated variation in spatial SOC stocks distribution. The model with 89% accuracy has proved to be an effective tool for predicting spatial distribution of SOC stocks in the study area. Thus, optical remote sensing data have immense potential for predicting SOC at larger scale. 相似文献
3.
遥感提取植物生理参数LAI/FPAR的研究进展与应用 总被引：19，自引：2，他引：17
植物生理参数LAI/FPAR是2个重要的陆地特征参量。利用遥感光谱模型并结合地面验证是提取区域尺度的LAI/FPAR最有效的途径。提取LAI/FPAR的模型主要有光谱指数模型和辐射传输模型两类,经过精确的辐射标定和大气纠正的遥感数据可以得到较高精度的LAI/FPAR数据。影响LAI/FPAR精度的因素很多,其中主要因素是像元的异质性、植被类型和物候期等。LAI/FPAR与作物产量有更直接的关系,也是大量作物生长模型的基础,利用这些参数可以实现真实的作物产量预测,特别是开展全球尺度的单产预测。 相似文献
4.
Seyed Armin Hashemi Mir Mozaffar Fallah Chai Shohreh Bayat 《Arabian Journal of Geosciences》2013,6(9):3363-3369
Vegetation indices have been introduced for analyzing and assessing the status of quantitative and qualitative characteristics of vegetation using satellite images. However, choosing the best indices to be used in forest biodiversity and vegetation is one of the important problems faced by the users. The purpose of this research is to evaluate six vegetation indices in the analysis of tree species diversity in the northern forests of Iran. The present research uses LISS III sensor data from IRS-P6 satellite. Geometric rectification of images was performed using ground control points, and Chavez model was used for atmospheric correction of the data. The six spectral vegetation indices included NDVI, IPVI, Ashburn Vegetation Index (AVI), TVI, TTVI, and RVI. Shannon–Wiener species diversity index was used to analyze diversity, and the value of the index was calculated in each sample plot. Then, the spectral values of each sample plot were extracted from different bands. The best subset regression was used to analyze the relationship between species diversity and the related bands. The results obtained from the regression showed that polynomial equations under scrutiny as independent variables can assess tree and shrub species diversity better than other bands and compounds used (R 2?=?0.47). The obtained results also indicated a higher capacity in the case of the AVI index for estimating tree species diversity in the under study area. 相似文献
5.
Detailed geochemical mapping of superficial lateritic formations is compared with recent high-resolution SPOT satellite images in the Dagadamou prospect in southern Mali.The two main landscape features standing out in SPOT images are expressed by thematic indices derived from multispectral data. They reflect the distribution of vegetation cover and the distinction between silty clay soils in the valleys and ferruginous duricrust exposed on the plateaus. Geochemical differentiation factors are closely related to the nature of sampled materials and reflect the relative amounts of major constituent minerals estimated by normative calculation.Duricrust samples with high Fe and Al content are also enriched in trace elements, P, V, Cr, As, Mo, Nb and Cu, immobilized in the weathering profile with secondary oxihydroxide minerals.Soils of flats are composed mainly of quartz and kaolinite; they also concentrate heavy minerals characterized by high contents of Zr, Ti, Ce and Y.Accumulation of detrital material at the periphery of duricrust plateaus is marked by a geochemical halo of higher contents in Zr and quartz at their periphery. This feature is clearly visible on SPOT imagery as a zone of high reflectance, devoid of vegetation.The density of vegetation on duricrust is related to its kaolinite content. Its distribution is characterized by a striped pattern, which is probably controlled by bedrock lithological structures preserved in the lateritic cover.This study shows the relationships, both direct and indirect, existing between spectral reflectance and geochemical composition of superficial lateritic formations. Many other landscape features identified with high resolution on SPOT images provide complementary information, which could be very helpful at various stages of geological and mineral exploration in lateritic terrain. 相似文献
6.
以深圳市东部滨海地区为试验区,对2004年11月21日ASTER遥感数据进行辐射和几何精校正处理,实地建立分类样地;根据多边形样地矢量数据计算分析12类地物在ASTER各波段光谱反射图和分类叠合图,同时进行植被指数和短波红外5个波段主成分分析;结合GIS并利用ASTER光谱波段、第一主成分、植被指数、立体像对生成的地形因子建立土地利用分类决策树表;再根据决策树表对ASTER影像进行土地利用分类。经验证,分类结果总体精度达到85.1%。应用效果表明,利用ASTER数据进行土地现状资源调查具有很好的性价比,能够满足土地利用现状调查的准确度和精度。 相似文献
7.
Spectral vegetation indices (VIs) are a well-known and widely used method for crop state estimation. The ability to monitor crop state by such indices is an important tool for agricultural management. Even though differences in imagery and point-based spectroscopy are obvious, their impact on crop state estimation by VIs is not well-studied. The aim of this study was to assess the performance level of the selected VIs calculated from spaceborne multispectral imagery and point-based field spectroscopy in application to crop state estimation. For this purpose, irrigated chickpea field was monitored by RapidEye satellite mission and additional measurements by field spectrometer were obtained. Estimated VIs average and coefficient of variation from each observation were compared with physical crop measurements: leaf water content, LAI and chlorophyll level. The results indicate that indices calculated from spaceborne spectral images regardless of the claimed response commonly react on phenology of the irrigated chickpea. This feature makes spaceborne spectral imagery an appropriate data source for monitoring crop development, crop water needs and yield prediction. VIs calculated from field spectrometer were sensitive for estimating pigment concentration and photosynthesis rate. Yet, a hypersensitivity of field spectral measures might lead to a very high variability (up to 69%) of the calculated values. Consequently, the high spatial variability of field spectral measurements depreciates the estimation agricultural field state by average mean only. Nevertheless, the spatial variability might have certain behavior trend, e.g., a significant increase in the active growth or stress and can be an independent feature for field state assessment. 相似文献
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9.
Hassan Mohamed AbdelazimNegm Mahmoud Salah Kazuo Nadaoka Mohamed Zahran 《Arabian Journal of Geosciences》2017,10(2):42
Bathymetric information for shallow coastal/lake areas is essential for hydrological engineering applications such as sedimentary processes and coastal studies. Remotely sensed imagery is considered a time-effective, low-cost, and wide-coverage solution for bathymetric measurements. This study assesses the performance of three proposed empirical models for bathymetry calculations in three different areas: Alexandria port, Egypt, as an example of a low-turbidity deep water area with silt-sand bottom cover and a depth range of 10.5 m; the Lake Nubia entrance zone, Sudan, which is a highly turbid, unstable, clay bottom area with water depths to 6 m; and Shiraho, Ishigaki Island, Japan, a coral reef area with varied depths ranging up to 14 m. The proposed models are the ensemble regression tree-fitting algorithm using bagging (BAG), ensemble regression tree-fitting algorithm of least squares boosting (LSB), and support vector regression algorithm (SVR). Data from Landsat 8 and Spot 6 satellite images were used to assess the performance of the proposed models. The three models were used to obtain bathymetric maps using the reflectance of green, red, blue/red, and green/red band ratios. The results were compared with corresponding results yielded by two conventional empirical methods, the neural network (NN) and the Lyzenga generalised linear model (GLM). Compared with echosounder data, BAG, LSB, and SVR results demonstrate higher accuracy ranges from 0.04 to 0.35 m more than Lyzenga GLM. The BAG algorithm, producing the most accurate results, proved to be the preferable algorithm for bathymetry calculation. 相似文献
10.
Lineament extraction from multi-resolution satellite imagery: a pilot study on Wadi Bani Malik, Jeddah, Kingdom of Saudi Arabia 总被引：1，自引：0，他引：1
Mohammed H. T. Qari 《Arabian Journal of Geosciences》2011,4(7-8):1363-1371
The study of structural lineaments is important for mineral exploration, geotectonic and geotechnical studies, and for the mitigation of geologic hazards. The present work deals with the extraction of lineaments from satellite imageries of different spatial resolutions as well as the analysis of these extracted lineaments. Wadi Bani Malik area located to the east of Jeddah city on the Red Sea coastal plain is chosen for such a study. Six types of digital satellite imagery data were used in the present study. These comprise satellite imagery of low spatial resolution (LSR) including Landsat MSS of 80-m resolution, Landsat TM of 30-m resolution, and Landsat TM of 25-m resolution; satellite imagery of moderate spatial resolution (MSR) including Landsat ETM+ panchromatic of 15-m resolution and SPOT panchromatic of 10-m resolution; and satellite imagery of high spatial resolution (HSR) including the Indian Remote Sensing satellite IRS data of 5-m resolution. As expected, the analysis of the extracted lineaments from different data sets shows that the imagery data of HSR of the Indian IRS data give the highest frequency of the extracted structural lineaments (N?=?3,235), while the imagery data of LSR of the Landsat MSS data give the lowest frequency of the extracted lineaments (N?=?89). The imagery data of MSR give moderate frequency (N?=?1,643) in average. Due to the present study, it is recommended to use the imagery data of HSR and MSR for the extraction of structural lineaments for detailed and regional studies, respectively. The imagery data of LSR are not recommended for such studies due to the fact that most of the real structural lineaments framework cannot be extracted; accordingly, it is not useful in the analyses of lineaments for geological purposes. 相似文献
11.
Adel Zein Bishta 《Arabian Journal of Geosciences》2018,11(23):755
Multispectral, multiresolution remotely sensed data were processed to emphasize geological interpretation of Jabal Daf-Wadi Fatima area. The investigated area is situated in the central western part of Saudi Arabia and geologically consists of igneous and metamorphosed rocks overlain by sedimentary sequence belonging to the Arabian-Nubian Shield. Three sets of digital satellite data, Landsat-7 ETM+, ASTER, and SPOT-5, were used in this study. The application of image processing techniques enables to identify and delineate the lithologic units and the structural features of the study area. The results of this study indicate that the confusion matrix of the three maximum likelihood supervised classifications of the three datasets shows that the Landsat ETM+ bands scored the best degree of average and overall accuracy (77 and 78%, respectively). This classification distinguishes most of the rock units for mapping in the investigated area. The supervised classification of ASTER and SPOT bands has lower degrees of accuracy than the classified Landsat data. The supervised classification of SPOT bands has a degree of average and overall accuracy of 66 and 67%, respectively, but it is the best for distinguishing the spectral signatures of the different members of Fatima Formation (lower, middle, and upper members). The statistical analyses of the confusion matrices of classifications and the interpretation of the produced classified thematic maps revealed that the classification accuracy does not necessary depend on the spatial resolution of satellite data. The data of the highest spatial resolution such as SPOT data are also very useful in emphasizing and classifying the rock units of a small outcrop area. The detailed geological map of Jabal Daf-Wadi Fatima area is interpreted in this work from supervised classified images of different resolutions as well as the structure map of this area. This study shows that it is preferable to use the supervised classifications of multiresolution data for rock unit discrimination in detailed field mapping. 相似文献
12.
岩石单元的结构、构造、差异风化和出露状况在遥感图像上综合表现为图形纹理特征即“图”标志，其矿物成分和组合则表现为光谱特征即“谱”标志.传统遥感岩石单元分类以利用其光谱特征为主，图形纹理特征为辅，因此分类精度有限.以新疆维吾尔自治区与甘肃省交界的北山西段为研究区，开展岩石单元图形指数和光谱指数协同分类方法研究.基于Worldview-2全色图像构建的图形指数，能够量化岩石单元的层理、构造、展布形态和微地貌等特征，包括0°和45°定向滤波图像及灰度共生矩阵计算出的同质性和异质性特征图像、熵特征图像；光谱指数基于Worldview-2多光谱图像和ASTER（Advanced Spaceborne Thermal Emission and Reflection Radiometer）短波红外波段图像利用比值、和-差方法构建.多源遥感图像构建的光谱指数其光谱波段涵盖可见光-近红外及短波红外，包括RI（Ratio index）ASTER、SI（Spectral index）ASTER、SIWorldview-2.采用面向对象方法对建立的图谱指数进行多尺度分割，依据不同岩石单元出露规模建立适宜的分割尺度，利用光谱指数自动提取相应岩石信息，实现岩石单元自动分类.结果表明，实验区基于图谱协同方法共划分出17类岩石单元，总体精度达到83.62%，而单独利用Worldview-2和ASTER图像，仅划分出13类和14类岩石单元.提出的图谱协同岩石分类方法可为我国西部高海拔深切割无人区地质调查及找矿工作提供新思路和遥感技术支撑. 相似文献
13.
Regional landslide susceptibility analysis using back-propagation neural network model at Cameron Highland,Malaysia 总被引：20，自引：6，他引：14
This paper presents landslide susceptibility analysis around the Cameron Highlands area, Malaysia using a geographic information
system (GIS) and remote sensing techniques. Landslide locations were identified in the study area from interpretation of aerial
photographs and field surveys. Topographical, geological data and satellite images were collected, processed, and constructed
into a spatial database using GIS and image processing. Ten landslide occurrence factors were selected as: topographic slope,
topographic aspect, topographic curvature and distance from drainage, lithology and distance from lineament, soil type, rainfall,
land cover from SPOT 5 satellite images, and the vegetation index value from SPOT 5 satellite image. These factors were analyzed
using an advanced artificial neural network model to generate the landslide susceptibility map. Each factor’s weight was determined
by the back-propagation training method. Then, the landslide susceptibility indices were calculated using the trained back-propagation
weights, and finally, the landslide susceptibility map was generated using GIS tools. The results of the neural network model
suggest that the effect of topographic slope has the highest weight value (0.205) which has more than two times among the
other factors, followed by the distance from drainage (0.141) and then lithology (0.117). Landslide locations were used to
validate the results of the landslide susceptibility map, and the verification results showed 83% accuracy. The validation
results showed sufficient agreement between the computed susceptibility map and the existing data on landslide areas. 相似文献
14.
15.
利用多光谱遥感数据提取植被污染信息的新方法 总被引：6，自引：1，他引：5
有效监测植被污染的现状和变化是空间遥感技术的优势。根据植被在生长过程中在由红光和近红外波段组成的“植被视面”上的位置和迁移规律,提出了通过建立数学模型进行坐标旋转进而提取反映植被生长状况的绿度信息的方法,并且采用多光谱ASTER卫星遥感数据对江西德兴铜矿区的植被污染进行了应用研究。结果表明此方法可以消除土壤背景的影响,有效地判别植被长势的强弱,为在植被茂密覆盖区根据植被的长势和分布状况来判别生态环境状况提供了新思路,为其他相似的卫星数据的应用提供了科学的参考依据。 相似文献
16.
Identifying effective vegetation biophysical and spectral parameters for investigating light to moderate grazing effects on grasslands improves management practices on grasslands. Using mixed grasslands as a case study, this paper compares responses of vegetation biophysical properties and spectral parameters derived from satellite images to grazing intensity, and identifies the suitable biophysical and spectral parameters to detect grazing effects in these areas. Biophysical properties including cover, canopy height and Leaf area index (LAI) were measured in three sites with different grazing managements and one benchmark site in 2008 and 2009 in Grasslands PlaceTypeNational Park and surrounding provincial pastures, Canada. Thirteen vegetation spectral indices, calculated by statistically combining different spectral information, were evaluated. The results indicate that canopy height and the ratio of photosynthetically active vegetation cover to non-photosynthetically active vegetation cover (PV/NPV) showed significant differences between ungrazed and grazed sites. All spectral vegetation indices except the canopy index (CI) show significant differences between grazing treatments. Red-Near infrared (Red-NIR) based vegetation indices, such as Modified Triangular Vegetation Index 1 (MTVI1), Soil-adjusted Vegetation Index (SAVI), are significantly correlated to the PV/NPV. Green/Mid-infrared (Green/MIR) related vegetation indices, i.e. Plant Senescence Reflectance Index (PRSI) and Normalized Canopy Index (NCI), show significant correlation with canopy height. Models based on a linear combination of MTVI1 and SAVI were developed for PV/NPV and PRSI and NCI for canopy height. Models that simulated PV/NPV and canopy height show significant correlations with grazing intensity, suggesting the feasibility of remote sensing to quantify light to moderate grazing effects in mixed grasslands. 相似文献
17.
Remotely sensed thermal infrared (TIR) data have been widely used to retrieve land surface temperature (LST). LST is an important parameter in the studies of urban thermal environment and dynamics. In the study, an attempt has been made using LANDSAT 8 thermal imagery to compute LST and the associated land cover parameters viz; land surface emissivity (LSE), normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI) and normalized difference water index (NDWI). Landsat 8 TIRS band 10 & 11 (thermal bands) during 21 Oct. 2016, 22 Nov.2016, 24 Dec. 2016 and 09 Jan. 2017 were processed for LST analysis. However, band 5 & band 4 of the imagery was processed for NDVI, band 6 & band 5 for NDBI and band 2 & band 5 for NDWI analysis. LST has been derived from both the bands 10 &11 and validated by in-situ observations on the date and time of satellite overpass from the study area. Band 10 derived LST have shown much temperature difference while comparing with the in-situ observations. However, LST derived from band 11 found similar & close to the in-situ measurements. Relationship between band 11 results and in-situ observed measurements were developed, which has showing a strong correlation with (r2 = 0.991). Land surface emissivity were also evaluated which shows variation in different land cover surfaces like vegetation, settlement, forest cover and water body. The study has proven that land surface temperature derived from satellite band 11 is the actual surface temperature of the study area. 相似文献
18.
Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper （ETM＋） data, which have better spectral resolution （8 bands） and spatial resolution （15 m in PAN band）, the synthesis processing techniques were presented to fulfill alteration information extraction： data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software （version 1.0）, developed by the Wuhan Zondy Cyber Technology Co., Ltd, China. In the study area application of extracting alteration information in the Zhaoyuan （招远） gold mines, Shandong （山东） Province, China, several hydorthermally altered zones （included two new sites） were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction. 相似文献
19.
以吉林省辽源市煤炭矿山为研究对象,通过对SPOT5卫星影像纠正、融合、解译等处理,快速、便捷地查清矿区的地质环境问题:矿区固体废物堆放、尾矿库分布情况;矿山采空区地面塌陷、山体开裂、滑坡、崩塌、泥石流、岩溶塌陷、煤田自燃等地质灾害分布情况;由矿产开发引发的水土流失、土地沙化、侵占土地、植被破坏的情况;矿区水体、植被、土壤污染状况等。通过矿山地质环境调查实践,总结出了SPOT5卫星影像最优波段组合、融合方法及矿山地质环境调查中的地物判读标志,从而使SPOT5卫星影像在遥感环境地质调查中发挥了重要作用。 相似文献
20.
近年来一系列中高分辨率立体成像卫星传感器相继发射成功,如法国的SPOT卫星、日本的ASTER和ALOS卫星,它们除了具有获取多光谱遥感数据的能力外,还具有立体成像的功能。随着计算机图像处理技术和卫星遥感立体成像技术的不断发展,地质体及其地形地貌的三维图像生成及其可视化技术得到了迅速发展。本研究介绍了利用ER-M apper图像处理软件提供的三维图像生成及可视化技术,将ASTER卫星遥感数据生成的数字高程模型与多光谱图像信息有机融合,生成地质体三维可视化图像,再现地质体的三维空间特征,从而从整体上直观、综合地对活动地质构造及其构造地貌特征进行可视化分析研究。本研究重点介绍了ASTER三维可视化立体遥感图像在晚第四纪活动构造和第四纪火山地貌研究中的应用,并展示了在阿尔泰山富蕴断裂带、北天山独山子背斜带、东昆仑断裂带以及长白山天池火山的研究实例。 相似文献