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The Generalized Difference Vegetation Index (GDVI) for Dryland Characterization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A large number of vegetation indices have been developed and widely applied in terrestrial ecosystem research in the recent decades. However, a certain limitation was observed while applying these indices in research in dry areas due to their low sensitivity to low vegetation cover. In this context, the objectives of this study are to develop a new vegetation index, namely, the Generalized Difference Vegetation Index (GDVI), and to examine its applicability to the assessment of dryland enviro...

Weicheng Wu

2014-01-01

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The Generalized Difference Vegetation Index (GDVI for Dryland Characterization  

Directory of Open Access Journals (Sweden)

Full Text Available A large number of vegetation indices have been developed and widely applied in terrestrial ecosystem research in the recent decades. However, a certain limitation was observed while applying these indices in research in dry areas due to their low sensitivity to low vegetation cover. In this context, the objectives of this study are to develop a new vegetation index, namely, the Generalized Difference Vegetation Index (GDVI, and to examine its applicability to the assessment of dryland environment. Based on the field investigation and crop Leaf Area Index (LAI measurement, five spring and summer Landsat TM and ETM+ images in the frame with Path/Row number of 174/35, and MODIS (Moderate Resolution Imaging Spectroradiometer LAI and vegetation indices (VIs data (MOD15A2 and MOD13Q1, of the same acquisition dates as the Landsat images, were acquired and employed in this study. The results reveal that, despite the same level of correlation with the fractional vegetation cover (FVC as other VIs, GDVI shows a better correlation with LAI and has higher sensitivity and dynamic range in the low vegetal land cover than other vegetation indices, e.g., the range of GDVI is higher than Normalized Difference Vegetation Index (NDVI,Soil-Adjusted Vegetation Index (SAVI, Enhanced Vegetation Index (EVI, Wide Dynamic Range Vegetation Index (WDRVI, and Soil-Adjusted and Atmospherically Resistant Vegetation Index (SARVI, by 164%–326% in woodland, 185%–720% in olive plantation, and 190%–867% in rangeland. It is, hence, concluded that GDVI is relevant for, and has great potential in, land characterization, as well as land degradation/desertification assessment in dryland environment.

Weicheng Wu

2014-01-01

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Relative sensitivity of Normalized Difference Vegetation Index (NDVI) and Microwave Polarization Difference Index (MPDI) for vegetation and desertification monitoring  

Science.gov (United States)

A simple equation relating the Microwave Polarization Difference Index (MPDI) and the Normalized Difference Vegetation Index (NDVI) is proposed which represents well data obtained from Nimbus 7/SMMR at 37 GHz and NOAA/AVHRR Channels 1 and 2. It is found that there is a limit which is characteristic of a particular type of cover for which both indices are equally sensitive to the variation of vegetation, and below which MPDI is more efficient than NDVI. The results provide insight into the relationship between water content and chlorophyll absorption at pixel size scales.

Becker, Francois; Choudhury, Bhaskar J.

1988-01-01

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Investigation of Vegetation Dynamics using Long-Term Normalized Difference Vegetation Index Time-Series  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: The Normalized Difference Vegetation Index (NDVI is the most extensively used satellite-derived index of vegetation health and density. Since climate is one of the most important factors affecting vegetation condition, satellite-derived vegetation indexes have been often used to evaluate climatic and environmental changes at regional and global scale. The proposed study attempted to investigate the temporal vegetation dynamics in the whole Africa using historical NDVI time-series. Approach: For this aim, 15 day maximum value NDVI composites at 8 km spatial resolution produced from the NASA Global Inventory Mapping and Monitoring System (GIMMS had been used. They were derived from data collected daily by NOAA AVHRR satellites. The AVHRR NDVI GIMMS dataset was freely available and gives global coverage over an extensive time period. First of all, the selected NDVI base data had been geometrically pre-processed and organized into a historical database implemented in order to grant their spatial integration. Starting from this archive, monthly and yearly NDVI historical time-series, extended from 1982-2006, had been then developed and analysed on a pixel basis. Several routines hade been developed in IDL (Interactive Data Language programming tool with the purpose of applying suitable statistical analysis techniques to the historical information in the database in order to identify the long-term trend components of generated NDVI time-series and extract vegetation dynamics. Specific tests had been then considered in order to define the validity of results. Results: The existence of clear regional trends of NDVI, both decreasing and increasing had been showed, which helped to highlight areas subject, respectively to reduction or increase in vegetation greenness. Conclusion: As the relationship between the NDVI and vegetation productivity was well established, these estimated long-term trend components may be also, with much more caution, related to historical and ongoing land degradation or improvement processes.

Tamara Bellone

2009-01-01

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Evaluation of vegetation cover using the normalized difference vegetation index (NDVI  

Directory of Open Access Journals (Sweden)

Full Text Available Soil loss by water erosion is the main cause of soil degradation in Brazil. However, erosion can be reduced by the presence of vegetation. The Normalized Difference Vegetation Index (NDVI makes it possible to identify the vegetative vigor of crops or natural vegetation which facilities the identification of areas with vegetation covers. This information is very important in identifying the phenomena which might be occurring in a particular area, especially those related to soil degradation by water erosion. Thus, the aim of this work was to assess the canopy cover by using NDVI, checking the image accuracy using the Coverage Index (CI based on the Stocking method, in the Sub-basin of Posses, which belongs to the Cantareira System, located in the Extrema municipality, Minas Gerais, Brazil. Landsat-5 TM images were used. The sub-basin of Posses was very altered in comparison to the surrounding areas. The NDVI technique proved to be a suitable tool to assess the uses that occur in the sub-basin of Posses, as validated by the Stocking methodology. The map derived from NDVI allowed the geographic distribution of different land uses to be observed and allowed for the identification of critical areas in relation to vegetation cover as well. This finding can be used to optimize efforts to recover and protect soil in areas with bare soil and degraded pasture, in order to reduce environmental degradation. The CI has not exceeded 40% for land use classes that occur in the majority of the sub-basin (91%, except in areas of woody vegetation.

Gabriela Camargos Lima

2013-08-01

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Analysis of the dynamics of African vegetation using the normalized difference vegetation index  

Science.gov (United States)

Images at a resolution of 8 km are currently being generated for the whole of Africa, displaying the normalized difference vegetation index (NDVI). These images have undergone a process of temporal compositing to reduce the effects of cloud cover and atmospheric variation. When the NDVI is plotted against time, different cover types are shown to have characteristic profiles corresponding closely with their phenology. The resultant pattern of NDVI values displayed on the images is analyzed in terms of the cover types present and local variations in rainfall. Comparison between images for 1983 and 1984 overall showed considerable similarities, but significant differences were observed in the northward extent of the greening wave in the Sahel, the greening up of the Kalahari Desert and East African communities. It is concluded that vegetation monitoring using NDVI images needs to be associated with scene stratification according to cover type.

Townshend, J. R. G.; Justice, C. O.

1986-01-01

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Sensitivity of the Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI) to Topographic Effects: A Case Study in High-density Cypress Forest  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Vegetation indices play an important role in monitoring variations in vegetation.The Enhanced Vegetation Index (EVI) proposed by the MODIS Land Discipline Groupand the Normalized Difference Vegetation Index (NDVI) are both global-based vegetationindices aimed at providing consistent spatial and temporal information regarding globalvegetation. However, many environmental factors such as atmospheric conditions and soilbackground may produce errors in these indices. The topographic effect is ano...

Guoyu Qiu; Yuyichi Onda; Jin Chen; Wei Yang; Bunkei Matsushita

2007-01-01

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Elk Distributions Relative to Spring Normalized Difference Vegetation Index Values  

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Full Text Available Rocky Mountain elk (Cervus elaphus that winter near San Antonio Mountain in northern New Mexico provide important recreational and economic benefits while creating management challenges related to temporospatial variation in their spring movements. Our objective was to examine spring distributions of elk in relation to vegetative emergence as it progresses across the landscape as measured by remote sensing. Spring distributions of elk were closely associated with greater photosynthetic activity of spring vegetation in 2 of 3 years as determined using NDVI values derived from AVHRR datasets. Observed elk locations were up to 271% greater than expected in the category representing the most photosynthetic activity. This association was not observed when analyses at a finer geographic scale were conducted. Managers facing challenges involving human-wildlife interactions and land-use issues should consider environmental conditions that may influence variation in elk association with greener portions of the landscape.

Bruce C. Thompson

2010-01-01

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Elk Distributions Relative to Spring Normalized Difference Vegetation Index Values  

International Nuclear Information System (INIS)

Rocky Mountain elk (Cervus elaphus) that winter near San Antonio Mountain in northern New Mexico provide important recreational and economic benefits while creating management challenges related to temporospatial variation in their spring movements. Our objective was to examine spring distributions of elk in relation to vegetative emergence as it progresses across the landscape as measured by remote sensing. Spring distributions of elk were closely associated with greater photosynthetic activity of spring vegetation in 2 of 3 years as determined using NDVI values derived from AVHRR datasets. Observed elk locations were up to 271% greater than expected in the category representing the most photosynthetic activity. This association was not observed when analyses at a finer geographic scale were conducted. Managers facing challenges involving human-wildlife interactions and land-use issues should consider environmental conditions that may influence variation in elk association with greener portions of the landscape.

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Evaluating drought in the United States using the emissivity difference vegetation index  

Science.gov (United States)

As monitoring vegetation and crops becomes increasingly important due to climate change, there arises the need for a monitoring scheme that places more weight on water availability as an indication of vegetation health and vitality. The Emissivity Difference Vegetation Index (EDVI) is the first step towards that type of monitoring scheme. With the potential for diurnal studies, there are applications towards agriculture monitoring, wildfire monitoring, and much more. EDVI is a synergetic product retrieved from microwave, visible, and infrared satellite measurements, as well as reanalysis. Since microwave measurements are more sensitive to vegetation water content, EDVI has the potential to capture intrinsic changes in vegetation. A new drought index is developed from EDVI, the Emissivity Vegetation Condition Index (EVCI). The high temporal sampling of EVCI will make it one of the more dynamic attempts to measure and investigate drought impacts on vegetation and crops on short-term scales. This new drought index will be compared to presently operational drought indices including the Palmer drought indices, the Vegetation Condition Index (VCI), and the Vegetation Health Index (VHI) for the period between 2009-2011 in the United States. The focus will be on improving the methodology of the EDVI retrieval and then examining two periods of identified drought, one in the Southern Great Plains in 2011, and one short-term drought in the Great Lakes region in 2010. The results indicate an agreement between ECVI and precipitation, and the drought episodes in 2010 and 2011 are resolved by EVCI. With a dataset beyond the three years used for this study it would be possible to correct more accurately for climatology.

Hirani, Hanisha K.

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Sensitivity of the Enhanced Vegetation Index (EVI and Normalized Difference Vegetation Index (NDVI to Topographic Effects: A Case Study in High-density Cypress Forest  

Directory of Open Access Journals (Sweden)

Full Text Available Vegetation indices play an important role in monitoring variations in vegetation.The Enhanced Vegetation Index (EVI proposed by the MODIS Land Discipline Groupand the Normalized Difference Vegetation Index (NDVI are both global-based vegetationindices aimed at providing consistent spatial and temporal information regarding globalvegetation. However, many environmental factors such as atmospheric conditions and soilbackground may produce errors in these indices. The topographic effect is another veryimportant factor, especially when the indices are used in areas of rough terrain. In thispaper, we theoretically analyzed differences in the topographic effect on the EVI and theNDVI based on a non-Lambertian model and two airborne-based images acquired from amountainous area covered by high-density Japanese cypress plantation were used as a casestudy. The results indicate that the soil adjustment factor “L” in the EVI makes it moresensitive to topographic conditions than is the NDVI. Based on these results, we stronglyrecommend that the topographic effect should be removed in the reflectance data beforethe EVI was calculated—as well as from other vegetation indices that similarly include a term without a band ratio format (e.g., the PVI and SAVI—when these indices are used in the area of rough terrain, where the topographic effect on the vegetation indices having only a band ratio format (e.g., the NDVI can usually be ignored.

Guoyu Qiu

2007-11-01

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Forest leaf area index determination : a multiyear satelliteindependent method based on within-stand normalized difference vegetation index spatial variability  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Leaf Area Index (LAI) and its spatial distribution are key features to describe the forest ecophysiological processes. A stable and reproducible relationship is obtained between the LAI and the standard deviation sNDVI of the pixel-based satellite-derived normalized difference vegetation indices (NDVI) of forest stands. In situ measurements of LAI have been performed with the LAI-2000 Plant Canopy Analyser over 8 years in the managed Fontainebleau forest (France) on about 31 stands each y...

Le Maire, G.; Franc?ois, C.; Soudani, Kamel; Davi, H.; Le Dantec, V.; Saugier, Bernard; Dufrene, E.

2006-01-01

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Integrated NDVI images for Niger 1986-1987. [Normalized Difference Vegetation Index  

Science.gov (United States)

Two NOAA AVHRR images are presented which provide a comparison of the geographic distribution of an integration of the normalized difference vegetation index (NDVI) for the Sahel zone in Niger for the growing seasons of 1986 and 1987. The production of the images and the application of the images for resource management are discussed. Daily large area coverage with a spatial resolution of 1.1 km at nadir were transformed to the NDVI and geographically registered to produce the images.

Harrington, John A., Jr.; Wylie, Bruce K.; Tucker, Compton J.

1988-01-01

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Atmospheric effects on the NDVI - Strategies for its removal. [Normalized Difference Vegetation Index  

Science.gov (United States)

The compositing technique used to derive global vegetation index (NDVI) from the NOAA AVHRR radiances reduces the residual effect of water vapor and aerosol on the NDVI. The reduction in the atmospheric effect is shown using a comprehensive measured data set for desert conditions, and a simulation for grass with continental aerosol. A statistical analaysis of the probability of occurrence of aerosol optical thickness and precipitable water vapor measured in different climatic regimes is used for this simulation. It is concluded that for a long compositing period (e.g., 27 days), the residual aerosol optical thickness and precipitable water vapor are usually too small to be corrected. For a 9-day compositing, the residual average aerosol effect may be about twice the correction uncertainty. For Landsat TM or Earth Observing System Moderate Resolution Imaging Spectrometer (EOS-MODIS) data, the newly defined atmospherically resistant vegetation index (ARVI) is more promising than possible direct atmospheric correction schemes, except for heavy desert dust conditions.

Kaufman, Y. J.; Tanre, D.; Holben, B. N.; Markham, B.; Gitelson, A.

1992-01-01

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Determination of Leaf Area Index, Total Foliar N, and Normalized Difference Vegetation Index for Arctic Ecosystems Dominated by Cassiope tetragona  

DEFF Research Database (Denmark)

Leaf area index (LAI) and total foliar nitrogen (TFN) are important canopy characteristics and crucial variables needed to simulate photosynthesis and ecosystem CO2 fluxes. Although plant communities dominated by Cassiope tetragona are widespread in the Arctic, LAI and TFN for this vegetation type have not been accurately quantified. We address this knowledge gap by (i) direct measurements of LAI and TFN for C. tetragona, and (ii) determining TFN-LAI and LAI–normalized difference vegetation index (NDVI) relationships for typical C. tetragona tundras in the subarctic (Sweden) and High Arctic (Greenland and Svalbard). Leaves of C. tetragona are 2–6 mm long and closely appressed to their stems forming parallelepiped shoots. We determined the LAI of C. tetragona by measuring the area of the leaves while still attached to the stem, then doubling the resulting one-sided area. TFN was determined from leaf N and biomass. The LAI-NDVI and TFN-LAI relationships showed high correlation and can be used to estimate indirectly LAI and TFN. The LAI-NDVI relationship for C. tetragona vegetation differed from a generic LAI-NDVI relationship for arctic tundra, whereas the TFN-LAI relationship did not. Overall, the LAI of C. tetragona tundra ranged from 0.4 to 1.1 m2 m–2 and TFN from 1.4 to 1.7 g N m–2.

Campioli, M; Street, LE

2009-01-01

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Fisher-Shannon information plane analysis of SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series to characterize vegetation recovery after fire disturbance  

Science.gov (United States)

The time dynamics of SPOT-VEGETATION Normalized Difference Vegetation Index (NDVI) time series are analyzed by using the statistical approach of the Fisher-Shannon (FS) information plane to assess and monitor vegetation recovery after fire disturbance. Fisher-Shannon information plane analysis allows us to gain insight into the complex structure of a time series to quantify its degree of organization and order. The analysis was carried out using 10-day Maximum Value Composites of NDVI (MVC-NDVI) with a 1 km × 1 km spatial resolution. The investigation was performed on two test sites located in Galizia (North Spain) and Peloponnese (South Greece), selected for the vast fires which occurred during the summer of 2006 and 2007 and for their different vegetation covers made up mainly of low shrubland in Galizia test site and evergreen forest in Peloponnese. Time series of MVC-NDVI have been analyzed before and after the occurrence of the fire events. Results obtained for both the investigated areas clearly pointed out that the dynamics of the pixel time series before the occurrence of the fire is characterized by a larger degree of disorder and uncertainty; while the pixel time series after the occurrence of the fire are featured by a higher degree of organization and order. In particular, regarding the Peloponneso fire, such discrimination is more evident than in the Galizia fire. This suggests a clear possibility to discriminate the different post-fire behaviors and dynamics exhibited by the different vegetation covers.

Lanorte, Antonio; Lasaponara, Rosa; Lovallo, Michele; Telesca, Luciano

2014-02-01

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Global Enhanced Vegetation Index  

Science.gov (United States)

By carefully measuring the wavelengths and intensity of visible and near-infrared light reflected by the land surface back up into space, the Moderate-resolution Imaging Spectroradiometer (MODIS) Team can quantify the concentrations of green leaf vegetation around the world. The above MODIS Enhanced Vegetation Index (EVI) map shows the density of plant growth over the entire globe. Very low values of EVI (white and brown areas) correspond to barren areas of rock, sand, or snow. Moderate values (light greens) represent shrub and grassland, while high values indicate temperate and tropical rainforests (dark greens). The MODIS EVI gives scientists a new tool for monitoring major fluctuations in vegetation and understanding how they affect, and are affected by, regional climate trends. For more information, read NASA Unveils Spectacular Suite of New Global Data Products from MODIS. Image courtesy MODIS Land Group/Vegetation Indices, Alfredo Huete, Principal Investigator, and Kamel Didan, University of Arizona

2002-01-01

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On the relationship between thermal emissivity and the Normalized Difference Vegetation Index for natural surfaces  

Science.gov (United States)

The spatial variation of both the thermal emissivity (8-14 microns) and Normalized Difference Vegetation Index (NDVI) was measured for a series of natural surfaces within a savanna environment in Botswana. The measurements were performed with an emissivity-box and with a combined red and near-IR radiometer, with spectral bands corresponding to NOAA/AVHRR. It was found that thermal emissivity was highly correlated with NDVI after logarithmic transformation, with a correlation coefficient of R = 0.94. This empirical relationship is of potential use for energy balance studies using thermal IR remote sensing. The relationship was used in combination with AVHRR (GAC), AVHRR (LAC), and Landsat (TM) data to demonstrate and compare the spatial variability of various spatial scales.

Van De Griend, A. A.; Owe, M.

1993-01-01

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Avaliação da cobertura vegetal pelo índice de vegetação por diferença normalizada (IVDN) / Evaluation of vegetation cover using the normalized difference vegetation index (NDVI)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A perda de solo por erosão hídrica é a principal causa da degradação do solo no Brasil. No entanto, a erosão pode ser reduzida pela presença da vegetação. O cálculo do Índice de Vegetação por Diferença Normalizada (IVDN) permite avaliar o vigor vegetativo de culturas ou vegetação natural o que facil [...] ita a identificação de áreas com cobertura vegetal. Esta informação é muito importante para identificar o fenômeno que pode estar ocorrendo em uma determinada área, especialmente aqueles relacionados à degradação do solo por erosão hídrica. Assim, o objetivo deste trabalho foi avaliar o índice de cobertura vegetal por IVDN e verificar a precisão utilizando o Índice de Cobertura (IC) de Stocking, na sub-bacia das Posses, a qual pertence ao Sistema Cantareira, localizada no município de Extrema, Minas Gerais, Brasil. Para tanto, utilizou-se as imagens Landsat-5 TM. A sub-bacia das Posses mostrou-se alterada quando comparada com a área de entorno. A técnica do IVDN mostrou-se com boa acurácia para identificar os usos que ocorrem na sub-bacia das Posses, sendo validados pela metodologia de Stocking. O mapeamento pelo IVDN permitiu localizar na sub-bacia a distribuição geográfica dos diferentes usos do solo e identificar as áreas críticas em relação à cobertura vegetal, e, assim planejar esforços para recuperação e proteção do solo nas áreas desnudas e com pastagem degradada, visando diminuição dos passivos ambientais. O IC não ultrapassou 40% para a maioria dos usos que ocorrem na sub-bacia (91%), excetuando as áreas de vegetação arbórea. Abstract in english Soil loss by water erosion is the main cause of soil degradation in Brazil. However, erosion can be reduced by the presence of vegetation. The Normalized Difference Vegetation Index (NDVI) makes it possible to identify the vegetative vigor of crops or natural vegetation which facilities the identifi [...] cation of areas with vegetation covers. This information is very important in identifying the phenomena which might be occurring in a particular area, especially those related to soil degradation by water erosion. Thus, the aim of this work was to assess the canopy cover by using NDVI, checking the image accuracy using the Coverage Index (CI) based on the Stocking method, in the Sub-basin of Posses, which belongs to the Cantareira System, located in the Extrema municipality, Minas Gerais, Brazil. Landsat-5 TM images were used. The sub-basin of Posses was very altered in comparison to the surrounding areas. The NDVI technique proved to be a suitable tool to assess the uses that occur in the sub-basin of Posses, as validated by the Stocking methodology. The map derived from NDVI allowed the geographic distribution of different land uses to be observed and allowed for the identification of critical areas in relation to vegetation cover as well. This finding can be used to optimize efforts to recover and protect soil in areas with bare soil and degraded pasture, in order to reduce environmental degradation. The CI has not exceeded 40% for land use classes that occur in the majority of the sub-basin (91%), except in areas of woody vegetation.

Gabriela Camargos, Lima; Marx Leandro Naves, Silva; Nilton, Curi; Mayesse Aparecida da, Silva; Anna Hoffmann, Oliveira; Junior Cesar, Avanzi; Marta Eichemberger, Ummus.

2013-08-01

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Using normalized difference vegetation index to estimate carbon fluxes from small rotationally grazed pastures  

Science.gov (United States)

Satellite-based normalized difference vegetation index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northeastern United States might be limited because paddock size is often smaller than the resolution limits of the satellite image. This research compared NDVI data from satellites with data obtained using a ground-based system capable of fine-scale (submeter) NDVI measurements. Gross primary productivity was measured by eddy covariance on two pastures in central Pennsylvania from 2003 to 2008. Weekly 250-m resolution satellite NDVI estimates were also obtained for each pasture from the moderate resolution imaging spectroradiometer (MODIS) sensor. Ground-based NDVI data were periodically collected in 2006, 2007, and 2008 from one of the two pastures. Multiple-regression and regression-tree estimates of GPP, based primarily on MODIS 7-d NDVI and on-site measurements of photosynthetically active radiation (PAR), were generally able to predict growing-season GPP to within an average of 3% of measured values. The exception was drought years when estimated and measured GPP differed from each other by 11 to 13%. Ground-based measurements improved the ability of vegetation indices to capture short-term grazing management effects on GPP. However, the eMODIS product appeared to be adequate for regional GPP estimates where total growing-season GPP across a wide area would be of greater interest than short-term management-induced changes in GPP at individual sites.

Skinner, R.H.; Wylie, B.K.; Gilmanov, T.G.

2011-01-01

 
 
 
 
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A Normalized Difference Vegetation Index (NDVI Time-Series of Idle Agriculture Lands: A Preliminary Study  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, the NDVI time-series collected from the study area between year 2003 and 2005 of all land cover types are plotted and compared. The study area is the agricultural zones in Banphai District, Khonkean, Thailand. The LANDSAT satellite images of different dates were first transformed into a time series of Normalized Difference Vegetation Index (NDVI images before the investigation. It can be visually observed that the NDVI time series of the Idle Agriculture Land (IAL has the NDVI values closed to zero. In other words, the trend of the NDVI values remains, approximately, unchanged about the zero level for the whole period of the study time. In contrast, the non-idle areas hold a higher level of the NDVI variation. The NDVI values above 0.5 can be found in these non-idle areas during the growing seasons. Thus, it can be hypothesized that the NDVI time-series of the different land cover types can be used for IAL classification. This outcome is a prerequisite to the follow-up study of the NDVI pattern classification that will be done in the near future.

Andrew K Skidmore

2011-01-01

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Simulating Visible/Infrared Imager Radiometer Suite Normalized Difference Vegetation Index Data Using Hyperion and MODIS  

Science.gov (United States)

The success of MODIS (the Moderate Resolution Imaging Spectrometer) in creating unprecedented, timely, high-quality data for vegetation and other studies has created great anticipation for data from VIIRS (the Visible/Infrared Imager Radiometer Suite). VIIRS will be carried onboard the joint NASA/Department of Defense/National Oceanic and Atmospheric Administration NPP (NPOESS (National Polar-orbiting Operational Environmental Satellite System) Preparatory Project). Because the VIIRS instruments will have lower spatial resolution than the current MODIS instruments--400 m versus 250 m--at nadir for the channels used to generate Normalized Difference Vegetation Index data, scientists need the answer to this question: how will the change in resolution affect vegetation studies? By using simulated VIIRS measurements, this question may be answered before the VIIRS instruments are deployed in space. Using simulated VIIRS products, the U.S. Department of Agriculture and other operational agencies can then modify their decision support systems appropriately in preparation for receipt of actual VIIRS data. VIIRS simulations and validations will be based on the ART (Application Research Toolbox), an integrated set of algorithms and models developed in MATLAB® that enables users to perform a suite of simulations and statistical trade studies on remote sensing systems. Specifically, the ART provides the capability to generate simulated multispectral image products, at various scales, from high spatial hyperspectral and/or multispectral image products. The ART uses acquired ("real") or synthetic datasets, along with sensor specifications, to create simulated datasets. For existing multispectral sensor systems, the simulated data products are used for comparison, verification, and validation of the simulated system's actual products. VIIRS simulations will be performed using Hyperion and MODIS datasets. The hyperspectral and hyperspatial properties of Hyperion data will be used to produce simulated MODIS and VIIRS products. Hyperion-derived MODIS data will be compared with near-coincident MODIS collects to validate both spectral and spatial synthesis, which will ascertain the accuracy of converting from MODIS to VIIRS. MODIS-derived VIIRS data is needed for global coverage and for the generation of time series for regional and global investigations. These types of simulations will have errors associated with aliasing for some scene types. This study will help quantify these errors and will identify cases where high quality, MODIS- derived VIIRS data will be available.

Ross, K. W.; Ryan, R. E.; Russell, J.

2006-12-01

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Global Trends in Seasonality of Normalized Difference Vegetation Index (NDVI, 1982–2011  

Directory of Open Access Journals (Sweden)

Full Text Available A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA procedure, over half (56.30% of land surfaces were found to exhibit significant trends. Almost half (46.10% of the significant trends belonged to three classes of seasonal trends (or changes. Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing an increase in the amplitude of the annual seasonal signal whereby increases in NDVI in the green season were balanced by decreases in the brown season. These areas were found primarily in grassland and shrubland regions. Class 3 was found primarily in the Taiga and Tundra biomes and exhibited increases in the annual summer peak in NDVI. While no single attribution of cause could be determined for each of these classes, it was evident that they are primarily found in natural areas (as opposed to anthropogenic land cover conversions and that they are consistent with climate-related ameliorations of growing conditions during the study period.

Assaf Anyamba

2013-09-01

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Normalized difference vegetation index for the South American continent used as a climatic variability indicator  

International Nuclear Information System (INIS)

The NOAA AVHRR GAC data set was used to produce Normalized Difference Vegetation Index (NDVI) maps for the South American Continent covering the period from August 1, 1981 to June 30, 1987. A 15-day maximum value composite procedure was used to partially eliminate the cloud contamination and atmospheric attenuation. Monthly evolution of NDVI for a dry and a wet year within the period studied was used to estimate the area covered by NDVI value less than 0.223, This value was used as an indicator of the drought area and the delineation of the Low rainfall areas in the continent. It was observed a well defined regional dependence of the drought area variability for the Northeast, Southwest and Northwest continent and also for the Amazon region. It is shown a relative estimation of the area coverage with NDVI less than 0.223 for the years 1982/83 and 1984/85. The dynamics of the drought area evolution in the continent is discussed. It is also presented a diagnosis of regional variability of the continental distribution of drought area from 1981 to 1987 for the months of May and September. This information is also used to discuss its relationship with the EL-Nino-Southern Oscillation (ENSO) and the South American Precipitation patterns during this period. It is suggested that the use of NDVI image to identify the dynamics of the drought induced by low rainfall may provide us valuable information to study the large scale climatic variation

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Rural cases of equine West Nile virus encephalomyelitis and the normalized difference vegetation index  

Science.gov (United States)

Data from an outbreak (August to October, 2002) of West Nile virus (WNV) encephalomyelitis in a population of horses located in northern Indiana was scanned for clusters in time and space. One significant (p = 0.04) cluster of case premises was detected, occurring between September 4 and 10 in the south-west part of the study area (85.70??N, 45.50??W). It included 10 case premises (3.67 case premises expected) within a radius of 2264 m. Image data were acquired by the Advanced Very High Resolution Radiometer (AVHRR) sensor onboard a National Oceanic and Atmospheric Administration polar-orbiting satellite. The Normalized Difference Vegetation Index (NDVI) was calculated from visible and near-infrared data of daily observations, which were composited to produce a weekly-1km2 resolution raster image product. During the epidemic, a significant (p<0.01) decrease (0.025 per week) in estimated NDVI was observed at all case and control premise sites. The median estimated NDVI (0.659) for case premises within the cluster identified was significantly (p<0.01) greater than the median estimated NDVI for other case (0.571) and control (0.596) premises during the same period. The difference in median estimated NDVI for case premises within this cluster, compared to cases not included in this cluster, was greatest (5.3% and 5.1%, respectively) at 1 and 5 weeks preceding occurrence of the cluster. The NDVI may be useful for identifying foci of WNV transmission. ?? Mary Ann Liebert, Inc.

Ward, M. P.; Ramsay, B. H.; Gallo, K.

2005-01-01

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Timing and patterns of ENSO impacts in Africa over the last 30 years: insights from Normalized Difference Vegetation Index data.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study we reassess and provide a more complete picture of the timing and patterns of ENSO impacts for the whole of Africa over the three last decades. We analyse the vegetation photosynthetic activity estimated by the NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) rather than rainfall itself, because NDVI allows us to document the impacts at fine space and time scales. The use of the monthly time-step adds important new insights to the findings of previous works based largely...

Philippon, Nathalie; Blais, Aure?lie; Martiny, Nade?ge; Camberlin, Pierre; Hoffman, Timm

2012-01-01

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Use of Normalized Difference Vegetation Index (NDVI) habitat models to predict breeding birds on the San Pedro River, Arizona  

Science.gov (United States)

Successful management practices of avian populations depend on understanding relationships between birds and their habitat, especially in rare habitats, such as riparian areas of the desert Southwest. Remote-sensing technology has become popular in habitat modeling, but most of these models focus on single species, leaving their applicability to understanding broader community structure and function largely untested. We investigated the usefulness of two Normalized Difference Vegetation Index (NDVI) habitat models to model avian abundance and species richness on the upper San Pedro River in southeastern Arizona. Although NDVI was positively correlated with our bird metrics, the amount of explained variation was low. We then investigated the addition of vegetation metrics and other remote-sensing metrics to improve our models. Although both vegetation metrics and remotely sensed metrics increased the power of our models, the overall explained variation was still low, suggesting that general avian community structure may be too complex for NDVI models.

McFarland, Tiffany Marie; van Riper, Charles, III

2013-01-01

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Models for the prediction of the cetane index of biofuels obtained from different vegetable oils using their fatty acid composition  

International Nuclear Information System (INIS)

The objective of the present work is to obtain a physical-mathematical model that establishes a relationship between the cetane index of biofuels obtained from different vegetable oils and its composition of essential fatty acid. This model is based on experimental data obtained by the authors of the present work and an experimental data reported by different extracted authors of indexed databases. The adjustment of the coefficients of the model is based on the obtaining of residual minima in the capacity of prediction of the model. Starting from these results it is established a very useful tool for the determination of such an important parameter for the fuel diesel as it is the cetane index obtained from an analysis of chemical composition and not obtained from tests in engines banks, to save time and economic resources. (author)

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Method for Tealeaves Quality Estimation Through Measurements of Degree of Polazation, Leaf Area Index, Photosynthesis Available Radiance and Normalized Difference Vegetation Index for Characterization of Tealeaves  

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Full Text Available Method for tealeaves quality estimation through measurements of Degree of Polarization: DP, Leaf Area Index: LAI, Photosynthesis Available Radiance: PAR and Normalized Difference Vegetation Index: NDVI for characterization of tealeaves is proposed. The method allows estimations of PAR, NDVI, Grow Index: GI by using measured Degree of Polarization: DP of tealeaves. Through experiments at the tea farm areas, it is found that the proposed method is validated. Also, the method is validated through Monte Carlo Ray Tracing: MCRT simulations for discrimination between prolate and oblate shapes of tealeaves. In accordance with growing tealeaves, prolate shape of tealeaves changes their shape to oblate shape. Therefore, growing stage can be estimated with DP measurements.

Kohei Arai

2013-11-01

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Estimation of regional surface resistance to evapotranspiration from NDVI and thermal-IR AVHRR data. [Normalized Difference Vegetation Index  

Science.gov (United States)

Infrared surface temperatures from satellite sensors have been used to infer evaporation and soil moisture distribution over large areas. However, surface energy partitioning to latent versus sensible heat changes with surface vegetation cover and water availability. The hypothesis that the relationship between surface temperature and canopy density is sensitivite to seasonal changes in canopy resistance of conifer forests is presently tested. Surface temperature and canopy density were computed for a 20 x 25 km forested region in Montana, from the NOAA/AVHRR for 8 days during the summer of 1985. A forest ecosystem model, FOREST-BGC, simulated canopy resistance for the same period. For all eight days, surface temperatures had high association with canopy density, measured as Normalized Difference Vegetation Index, implying that latent heat exchange is the major cause of spatial variations in surface radiant tmeperatures.

Nemani, Ramakrishna R.; Running, Steven W.

1989-01-01

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Normalized Difference Vegetation Index as a tool for wheat yield estimation: a case study from Faisalabad, Pakistan.  

Science.gov (United States)

For estimation of grain yield in wheat, Normalized Difference Vegetation Index (NDVI) is considered as a potential screening tool. Field experiments were conducted to scrutinize the response of NDVI to yield behavior of different wheat cultivars and nitrogen fertilization at agronomic research area, University of Agriculture Faisalabad (UAF) during the two years 2008-09 and 2009-10. For recording the value of NDVI, Green seeker (Handheld-505) was used. Split plot design was used as experimental model in, keeping four nitrogen rates (N1 = 0 kg ha(-1), N2 = 55 kg ha(-1), N3 = 110 kg ha(-1), and N4 = 220 kg ha(-1)) in main plots and ten wheat cultivars (Bakkhar-2001, Chakwal-50, Chakwal-97, Faisalabad-2008, GA-2002, Inqlab-91, Lasani-2008, Miraj-2008, Sahar-2006, and Shafaq-2006) in subplots with four replications. Impact of nitrogen and difference between cultivars were forecasted through NDVI. The results suggested that nitrogen treatment N4 (220 kg?ha(-1)) and cultivar Faisalabad-2008 gave maximum NDVI value (0.85) at grain filling stage among all treatments. The correlation among NDVI at booting, grain filling, and maturity stages with grain yield was positive (R(2) = 0.90; R(2) = 0.90; R(2) = 0.95), respectively. So, booting, grain filling, and maturity can be good depictive stages during mid and later growth stages of wheat crop under agroclimatic conditions of Faisalabad and under similar other wheat growing environments in the country. PMID:25045744

Sultana, Syeda Refat; Ali, Amjed; Ahmad, Ashfaq; Mubeen, Muhammad; Zia-Ul-Haq, M; Ahmad, Shakeel; Ercisli, Sezai; Jaafar, Hawa Z E

2014-01-01

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Correlation of meteorological parameters and remotely sensed normalized difference vegetation index (NDVI) with cotton leaf curl virus (CLCV) in Multan  

International Nuclear Information System (INIS)

Climate change and weather has a profound effect on the spread of Cotton Leaf Curl Virus (CLCV) which is transmitted by whitefly. Climate change is altering temperature and precipitation patterns, resulting in the shift of some insect/pest from small population to large population thus effecting crops yield. To find out the relationship between the weather conditions, outburst of CLCV and changes in Normalized Difference Vegetation Index (NDVI) values due to the outburst of CLCV, a study was carried out for tehsil Multan. Data was acquired for the months of June, July, August and September for the year 2010. Regression analysis between CLCV and meteorological conditions as well as between CLCV and NDVI was performed. Meteorological parameters included temperature, humidity, precipitation, cloud cover, wind direction, pan evaporation and sunshine hours. NDVI values were calculated from SPOT satellite imagery (1km) using ArcMap10 and WinDisp v5.1. Correlation coefficients obtained in most of the cases were acceptable however the significance F and P-value were higher than their critical value at 95% level of significance. Therefore significant correlation was found only between CLCV and temperature and between CLCV and PAN evaporation during the month of July.

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Online Measurement of Soil Organic Carbon as Correlated with Wheat Normalised Difference Vegetation Index in a Vertisol Field  

Science.gov (United States)

This study explores the potential of visible and near infrared (vis-NIR) spectroscopy for online measurement of soil organic carbon (SOC). It also attempts to explore correlations and similarities between the spatial distribution of SOC and normalized differential vegetation index (NDVI) of a wheat crop. The online measurement was carried out in a clay vertisol field covering 10?ha of area in Karacabey, Bursa, Turkey. Kappa statistics were carried out between different SOC and NDVI data to investigate potential similarities. Calibration model of SOC in full cross-validationresulted in a good accuracy (R2 = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81). The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R2 = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R2 = 0.60, RMSEP = 0.20%, and RPD = 1.41). Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map. PMID:25097882

Tekin, Yucel; Ulusoy, Yahya; Tumsavas, Zeynal; Mouazen, Abdul M.

2014-01-01

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Evaluation of the relation between evapotranspiration and normalized difference vegetation index for downscaling the simplified surface energy balance model  

Science.gov (United States)

The Simplified Surface Energy Balance (SSEB) model uses satellite imagery to estimate actual evapotranspiration (ETa) at 1-kilometer resolution. SSEB ETa is useful for estimating irrigation water use; however, resolution limitations restrict its use to regional scale applications. The U.S. Geological Survey investigated the downscaling potential of SSEB ETa from 1 kilometer to 250 meters by correlating ETa with the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer instrument (MODIS). Correlations were studied in three arid to semiarid irrigated landscapes of the Western United States (Escalante Valley near Enterprise, Utah; Palo Verde Valley near Blythe, California; and part of the Columbia Plateau near Quincy, Washington) during several periods from 2002 to 2008. Irrigation season ETa-NDVI correlations were lower than expected, ranging from R2 of 0.20 to 0.61 because of an eastward 2-3 kilometer shift in ETa data. The shift is due to a similar shift identified in the land-surface temperature (LST) data from the MODIS Terra satellite, which is used in the SSEB model. Further study is needed to delineate the Terra LST shift, its effect on SSEB ETa, and the relation between ETa and NDVI.

Haynes, Jonathan V.; Senay, Gabriel B.

2012-01-01

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Early detection of eruptive dykes revealed by normalized difference vegetation index (NDVI) on Mt. Etna and Mt. Nyiragongo  

Science.gov (United States)

Flank-fissure eruptions involve lateral injection and propagation of magma in a volcanic edifice along pre-existing fractures in the direction of the rift zones where magma intrusion and lava flow production are concentrated over time. Thus, the identification and mapping of active fractures and faults is a fundamental aspect of studies of active volcanic systems. However, gradual dyke wedge emplacement at depth in well-fractured zones on volcano flanks and in volcanic rift zones does not necessarily trigger large amplitude deformation signals susceptible to be recorded months or even years before the actual eruption. Here we show that active and potentially eruptive areas can be detected up to 2 yrs before the arrival to the surface of the final eruptive dyke and venting of lava flows by processing satellite images applying a normalized difference vegetation index (NDVI) algorithm. A posteriori analysis of satellite images indeed reveals that the surficial effects of dyke wedge injection and ascent on plant growth were apparent for Mt. Etna from 2000 to 2002 and for Mt. Nyiragongo in 2001, thus months to years before they erupted.

Houlié, N.; Komorowski, J. C.; de Michele, M.; Kasereka, M.; Ciraba, H.

2006-06-01

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Comparative analysis of SPOT, Landsat, MODIS, and AVHRR normalized difference vegetation index data on the estimation of leaf area index in a mixed grassland ecosystem  

Science.gov (United States)

Many grassland studies have depended on or are currently depending on the Landsat series of satellite sensors for monitoring work. However, given the identified gaps in Landsat data, alternatives to Landsat imagery need to be tested in an operational environment. In this study, normalized difference vegetation index (NDVI) values are derived from a Système Pour l'Observation de la Terre (SPOT), Moderate Resolution Imaging Spectroradiometer (MODIS), and Advanced Very High Resolution Radiometer (AVHRR) image and compared to the NDVI values from a Landsat image for LAI estimation in a semi-arid heterogeneous grassland. Results indicate a high agreement between Landsat and SPOT data with R2 over 85% at all buffer levels (100, 250, and 1000 m), and a significant but lower agreement between MODIS and Landsat with R2 around 28% at 250 m buffer level to 37% at 100 m buffer level. Based on in situ measurements of LAI in 22 homogeneous sites, the relationships established between LAI and NDVI show that SPOT and Landsat could predict LAI with acceptable accuracy, but MODIS and AVHRR cannot quantify the spatial variation in LAI measurements. Data fusion or blending techniques that combine the spectral information of high spatial/low temporal resolution data with low spatial/high temporal resolution data may be considered to study semi-arid heterogeneous grasslands.

Tong, Alexander; He, Yuhong

2013-01-01

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Forest leaf area index determination: A multiyear satellite-independent method based on within-stand normalized difference vegetation index spatial variability  

Science.gov (United States)

The Leaf Area Index (LAI) and its spatial distribution are key features to describe the forest ecophysiological processes. A stable and reproducible relationship is obtained between the LAI and the standard deviation ?NDVI of the pixel-based satellite-derived normalized difference vegetation indices (NDVI) of forest stands. In situ measurements of LAI have been performed with the LAI-2000 Plant Canopy Analyser over 8 years in the managed Fontainebleau forest (France) on about 31 stands each year, including oak, beech, and mixed oak-beech stands. Simultaneous satellite images have been acquired, atmospherically and geometrically corrected, and included into a geographic information system to get the mean NDVI and the ?NDVI for each stand. A total of six different satellites with a 20- to 30-m spatial resolution have been considered over the eight studied years: SPOT1, SPOT2, SPOT4, LANDSAT ETM+, IKONOS, and HYPERION. The mean LAI of a stand is linked to the ?NDVI with a unique relationship that appears to be mostly year- and satellite-independent, because the ?NDVI is nearly insensitive to additive or proportional shifts on NDVI. The theoretical bases of the ?NDVI-LAI relationship are investigated. The results show the combined importance of the shape of the within-stand LAI distribution (following a Weibull probability density function) and the shape of the within-stand LAI-NDVI curves (showing a saturation). The root mean square error of the predicted LAI over the 259 samples is 1.14 m2/m2 when all years and satellites are considered, using the following equation: LAI = -2.45 ln(?NDVI) - 5.58 (r2 = 0.63).

Le Maire, G.; FrançOis, C.; Soudani, K.; Davi, H.; Le Dantec, V.; Saugier, B.; Dufrêne, E.

2006-06-01

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Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI3g at Global Scales  

Directory of Open Access Journals (Sweden)

Full Text Available Satellite observations of surface reflected solar radiation contain information about variability in the absorption of solar radiation by vegetation. Understanding the causes of variability is important for models that use these data to drive land surface fluxes or for benchmarking prognostic vegetation models. Here we evaluated the interannual variability in the new 30.5-year long global satellite-derived surface reflectance index data, Global Inventory Modeling and Mapping Studies normalized difference vegetation index (GIMMS NDVI3g. Pearson’s correlation and multiple linear stepwise regression analyses were applied to quantify the NDVI interannual variability driven by climate anomalies, and to evaluate the effects of potential interference (snow, aerosols and clouds on the NDVI signal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systems where in some regions and seasons > 40% of the NDVI variance could be explained by precipitation anomalies. Temperature correlations were strongest in northern mid- to high-latitudes in the spring and early summer where up to 70% of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America, winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wet season precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

Alvaro Ivanoff

2013-08-01

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Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales  

Science.gov (United States)

Satellite observations of surface reflected solar radiation contain informationabout variability in the absorption of solar radiation by vegetation. Understanding thecauses of variability is important for models that use these data to drive land surface fluxesor for benchmarking prognostic vegetation models. Here we evaluated the interannualvariability in the new 30.5-year long global satellite-derived surface reflectance index data,Global Inventory Modeling and Mapping Studies normalized difference vegetation index(GIMMS NDVI3g). Pearsons correlation and multiple linear stepwise regression analyseswere applied to quantify the NDVI interannual variability driven by climate anomalies, andto evaluate the effects of potential interference (snow, aerosols and clouds) on the NDVIsignal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systemswhere in some regions and seasons 40 of the NDVI variance could be explained byprecipitation anomalies. Temperature correlations were strongest in northern mid- to-high-latitudes in the spring and early summer where up to 70 of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America,winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wetseason precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

Zeng, Fanwei; Collatz, George James; Pinzon, Jorge E.; Ivanoff, Alvaro

2013-01-01

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Satellite monitoring of vegetation dynamics: Sensitivity enhancement by the wide dynamic range vegetation index  

Science.gov (United States)

Synoptic monitoring of vegetation dynamics relies on satellite observations of the distinctive spectral contrast between red and near infrared reflectance that photosynthetically active green vegetation exhibits. It has long been recognized that the Normalized Difference Vegetation Index (NDVI) suffers a rapid decrease of sensitivity at moderate-to-high densities of photosynthetic green biomass. This decrease can conceal detection of vegetation change in croplands, woodlands, and productive grasslands. We applied a recent, straightforward modification of the NDVI, the Wide Dynamic Range Vegetation Index (WDRVI), to a standard AVHRR dataset to assess its sensitivity to variability within ecoregions and across years, relative to NDVI. In productive ecoregions, the sensitivity increased within a single year by up to 47% and the sensitivity to interannual variability increased by up to 100%. The WDRVI exhibited no increase in sensitivity in ecoregions with sparse vegetation. These findings have significant implications for diverse applications of vegetation monitoring products.

Viña, Andrés; Henebry, Geoffrey M.; Gitelson, Anatoly A.

2004-02-01

 
 
 
 
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Using MODIS Normalized Difference Vegetation Index to monitor seasonal and inter-annual dynamics of wetland vegetation in the Great Artesian Basin: a baseline for assessment of future changes in a unique ecosystem  

Science.gov (United States)

The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland area and the discharge associated with individual springs, providing a potential means of monitoring groundwater flow using measurements of wetland area. Previous studies using this relationship to monitor Great Artesian Basin springs have used aerial photography or high resolution satellite images, giving sporadic temporal information. These "snapshot " studies need to be placed within a longer and more regular context to better assess changes in response to aquifer draw-downs. In this study, the potential of medium resolution MODIS Normalized Difference Vegetation Index data for studying the long-term and high frequency temporal dynamics of wetland vegetation at the Dalhousie Spring Complex of the GAB is tested. Photosynthetic activity within Dalhousie wetlands could be differentiated from surrounding land responses. The study showed good correlation between wetland vegetated area and groundwater flow, but also the important influence of natural species phenologies, rainfall, and human activity on the observed seasonal and inter-annual vegetation dynamic. Declining trends in the extent of wetland areas were observed over the 2000- 2009 period followed by a return of wetland vegetation since 2010. This study underlined the need to continue long-term medium resolution satellite studies of the Great Artesian Basin as these data provide a good understanding of variability within the wetlands, give temporal context for less frequent studies and a strong baseline for assessment of future changes.

Petus, C.; Lewis, M.; White, D.

2012-07-01

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A Wetness Index Using Terrain-Corrected Surface Temperature and Normalized Difference Vegetation Index Derived from Standard MODIS Products: An Evaluation of Its Use in a Humid Forest-Dominated Region of Eastern Canada  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we develop a method to estimate land-surface water content in amostly forest-dominated (humid and topographically-varied region of eastern Canada. Theapproach is centered on a temperature-vegetation wetness index (TVWI that uses standard 8-day MODIS-based image composites of land surface temperature (TS and surface reflectanceas primary input. In an attempt to improve estimates of TVWI in high elevation areas, terrain-induced variations in TS are removed by applying grid, digital elevation model-basedcalculations of vertical atmospheric pressure to calculations of surface potential temperature(θS. Here, θS corrects TS to the temperature value to what it would be at mean sea level (i.e.,~101.3 kPa in a neutral atmosphere. The vegetation component of the TVWI uses 8-daycomposites of surface reflectance in the calculation of normalized difference vegetation index(NDVI values. TVWI and corresponding wet and dry edges are based on an interpretation ofscatterplots generated by plotting θS as a function of NDVI. A comparison of spatially-averaged field measurements of volumetric soil water content (VSWC and TVWI for the 2003-2005 period revealed that variation with time to both was similar in magnitudes. Growing season, point mean measurements of VSWC and TVWI were 31.0% and 28.8% for 2003, 28.6% and 29.4% for 2004, and 40.0% and 38.4% for 2005, respectively. An evaluation of the long-term spatial distribution of land-surface wetness generated with the new θS-NDVI function and a process-based model of soil water content showed a strong relationship (i.e., r2 = 95.7%.

Roger M. Cox

2007-10-01

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Série temporal de índice de vegetação sobre diferentes tipologias vegetais no Rio Grande do Sul / Time series of vegetation index for different vegetation types in Rio Grande do Sul  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com este trabalho objetivou-se identificar a dinâmica fenológica das principais tipologias vegetais do Rio Grande do Sul, para o período de 2000 a 2010, utilizando-se dados de Enhanced Vegetation Index, através da transformada de ondaleta. A identificação da fenologia em ciclos ou padrões sazonais e [...] m séries temporais de índices de vegetação, obtidos por sensores orbitais, permite a observação de anomalias e os efeitos de mudanças climáticas ou ambientais. Um perfil temporal do Enhanced Vegetation Index foi construído para o Rio Grande do Sul e retiradas amostras para quatro tipologias vegetais: campo nativo, floresta ombrófila mista, cultivo de soja e de arroz. Essas amostras foram submetidas à transformada de ondaleta, que permitiu a decomposição da série e apresentação dos dados em relação ao tempo e frequência com que os eventos fenológicos ocorreram. Os dados apresentaram regularidade na dinâmica das tipologias vegetais testadas, com ciclos anuais de maior vigor e crescimento vegetal nas estações de primavera e verão e menor no outono e inverno. Abstract in english The objective of this study was the identification of the phenology dynamics of the main types of vegetation of Rio Grande do Sul state, for the period from 2000 to 2010, using Enhanced Vegetation Index data through the wavelet transform. The identification of cycles or seasonal patterns in time ser [...] ies of vegetation indices obtained by orbital sensors allows the observation of anomalies and effects of climate and environmental change. A temporal profile of Enhanced Vegetation Index was built for the Rio Grande do Sul region, where samples of the four main plant typologies were selected: native grassland, mixed ombrophilous forest, soybean and rice crop. These samples were submitted to the wavelet transform, which allowed the decomposition of the series and presentation of data in relation to time and frequency with which the phenological events have occurred. The data showed regularity in the dynamics of vegetation types tested, with annual cycles of plant growth and higher Enhanced Vegetation Index values in spring and summer and lower Enhanced Vegetation Index values in autumn and winter.

Tatiana M., Kuplich; Andreise, Moreira; Denise C., Fontana.

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How Normalized Difference Vegetation Index (NDVI Trendsfrom Advanced Very High Resolution Radiometer (AVHRR and Système Probatoire d’Observation de la Terre VEGETATION (SPOT VGT Time Series Differ in Agricultural Areas: An Inner Mongolian Case Study  

Directory of Open Access Journals (Sweden)

Full Text Available Detailed information from global remote sensing has greatly advanced ourunderstanding of Earth as a system in general and of agricultural processes in particular.Vegetation monitoring with global remote sensing systems over long time periods iscritical to gain a better understanding of processes related to agricultural change over longtime periods. This specifically relates to sub-humid to semi-arid ecosystems, whereagricultural change in grazing lands can only be detected based on long time series. Byintegrating data from different sensors it is theoretically possible to construct NDVI timeseries back to the early 1980s. However, such integration is hampered by uncertainties inthe comparability between different sensor products. To be able to rely on vegetationtrends derived from integrated time series it is therefore crucial to investigate whether vegetation trends derived from NDVI and phenological parameters are consistent acrossproducts. In this paper we analyzed several indicators of vegetation change for a range ofagricultural systems in Inner Mongolia, China, and compared the results across differentsatellite archives. Specifically, we compared two of the prime NDVI archives—AVHRR Global Inventory Modeling and Mapping Studies (GIMMS and SPOT Vegetation (VGTNDVI. Because a true accuracy assessment of long time series is not possible, we furthercompared SPOT VGT NDVI with NDVI from MODIS Terra as a benchmark. We foundhigh similarities in interannual trends, and also in trends of the seasonal amplitude andintegral between SPOT VGT and MODIS Terra (r > 0.9. However, we observedconsiderable disagreements in NDVI-derived trends between AVHRR GIMMS and SPOTVGT. We detected similar discrepancies for trends based on phenological parameters, suchas amplitude and integral of NDVI curves corresponding to seasonal vegetation cycles.Inconsistencies were partially related to land cover and vegetation density. Differentpre-processing schemes and the coarser spatial resolution of AVHRR GIMMS introducedfurther uncertainties. Our results corroborate findings from other studies that vegetationtrends derived from AVHRR GIMMS data not always reflect true vegetation changes. Amore thorough understanding of the factors introducing uncertainties in AVHRR GIMMStime series is needed, and we caution against using AVHRR GIMMS data in regionalstudies without applying regional sensitivity analyses. 

Patrick Hostert

2012-11-01

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Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index  

Energy Technology Data Exchange (ETDEWEB)

The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.

Walker, D A; Bhatt, U S; Raynolds, M K; Romanovsky, V E [University of Alaska Fairbanks, Fairbanks, AK (United States); Leibman, M O; Gubarkov, A A; Khomutov, A V; Moskalenko, N G; Orekhov, P; Ukraientseva, N G [Earth Cryosphere Institute, Russian Academy of Science, Siberian Branch, Tyumen (Russian Federation); Epstein, H E; Yu, Q [University of Virginia, Charlottesville, VA (United States); Forbes, B C; Kaarlejaervi, E [Arctic Center, University of Lapland, Rovaniemi (Finland); Comiso, J C [NASA Goddard Space Flight Center, MD (United States); Jia, G J [Chinese Academy of Sciences, Institute for Atmospheric Physics, Beijing (China); Kaplan, J O [Swiss Federal Institute for Forest Snow and Landscape Research, Birmensdorf (Switzerland); Kumpula, T [University of Joensuu, Joensuu (Finland); Kuss, P [University of Berne, Berne (Switzerland); Matyshak, G [Moscow State University, Moscow (Russian Federation)

2009-10-15

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Wide Dynamic Range Vegetation Index for remote quantification of biophysical characteristics of vegetation.  

Science.gov (United States)

The Normalized Difference Vegetation Index (NDVI) is widely used for monitoring, analyzing, and mapping temporal and spatial distributions of physiological and biophysical characteristics of vegetation. It is well documented that the NDVI approaches saturation asymptotically under conditions of moderate-to-high aboveground biomass. While reflectance in the red region (rho(red)) exhibits a nearly flat response once the leaf area index (LAI) exceeds 2, the near infrared (NIR) reflectance (PNIR) continue to respond significantly to changes in moderate-to-high vegetation density (LAI from 2 to 6) in crops. However, this higher sensitivity of the rho(NIR) has little effect on NDVI values once the rho(NIR) exceeds 30%. In this paper a simple modification of the NDVI was proposed. The Wide Dynamic Range Vegetation Index, WDRVI = (a * rho(NIR-rho(red))/(a * rho(NIR) + rho(red)), where the weighting coefficient a has a value of 0.1-0.2, increases correlation with vegetation fraction by linearizing the relationship for typical wheat, soybean, and maize canopies. The sensitivity of the WDRVI to moderate-to-high LAI (between 2 and 6) was at least three times greater than that of the NDVI. By enhancing the dynamic range while using the same bands as the NDVI, the WDRVI enables a more robust characterization of crop physiological and phenological characteristics. Although this index needs further evaluation, the linear relationship with vegetation fraction and much higher sensitivity to change in LAI will be especially valuable for precision agriculture and monitoring vegetation status under conditions of moderate-to-high density. It is anticipated that the new index will complement the NDVI and other vegetation indices that are based on the red and NIR spectral bands. PMID:15022830

Gitelson, Anatoly A

2004-02-01

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Functional analysis of normalized difference vegetation index curves reveals overwinter mule deer survival is driven by both spring and autumn phenology.  

Science.gov (United States)

Large herbivore populations respond strongly to remotely sensed measures of primary productivity. Whereas most studies in seasonal environments have focused on the effects of spring plant phenology on juvenile survival, recent studies demonstrated that autumn nutrition also plays a crucial role. We tested for both direct and indirect (through body mass) effects of spring and autumn phenology on winter survival of 2315 mule deer fawns across a wide range of environmental conditions in Idaho, USA. We first performed a functional analysis that identified spring and autumn as the key periods for structuring the among-population and among-year variation of primary production (approximated from 1 km Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index (NDVI)) along the growing season. A path analysis showed that early winter precipitation and direct and indirect effects of spring and autumn NDVI functional components accounted for 45% of observed variation in overwinter survival. The effect size of autumn phenology on body mass was about twice that of spring phenology, while direct effects of phenology on survival were similar between spring and autumn. We demonstrate that the effects of plant phenology vary across ecosystems, and that in semi-arid systems, autumn may be more important than spring for overwinter survival. PMID:24733951

Hurley, Mark A; Hebblewhite, Mark; Gaillard, Jean-Michel; Dray, Stéphane; Taylor, Kyle A; Smith, W K; Zager, Pete; Bonenfant, Christophe

2014-01-01

48

[Construction of age group vegetation index and preliminary application].  

Science.gov (United States)

In the present paper, one remote sensing index-age group vegetation index (AGVI) was put forward, and its feasibility was verified. Taking 518 groups of pine forest age group data collected in 13 counties (cities) of Sanming, Jiangle, Shaxian, Nanping, Huaan, Yunxiao, Nanping, Anxi, Putian, Changting, Jianyang, Ningde and Fuqing, Fujian Province and HJ-1 CCD multi-spectral image at the same time-phase as the basis, the spectrum differences of blue, green, red, near infrared and NDVI of each age group were analyzed, showing the characteristics of young forest>middle-aged forest>over-mature forest>mature forest>near mature forest at near infrared band and mature forest>near mature forest>over-mature forest>young forest>middle-aged forest at NDVI, thus the age group vegetation index (AGVI) was constructed; the index could increase the absolute and relative spectrum differences among age groups. For the pine forest AGVI, cluster analysis was conducted with K-mean method, showing that the division accuracy of pine forest age group was 80.45%, and the accurate rate was 90.41%. Therefore, the effectiveness of age group vegetation index constructed was confirmed. PMID:25358177

Xu, Zhang-hua; Li, Cong-hui; Liu, Jian; Yu, Kun-yong; Gong, Cong-hong; Tang, Meng-ya

2014-06-01

49

Mapeamento do índice de vegetação da diferença normalizada em lavoura de algodão / Mapping of the normalized difference vegetation index in cotton field  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os dados de sensoriamento remoto em campo podem fornecer informações detalhadas sobre a variabilidade de parâmetros biofísicos ligados à produtividade em grandes áreas e apresentam potencial para o monitoramento destes parâmetros, ao longo de todo o ciclo de desenvolvimento da cultura. Este trabalho [...] objetivou mapear a variabilidade espacial do índice de vegetação da diferença normalizada (NDVI) e seus componentes, em duas lavouras comerciais de algodão (Gossipium hirsutum L.), utilizando sensor óptico ativo, em nível terrestre. Os dados foram coletados utilizando-se sensor instalado em um pulverizador autopropelido agrícola. Um receptor GPS foi acoplado ao sensor, para a obtenção das coordenadas dos pontos de amostragem. As leituras foram realizadas em faixas espaçadas em 21,0 m, aproveitando-se as passadas do veículo no momento da pulverização de agroquímicos, e os dados submetidos à análise estatística clássica e geoestatística. Mapas de distribuição espacial das variáveis foram elaborados pela interpolação por krigagem. Observou-se maior variabilidade espacial do NDVI e da reflectância espectral da vegetação na região do infravermelho próximo (IVP) (880 nm) e do visível (590 nm) na lavoura com maior estresse fisiológico, devido ao ataque do percevejo castanho [Scaptocoris castanea (Hem.: Cydnidae)], em relação à lavoura sadia. Abstract in english The remote sensing data obtained at field level can provide detailed information about the variability of biophysical parameters related to yield over large areas, and present potential for monitoring these parameters throughout the crop development cycle. This study aimed to map the spatial variabi [...] lity of the Normalized Difference Vegetation Index (NDVI) and its components in two commercial cotton (Gossipium hirsutum L.) fields, by using an active optical sensor at the ground level. Data were collected with the aid of an optical sensor installed in a self-propelled agricultural sprayer. A GPS receiver was connected to the sensor, in order to obtain the coordinates of the sampling points. The readings were performed in rows spaced 21.0 m apart by the sensor installed on a vehicle, during the spraying operation, and data analyzed by using the classical statistics and geostatistics. Spatial distribution maps of the variables were generated by kriging interpolation. It was observed a higher spatial variability of NDVI and spectral reflectance of vegetation in the region of near infrared (NIR) (880 nm) and visible infrared (590 nm) in the crop with higher physiological stress, due to the brown bug [Scaptocoris castanea (Hem.: Cydnidae)] attack, when compared to the healthy one.

Anamari Viegas de Araujo, Motomiya; José Paulo, Molin; Wagner Rogerio, Motomiya; Fábio Henrique, Rojo Baio.

2012-03-01

50

Mapeamento do índice de vegetação da diferença normalizada em lavoura de algodão / Mapping of the normalized difference vegetation index in cotton field  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os dados de sensoriamento remoto em campo podem fornecer informações detalhadas sobre a variabilidade de parâmetros biofísicos ligados à produtividade em grandes áreas e apresentam potencial para o monitoramento destes parâmetros, ao longo de todo o ciclo de desenvolvimento da cultura. Este trabalho [...] objetivou mapear a variabilidade espacial do índice de vegetação da diferença normalizada (NDVI) e seus componentes, em duas lavouras comerciais de algodão (Gossipium hirsutum L.), utilizando sensor óptico ativo, em nível terrestre. Os dados foram coletados utilizando-se sensor instalado em um pulverizador autopropelido agrícola. Um receptor GPS foi acoplado ao sensor, para a obtenção das coordenadas dos pontos de amostragem. As leituras foram realizadas em faixas espaçadas em 21,0 m, aproveitando-se as passadas do veículo no momento da pulverização de agroquímicos, e os dados submetidos à análise estatística clássica e geoestatística. Mapas de distribuição espacial das variáveis foram elaborados pela interpolação por krigagem. Observou-se maior variabilidade espacial do NDVI e da reflectância espectral da vegetação na região do infravermelho próximo (IVP) (880 nm) e do visível (590 nm) na lavoura com maior estresse fisiológico, devido ao ataque do percevejo castanho [Scaptocoris castanea (Hem.: Cydnidae)], em relação à lavoura sadia. Abstract in english The remote sensing data obtained at field level can provide detailed information about the variability of biophysical parameters related to yield over large areas, and present potential for monitoring these parameters throughout the crop development cycle. This study aimed to map the spatial variabi [...] lity of the Normalized Difference Vegetation Index (NDVI) and its components in two commercial cotton (Gossipium hirsutum L.) fields, by using an active optical sensor at the ground level. Data were collected with the aid of an optical sensor installed in a self-propelled agricultural sprayer. A GPS receiver was connected to the sensor, in order to obtain the coordinates of the sampling points. The readings were performed in rows spaced 21.0 m apart by the sensor installed on a vehicle, during the spraying operation, and data analyzed by using the classical statistics and geostatistics. Spatial distribution maps of the variables were generated by kriging interpolation. It was observed a higher spatial variability of NDVI and spectral reflectance of vegetation in the region of near infrared (NIR) (880 nm) and visible infrared (590 nm) in the crop with higher physiological stress, due to the brown bug [Scaptocoris castanea (Hem.: Cydnidae)] attack, when compared to the healthy one.

Anamari Viegas de Araujo, Motomiya; José Paulo, Molin; Wagner Rogerio, Motomiya; Fábio Henrique, Rojo Baio.

51

Early Detection of Eruptive Dykes Revealed by Normalized Difference Vegetation Index (NDVI) on Nyiragongo and Etna Volcanoes: Implications for Dyke Wedge Emplacement, Monitoring, and Risk Assessment.  

Science.gov (United States)

Flank-fissure eruptions involve lateral injection and propagation of magma in a volcanic edifice along pre- existing fractures in the direction of a volcanic rift zone (VRZ) where magma intrusion and lava flow production are concentrated over time. Gradual dyke wedge emplacement on volcano flanks and in VRZ's does not necessarily trigger large amplitude deformation signals susceptible to be recorded months or even years before the actual eruption. We show that active and potentially eruptive areas in a VRZ can be detected up to 2 years before the arrival to the surface of the final eruptive dyke and venting of lava flows by processing satellite images applying a Normalized Difference Vegetation Index (NDVI) algorithm. A positive NDVI anomaly is indicative of excessive photosynthetic plant activity. A posteriori analysis of satellite images reveal that a high- NDVI linear anomaly was apparent in vegetated areas of VRZ's on Etna from 2000 to 2002 and on Nyiragongo in June 2001, several months to years before eruptive fractures formed directly above the NDVI anomaly. We propose that the observed NDVI linear anomalies are the signature of the integrated physico-chemical effects (increased heat and CO2 flux, H2O condensation) caused by the structurally-controlled progressive injection and propagation, in a VRZ and a few months to years before the eruption, of a series of dykes (dyke wedge) that did not reach the surface. We focus of Nyiragongo volcano where historical flank-fissure eruptions from lava lake drainage in 1977 and 2002 show a link with tectonics of the Kivu rift (western branch of the East African Rift System). In 2002, dykes were injected in the southern VRZ bounded by Kivu rift normal faults and propagated over 14 km producing lava flows that caused widespread destruction in the city of Goma. Data from Nyiragongo suggest that as a dyke wedge is formed and repeatedly reactivated, final eruptive dykes can be injected easily and can propagate rapidly further along the VRZ impacting populated areas far from the magmatic conduit. This has important implications for understanding the current process of magma convection feeding the active Nyiragongo lava lake as well as potential small-volume lateral magma injections into the reactivated southern VRZ. The NDVI processing methodology has potentially important implications for monitoring networks on deeply vegetated restless volcanoes with limited or difficult access. More importantly, on volcanoes where eruptive style changes from crater-centered to eccentric flank activity or for which new inactive VRZ's could be reactivated towards populated areas, our methodology constitutes a new tool for early detection of potential flank eruptive vents. By improving the understanding of the link between edifice structure and eruptive activity of effusive volcanoes it can significantly improve integrated risk analysis and the effectiveness of early-detection warning systems for populations at risk.

Komorowski, J.; Houlié, N.; Kasereka, C. M.; Ciraba, H.

2006-12-01

52

Investigation on the Patterns of Global Vegetation Change Using a Satellite-Sensed Vegetation Index  

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Full Text Available The pattern of vegetation change in response to global change still remains a controversial issue. A Normalized Difference Vegetation Index (NDVI dataset compiled by the Global Inventory Modeling and Mapping Studies (GIMMS was used for analysis. For the period 1982–2006, GIMMS-NDVI analysis indicated that monthly NDVI changes show homogenous trends in middle and high latitude areas in the northern hemisphere and within, or near, the Tropic of Cancer and Capricorn; with obvious spatio-temporal heterogeneity on a global scale over the past two decades. The former areas featured increasing vegetation activity during growth seasons, and the latter areas experienced an even greater amplitude in places where precipitation is adequate. The discussion suggests that one should be cautious of using the NDVI time-series to analyze local vegetation dynamics because of its coarse resolution and uncertainties.

Ainong Li

2010-06-01

53

STUDY ON THE VARIABILITY OF "NORMALIZED DIFFERENCE VEGETATION INDEX/NDVI" BY INDICATIVE KRIGING = ESTUDO DA VARIABILIDADE DO "ÍNDICE DE VEGETAÇÃO POR DIFERENÇA NORMALIZADA/NDVI" UTILIZANDO KRIGAGEM INDICATIVA  

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Full Text Available The main purpose of this paper was to evaluate the “Normalized Difference Vegetation Index” (NDVI in an area at Baixada Santista, coastland of São Paulo State, Brazil, using the geostatistic technique of indicative kriging. The analyses were made using sensor TM images (Landsat satellite, dated from February/1989 and January/1997. The obtained NDVI maps showed vegetation loss during the analyzed period, and the probabilities map, resulting from the difference between the two periods of time, indicated a distinct contrast between loss and gains of vegetation index. Vegetation mapping and application of indicative kriging were shown as beingquite useful for monitoring and environmental management, being able to provide good results when jointly used. = Este trabalho teve por objetivo principal analisar o “índice de vegetação por diferença normalizada” (NDVI em uma área da Baixada Santista, litoral paulista,utilizando a técnica geoestatística da krigagem indicativa. As análises foram feitas em imagens do sensor TM do satélite Landsat datadas de fevereiro de 1989 e janeiro de 1997. Os mapas obtidos do NDVI mostraram perda de vegetação de um modo geral, durante o período analisado, e o mapa de probabilidades resultante da diferença entreos dois períodos indicou forte contraste entre perdas e ganhos do índice de vegetação. O mapeamento da vegetação e a aplicação da krigagem indicativa mostraram-se ferramentas de grande aplicabilidade para o monitoramento e gerenciamento ambiental e podem proporcionar bons resultados quando utilizadas de forma integrada.

Roberto Wagner Lourenço

2004-01-01

54

[MTCARI: A kind of vegetation index monitoring vegetation leaf chlorophyll content based on hyperspectral remote sensing].  

Science.gov (United States)

The chlorophyll content of plant has relative correlation with photosynthetic capacity and growth levels of plant. It affects the plant canopy spectra, so the authors can use hyperspectral remote sensing to monitor chlorophyll content. By analyzing existing mature vegetation index model, the present research pointed out that the TCARI model has deficiencies, and then tried to improve the model. Then using the PROSPECT+SAIL model to simulate the canopy spectral under different levels of chlorophyll content and leaf area index (LAI), the related constant factor has been calculated. The research finally got modified transformed chlorophyll absorption ratio index (MTCARI). And then this research used optimized soil background adjust index (OSAVI) to improve the model. Using the measured data for test and verification, the model has good reliability. PMID:23156785

Meng, Qing-ye; Dong, Heng; Qin, Qi-ming; Wang, Jin-liang; Zhao, Jiang-hua

2012-08-01

55

Variation of Ecosystem Respiration with Different Vegetations at Different Microtopographies  

Science.gov (United States)

Department of Biology, San Diego State University, San Diego, CA 92182, USA Abstract: Arctic tundra is one of the significant stocks of terrestrial soil carbon. With global climate change, it is likely that the distribution of vegetation types was altered at high latitudes. Consequently the ecosystem CO2 emission will be changed with the alteration. To predict the change trend due to global change in the future, it is critical to clarify the variation of CO2 emission from ecosystem to atmosphere at different topographies and vegetation types. In this study, we conducted 16 plots with three different vegetation types: Dry lichen, Sphagnum moss, Carex at five different micro topographies: low center polygon, high center polygon, rim, trough and flat at Barrow, Alaska. Automatic chamber system Licor-8100 and Licor-8150 were applied to observe ecosystem respiration continually from middle June 2007 to the end of August 2007. Soil temperature, soil moisture were measured at the same time. Thaw depth, water table and Normalized Difference Vegetation Index (NDVI) were observed at each plot with a frequency once a week. As a result, the flat area with Carex vegetation was significantly greater than other micro topographies with other vegetations. High center polygons have the lowest ecosystem respiration even with different vegetations. These results suggest that both micro topography and vegetation play key role on the variability of ecosystem CO2 emission. Middle-level water table, high thaw depth, and appropriate NDVI will increase the emission of CO2 from ecosystem to atmosphere. With the season changing, ecosystem respiration increased with higher temperature and lower water table and soil moisture. Key words: ecosystem respiration, microtopography, vegetation type

Tang, Y.; Oechel, W.

2007-12-01

56

Estimating Crop Coefficients Using Remote Sensing-Based Vegetation Index  

Directory of Open Access Journals (Sweden)

Full Text Available Crop coefficient (Kc-based estimation of crop evapotranspiration is one of the most commonly used methods for irrigation water management. However, uncertainties of the generalized dual crop coefficient (Kc method of the Food and Agricultural Organization of the United Nations Irrigation and Drainage Paper No. 56 can contribute to crop evapotranspiration estimates that are substantially different from actual crop evapotranspiration. Similarities between the crop coefficient curve and a satellite-derived vegetation index showed potential for modeling a crop coefficient as a function of the vegetation index. Therefore, the possibility of directly estimating the crop coefficient from satellite reflectance of a crop was investigated. The Kc data used in developing the relationship with NDVI were derived from back-calculations of the FAO-56 dual crop coefficients procedure using field data obtained during 2007 from representative US cropping systems in the High Plains from AmeriFlux sites. A simple linear regression model ( is developed to establish a general relationship between a normalized difference vegetation index (NDVI from a moderate resolution satellite data (MODIS and the crop coefficient (Kc calculated from the flux data measured for different crops and cropping practices using AmeriFlux towers. There was a strong linear correlation between the NDVI-estimated Kc and the measured Kc with an r2 of 0.91 and 0.90, while the root-mean-square error (RMSE for Kc in 2006 and 2007 were 0.16 and 0.19, respectively. The procedure for quantifying crop coefficients from NDVI data presented in this paper should be useful in other regions of the globe to understand regional irrigation water consumption.

Kenneth Hubbard

2013-03-01

57

[Soil moisture estimation model based on multiple vegetation index].  

Science.gov (United States)

Estimating soil moisture conveniently and exactly is a hot issues in water resource monitoring among agriculture and forestry. Estimating soil moisture based on vegetation index has been recognized and applied widely. 8 vegetation indexes were figured out based on the hyper-spectral data measured by portable spectrometer. The higher correlation indexes among 8 vegetation indexes and surface vegetation temperature were selected by Gray Relative Analysis method (GRA). Then, these selected indexes were analyzed using Multiple Linear Regression to establish soil moisture estimation model based on multiple vegetation indexes, and the model accuracy was evaluated. The accuracy evaluation indicated that the fitting was satisfied and the significance was 0.000 (P measured soil moisture with R2 reached 0.636 1 and RMSE 2.149 9. This method introduced multiple vegetation indexes into soil water content estimating over micro scale by non-contact measuring method using portable spectrometer. The exact estimation could be an appropriate replacement for remote sensing inversion and direct measurement. The model could estimate soil moisture quickly and accurately, and provide theory and technology reference for water resource management in agriculture and forestry. PMID:25358174

Wu, Hai-long; Yu, Xin-xiao; Zhang, Zhen-ming; Zhang, Yan

2014-06-01

58

An initial assessment of Suomi NPP VIIRS vegetation index EDR  

Science.gov (United States)

The Suomi National Polar-orbiting Partnership (S-NPP) satellite with Visible/Infrared Imager/Radiometer Suite (VIIRS) onboard was launched in October 2011. VIIRS is the primary instrument for a suite of Environmental Data Records (EDR), including Vegetation Index (VI) EDR, for weather forecasting and climate research. The VIIRS VI EDR operational product consists of the Top of the Atmosphere (TOA) Normalized Difference Vegetation Index (NDVI), the Top of the Canopy (TOC) Enhanced Vegetation Index (EVI), and per-pixel product quality information. In this paper, we report results of our assessment of the early VIIRS VI EDR (beta quality) using Aqua MODIS and NOAA-18 AVHRR/3 as a reference for May 2012 to March 2013. We conducted two types of analyses focused on an assessment of physical (global scale) and radiometric (regional scale) performances of VIIRS VI EDR. Both TOA NDVI and TOC EVI of VIIRS showed spatial and temporal trends consistent with the MODIS counterparts, whereas VIIRS TOA NDVI was systematically higher than that of AVHRR. Performance of the early VIIRS VI EDR was limited by a lack of adequate per-pixel quality information, commission/omission errors of the cloud mask, and uncertainties associated with the surface reflectance retrievals. A number of enhancements to the VI EDR are planned, including: (1) implementation of a TOC EVI back-up algorithm, (2) addition of more detailed quality flags on aerosols, clouds, and snow cover, and (3) implementation of gridding and temporal compositing. A web-based, product quality monitoring tool has been developed and automated product validation protocols are being prototyped.

Vargas, M.; Miura, T.; Shabanov, N.; Kato, A.

2013-11-01

59

Investigation of soil influences in AVHRR red and near-infrared vegetation index imagery  

Science.gov (United States)

The effects of soil optical properties on vegetation index imagery are analyzed with ground-based spectral measurements and both simulated and actual AVHRR data from the NOAA satellites. Soil effects on vegetation indices were divided into primary variations associated with the brightness of bare soils, secondary variations attributed to 'color' differences among bare soils, and soil-vegetation spectral mixing. Primary variations were attributed to shifts in the soil line owing to atmosphere or soil composition. Secondary soil variance was responsible for the Saharan desert 'artefact' areas of increased vegetation index response in AVHRR imagery.

Huete, A. R.; Tucker, C. J.

1991-01-01

60

Global Data Sets of Vegetation Leaf Area Index (LAI3g and Fraction of Photosynthetically Active Radiation (FPAR3g Derived from Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI3g for the Period 1981 to 2011  

Directory of Open Access Journals (Sweden)

Full Text Available Long-term global data sets of vegetation Leaf Area Index (LAI and Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR are critical to monitoring global vegetation dynamics and for modeling exchanges of energy, mass and momentum between the land surface and planetary boundary layer. LAI and FPAR are also state variables in hydrological, ecological, biogeochemical and crop-yield models. The generation, evaluation and an example case study documenting the utility of 30-year long data sets of LAI and FPAR are described in this article. A neural network algorithm was first developed between the new improved third generation Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI3g and best-quality Terra Moderate Resolution Imaging Spectroradiometer (MODIS LAI and FPAR products for the overlapping period 2000–2009. The trained neural network algorithm was then used to generate corresponding LAI3g and FPAR3g data sets with the following attributes: 15-day temporal frequency, 1/12 degree spatial resolution and temporal span of July 1981 to December 2011. The quality of these data sets for scientific research in other disciplines was assessed through (a comparisons with field measurements scaled to the spatial resolution of the data products, (b comparisons with broadly-used existing alternate satellite data-based products, (c comparisons to plant growth limiting climatic variables in the northern latitudes and tropical regions, and (d correlations of dominant modes of interannual variability with large-scale circulation anomalies such as the EI Niño-Southern Oscillation and Arctic Oscillation. These assessment efforts yielded results that attested to the suitability of these data sets for research use in other disciplines. The utility of these data sets is documented by comparing the seasonal profiles of LAI3g with profiles from 18 state-of-the-art Earth System Models: the models consistently overestimated the satellite-based estimates of leaf area and simulated delayed peak seasonal values in the northern latitudes, a result that is consistent with previous evaluations of similar models with ground-based data. The LAI3g and FPAR3g data sets can be obtained freely from the NASA Earth Exchange (NEX website.

Ranga B. Myneni

2013-02-01

 
 
 
 
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An Assessment of Mining Activities Impact on Vegetation in Bukuru Jos Plateau State Nigeria Using Normalized Differential Vegetation Index (NDVI  

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Full Text Available The study area has a pathetic and deplorable condition of landuse/ landcover. The vegetal cover in the area has to be removed from the activities of tin mining which consequently resulted into adverse environmental effect such as erosion. Different forms of human induced stress such as tin mining and heavy rainfall have severely degraded soils on the Jos Plateau. Such degradation problems are also caused by deforestation, inappropriate farming system, bush burning and over-grazing which are hostile to the environment. The impact of tin mining has greatly affected the natural ecology of the study area Bukuru. Micro and macro organisms and plants have been stripped off their natural habitat due to tin mining activities. This paper therefore, assesses the mining activities impact on the vegetation in Bukuru area of Jos plateau in Nigeria. Normalized Differential Vegetation Index (NDVI techniques was adopted to Maps effect of tin mining on the vegetation for the period between 1975 and 2007 using LandSat satellite data. The result of the differential vegetation index analysis reveals a decline in vegetated surfaces in 1986 ranging from 0.04 to 0.58 indicating 0.05 and continuous loss in vegetation over the study area in 2007 (vegetated surface decrease by 0.08 between 1986 and 2007. The decrease in vegetated surface is due to intensive mining and cultivation.

Musa Haruna D.

2011-11-01

62

Analysis of Vegetation Index Variations and the Asian Monsoon Climate  

Science.gov (United States)

Vegetation growth depends on local climate. Significant anthropogenic land cover and land use change activities over Asia have changed vegetation distribution as well. On the other hand, vegetation is one of the important land surface variables that influence the Asian Monsoon variability through controlling atmospheric energy and water vapor conditions. In this presentation, the mean and variations of vegetation index of last decade at regional scale resolution (5km and higher) from MODIS have been analyzed. Results indicate that the vegetation index has been reduced significantly during last decade over fast urbanization areas in east China, such as Yangtze River Delta, where local surface temperatures were increased significantly in term of urban heat Island. The relationship between vegetation Index and climate (surface temperature, precipitation) over a grassland in northern Asia and over a woody savannas in southeast Asia are studied. In supporting Monsoon Asian Integrated Regional Study (MAIRS) program, the data in this study have been integrated into Giovanni, the online visualization and analysis system at NASA GES DISC. Most images in this presentation are generated from Giovanni system.

Shen, Sunhung; Leptoukh, Gregory G.; Gerasimov, Irina

2012-01-01

63

A Novel Moisture Adjusted Vegetation Index (MAVI) to Reduce Background Reflectance and Topographical Effects on LAI Retrieval  

Science.gov (United States)

A new moisture adjusted vegetation index (MAVI) is proposed using the red, near infrared, and shortwave infrared (SWIR) reflectance in band-ratio form in this paper. The effectiveness of MAVI in retrieving leaf area index (LAI) is investigated using Landsat-5 data and field LAI measurements in two forest and two grassland areas. The ability of MAVI to retrieve forest LAI under different background conditions is further evaluated using canopy reflectance of Jack Pine and Black Spruce forests simulated by the 4-Scale model. Compared with several commonly used two-band vegetation index, such as normalized difference vegetation index, soil adjusted vegetation index, modified soil adjusted vegetation index, optimized soil adjusted vegetation index, MAVI is a better predictor of LAI, on average, which can explain 70% of variations of LAI in the four study areas. Similar to other SWIR-related three-band vegetation index, such as modified normalized difference vegetation index (MNDVI) and reduced simple ratio (RSR), MAVI is able to reduce the background reflectance effects on forest canopy LAI retrieval. MAVI is more suitable for retrieving LAI than RSR and MNDVI, because it avoids the difficulty in properly determining the maximum and minimum SWIR values required in RSR and MNDVI, which improves the robustness of MAVI in retrieving LAI of different land cover types. Moreover, MAVI is expressed as ratios between different spectral bands, greatly reducing the noise caused by topographical variations, which makes it more suitable for applications in mountainous area. PMID:25025128

Zhu, Gaolong; Ju, Weimin; Chen, J. M.; Liu, Yibo

2014-01-01

64

The use of a satellite derived vegetation index for assessment of the urban heat island effect  

Science.gov (United States)

Satellite derived normalized difference (ND) vegetation index data, based on urban and rural region composed of a variety of land surface environments, are evaluated. These data are linearly related to the difference in observed urban and rural minimum temperatures. It is concluded that the difference in the ND index between urban and rural regions reflects the difference in the surface properties (evaporation and heat storage capacity) of these two environments and urban and rural minimum temperatures (the urban heat island effect).

Gallo, Kevin P.; Tarpley, J. D.; Mcnab, Alan L.; Karl, Thomas R.; Brown, Jesslyn F.

1993-01-01

65

Vegetation classification and soil moisture calculation using land surface temperature (LST) and vegetation index (VI)  

Science.gov (United States)

In this paper, the temperature-missivity separating (TES) method and normalized difference vegetation index (NDVI) are introduced, and the hyperspectral image data are analyzed using land surface temperature (LST) and NDVI channels which are acquired by Operative Module Imaging Spectral (OMIS) in Beijing Precision Agriculture Demonstration Base in Xiaotangshan town, Beijing in 26 Apr, 2001. Firstly, the 6 kinds of ground targets, which are winter wheat in booting stage and jointing stage, bare soil, water in ponds, sullage in dry ponds, aquatic grass, are well classified using LST and NDVI channels. Secondly, the triangle-like scatter-plot is built and analyzed using LST and NDVI channels, which is convenient to extract the information of vegetation growth and soil's moisture. Compared with the scatter-plot built by red and near-infrared bands, the spectral distance between different classes are larger, and the samples in the same class are more convergent. Finally, we design a logarithm VIT model to extract the surface soil water content (SWC) using LST and NDVI channel, which works well, and the coefficient of determination, R2, between the measured surface SWC and the estimated is 0.634. The mapping of surface SWC in the wheat area are calculated and illustrated, which is important for scientific irrigation and precise agriculture.

Liu, Liangyun; Zhang, Bing; Xu, Genxing; Zheng, Lanfen; Tong, Qingxi

2002-03-01

66

Radiative transfer in shrub savanna sites in Niger: Preliminary results from HAPEX-Sahel. Part 3: Optical dynamics and vegetation index sensitivity to biomass and plant cover  

Science.gov (United States)

A shrub savannah landscape in Niger was optically characterized utilizing blue, green, red and near-infrared wavelengths. Selected vegetation indices were evaluated for their performance and sensitivity to describe the complex Sahelian soil/vegetation canopies. Bidirectional reflectance factors (BRF) of plants and soils were measured at several view angles, and used as input to various vegetation indices. Both soil and vegetation targets had strong anisotropic reflectance properties, rendering all vegetation index (6) responses to be a direct function of sun and view geometry. Soil background influences were shown to alter the response of most vegetation indices. N-space greenness had the smallest dynamic range in VI response, but the n-space brightness index provided additional useful information. The global environmental monitoring index (GEMI) showed a large 6 dynamic range for bare soils, which was undesirable for a vegetation index. The view angle response of the normalized difference vegetation index (NDVI), atmosphere resistant vegetation index (ARVI) and soil atmosphere resistant vegetation index (SARVI) were asymmetric about nadir for multiple view angles, and were, except for the SARVI, altered seriously by soil moisture and/or soil brightness effects. The soil adjusted vegetation index (SAVI) was least affected by surface soil moisture and was symmetric about nadir for grass vegetation covers. Overall the SAVI, SARVI and the n-space vegetation index performed best under all adverse conditions and were recommended to monitor vegetation growth in the sparsely vegetated Sahelian zone.

vanLeeuwen, W. J. D.; Huete, A. R.; Duncan, J.; Franklin, J.

1994-01-01

67

Distinguishing land use types using surface albedo and normalized difference vegetation index derived from the SEBAL model for the Atankwidi and Afram sub-catchments in Ghana  

Directory of Open Access Journals (Sweden)

Full Text Available Distinguishing land use types is mostly done through field surveys which does not easily capture the spatial changes in the land use/cover types. In this study, the Surface Energy Balance Algorithm for Land (SEBAL model was used to estimate surface albedo and NDVI, for different land use/cover types for two sub-catchments (i.e., Atankwidi and Afram in the Volta Basin of Ghana. The mean coefficient of variation (CV for individual land use/cover types compared to the mean CV for a given site was then used to distinguish among the land use/cover types. It was found that these parameters derived from the SEBAL model can be used to distinguish among different land use/cover types in the two sub-catchments. SEBAL estimates for surface albedo and NDVI across the different land use/cover types varied from 0.05 to 0.22 and -0.41 to 0.38, respectively. The range of CVs for surface albedo and NDVI, were 5-22% and 7-175%, respectively across the different land use/cover types for the two catchments. The results of this study demonstrate that SEBAL’s derived surface albedo and NDVI can be used to distinguish land use/cover types in catchments similar to those of the study areas with few ground measurements.

Tayari Salifu

2012-01-01

68

Vegetation  

DEFF Research Database (Denmark)

• Over the past 30 years (1982-2011), the Normalized Difference Vegetation Index (NDVI), an index of green vegetation, has increased 15.5% in the North American Arctic and 8.2% in the Eurasian Arctic. In the more southern regions of Arctic tundra, the estimated aboveground plant biomass has increased 20-26%. • Increasing shrub growth and range extension throughout the Low Arctic are related to winter and early growing season temperature increases. Growth of other tundra plant types, including graminoids and forbs, is increasing, while growth of mosses and lichens is decreasing. • Increases in vegetation (including shrub tundra expansion) and thunderstorm activity, each a result of Arctic warming, have created conditions that favor a more active Arctic fire regime.

Epstein, H.E.; Walker, D.A.

2012-01-01

69

On the terminology of the spectral vegetation index (NIR – SWIR)/(NIR + SWIR)  

Science.gov (United States)

The spectral vegetation index (?NIR – ?SWIR)/(?NIR + ?SWIR), where ?NIR and ?SWIR are the near-infrared (NIR) and shortwave-infrared (SWIR) reflectances, respectively, has been widely used to indicate vegetation moisture condition. This index has multiple names in the literature, including infrared index (II), normalized difference infrared index (NDII), normalized difference water index (NDWI), normalized difference moisture index (NDMI), land surface water index (LSWI), and normalized burn ratio (NBR), etc. After reviewing each term’s definition, associated sensors, and channel specifications, we found that the index consists of three variants, differing only in the SWIR region (1.2–1.3 µm, 1.55–1.75 µm, or 2.05–2.45 µm). Thus, three terms are sufficient to represent these three SWIR variants; other names are redundant and therefore unnecessary. Considering the spectral representativeness, the term’s popularity, and the “rule of priority” in scientific nomenclature, NDWI, NDII, and NBR, each corresponding to the three SWIR regions, are more preferable terms.

Ji, Lel; Zhang, Li; Wylie, Bruce K.; Rover, Jennifer

2011-01-01

70

The use of a vegetation index for assessment of the urban heat island effect  

Science.gov (United States)

A vegetation index and radiative surface temperature were derived from NOAA-11 Advanced Very High Resolution Radiometer (AVHRR) data for the Seattle, WA region from 28 June through 4 July 1991. The vegetation index and surface temperature values were computed for locations of weather observation stations within the region and compared to observed minimum air temperatures. These comparisons were used to evaluate the use of AVHRR data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). AVHRR derived normalized difference vegetation index (NDVI) and radiant surface temperature data from a one week composite product were both related significantly to observed minimum temperatures, however, the vegetation index accounted for a greater amount of the spatial variation observed in mean minimum temperatures. The difference in the NDVI between urban and rural regions appears to be an indicator of the difference in surface properties (i.e., evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures.

Gallo, K. P.; Mcnab, A. L.; Karl, T. R.; Brown, J. F.; Hood, J. J.; Tarpley, J. D.

1993-01-01

71

Use of a wetland index to evaluate changes in riparian vegetation after livestock exclusion  

Science.gov (United States)

A method was developed to characterize ecological integrity of riparian sites based on the abundance of hydric species. This wetland index can be calculated with species data, or with community type data as performed here. Classified riparian community types were used to describe vegetation at 14 livestock exclosures and adjacent grazed areas. Community type wetland index values were generated and used to calculate site wetland index values. It was hypothesized that removal of livestock would result in higher wetland index values because of release from herbivory and decreased physical disturbance of vegetation, streambanks, and soil. The wetland index for exclosures was about 12% higher than grazed sites; differences were statistically significant (p exclusion may have contributed to the greater bank stability (p = 0.002) and smaller width-to-depth ratio (p = 0.005) in exclosures. Challenges were encountered in using community types to describe and compare site vegetation, which could be avoided with species data collection. The wetland index can be a tool to monitor sites over time, compare sites with similar environments, or compare sites for which environmental differences can be accounted. ?? 2007 American Water Resources Association.

Coles-Ritchie, M. C.; Roberts, D.W.; Kershner, J.L.; Henderson, R.C.

2007-01-01

72

Validating a Dynamic Global Vegetation Model with Remotely Sensed Vegetation Index  

Directory of Open Access Journals (Sweden)

Full Text Available The present study aims to evaluate the ability of IBIS model to capture the difference in vegetation characteristics among six major biomes in the Northeast China Transect and to calibrate the simulated LAI by IBIS, using the product of MODIS LAI (Leaf Area Index. The results showed that IBIS simulated a little lower growing season LAI over temperate evergreen conifer forest and boreal evergreen forest, while it overestimated LAI relative to MODIS in non-growing season. IBIS performed poorly on LAI over savanna, grassland and shrub land, compared with MODIS and it nearly simulated higher LAI throughout the year. Based on regression analysis, the simulating LAI by IBIS (Integrated Biosphere Simulator presented a significant linear correlation with that from MODIS over temperate evergreen conifer forest in spring and winter, boreal evergreen forest throughout the year and grassland from summer to early autumn. Therefore, it was help to adjust the model parameters over these plant functional types to calibrate the estimated LAI in a large spatial scale.

Jiaxin Jin

2013-02-01

73

Mapping potato crop height and leaf area index through vegetation indices using remote sensing in Cyprus  

Science.gov (United States)

This paper aims to model leaf area index (LAI) and crop height to spectral vegetation indices (VI), such as normalized difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI), and weighted difference vegetation index (WDVI). The intended purpose is to create empirical statistical models to support evapotranspiration algorithms applied under the current conditions in the island of Cyprus. Indeed, a traditionally agricultural area was selected in the Mandria Village in the Paphos District area in Cyprus, where one of the island's main exported crops, potatoes, are cultivated. A GER-1500 field spectroradiometer was used in this study in order to retrieve the necessary spectrum data of the different crops for estimating the VI's. A field campaign was undertaken with spectral measurements of LAI and crop height using the Sun-Scan canopy analyzer, acquired simultaneously with the spectroradiometric measurements between March and April of 2008 and 2009. Regarding the measurements, the phenological cycle of potatoes was followed. Several regression models have been applied to relate LAI/crop height and the three indices. It was found that the best fitted vegetation index to both LAI and crop height was WDVI. When LAI was regressed against WDVI for potatoes, the determination coefficient (R2) was 0.72, while for crop height R2 reached 0.78. Two Landsat TM-5 images acquired simultaneously during the spectroradiometric and LAI and crop height measurements are used to validate the proposed regression model. From the whole analysis it was found that the modeled results are very close to real values. This fact enables the specific empirical models to be used in the future for hydrological purposes.

Papadavid, George; Hadjimitsis, Diofantos; Toulios, Leonidas; Michaelides, Silas

2011-01-01

74

[Correlation analysis of simulated MODIS vegetation indices and rice leaf area index and leaf chlorophyll content].  

Science.gov (United States)

This paper studied the correlations between rice leaf area index (LAI), leaf chlorophyll content (CHL. C), hyperspectral data, normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and red-edge position (REP). The results showed that LAI had a close correlation with visible and NIR bands, and CHL. C had the highest correlation with red band. A strong non-linear correlation was found between the LAI and REP of two rice varieties. For common rice, REP, EVI and NDVI were well related with LAI, but for hybrid rice, REP and EVI were more sensitive than NDVI to LAI. In 2003, REP, EVI and NDVI were well related with CHL. C. PMID:15573989

Cheng, Qian; Huang, Jingfeng; Wang, Renchao; Tang, Yanlin

2004-08-01

75

[Construction of vegetation shadow index (SVI) and application effects in four remote sensing images].  

Science.gov (United States)

Taking the images of Landsat TM, ALOS AVNIR-2, CBERS-02B CCD and HJ-1 CCD as the experimental data, for increasing the differences among shaded area, bright area and water further, the present paper construed a novel vegetation index-Shaded Vegetation Index(SVI), which can not only keep the absolute differences among bright area, shaded area and water area in the near-infrared band, but also can enlarge NDVI, eliminate the possible mixes, and change the histogram "skewed" phenomenon of NDVI, so the vegetation index value is closer to normal distribution, and more in line with the filed condition; this new index was applied to the surface features of large difference of the near-infrared radiation characteristics. Verified by accuracy assessment for the bright area, shaded area and water area recognition effects with SVI, it was showed that the overall classification accuracies of these images were up to 98. 89%, 100%, 97.78% and 97.78% respectively, with the overall Kappa statistics of 0.9833, 1, 0.9667, and 0.966 7, indicating that SVI has excellent detection effects for bright area, shaded area and water area; the statistical comparison of sub-images between SVI and NDVI also illustrated the reliability and effectiveness of SVI, which can be applied in the shadow removal for remote sensing images. PMID:24611403

Xu, Zhang-Hua; Liu, Jian; Yu, Kun-Yong; Liu, Tao; Gong, Cong-Hong; Tang, Meng-Ya; Xie, Wan-Jun; Li, Zeng-Lu

2013-12-01

76

Analysis of agricultural drought using vegetation temperature condition index (VTCI) from Terra/MODIS satellite data.  

Science.gov (United States)

The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use of combination of surface temperature and NDVI which provides vegetation and moisture conditions simultaneously. Since drought stress effects on agriculture are closely linked to actual evapotranspiration, we used a vegetation temperature condition index (VTCI) which is more closely related to crop water status and holds a key place in real-time drought monitoring and assessment. In this study, NDVI and land surface temperature (T (s)) from MODIS 8-day composite data during cloud-free period (September-October) were adopted to construct an NDVI-T (s) space, from which the VTCI was computed. The crop moisture index (based on estimates of potential evapotranspiration and soil moisture depletion) was calculated to represent soil moisture stress on weekly basis for 20 weather monitoring stations. Correlation and regression analysis were attempted to relate VTCI with crop moisture status and crop performance. VTCI was found to accurately access the degree and spatial extent of drought stress in all years (2000, 2002, and 2004). The temporal variation of VTCI also provides drought pattern changes over space and time. Results showed significant and positive relations between CMI (crop moisture index) and VTCI observed particularly during prominent drought periods which proved VTCI as an ideal index to monitor terminal drought at regional scale. VTCI had significant positive relationship with yield but weakly related to crop anomalies. Duration of terminal drought stress derived from VTCI has a significant negative relationship with yields of major grain and oilseeds crops, particularly, groundnut. PMID:22200944

Patel, N R; Parida, B R; Venus, V; Saha, S K; Dadhwal, V K

2012-12-01

77

Scaling effects on area-averaged fraction of vegetation cover derived using a linear mixture model with two-band spectral vegetation index constraints  

Science.gov (United States)

This study investigated the mechanisms underlying the scaling effects that apply to a fraction of vegetation cover (FVC) estimates derived using two-band spectral vegetation index (VI) isoline-based linear mixture models (VI isoline-based LMM). The VIs included the normalized difference vegetation index, a soil-adjusted vegetation index, and a two-band enhanced vegetation index (EVI2). This study focused in part on the monotonicity of an area-averaged FVC estimate as a function of spatial resolution. The proof of monotonicity yielded measures of the intrinsic area-averaged FVC uncertainties due to scaling effects. The derived results demonstrate that a factor ?, which was defined as a function of "true" and "estimated" endmember spectra of the vegetated and nonvegetated surfaces, was responsible for conveying monotonicity or nonmonotonicity. The monotonic FVC values displayed a uniform increasing or decreasing trend that was independent of the choice of the two-band VI. Conditions under which scaling effects were eliminated from the FVC were identified. Numerical simulations verifying the monotonicity and the practical utility of the scaling theory were evaluated using numerical experiments applied to Landsat7-Enhanced Thematic Mapper Plus (ETM+) data. The findings contribute to developing scale-invariant FVC estimation algorithms for multisensor and data continuity.

Obata, Kenta; Huete, Alfredo R.

2014-01-01

78

Vegetation Phenology and Vegetation Index Products from Multiple Long Term Satellite Data Records  

Science.gov (United States)

Phenology is the expression of the seasonal cycle of all biotic processes. It is the pulse of our planet, and is an essential and critical component of environmental science influencing biodiversity, species interactions, their ecological functioning, and their effects on fluxes of water, energy, and biogeochemical elements at various scales. Changes in phenology depict an integrated response to environmental change and provide valuable information for global change research, land degradation studies, integrated pest and invasive species management, drought monitoring, wildfire risk assessment, and agricultural production. In this NASA Making Earth System data records for Use in Research Environments (NASA-MEaSUREs) project our multi-institution team of investigators plans to generate a seamless and consistent sensor independent Earth System Data Record and Climate Data Record (ESDR/CDR) quality measures of landscape phenology and vegetation index (VI), by fusing measurements from different satellite missions and sensors. We plan to use the AVHRR, MODIS and VIIRS daily surface reflectance products and design sensor independent algorithms that can be applied to these multi-sensor data sets. Our project aims at generating, documenting, and delivering 30+ years of consistent and well characterized ESDR/CDR quality daily measurements of land surface VI and annual phenology parameters at a climate modeling grid resolution (CMG, 0.05 deg). In collaboration with the newly established USA national phenology network (USA-NPN), we plan to correlate these remote sensing based measurements of phenology and VI with ground observations. We aim at evaluating the consistency and accuracy of these products by comparing them with in situ growing season phenology observations over different biomes, latitudinal and elevational gradients. We plan to distribute these products through the USGS EROS center and support them via a web based interactive visualization system. We will enlist key science and modeling community users, as well as the USA-NPN, in the process of evaluating the merits of these ESDR/CDR products. A user working group (UWG) will advise this effort and link it with the wider national and international user and scientific communities.

Didan, K.; van Leeuwen, W.; Miura, T.; Friedl, M.; Zhang, X.; Czapla-Myers, J.; Jenkerson, C. B.; Maiersperger, T. K.

2008-12-01

79

Vegetative Growth Performance of Different Plum Rootstocks  

Directory of Open Access Journals (Sweden)

Full Text Available The study was conducted to investigate the vegetative growth performance of Damascos, Myrobalan and Desi plum (Prunus domistica L. rootstocks propagated by hardwood cuttings at Peshawar, during 1999. Desi (Local plum gained maximum number (176.75 of roots, root length (58.75 cm, shoot length (375.95 cm, shoot diameter (1.82 cm and survival (73.33 percentage, while there was no differences in the sprouting percentage among all rootstocks.

Noor Rahman

2000-01-01

80

Estimation of Air Temperature Using Temperature-Vegetation Index (TVX Method  

Directory of Open Access Journals (Sweden)

Full Text Available The determination of air temperature is important in the energy balance calculation, hydrology and meteorological studies. In this regard, the limited number of meteorological stations is one of the serious problems for air temperature determination on a large spatial scale. The remote sensing technique by covering large areas and using updated satellite images might be appropriate for estimation of this parameter. In this research, the negative correlation between land surface temperature and vegetation index (NDVI has been used for air temperature estimation through TVX method in which the inference of air temperature is based on the hypothesis that the temperature of the dense vegetation canopy is close to air temperature. For investigation the performance of TVX method, images of MODIS sensor have been applied for the Sefidrod River basin in the years 1381- 1382-1384. The spilt window technique which was developed by Price has been used for land surface temperature calculation. The mean difference between observed and estimated land surface temperature using Price algorithm was about 6.2Co. This error can affect the air temperature values. Because of using NDVI index in TVX method, this method has the sensitivity to the vegetation density, though in the parts with sparse vegetation, the value of error increases. 4 percent variation of air temperature against the 0.05 increasing of maximum NDVI indicates the high performance of TVX method for air temperature estimation in large areas.

L. Parviz

2011-07-01

 
 
 
 
81

Sensitivity of leaf chlorophyll concentration of a broad-ban vegetation index at the canopy scale  

International Nuclear Information System (INIS)

The development from a field spectrometric experiment of the chlorophyll vegetation index (CVI), a broad-band 6. sensitive to leaf chlorophyll concentration at the canopy scale, and of its optimized version (OCVI) are described. A single correction factor is incorporated in the OCVI algorithm to take into account the different spectral behaviours due to crop and soil types, sensor spectral resolution and scene sun zenith angle. The sensitivity of different broad-band 6., including CVI, to leaf cholophyll concentration is compared for a wide range of soils and crops conditions and for different sun zenith angles by the analysis of a PROSPECT+SAILH syntetic dataset

82

Vegetation Index Differencing for Broad-Scale Assessment of Productivity Under Prolonged Drought and Sequential High Rainfall Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Spatially-explicit depictions of plant productivity over large areas are critical to monitoring landscapes in highly heterogeneous arid ecosystems. Applying radiometric change detection techniques we sought to determine whether: (1 differences between pre- and post-growing season spectral vegetation index values effectively identify areas of significant change in vegetation; and (2 areas of significant change coincide with altered ecological states. We differenced NDVI values, standardized difference values to Z-scores to identify areas of significant increase and decrease in NDVI, and examined the ecological states associated with these areas. The vegetation index differencing method and translation of growing season NDVI to Z-scores permit examination of change over large areas and can be applied by non-experts. This method identified areas with potential for vegetation/ecological state transition and serves to guide field reconnaissance efforts that may ultimately inform land management decisions for millions of acres of federal lands.

Caitriana M. Steele

2013-01-01

83

Analyzing Vegetation Change in an Elephant-Impacted Landscape Using the Moving Standard Deviation Index  

Directory of Open Access Journals (Sweden)

Full Text Available Northern Botswana is influenced by various socio-ecological drivers of landscape change. The African elephant (Loxodonta africana is one of the leading sources of landscape shifts in this region. Developing the ability to assess elephant impacts on savanna vegetation is important to promote effective management strategies. The Moving Standard Deviation Index (MSDI applies a standard deviation calculation to remote sensing imagery to assess degradation of vegetation. Used previously for assessing impacts of livestock on rangelands, we evaluate the ability of the MSDI to detect elephant-modified vegetation along the Chobe riverfront in Botswana, a heavily elephant-impacted landscape. At broad scales, MSDI values are positively related to elephant utilization. At finer scales, using data from 257 sites along the riverfront, MSDI values show a consistent negative relationship with intensity of elephant utilization. We suggest that these differences are due to varying effects of elephants across scales. Elephant utilization of vegetation may increase heterogeneity across the landscape, but decrease it within heavily used patches, resulting in the observed MSDI pattern of divergent trends at different scales. While significant, the low explanatory power of the relationship between the MSDI and elephant utilization suggests the MSDI may have limited use for regional monitoring of elephant impacts.

Timothy J. Fullman

2014-01-01

84

Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorith...

Scott, Russell L.; Uyen Nguyen; Glenn, Edward P.; Nagler, Pamela L.; Tanya Doody

2013-01-01

85

Value of Using Different Vegetative Indices to Quantify Agricultural Crop Characteristics at Different Growth Stages under Varying Management Practices  

Directory of Open Access Journals (Sweden)

Full Text Available The paper investigates the value of using distinct vegetation indices to quantify and characterize agricultural crop characteristics at different growth stages. Research was conducted on four crops (corn, soybean, wheat, and canola over eight years grown under different tillage practices and nitrogen management practices that varied rate and timing. Six different vegetation indices were found most useful, depending on crop phenology and management practices: (a simple ratio for biomass, (b NDVI for intercepted PAR, (c SAVI for early stages of LAI, (d EVI for later stages of LAI, (e CIgreen for leaf chlorophyll, (f NPCI for chlorophyll during later stages, and (g PSRI to quantify plant senescence. There were differences among varieties of corn and soybean for the vegetation indices during the growing season and these differences were a function of growth stage and vegetative index. These results clearly imply the need to use multiple vegetation indices to best capture agricultural crop characteristics.

John H. Prueger

2010-02-01

86

Agricultural Drought Pattern in West Java Using Thermal Vegetation Index from Modis-Terra Satellite  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study examines agricultural drought paddy fields in West Java. The aims of this research are to know the pattern and distribution of paddy field drought in West Java and the correlation between drought and the physical characteristics. The agricultural drought is obtained from TVI (Thermal Vegetation Index) model. TVI is derived from MODIS Terra satellite image, which is the ratio between the LST (Land Surface Temperature) and EVI (Enhanced Vegetation Index). Physical factors studied are...

Sri Hardiyanti Purwadhi; Rahmatulloh; Dini Daruati

2013-01-01

87

Sensitivity of vegetation indices to different burn and vegetation ratios using LANDSAT-5 satellite data  

Science.gov (United States)

The application of vegetation indices is a very common approach in remote sensing of burned areas to either map the fire scar or estimate burn severity since they minimize the effect of exogenous factors and enhance the correlation with the internal parameters of vegetation. In a recent study we found that the original spectral channels, based on which these indices are estimated, are sensitive to external parameters of the vegetation as for example the spectral reflectance of the background soil. In such cases, the influence of the soil in the reflectance values is different in the various spectral regions depending on its type. These problems are further enhanced by the non-homogeneous pixels, as created from fractions of different types of land cover. Parnitha (Greece), where a wildfire occurred on July 2007, was established as test site. The purpose of this work is to explore the sensitivity of vegetation indices when used to estimate and map different fractions of fire-scorched (burned) and non fire-scorched (vegetated) areas. IKONOS, a very high resolution satellite imagery, was used to create a three-class thematic map to extract the percentages of vegetation, burned surfaces, and bare soil. Using an overlaid fishnet we extracted samples of completely "burned", completely "vegetated" pixels and proportions with different burn/vegetation ratios (45%-55% burned - 45%-55% vegetation, 20%-30% burned - 70%- 80% vegetation, 70%-80% burned - 20%-30% vegetation). Vegetation indices were calculated (NDVI, IPVI, SAVI) and their values were extracted to characterize the mentioned classes. The main findings of our recent research were that vegetation indices are less sensitive to external parameters of the vegetation by minimizing external effects. Thus, the semi-burned classes were spectrally more consistent to their different fractions of scorched and non-scorched vegetation, than the original spectral channels based on which these indices are estimated.

Pleniou, M.; Koutsias, N.

2013-08-01

88

Experimental testing of a volume index as a fast method for estimating carbon stock in the understorey vegetation  

Directory of Open Access Journals (Sweden)

Full Text Available The biomass of understory vegetation has an important role in several forest ecosystem processes, though it is not frequently included in forest inventory programs, which are commonly focused on the tree component. The objective of the study is to test a fast procedure for obtaining an accurate estimation of three components of the aboveground understory vegetation: herbaceous, bush, regeneration. For such a purpose a Volume Index has been calculated on the basis of the product between the percent coverage of vegetation and the average height of the three different components of understory vegetation. The index has been quantified in twenty clusters of four squared plots 1 m2 wide; clusters were located in two study areas in the northern part of Molise Region (southeastern Italy. For each plot, the dry biomass has been collected and weighted, and then transformed in carbon stock. This study presents the field protocol and the achieved results in terms of measured aboveground understorey carbon stock in six different forest and pre-forest types (the average carbon stock was 1.19 t C ha-1 and correlation between Volume Index and carbon stock (the Pearson’s correlation index was 0.8 on 309 field observations.

Chirici G

2009-05-01

89

Land Cover Change Detection from MODIS Vegetation Index Time Series Data  

Science.gov (United States)

Quantifiable knowledge about changes occurring in land cover and land use at a global scale is key to effective planning for sustainable use of diminishing natural resources such as forest cover and agricultural land. Accurate and timely information about land cover and land use changes is therefore of significant interest to earth and climate scientists as well as policy and decision makers. Recently, global time series data sets, such as Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation Index (EVI), have become publicly available and have been used to identify changes in vegetation cover. In this talk, we will discuss our work that analyzes the MODIS EVI time series data sets for global land cover change detection. Our group has developed a suite of time series change detection methods that are used to identify EVI time series with patterns indicative of land cover disturbance such as abrupt or gradual change, or changes in the recurring annual vegetation pattern. These algorithms can successfully identify different land cover change events such as deforestation, forest fires, agricultural conversions, and degradation due to insect damage at a global scale. In context of land cover monitoring, one of the significant challenges is posed by the differences in inter-annual variability and noise characteristics of different land cover types. These data characteristics can significantly impact change detection performance especially in land cover types such as farms, grasslands and tropical forests. We will discuss our recent work that incorporates a bootstrap-based normalization of change detection scores to account for the natural variability present in vegetation time series data. We studied the strengths and weakness of our proposed normalizing approaches in the context of characteristics of land cover data such as seasonality and noise and showed that relative performance of normalization approaches vary significantly depending on the characteristics of the data.

Mithal, V.; O'Connor, Z.; Steinhaeuser, K.; Boriah, S.; Kumar, V.; Potter, C. S.; Klooster, S. A.

2012-12-01

90

Estimation of green leaf area index of crops: Sensitivity of vegetation indices  

Science.gov (United States)

Green leaf area index (gLAI) is an important biophysical characteristic used in climate, ecological, and crop yield models. There is a need for a rapid and accurate estimation of gLAI on a global scale. Traditionally used vegetation indices (VIs) have shown to saturate at moderate-to-high gLAI (e.g. NDVI) or are less sensitive to gLAI at low-to-moderate values of gLAI. The goal of this study was to determine the best suitable VIs for use in a combined vegetation index for estimating gLAI in crops in the entire wide dynamic range of gLAI. The study area consisted of three fields in eastern Nebraska, USA under different management conditions for the years 2001-2008 for a total of 24 field-years. The dynamic range of maize was 0-6.5 m2/m2 and soybean was 0-5.5 m2/m2. NDVI-like indices were the most sensitive to gLAI below 3 m2/m2 while Simple Ratio (SR) and the Chlorophyll Indices (CI) were more sensitive to gLAI above 3 m2/m2. MTCI was the only VI that was equally sensitive to gLAI in the entire dynamic range; however, it was species-specific. Only Red Edge NDVI and CIred edge were not species-specific. In order to benefit from different sensitivities of the indices to low-to-moderate and moderate-to-high gLAI, this study suggests building relationships using VIs in specific dynamic ranges of maximal sensitivity to gLAI. We suggest using NDVI and Simple Ratio (maize: RMSE = 0.71 m2/m2; soybean: RMSE = 0.53 m2/m2) for MODIS data. We suggest the using non-species-specific VIs, Red Edge NDVI and CIred edge (RMSE = 0.63 m2/m2) for MERIS data. For users which prefer to use a single index, we suggest a scaled combined vegetation index using Red Edge NDVI and CIred edge (RMSE = 0.56 m2/m2); however, this approach reduces the sensitivity of the specific indices in the dynamic range of which they are most sensitive.

Nguy-Robertson, A. L.; Gitelson, A. A.; Peng, Y.; Vina, A.; Arkebauer, T. J.; Rundquist, D.

2011-12-01

91

Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index  

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Full Text Available Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa based on the Enhanced Vegetation Index (EVI from the Moderate Resolution Imaging Spectrometer (MODIS sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo. The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 ? e?bEVI ? c], where the term (1 ? e?bEVI is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73. It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89 difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

Russell L. Scott

2013-08-01

92

Estimating riparian and agricultural evapotranspiration by reference crop evapotranspiration and MODIS Enhanced Vegetation Index  

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Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 ? e?bEVI) ? c], where the term (1 ? e?bEVI) is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73). It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89) difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

Nagler, Pamela L.; Glenn, Edward P.; Nguyen, Uyen; Scott, Russell; Doody, Tania

2013-01-01

93

Variação do Índice de Vegetação por Diferença Normalizada na lagoa Itapeva, litoral norte do Rio Grande do Sul, Brasil, a partir de análise de séries temporais / Variations of the Normalized Difference Vegetation Index (NDVI in the Itapeva-RS Lake, north coast of Rio Grande do Sul, Brazil, from Temporal Series Analysis  

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Full Text Available The objective of this study was to analyze the pattern spatial-temporal values of the Normalized DifferenceVegetation Index (NDVI in Itapeva-RS lake, using Landsat TM5 and ETM + 7 images, from1985 through 2010. For the analysis of space-temporal behavior classes was used Normalized DifferenceVegetation Index (NDVI classes and Temporal Series Analysis (TSA. To validate the observed patternswere collected water samples from six points in the Itapeva Lake for clorofila_a, Total suspendedsolids and Secchi disk transparency. These results were correlated with NDVI values. The NDVI classesmaps generated after analysis of TSA, showed dynamic patterns of seasonal and spatial associated withenvironmental variables that were actuating, allowing the establishment of three distinctive surfaces inItapeva Lake: north, center and south. The Temporal Series Analysis of images shows that the increaseand decrease of NDVI values are associated with periods of phytoplankton bloom. One concluded thatthe Temporal Series Analysis of Landsat images was satisfactory with regard to the behavior of spatialand temporal variation of NDVI classes.

2013-10-01

94

[Assessment of chlorophyll content using a new vegetation index based on multi-angular hyperspectral image data].  

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The fast estimation of chlorophyll content is significant for understanding the crops growth, monitoring the disease and insect, and assessing the yield of crops. This study gets the hyperspectral imagery data by using a self-developed multi-angular acquisition system during the different maize growth period, the reflectance of maize canopy was extracted accurately from the hyperspectral images under different view angles in the principal plane. The hot-dark-spot index (HDS) of red waveband was calculated through the analysis of simulated values by ACRM model and measured values, then this index was used to modify the vegetation index (TCARI), thus a new vegetation index (HD-TCARI) based on the multi-angular observation was proposed. Finally, the multi-angular hyperspectral imagery data was used to validate the vegetation indexes. The result showed that HD-TCARI could effectively reduce the LAI effects on the assessment of chlorophyll content. When the chlorophyll content was greater than 30 ?g x cm(-2), the correlation (R2) between HD-TCARI and LAI was only 26.88%-28.72%. In addition, the HD-TCARI could resist the saturation of vegetation index during the assessment of high chlorophyll content. When the LAI varled from 1 to 6, the linear relation between HD-TCARI and chlorophyll content could be improved by 9% compared with TCARI. The ground validation of HD-TCARI by multi-angular hyperspectral image showed that the linear relation between HD-TCARI and chlorophyll content (R2 = 66.74%) was better than the TCARI (R2 = 39.92%), which indicated that HD-TCARI has good potentials for estimating the chlorophyll content. PMID:25358171

Liao, Qin-hong; Zhang, Dong-yan; Wang, Ji-hua; Yang, Gui-jun; Yang, Hao; Coburn, Craig; Wong, Zhijie; Wang, Da-cheng

2014-06-01

95

[Evaluating the utility of MODIS vegetation index for monitoring agricultural drought].  

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The exclusive shortwave bands provided by MODIS sensors offer new opportunities for agricultural drought monitoring, since they are very sensitive to vegetation moisture. In the present work, we selected Songnen Plain in Northeast China as study area aiming at monitoring agricultural drought of dry farmland here. Four types of vegetation water indices and vegetation greenness indices were calculated from the 8-day composite MODIS product (MODO9A1) in vegetation growing season between 2001 and 2010, respectively. Multi-scale standardized precipitation index (SPI) derived from precipitation data of weather stations was used as reference data to estimate drought sensitivity of various vegetation indices, and a pixel-to-weather station paired correlation approach was used to calculate the Pearson correlation coefficient between vegetation index and SPIs. The result indicated that vegetation water indices established by near infrared and shortwave infrared bands outperformed vegetation greenness indices based on visible and near infrared bands. Of these indices, NDII7 performs the best with highest correlation coefficients across all SPIs. The authors' results demonstrated the potential of MODIS shortwave spectral bands in monitoring agricultural drought, and this provides new insights to future research. PMID:23705448

Li, Hua-Peng; Zhang, Shu-Qing; Gao, Zi-Qiang; Sun, Yan

2013-03-01

96

Local Illumination Influence on Vegetation Indices and Plant Area Index (PAI Relationships  

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Full Text Available Relationships between biophysical parameters and radiometric data have been tested and evaluated by several professionals using empirical and/or physical approaches. Remote sensing data collected from airborne or orbital platforms are, of course, influenced by different factors, such as illumination/observation geometry (data collection geometry, atmospheric effects, etc., rather than by target spectral properties. Besides that, the target topographic positioning actually defines the amount of incident energy, as well as the amount of energy that is reflected toward the sensor. The sum of both data collection geometry and topographic positioning defines the so-called “local illumination”. The objective of this paper was to evaluate the influence of local illumination on empirical relationships between a biophysical variable (plant area index, PAI and two vegetation indices calculated from Resourcesat/Linear Imaging Self-Scanner sensor (LISS-3 orbital data. Local illumination was expressed by the cosine factor (Fcos and calculated from topographic and solar position data at three different dates. The study area was based on a typical Brazilian southeastern forest fragment located in the Augusto Ruschi municipal preservation park dispersed on roughhouse topography. PAI was estimated by hemispherical photographs taken under the forest canopy from sample points arbitrarily dispersed on the forest fragment. Results confirmed a stronger relationship between vegetation indices and local illumination conditions.

Flávio Jorge Ponzoni

2014-07-01

97

Development and evaluation of a modis vegetation index compositing algorithm for long-term climate studies  

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The acquisition of remote sensing data having an investigated quality level constitutes an important step to advance our understanding of the vegetation response to environmental factors. Spaceborne sensors introduce additional challenges that should be addressed to assure that derived findings are based on real phenomena, and not biased or misguided by instrument features or processing artifacts. As a consequence, updates to incorporate new advances and user requirements are regularly found on most cutting edge systems such as the Moderate Resolution Imaging Spectroradiometer (MODIS) system. In this dissertation, the objective was to design, characterize and assess any possible departure from current values, a MODIS vegetation index (VI) algorithm for restoring the continuity 16-day 1-km product, based on the new 8-day 500-m MODIS surface reflectance (SR) product scheduled for the forthcoming MODIS Collection 6 (C6). Additionally, the impact of increasing the time resolution (by reducing the compositing period) from 16 to 8 days for the future basic MODIS C6 VI product was also assessed. The performance of the proposed algorithm was evaluated using high quality reference data and known biophysical relationships at several spatial and temporal scales. Firstly, it was evaluated using data from the AERONET-based Surface Reflectance Validation Network (ASRVN), FLUXNET-derived ecosystem gross primary productivity (GPP) and an analysis of the seasonality parameters derived from current Collection 5 (C5) and proxy C6 VI collections. The performance of the 8-day VI version was evaluated and contrasted with current 16-day using the reported correlation of the Enhanced Vegetation Index (EVI) with the GPP derived from CO2 flux measurements. Secondly, we performed an analysis at spatial level using entire images (or "tiles") to assess the Bidirectional Reflectance Distribution Function (BRDF) effects on the VI product, as these can cause biases on the SR and VIs from scanning radiometers. Lastly, we evaluated the performance of the proposed algorithm for detecting inter-annual VI anomalies from long-term time series, as compared with current MODIS VI C5. For this, we analyzed the EVI anomalies from a densely vegetated evergreen region, for the period July--September (2000--2010). Results showed a high general similarity between results from both algorithms, but also systematic differences, suggesting that proposed algorithm towards C6 may represent an advance in the reduction of uncertainties for the MODIS VI product.

Solano Barajas, Ramon

98

Tropical forest biomass and successional age class relationships to a vegetation index derived from Landsat TM data  

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Forest stand structure and biomass data were collected using conventional forest inventory techniques in tropical, subtropical, and warm temperate forest biomes. The feasibility of detecting tropical forest successional age class and total biomass differences using Landsat-Thematic mapper (TM) data, was evaluated. The Normalized Difference Vegetation Index (NDVI) calculated from Landsat-TM data were not significantly correlated with forest regeneration age classes in the mountain terrain of the Luquillo Experimental Forest, Puerto Rico. The low sun angle and shadows cast on steep north and west facing slopes reduced spectral reflectance values recorded by TM orbital altitude. The NDVI, calculated from low altitude aircraft scanner data, was significatly correlated with forest age classes. However, analysis of variance suggested that NDVI differences were not detectable for successional forests older than approximately 15-20 years. Also, biomass differences in young successional tropical forest were not detectable using the NDVI. The vegetation index does not appear to be a good predictor of stand structure variables (e.g., height, diameter of main stem) or total biomass in uneven age, mixed broadleaf forest. Good correlation between the vegetation index and low biomass in even age pine plantations were achieved for a warm temperate study site. The implications of the study for the use of NDVI for forest structure and biomass estimation are discussed.

Sader, Steven A.; Waide, Robert B.; Lawrence, William T.; Joyce, Armond T.

1989-01-01

99

Monitoring responses of Mason Pine to acid rain in China based on remote sensing vegetation index  

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Since the 1970s, acid rain has remained in the public spotlight in both Europe and the United States and recently has emerged as an important problem in other regions such as Southeast Asia. To reveal responses of Masson Pine to acid rain during a long time series in central China, we used the interpolation dataset of acid rain and the Global Inventory Modeling and Mapping Studies (GIMMS) normalized difference vegetation index (NDVI) data to derive the monthly pH and NDVI trajectories based on acidity gradients from 1992 to 2006. Then we analyzed inter-annual and seasonal variation of vegetation growth by improved sinusoidal fitting and regression analysis. In the environment of strong acidity and moderate acidity, the growth of Masson Pine was inhibited during the study period, while the slight acidity promoted growth of Masson Pine to some extent. For the multi-year monthly changing trend of NDVI, late spring to mid autumn, the NDVI showed a decreasing trend, especially in June, while from late autumn to the following spring, the NDVI showed a rising tendency, specifically in December and March.

Jin, Jiaxin; Jiang, Hong; Hou, Chunliang; Zhang, Xiuying; Wang, Ying

2014-03-01

100

VIP Data Explorer: A Tool for Exploring 30 years of Vegetation Index and Phenology Observations  

Science.gov (United States)

Continuous acquisition of global satellite imagery over the years has contributed to the creation of long term data records from AVHRR, MODIS, TM, SPOT-VGT and other sensors. These records account for 30+ years, as these archives grow, they become invaluable tools for environmental, resources management, and climate studies dealing with trends and changes from local, regional to global scale. In this project, the Vegetation Index and Phenology Lab (VIPLab) is processing 30 years of daily global surface reflectance data into an Earth Science Data Record of Vegetation Index and Phenology metrics. Data from AVHRR (N07,N09,N11 and N14) and MODIS (AQUA and TERRA collection 5) for the periods 1981-1999 and 2000-2010, at CMG resolution were processed into one seamless and sensor independent data record using various filtering, continuity and gap filling techniques (Tsend-Ayush et al., AGU 2011, Rivera-Camacho et al, AGU 2011). An interactive online tool (VIP Data Explorer) was developed to support the visualization, qualitative and quantitative exploration, distribution, and documentation of these records using a simple web 2.0 interface. The VIP Data explorer (http://vip.arizona.edu/viplab_data_explorer) can display any combination of multi temporal and multi source data, enable the quickly exploration and cross comparison of the various levels of processing of this data. It uses the Google Earth (GE) model and was developed using the GE API for images rendering, manipulation and geolocation. These ESDRs records can be quickly animated in this environment and explored for visual trends and anomalies detection. Additionally the tool enables extracting and visualizing any land pixel time series while showing the different levels of processing it went through. User can explore this ESDR database within this data explorer GUI environment, and any desired data can be placed into a dynamic "cart" to be ordered and downloaded later. More functionalities are planned and will be added to this data explorer tool as the project progresses.

Barreto-munoz, A.; Didan, K.; Rivera-Camacho, J.; Yitayew, M.; Miura, T.; Tsend-Ayush, J.

2011-12-01

 
 
 
 
101

Cooling parameters for fruits and vegetables of different sizes in a hydrocooling system  

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Full Text Available The cooling of fruits and vegetables in hydrocooling system can be a suitable technique. This work aimed to define cooling time for fruits and vegetables of different sizes, presenting practical indexes that could be used to estimate cooling time for produce with similar characteristics. Fruits (orange melon-Cucumis melo, mango-Mangifera indica, guava-Psidium guajava, orange-Citrus sinensis Osbeck, plum-Prunus domestica, lime-Citrus limon, and acerola-Prunus cerasus and vegetables (cucumber-Cucumis sativus, carrot-Daucus carota, and green bean-Phaseolus vulgaris, were cooled in a hydrocooling system at 1°C. The volume of fruits and vegetables ranged between 8.18 cm³ and 1,150.35 cm³, and between 13.06 cm³ and 438.4 cm³, respectively. Cooling time varied proportionally to produce volume (from 8.5 to 124 min for fruits, and from 1.5 to 55 min, for vegetables. The relationship between volume and time needed to cool fruits (from 1.03 min cm-3 to 0.107 min cm-3 and vegetables (from 0.06 min cm-3 to 0.12 min cm-3 is an index that could be used to estimate cooling time for fruits and vegetables with similar dimensions as those presented in this work.

Teruel Bárbara

2004-01-01

102

Remote sensing of Japanese beech forest decline using an improved Temperature Vegetation Dryness Index (iTVDI  

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Full Text Available The Tanzawa Mountains, which cover parts of Kanagawa, Yamanashi and Shizuoka prefectures in Japan, are known for their natural beech forests. Since the 1980s, decline of the beech forests, probably caused by air pollution, water stress and insect infestation, has become a serious problem. We estimated the natural beech forest mortality rate in the mountains by using multi-temporal 8-day composite data recorded at the MODIS instrument aboard the Terra satellite, daily air temperature data at meteorological stations (AMeDAS in 2007, and a global digital elevation model obtained from ASTER aboard the Terra satellite. For the estimation, we used a Normalized Difference Vegetation Index (NDVI indicating the vegetation density, a Temperature Vegetation Dryness Index (TVDI, and an improved TVDI (iTVDI indicating the differences in transpiration rates between areas of similar vegetation density. We compared the NDVI, TVDI, and iTVDI maps with an existing mortality map of beech forests in the study area to verify their accuracy. To produce iTVDI maps, we calculated maps of air temperature by using ambient air temperature and elevation data. By interpolation using an environmental lapse rate, we calibrated air temperature maps with good accuracy (RMSE = 0.49 °C. The iTVDI map could detect mortality more accurately than the NDVI and TVDI maps in both spring and summer. Use of iTVDI enabled us to detect forest decline caused by air pollution and water deficits, inducing a reduction in transpiration rates. This index should be useful for monitoring vegetation decline.

Ishimura A

2011-11-01

103

Spatiotemporal analysis of vegetation index after typhoons in the mountainous watershed  

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An extensive land cover change was triggered by a series of typhoons, especially Typhoon Morakot in 2009 in Taiwan. The normalized difference vegetation index (NDVI) series from multiple satellite images were applied to monitor the change processes of land cover. This study applied spatiotemporal analysis tools, including empirical orthogonal functions (EOF), and multiple variograms in analyzing space-time NDVI data, and detected the effects of large chronological disturbances in the characteristics of land cover changes. Spatiotemporal analysis delineated the temporal patterns and spatial variability of NDVI caused by these large typhoons. Results showed that mean of NDVI decreased but spatial variablity of NDVI increased after typhoons in the study area. The EOF can clarify the major component of NDVI variations and identify the core area of the NDVI changes. Various approaches showed consistent results that Typhoon Morakot significantly lowered the NDVI in land cover change process. Furthermore, the spatiotemporal analysis is an effective monitoring tool, which advocates the use of the index for the quantification of land cover change and resilience.

Chu, Hone-Jay

2014-05-01

104

Estimating Crop Coefficients Using Remote Sensing-Based Vegetation Index  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Crop coefficient (Kc)-based estimation of crop evapotranspiration is one of the most commonly used methods for irrigation water management. However, uncertainties of the generalized dual crop coefficient (Kc) method of the Food and Agricultural Organization of the United Nations Irrigation and Drainage Paper No. 56 can contribute to crop evapotranspiration estimates that are substantially different from actual crop evapotranspiration. Similarities between the crop coefficient curve and a sate...

Kenneth Hubbard; Baburao Kamble; Ayse Kilic

2013-01-01

105

Savanna vegetation-fire-climate relationships differ among continents.  

Science.gov (United States)

Ecologists have long sought to understand the factors controlling the structure of savanna vegetation. Using data from 2154 sites in savannas across Africa, Australia, and South America, we found that increasing moisture availability drives increases in fire and tree basal area, whereas fire reduces tree basal area. However, among continents, the magnitude of these effects varied substantially, so that a single model cannot adequately represent savanna woody biomass across these regions. Historical and environmental differences drive the regional variation in the functional relationships between woody vegetation, fire, and climate. These same differences will determine the regional responses of vegetation to future climates, with implications for global carbon stocks. PMID:24482480

Lehmann, Caroline E R; Anderson, T Michael; Sankaran, Mahesh; Higgins, Steven I; Archibald, Sally; Hoffmann, William A; Hanan, Niall P; Williams, Richard J; Fensham, Roderick J; Felfili, Jeanine; Hutley, Lindsay B; Ratnam, Jayashree; San Jose, Jose; Montes, Ruben; Franklin, Don; Russell-Smith, Jeremy; Ryan, Casey M; Durigan, Giselda; Hiernaux, Pierre; Haidar, Ricardo; Bowman, David M J S; Bond, William J

2014-01-31

106

Wheat Yield Forecasting for Punjab Province from Vegetation Index Time Series and Historic Crop Statistics  

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Full Text Available Policy makers, government planners and agricultural market participants in Pakistan require accurate and timely information about wheat yield and production. Punjab Province is by far the most important wheat producing region in the country. The manual collection of field data and data processing for crop forecasting by the provincial government requires significant amounts of time before official reports can be released. Several studies have shown that wheat yield can be effectively forecast using satellite remote sensing data. In this study, we developed a methodology for estimating wheat yield and area for Punjab Province from freely available Landsat and MODIS satellite imagery approximately six weeks before harvest. Wheat yield was derived by regressing reported yield values against time series of four different peak-season MODIS-derived vegetation indices. We also tested deriving wheat area from the same MODIS time series using a regression-tree approach. Among the four evaluated indices, WDRVI provided more consistent and accurate yield forecasts compared to NDVI, EVI2 and saturation-adjusted normalized difference vegetation index (SANDVI. The lowest RMSE values at the district level for forecast versus reported yield were found when using six or more years of training data. Forecast yield for the 2007/2008 to 2012/2013 growing seasons were within 0.2% and 11.5% of final reported values. Absolute deviations of wheat area and production forecasts from reported values were slightly greater compared to using the previous year's or the three- or six-year moving average values, implying that 250-m MODIS data does not provide sufficient spatial resolution for providing improved wheat area and production forecasts.

Jan Dempewolf

2014-10-01

107

Evaluation of vegetation post-fire resilience in the Alpine region using descriptors derived from MODIS spectral index time series  

Science.gov (United States)

In this study a method based on the analysis of MODerate-resolution Imaging Spectroradiometer (MODIS) time series is proposed to estimate the post-fire resilience of mountain vegetation (broadleaf forest and prairies) in the Italian Alps. Resilience is defined herewith as the ability of a dynamical system to counteract disturbances. It can be quantified by the amount of time the disturbed system takes to resume, in statistical terms, an ecological functionality comparable with its undisturbed behavior. Satellite images of the Normalized Difference Vegetation Index (NDVI) and of the Enhanced Vegetation Index (EVI) with spatial resolution of 250m and temporal resolution of 16 days in the 2000-2012 time period were used. Wildfire affected areas in the Lombardy region between the years 2000 and 2010 were analysed. Only large fires (affected area >40ha) were selected. For each burned area, an undisturbed adjacent control site was located. Data pre-processing consisted in the smoothing of MODIS time series for noise removal and then a double logistic function was fitted. Land surface phenology descriptors (proxies for growing season start/end/length and green biomass) were extracted in order to characterize the time evolution of the vegetation. Descriptors from a burned area were compared to those extracted from the respective control site by means of the one-way analysis of variance. According to the number of subsequent years which exhibit statistically meaningful difference between burned and control site, five classes of resilience were identified and a set of thematic maps was created for each descriptor. The same method was applied to all 84 aggregated events and to events aggregated by main land cover. EVI index results more sensitive to fire impact than NDVI index. Analysis shows that fire causes both a reduction of the biomass and a variation in the phenology of the Alpine vegetation. Results suggest an average ecosystem resilience of 6-7 years. Moreover, broadleaf forest and prairies show different post-fire behavior in terms of land surface phenology descriptors. In addition to the above analysis, another method is proposed, which derives from the qualitative theory of dynamical systems. The (time dependent) spectral index of a burned area over the period of one year was plotted against its counterpart from the control site. Yearly plots (or scattergrams) before and after the fire were obtained. Each plot is a sequence of points on the plane, which are the vertices of a generally self-intersecting polygonal chain. Some geometrical descriptors were obtained from the yearly chains of each fire. Principal Components Analysis (PCA) of geometrical descriptors was applied to a set of case studies and the obtained results provide a system dynamics interpretation of the natural process.

Di Mauro, Biagio; Fava, Francesco; Busetto, Lorenzo; Crosta, Giovanni Franco; Colombo, Roberto

2013-04-01

108

Estimating soil moisture and the relationship with crop yield using surface temperature and vegetation index  

Science.gov (United States)

Soil moisture availability affects rainfed crop yield. Therefore, the development of methods for pre-harvest yield prediction is essential for the food security. A study was carried out to estimate regional crop yield using the Temperature Vegetation Dryness Index (TVDI). Triangular scatters from land surface temperature (LST) and enhanced vegetation index (EVI) space from MODIS (Moderate Resolution Imaging Spectroradiometer) were utilized to obtain TVDI and to estimate soil moisture availability. Then soybean and wheat crops yield was estimated on four agro-climatic zones of Argentine Pampas. TVDI showed a strong correlation with soil moisture measurements, with R2 values ranged from 0.61 to 0.83 and also it was in agreement with spatial pattern of soil moisture. Moreover, results showed that TVDI data can be used effectively to predict crop yield on the Argentine Pampas. Depending on the agro-climatic zone, R2 values ranged from 0.68 to 0.79 for soybean crop and 0.76 to 0.81 for wheat. The RMSE values were 366 and 380 kg ha-1 for soybean and they varied between 300 and 550 kg ha-1 in the case of wheat crop. When expressed as percentages of actual yield, the RMSE values ranged from 12% to 13% for soybean and 14% to 22% for wheat. The bias values indicated that the obtained models underestimated soybean and wheat yield. Accurate crop grain yield forecast using the developed regression models was achieved one to three months before harvest. In many cases the results were better than others obtained using only a vegetation index, showing the aptitude of surface temperature and vegetation index combination to reflect the crop water condition. Finally, the analysis of a wide range of soil moisture availability allowed us to develop a generalized model of crop yield and dryness index relationship which could be applicable in other regions and crops at regional scale.

Holzman, M. E.; Rivas, R.; Piccolo, M. C.

2014-05-01

109

Generating Vegetation Leaf Area Index Earth System Data Record from Multiple Sensors. Part 2; Implementation, Analysis and Validation  

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The evaluation of a new global monthly leaf area index (LAI) data set for the period July 1981 to December 2006 derived from AVHRR Normalized Difference Vegetation Index (NDVI) data is described. The physically based algorithm is detailed in the first of the two part series. Here, the implementation, production and evaluation of the data set are described. The data set is evaluated both by direct comparisons to ground data and indirectly through inter-comparisons with similar data sets. This indirect validation showed satisfactory agreement with existing LAI products, importantly MODIS, at a range of spatial scales, and significant correlations with key climate variables in areas where temperature and precipitation limit plant growth. The data set successfully reproduced well-documented spatio-temporal trends and inter-annual variations in vegetation activity in the northern latitudes and semi-arid tropics. Comparison with plot scale field measurements over homogeneous vegetation patches indicated a 7% underestimation when all major vegetation types are taken into account. The error in mean values obtained from distributions of AVHRR LAI and high-resolution field LAI maps for different biomes is within 0.5 LAI for six out of the ten selected sites. These validation exercises though limited by the amount of field data, and thus less than comprehensive, indicated satisfactory agreement between the LAI product and field measurements. Overall, the intercomparison with short-term LAI data sets, evaluation of long term trends with known variations in climate variables, and validation with field measurements together build confidence in the utility of this new 26 year LAI record for long term vegetation monitoring and modeling studies.

Ganguly, Sangram; Samanta, Arindam; Schull, Mitchell A.; Shabanov, Nikolay V.; Milesi, Cristina; Nemani, Ramajrushna R,; Knyazikhin, Yuri; Myneni, Ranga B.

2008-01-01

110

Predicting maize yield in Zimbabwe using dry dekads derived from remotely sensed Vegetation Condition Index  

Science.gov (United States)

Maize is a key crop contributing to food security in Southern Africa yet accurate estimates of maize yield prior to harvesting are scarce. Timely and accurate estimates of maize production are essential for ensuring food security by enabling actionable mitigation strategies and policies for prevention of food shortages. In this study, we regressed the number of dry dekads derived from VCI against official ground-based maize yield estimates to generate simple linear regression models for predicting maize yield throughout Zimbabwe over four seasons (2009-10, 2010-11, 2011-12, and 2012-13). The VCI was computed using Normalized Difference Vegetation Index (NDVI) time series dataset from the SPOT VEGETATION sensor for the period 1998-2013. A significant negative linear relationship between number of dry dekads and maize yield was observed in each season. The variation in yield explained by the models ranged from 75% to 90%. The models were evaluated with official ground-based yield data that was not used to generate the models. There is a close match between the predicted yield and the official yield statistics with an error of 33%. The observed consistency in the negative relationship between number of dry dekads and ground-based estimates of maize yield as well as the high explanatory power of the regression models suggest that VCI-derived dry dekads could be used to predict maize yield before the end of the season thereby making it possible to plan strategies for dealing with food deficits or surpluses on time.

Kuri, Farai; Murwira, Amon; Murwira, Karin S.; Masocha, Mhosisi

2014-12-01

111

Heavy metal absorption by vegetables grown in different soils  

International Nuclear Information System (INIS)

The authors study the bibliographic and experimental data on absorption by vegetables of several heavy metals present in the soil or brought to it via fertilizations, especially with the use of compost coming from waste treatment plants. The presence of heavy metals in the soil causes increased levels of these toxic substances in the edible parts of the vegetables grown in that soil. Not to be neglected is also the absorption by the leaf apparatus of airborne particulate containing heavy metals which deposit on the parts of the vegetable exposed to the air. The available data lack homogeneity of investigation as they have been draw from studies which followed different methodologies. Therefore further studies are required in order to: eliminate some of the variables that might affect the absorption of metals from the soil and supply comparable data. Moreover, a greater number of vegetable species and their different edible parts will have to be taken into consideration

112

Estimate soil moisture using trapezoidal relationship between remotely sensed land surface temperature and vegetation index  

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Full Text Available The trapezoidal relationship between surface temperature (Ts and vegetation index (VI was used to estimate soil moisture in the present study. An iterative algorithm is proposed to estimate the vertices of the Ts~VI trapezoid theoretically for each grid, and then WDI is calculated for each grid using MODIS remotely sensed measurements of surface temperature and enhanced vegetation index (EVI. The capability of using WDI based on Ts~VI trapezoid to estimate soil moisture is evaluated using soil moisture observations and antecedent precipitation in the Walnut Gulch Experimental Watershed (WGEW in Arizona, USA. The result shows that, Ts~VI trapezoid based WDI can well capture temporal variation in surface soil moisture, but the capability of detecting spatial variation is poor for such a semi-arid region as WGEW.

W. Wang

2010-11-01

113

METHANOL TRANSESTERIFICATION OF DIFFERENT VEGETABLE OILS  

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Full Text Available The result of the investigation on methyl esters obtained on the basis of used sunflower oil, rapeseed oil and soybean oil are given in this paper. Transesterification reaction conditions that affect yield and purity of the product esters including oil quality, type and concentration of catalyst, temperature and reaction time were examined. Methanol esterification of different oils at 60 0C with 1-10 % (v/v sodium met-oxide was studied. With appropriate percent of sodium met-oxide, temperature 60 0C and 1 hour, all investigated oils were sufficiently transesterified and could be used as fuel in diesel engines.

Slavi Kunev Ivanov

2007-06-01

114

On the relationship between some production parameters and a vegetation index in viticulture  

Science.gov (United States)

The use and timing of many agronomical practices such as the scheduling of irrigation and harvesting are dependent on accurate vineyard sampling of qualitative and productive parameters. Crop forecasting also depends on the representativeness of vineyard samples during the whole phenological period. This manuscript summarizes the last two years of precision viticulture in Sicily (Italy); agronomic campaigns were carried out in 2012 and 2013 within the "Tenute Rapitalà" and "Donnafugata" farms. Normalized Difference Vegetation Index derived from satellite images (RapidEye) acquired at berry set, pre-veraison and ripening phenological stages (occurred at June, July and August respectively) have been related to production parameters (sugar and anthocyanins contents) at harvesting of a selected red autochthonous cultivar (Nero D'Avola). The research aims to assess how robust are prediction models based on simple linear regression analysis, in particular: 1) whether there is a suitable period for acquiring the remote sensing image to evaluate these parameters at harvesting, when their knowledge is required; 2) if these relationships are consistent between years or need to be re-calibrated; 3) the models transferability to other vineyard of the same cultivar.

Santangelo, Tanino; Di Lorenzo, R.; La Loggia, G.; Maltese, A.

2013-10-01

115

Intra-sensor Spectral Compatibility Analysis of the Enhanced Vegetation Index for Moderate Resolution Imagers Using Hyperion  

Science.gov (United States)

Spectral vegetation indices (VIs) are one of the more important satellite products for monitoring and characterizing seasonal dynamics and interannual variability of terrestrial vegetation in regional to global scales. The enhanced vegetation index (EVI), designed for the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, has been shown to effectively characterize global vegetation states and ecosystem processes, and encompass the range of biophysical/biochemical information in manners to complement the conventional, normalized difference vegetation index (NDVI). Because the EVI is limited to sensor systems designed with a blue band, a 2-band EVI, without a blue band, was recently developed (referred to as the EVI2), which has the best similarity with the 3-band EVI for the MODIS sensors, particularly when residual atmospheric effects are insignificant and data quality is good. In this study, we evaluated intra-sensor spectral compatibility between the EVI and EVI2 and their sensitivities to aerosol contaminations for select moderate resolution imaging sensors, including Visible/Infrared Imager/Radiometer Suite (VIIRS), MODIS, Second Generation Global Imager (S-GLI), and SPOT-4 VEGETATION, and for Landsat-7 Enhanced Thematic Mapper Plus (ETM+), using a global set of Earth Observing One (EO-1) Hyperion hyperspectral data. Hyperion scenes were spectrally aggregated into red, near-infrared (NIR), and blue bandpasses of the five sensors and spatially aggregated into 1 km resolution pixels. Two atmospheric correction scenarios were also applied to examine the impact of the atmosphere on intra-sensor EVI/EVI2 compatibility: (1) Rayleigh/ozone/water vapor (ROW)-corrected and (2) total-atmosphere-corrected 'top-of-canopy (TOC)' reflectances. The EVI of all the five sensor bandpasses exhibited great resistance to atmospheric aerosol contaminations. The EVI2 of every sensor was, on the other hand, impacted by the aerosol effects as it no longer possesses the aerosol resistance term. The EVI and EVI2 showed the best similarities for MODIS and ETM+ bands. Their similarities degraded for VIIRS bands and were the worst for VEGETATION and S-GLI bands for which EVI and EVI2 differences reached 0.04 EVI units. These results indicate that the EVI2 may require an adjustment or optimization for some sensor bandpasses in order to retain intra-sensor compatibility with the EVI.

Miura, T.; Obata, K.; Huete, A. R.

2013-12-01

116

Non-Lambertian Corrected Albedo and Vegetation Index for Estimating Land Evapotranspiration in a Heterogeneous Semi-Arid Landscape  

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Full Text Available The application of energy balance algorithms to remotely sensed imagery often fails to account for surface roughness variation with diverse land cover, resulting in poor resolution of evapotranspiration (ET variations. Furthermore, the assumption of a horizontally homogeneous Lambertian surface reflecting energy equally in all directions affects the calculations of albedo and vegetation index. The primary objective of this study is to improve the accuracy of the estimation and discrimination of ET among different land cover types in Southern New Mexico from ASTER datasets, by formulating the spatial variation of non-Lambertian reflectance using a wavelength-dependent Minnaert function.

Isabella Mariotto

2010-03-01

117

A comparison of two different approaches for mapping potential ozone damage to vegetation. A model study  

International Nuclear Information System (INIS)

Two very different types of approaches are currently in use today for indicating risk of ozone damage to vegetation in Europe. One approach is the so-called AOTX (accumulated exposure over threshold of X ppb) index, which is based upon ozone concentrations only. The second type of approach entails an estimate of the amount of ozone entering via the stomates of vegetation, the AFstY approach (accumulated stomatal flux over threshold of Y nmol m-2 s-1). The EMEP chemical transport model is used to map these different indicators of ozone damage across Europe, for two illustrative vegetation types, wheat and beech forests. The results show that exceedences of critical levels for either type of indicator are widespread, but that the indicators give very different spatial patterns across Europe. Model simulations for year 2020 scenarios suggest reductions in risks of vegetation damage whichever indicator is used, but suggest that AOT40 is much more sensitive to emission control than AFstY values. - Model calculations of AOT40 and AFstY show very different spatial variations in the risks of ozone damage to vegetation

118

Net Radiation and Vegetation NDVI  

Science.gov (United States)

This site allows you to combine the NDVI vegetation index with Net Solar Radiation values. The Normalized Difference Vegetation Index, or NDVI, is an index of green leaf density. The higher the value, the more luxuriant the vegetation. This is but one of many animated datasets that can be combined to introduce correlations and interactions between radiant energy and the biosphere.

Observatory, Nasa E.; Nasa

119

Estimation of soil moisture using trapezoidal relationship between remotely sensed land surface temperature and vegetation index  

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Full Text Available The trapezoidal relationship between land surface temperature (Ts and Vegetation Index (VI was used to estimate soil moisture in the present study. An iterative algorithm is proposed to estimate the vertices of the Ts ~ VI trapezoid theoretically for each pixel, and then Water Deficit Index (WDI is calculated based on the Ts ~ VI trapezoid using MODIS remotely sensed measurements of surface temperature and enhanced vegetation index (EVI. The capability of using WDI based on Ts ~ VI trapezoid to estimate soil moisture is evaluated using soil moisture observations and antecedent precipitation in the Walnut Gulch Experimental Watershed (WGEW in Arizona, USA. The result shows that, the Ts ~ VI trapezoid based WDI can capture temporal variation in surface soil moisture well, but the capability of detecting spatial variation is poor for such a semi-arid region as WGEW.

W. Wang

2011-05-01

120

Mathematical modeling riparian vegetation zonation in semiarid conditions based on a transpiration index.  

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Initially riparian vegetation modeling was focused on the study of ecological patches without taking into account the interactive effects of structures and processes in between them (Tabacchi et al., 1998). One of the greatest challenges, when carrying out a riparian ecosystem restoration, is to understand the physical and ecological processes of a system and the interaction and feedback within these processes. Jorde (2002) pointed out the importance of addressing complex linkages between processes and biotic interactions in research and in the development of restoration projects over larger spatial and temporal scales in the future. According to Tabacchi et al. (2000), the water cycle in riparian zones depends on three important relations: the water absorption by the plants, water storage and atmospherical return by evaporation. During recent years a variety of ecological models have taken into account the changes in the plant species as consequence of changes in the environmental variables and hydrological alterations (Baptist, 2005; Braatne et al., 2002; Glenz, 2005; Hooke et al., 2005; Murphy et al., 2006). Most of these models are based on functional relationships between river hydrology and vegetation species or communities. In semiarid regions we make the hypothesis transpiration will be one of the key factors determining the riparian vegetation presence and therefore, we will not consider in our model other factors as recruitment, flood damages, etc. The objectives of this work are: firstly to develop a model capable of simulating several riparian vegetation types which can be applied in a wide range of conditions across Mediterranean environments; and secondly to calibrate and to validate the model in several Mediterranean river stretches of the Iberian Peninsula, both in undisturbed and disturbed flow regimes. To achieve these objectives the following methodology has been applied. The model has been conceptualized as a static tank flow model based on the actual evapotranspiration of the riparian plants. This tank represents a portion of soil of the superficial root layer. The lower capacity limit of this tank is the permanent wilting moisture of the soil sample. On the other hand the upper capacity limit is the field capacity moisture. The tank's input flows are the precipitation, the root water rise and the capillary water rise. In contrast output flows are the actual evapotranspiration and the excess water of the tank. The most relevant model parameters are the soil retention curves, vegetation functional type parameters (specially related to root depths and the transpiration efficiency factors) and the daily hidro-meteorological data, which are water table elevation, precipitation and potential evapotranspiration. The model runs for a limited amount of vegetation functional types. In our simulations the following four functional types were used: Riparian Herbs; Riparian Juveniles and Small Scrubs, Riparian Trees and Big Shrubs; and Terrestrial Vegetation. The general model output variable is an evapotranspiration index based in the quotient between the current and the potential evapotranspiration. This index is used to determine the suitability of the simulated vegetation functional types to certain environmental conditions. Secondly, a sensitivity analysis was made for determining the most relevant model parameters. Finally the model has been calibrated and validated using as objective function a confusion matrix which compares the observed and the simulated riparian vegetation zonation. The calibration/validation processes have been carried out in seven study sites of the Jucar River Basin District. Four of those sites have a natural flow regime and three of them a regulated flow regime due to the presence of dams. Results have shown that the model is capable of providing effective simulations in compared to the observed riparian vegetation.

Real, Joaquin; Morales, Marco; Garcia, Alicia; Garofano, Virginia; Martinez-Capel, Francisco; Frances, Felix

2010-05-01

 
 
 
 
121

Study of vegetation index selection and changing detection thresholds in land cover change detection assessment using change vector analysis  

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In recent years, Vietnamese rapidly developing economy has led to speedy changes in land cover. The study of changing detection of land cover plays an important role in making the strategy of the managers. There are two main approaches in changing detection research by using remote sensing and GIS: post- classification change detection analysis approach and pre-classification changing spectral determination approach. Each has their own different advantages and disadvantages. The second one is further divided into: Image Differencing, Multi-date Principal Component Analysis (MPCA); Change Vector Analysis (CVA). In this study, researchers introduce CVA method. This method is based on two important index to show the primary feature of land cover, such as: vegetation index (NDVI-) and barren land index (-BI). Ability to apply methods of CVA has been mentioned in the studies [1, 2, 3, and 4]. However, in these studies did not mention the NDVI index selection and changing detection threshold in changing detection assessment? This paper proposes application to solve these two problems.

Nguyen, Duy; Tran, Giang

2012-07-01

122

Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest  

Science.gov (United States)

It is challenging to detect burn severity and vegetation recovery because of the relatively long time period required to capture the ecosystem characteristics. Multitemporal remote sensing data can providemultitemporal observations before, during and after a wildfire, and can improve the change detection accuracy. The goal of this study is to examine the correlations between multitemporal spectral indices and field-observed burn severity, and to provide a practical method to estimate burn severity and vegetation recovery. The study site is the Jasper Fire area in the Black Hills National Forest, South Dakota, that burned during August and September 2000. Six multitemporal Landsat images acquired from 2000 (pre-fire), 2001 (post-fire), 2002, 2003, 2005 and 2007 were used to assess burn severity. The normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized burn ratio (NBR), integrated forest index (IFI) and the differences of these indices between the pre-fire and post-fire years were computed and analysed with 66 field-based composite burn index (CBI) plots collected in 2002. Results showed that differences of NDVI and differences of EVI between the pre-fire year and the first two years post-fire were highly correlated with the CBI scores. The correlations were low beyond the second year post-fire. Differences of NBR had good correlation with CBI scores in all study years. Differences of IFI had low correlation with CBI in the first year post-fire and had good correlation in later years. A CBI map of the burnt area was produced using regression tree models and the multitemporal images. The dynamics of four spectral indices from 2000 to 2007 indicated that both NBR and IFI are valuable for monitoring long-term vegetation recovery. The high burn severity areas had a much slower recovery than the moderate and low burn areas. ?? 2011 Taylor & Francis.

Chen, X.; Vogelmann, J.E.; Rollins, M.; Ohlen, D.; Key, C.H.; Yang, L.; Huang, C.; Shi, H.

2011-01-01

123

Exposure to vegetable variety in infants weaned at different ages.  

Science.gov (United States)

The aim of the current study was to examine the effectiveness of different vegetable exposure methods (variety versus single taste) over a 9 day period in two groups of infants; those introduced to solids prior to the age of 5.5 months, and those introduced after 5.5 months. Sixty parent-infant dyads were recruited in South Birmingham, UK. Infants' acceptance of a novel vegetable (pea puree) was measured after a 9 day exposure period in the infants a week after they were first introduced to solid foods. During the exposure period half of each age group was given carrot every day, and the other half was given a variety pack of courgette, parsnip and sweet potato. A baseline measurement of the infants' acceptance of a vegetable (carrot) was taken prior to the exposure period. There was no difference between the groups in consumption of the baseline vegetable (carrot). There were no main effects of exposure group or age group on consumption of pea after the exposure period. There was, however, an interaction between the age of introduction and exposure group on consumption of the new vegetable (pea). In particular, infants weaned at 6 months in the single taste group ate significantly less pea puree than those in the variety group. These findings suggest that infants, who are weaned at 6 months or later, may benefit from being weaned onto a variety of tastes rapidly to ensure adequate exposure to taste. This study constitutes some of the first evidence to suggest that there may be a sensitive period for the acceptance of tastes between the ages of 4 and 6 months. PMID:24685457

Coulthard, Helen; Harris, Gillian; Fogel, Anna

2014-07-01

124

Agricultural Drought Pattern in West Java Using Thermal Vegetation Index from Modis-Terra Satellite  

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Full Text Available This study examines agricultural drought paddy fields in West Java. The aims of this research are to know the pattern and distribution of paddy field drought in West Java and the correlation between drought and the physical characteristics. The agricultural drought is obtained from TVI (Thermal Vegetation Index model. TVI is derived from MODIS Terra satellite image, which is the ratio between the LST (Land Surface Temperature and EVI (Enhanced Vegetation Index. Physical factors studied are rainfall, l slope, geomorphology, soil drainage, and irrigation areas. The most severe drought occurred in September 2006 because of El Nino, covering 806,564 ha, and distributed in almost all West Java Province while the lowest occurred in September 2010 because of La Nina, covering 101,959 ha, and mostly distributed in Subang and Indramayu district. Spatial distribution of drought in 2000-2011 has the same pattern. At the start of the dry season (May drought occurred in the north (along the coast then expanded to the east / south in the middle of the dry season (July-August and then increased further to the west at the end of the dry season (September. Incidence of drought has correlation with the physical condition of the area, but the most influential is the rainfall based on Chi-square test.

Sri Hardiyanti Purwadhi

2013-04-01

125

Relationships between evaprorative fraction and remotely sensed vegetation index and microwave brightness temperature for semiarid rangelands  

Science.gov (United States)

Measurements of the microwave brightness temperature (TB) with the Pushbroom Microwave Radiometer (PBMR) over the Walnut Gulch Experiment Watershed were made on selected days during the MONSOON 90 field campaign. The PBMR is an L-band instrument (21-cm wavelength) that can provide estimates of near-surface soil moisture over a variety of surfaces. Aircraft observations in the visible and near-infrared wavelengths collected on selected days also were used to compute a vegetation index. Continuous micrometeorological measurements and daily soil moisture samples were obtained at eight locations during experimental period. Two sites were instrumented with time domain reflectometry probes to monitor the soil moisture profile. The fraction of available energy used for evapotranspiration was computed by taking the ratio of latent heat flux (LE) to the sum of net radiation (Rn) and soil heat flux (G). This ratio is commonly called the evaporative fraction (EF) and normally varies between 0 and 1 under daytime convective conditions with minimal advection. A wide range of environmental conditions existed during the field campaign, resulting in average EF values for the study area varying from 0.4 to 0.8 and values of TB ranging from 220 to 280 K. Comparison between measured TB and EF for the eight locations showed an inverse relationship. Other days were included in the analysis by estimating TB with the soil moisture data. Because transpiration from the vegetation is more strongly coupled to root zone soil moisture, significant scatter in this relationship existed at high values of TB or dry near-surface soil moisture conditions. The variation in EF under dry near-surface soil moisture conditions was correlated to the amount of vegetation cover estimated with a remotely sensed vegetation index. These findings indicate that information obtained from optical and microwave data can be used for quantifying the energy balance of semiarid areas. The microwave data can indicate when soil evaporation is significantly contributing to EF, while the optical data is helpful for quantifying the spatial variation in EF due to the distribution of vegetation cover.

Kustas, W. P.; Schimugge, T. J.; Humes, K. S.; Jackson, T. J.; Parry, R.; Weltz, M. A.; Moran, M. S.

1993-01-01

126

Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring  

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Full Text Available Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs, from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER (15 m and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS (250 m – 500 m sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors’ products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house” surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results associated with the ASTER algorithm, including additional quality assessments of the ASTER and MODIS products with other atmospheric radiative transfer codes.

Hirokazu Yamamoto

2008-04-01

127

Soil microbial properties under different vegetation types on Mountain Han.  

Science.gov (United States)

This study investigated the influence of broadleaf and conifer vegetation on soil microbial communities in a distinct vertical distribution belt in Northeast China. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths from four vegetation types at different altitudes, which were characterized by poplar (Populus davidiana) (1250-1300 m), poplar (P. davidiana) mixed with birch (Betula platyphylla) (1370-1550 m), birch (B. platyphylla) (1550-1720 m), and larch (Larix principis-rupprechtii) (1840-1890 m). Microbial biomass and community structure were determined using the fumigation-extraction method and phospholipid fatty acid (PLFA) analysis, and soil fungal community level physiological profiles (CLPP) were characterized using Biolog FF Microplates. It was found that soil properties, especially soil organic carbon and water content, contributed significantly to the variations in soil microbes. With increasing soil depth, the soil microbial biomass, fungal biomass, and fungal catabolic ability diminished; however, the ratio of fungi to bacteria increased. The fungal ratio was higher under larch forests compared to that under poplar, birch, and their mixed forests, although the soil microbial biomass was lower. The direct contribution of vegetation types to the soil microbial community variation was 12%. If the indirect contribution through soil organic carbon was included, variations in the vegetation type had substantial influences on soil microbial composition and diversity. PMID:23737003

Wang, Miao; Qu, Laiye; Ma, Keming; Yuan, Xiu

2013-06-01

128

Use of Radar Vegetation Index (RVI) in Passive Microwave Algorithms for Soil Moisture Estimates  

Science.gov (United States)

The Soil Moisture Active Passive (SMAP) satellite will provide a unique opportunity for the estimation of soil moisture by having simultaneous radar and radiometer measurements available. As with the Soil Moisture and Ocean Salinity (SMOS) satellite, the soil moisture algorithms will need to account for the contribution of vegetation to the brightness temperature. Global maps of vegetation volumetric water content (VWC) are difficult to obtain, and the SMOS mission has opted to estimate the optical depth of standing vegetation by using a relationship between the VWC and the leaf area index (LAI). LAI is estimated from optical remote sensing or through soil-vegetation-atmosphere transfer modeling. During the growing season, the VWC of agricultural crops can increase rapidly, and if cloud cover exists during an optical acquisition, the estimation of LAI may be delayed, resulting in an underestimation of the VWC and overestimation of the soil moisture. Alternatively, the radar vegetation index (RVI) has shown strong correlation and linear relationship with VWC for rice and soybeans. Using the SMAP radar to produce RVI values that are coincident to brightness temperature measurements may eliminate the need for LAI estimates. The SMAP Validation Experiment 2012 (SMAPVEX12) was a cal/val campaign for the SMAP mission held in Manitoba, Canada, during a 6-week period in June and July, 2012. During this campaign, soil moisture measurements were obtained for 55 fields with varying soil texture and vegetation cover. Vegetation was sampled from each field weekly to determine the VWC. Soil moisture measurements were taken coincident to overpasses by an aircraft carrying the Passive and Active L-band System (PALS) instrumentation. The aircraft flew flight lines at both high and low altitudes. The low altitude flight lines provided a footprint size approximately equivalent to the size of the SMAPVEX12 field sites. Of the 55 field sites, the low altitude flight lines provided measurements for 15 fields. One field was planted in corn; three were pasture; six were soybeans; three were wheat; and two were winter wheat. The average RVI for each field was determined for each PALS overpass, with sampled radar data confined to the field dimensions. A linear interpolation was conducted between measured values of VWC to estimate a daily VWC value. A linear regression was conducted between the average VWC and the RVI, for each vegetation type. A positive linear relationship was found for all crops, with the exception of pasture. The correlation between the RVI and VWC was strong for corn and pasture, but moderate for soybeans and winter wheat; however, the correlation for corn was not significant. The developed models were utilized to provide a calculated VWC which was inputted into a modified version of the Land Parameter Retrieval Model (LPRM) to determine the error associated with using a calculated VWC from the RVI versus measured VWC data. The LPRM outputs for both scenarios were compared to the PALS radiometer measurements of brightness temperature.

Rowlandson, T. L.; Berg, A. A.

2013-12-01

129

[Comparison of GIMMS and MODIS normalized vegetation index composite data for Qing-Hai-Tibet Plateau].  

Science.gov (United States)

Consistent NDVI time series are basic and prerequisite in long-term monitoring of land surface properties. Advanced very high resolution radiometer (AVHRR) measurements provide the longest records of continuous global satellite measurements sensitive to live green vegetation, and moderate resolution imaging spectroradiometer (MODIS) is more recent typical with high spatial and temporal resolution. Understanding the relationship between the AVHRR-derived NDVI and MODIS NDVI is critical to continued long-term monitoring of ecological resources. NDVI time series acquired by the global inventory modeling and mapping studies (GIMMS) and Terra MODIS were compared over the same time periods from 2000 to 2006 at four scales of Qinghai-Tibet Plateau (whole region, sub-region, biome and pixel) to assess the level of agreement in terms of absolute values and dynamic change by independently assessing the performance of GIMMS and MODIS NDVI and using 495 Landsat samples of 20 km x20 km covering major land cover type. High correlations existed between the two datasets at the four scales, indicating their mostly equal capability of capturing seasonal and monthly phenological variations (mostly at 0. 001 significance level). Simi- larities of the two datasets differed significantly among different vegetation types. The relative low correlation coefficients and large difference of NDVI value between the two datasets were found among dense vegetation types including broadleaf forest and needleleaf forest, yet the correlations were strong and the deviations were small in more homogeneous vegetation types, such as meadow, steppe and crop. 82% of study area was characterized by strong consistency between GIMMS and MODIS NDVI at pixel scale. In the Landsat NDVI vs. GIMMS and MODIS NDVI comparison of absolute values, the MODIS NDVI performed slightly better than GIMMS NDVI, whereas in the comparison of temporal change values, the GIMMS data set performed best. Similar with comparison results of GIMMS and MODIS NDVI, the consistency across the three datasets was clearly different among various vegetation types. In dynamic changes, differences between Landsat and MODIS NDVI were smaller than Landsat NDVI vs. GIMMS NDVI for forest, but Landsat and GIMMS NDVI agreed better for grass and crop. The results suggested that spatial patterns and dynamic trends of GIMMS NDVI were found to be in overall acceptable agreement with MODIS NDVI. It might be feasible to successfully integrate historical GIMMS and more recent MODIS NDVI to provide continuity of NDVI products. The accuracy of merging AVHRR historical data recorded with more modern MODIS NDVI data strongly depends on vegetation type, season and phenological period, and spatial scale. The integration of the two datasets for needleleaf forest, broadleaf forest, and for all vegetation types in the phenological transition periods in spring and autumn should be treated with caution. PMID:24830255

Du, Jia-Qiang; Shu, Jian-Min; Wang, Yue-Hui; Li, Ying-Chang; Zhang, Lin-Bo; Guo, Yang

2014-02-01

130

Variação do Índice de Vegetação por Diferença Normalizada na lagoa Itapeva, litoral norte do Rio Grande do Sul, Brasil, a partir de análise de séries temporais / Variations of the Normalized Difference Vegetation Index (NDVI) in the Itapeva-RS lake, north coast of Rio Grande do Sul, Brazil, from temporal series analysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo do trabalho foi analisar os padrões de comportamento espaço-temporal dos valores do Índice de Vegetação por Diferença Normalizada (NDVI) na lagoa Itapeva-RS, por meio de imagens Landsat TM5 e ETM+7, compreendendo o período de 1985 a 2010. Para a análise do comportamento espaço-temporal fo [...] ram utilizadas classes de Índice de Vegetação por Diferença Normalizada (NDVI) e Análise por Séries Temporais (TSA) de imagens. Para validação dos padrões observados foram coletadas amostras de água em seis pontos na lagoa Itapeva para clorofila_a, Totais de Sólidos Suspensos e transparência do disco Secchi. Estes resultados foram correlacionados com os valores de NDVI. Os mapas de classes de NDVI gerados após a análise da TSA evidenciaram padrões de dinâmica espaciais e sazonais associados as variáveis ambientais atuantes, permitindo o estabelecimento de três grandes compartimentos para a lagoa Itapeva: norte, centro e sul. A análise da série temporal de imagens mostra que o aumento e o decréscimo dos valores de NDVI estão associados aos períodos de floração do fitoplâncton. Concluiu-se que a análise da Série Temporal de imagens Landsat foi satisfatória no que se refere ao comportamento espaço-temporal da variação das classes de NDVI. Abstract in english The objective of this study was to analyze the pattern spatial-temporal values of the Normalized Difference Vegetation Index (NDVI) in Itapeva-RS lake, using Landsat TM5 and ETM + 7 images, from 1985 through 2010. For the analysis of space-temporal behavior classes was used Normalized Difference Veg [...] etation Index (NDVI) classes and Temporal Series Analysis (TSA). To validate the observed patterns were collected water samples from six points in the Itapeva Lake for clorofila_a, Total suspended solids and Secchi disk transparency. These results were correlated with NDVI values. The NDVI classes maps generated after analysis of TSA, showed dynamic patterns of seasonal and spatial associated with environmental variables that were actuating, allowing the establishment of three distinctive surfaces in Itapeva Lake: north, center and south. The Temporal Series Analysis of images shows that the increase and decrease of NDVI values are associated with periods of phytoplankton bloom. One concluded that the Temporal Series Analysis of Landsat images was satisfactory with regard to the behavior of spatial and temporal variation of NDVI classes.

Juliane Beatriz, Lissner; Laurindo Antonio, Guasselli.

131

Variação do Índice de Vegetação por Diferença Normalizada na lagoa Itapeva, litoral norte do Rio Grande do Sul, Brasil, a partir de análise de séries temporais / Variations of the Normalized Difference Vegetation Index (NDVI) in the Itapeva-RS lake, north coast of Rio Grande do Sul, Brazil, from temporal series analysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo do trabalho foi analisar os padrões de comportamento espaço-temporal dos valores do Índice de Vegetação por Diferença Normalizada (NDVI) na lagoa Itapeva-RS, por meio de imagens Landsat TM5 e ETM+7, compreendendo o período de 1985 a 2010. Para a análise do comportamento espaço-temporal fo [...] ram utilizadas classes de Índice de Vegetação por Diferença Normalizada (NDVI) e Análise por Séries Temporais (TSA) de imagens. Para validação dos padrões observados foram coletadas amostras de água em seis pontos na lagoa Itapeva para clorofila_a, Totais de Sólidos Suspensos e transparência do disco Secchi. Estes resultados foram correlacionados com os valores de NDVI. Os mapas de classes de NDVI gerados após a análise da TSA evidenciaram padrões de dinâmica espaciais e sazonais associados as variáveis ambientais atuantes, permitindo o estabelecimento de três grandes compartimentos para a lagoa Itapeva: norte, centro e sul. A análise da série temporal de imagens mostra que o aumento e o decréscimo dos valores de NDVI estão associados aos períodos de floração do fitoplâncton. Concluiu-se que a análise da Série Temporal de imagens Landsat foi satisfatória no que se refere ao comportamento espaço-temporal da variação das classes de NDVI. Abstract in english The objective of this study was to analyze the pattern spatial-temporal values of the Normalized Difference Vegetation Index (NDVI) in Itapeva-RS lake, using Landsat TM5 and ETM + 7 images, from 1985 through 2010. For the analysis of space-temporal behavior classes was used Normalized Difference Veg [...] etation Index (NDVI) classes and Temporal Series Analysis (TSA). To validate the observed patterns were collected water samples from six points in the Itapeva Lake for clorofila_a, Total suspended solids and Secchi disk transparency. These results were correlated with NDVI values. The NDVI classes maps generated after analysis of TSA, showed dynamic patterns of seasonal and spatial associated with environmental variables that were actuating, allowing the establishment of three distinctive surfaces in Itapeva Lake: north, center and south. The Temporal Series Analysis of images shows that the increase and decrease of NDVI values are associated with periods of phytoplankton bloom. One concluded that the Temporal Series Analysis of Landsat images was satisfactory with regard to the behavior of spatial and temporal variation of NDVI classes.

Juliane Beatriz, Lissner; Laurindo Antonio, Guasselli.

2013-08-01

132

Camera derived vegetation greenness index as proxy for gross primary production in a low Arctic wetland area  

DEFF Research Database (Denmark)

The Arctic is experiencing disproportionate warming relative to the global average, and the Arctic ecosystems are as a result undergoing considerable changes. Continued monitoring of ecosystem productivity and phenology across temporal and spatial scales is a central part of assessing the magnitude of these changes. This study investigates the ability to use automatic digital camera images (DCIs) as proxy data for gross primary production (GPP) in a complex low Arctic wetland site. Vegetation greenness computed from DCIs was found to correlate significantly (R-2 = 0.62, p <0.001) with a normalized difference vegetation index (NDVI) product derived from the WorldView-2 satellite. An object-based classification based on a bi-temporal image composite was used to classify the study area into heath, copse, fen, and bedrock. Temporal evolution of vegetation greenness was evaluated and modeled with double sigmoid functions for each plant community. GPP at light saturation modeled from eddy covariance (EC) flux measurements were found to correlate significantly with vegetation greenness for all plant communities in the studied year (i.e., 2010), and the highest correlation was found between modeled fen greenness and GPP (R-2 = 0.85, p <0.001). Finally, greenness computed within modeled EC footprints were used to evaluate the influence of individual plant communities on the flux measurements. The study concludes that digital cameras may be used as a cost-effective proxy for potential GPP in remote Arctic regions. (C) 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS) Published by Elsevier B.V. All rights reserved.

Westergaard-Nielsen, Andreas; Lund, Magnus

2013-01-01

133

Lipid Peroxidation in Rat Liver using Different Vegetable Oils  

International Nuclear Information System (INIS)

The objective of the study was to evaluate the effect of different vegetable oils (Red Palm Olien (RPO), Palm Olein (PO), Corn Oil (CO) and Coconut Oil on lipid peroxidation of rat liver. One hundred and thirty two Sprague Dawley male rats were randomly divided into two groups. The first group contains seventy two rats were divided into twelve groups of 6 rats per group and were treated with different concentrations of RPO (5 %, 10 % and 15 %) for 2, 4 and 8 weeks. The second group contains sixty male rats were randomly divided into ten groups of 6 rats per group and were treated with 15 % of RPO, PO, CO and COC for 4 and 8 weeks. The results shows that after 8 weeks of treatment the malonaldehyde (MDA) value in RPO group was significantly lower (P?0.05) than control or vegetable oils studied. These experiments suggested that red palm olein antioxidants present in rat diets may better attenuate peroxyl radical than other vegetable oil studied. (author)

134

Determination index of compatible vegetable species with the lines of electric power transmission  

International Nuclear Information System (INIS)

With the purpose of designing methods to clearly identify which plant species generate electrical ground discharges in energy transmission line service corridors and thus avoid the frequent pruning of all Vegetation present in the corridors this study proposes and evaluates compatibility index of plant species with transmission lines, based on six variables: maximum height, growth form, ecological group, life zone, and abundance and frequency of each species. This index was tested in 20 plots of information was collected on all vascular plans present yielding 2147 individuals belonging to 485 species and 105 families, the most discriminating variables in the model were life zone and ecological group, based upon an analysis of principal components. This index applied to the 147 fully identified species with DBH = 2,5 cm showed that Cecropia peltata and Jacaranda copaia were the most problematic species for service lines. Furthermore, a catalogue was developed containing general information and a photographic record of some of the species considered as compatible as a reference for use during maintenance work

135

Integración del Índice de Vegetación de la Diferencia Normalizada (NDVI y del Ciclo Fenológico de Maíz para Estimar el Rendimiento a Escala Departamental en Córdoba, Argentina Normalized Difference Vegetation Index (NDVI and Phenological Data Integration to Estimate County Yield of Corn in Córdoba, Argentina  

Directory of Open Access Journals (Sweden)

Full Text Available La integración de datos radiométricos con información agroclimática puede resultar en mejores procedimientos para evaluar el estado y evolución de los cultivos. En este trabajo, datos del calendario fenológico del cultivo de maíz (Zea mays L., estimados a partir de procedimientos de sumas térmicas, fueron integrados con registros del Indice de Vegetación de la Diferencia Normalizada (NDVI de cobertura global del sistema Radiómetro Avanzado de Muy Alta Resolución de la Administración Nacional del Océano y la Atmósfera de los Estados Unidos (NOAA-AVHRR, con los siguientes objetivos: i evaluar la relación entre el NDVI y el rendimiento de maíz en distintas etapas del ciclo del cultivo; ii analizar la influencia de la fecha de siembra, y iii desarrollar un modelo de pronóstico del rendimiento de maíz a escala departamental. Los valores acumulados de NDVI presentaron una asociación positiva con el rendimiento de maíz, variable de acuerdo a la etapa de desarrollo y la fecha de siembra consideradas. Durante la etapa reproductiva, el NDVI expresó una elevada asociación con el rendimiento en cualquier fecha de siembra eventual, alcanzando valores de correlación significativos (P Integration of satellite data with agroclimatic information can result in better procedures to evaluate the state and evolution of grain crops. In this work, phenologic calendar of corn (Zea mays L. crop based on growing-degree days procedures was integrated with Normalized Difference Vegetation Index (NDVI estimations from global coverage of National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR system. The main objectives were: i to evaluate the relationship between NDVI and corn yield in different stages of crop cycle; ii to analyze the influence of sowing date, and iii to develop a predictive model of county (departmental corn yield using satellite and ground data. The NDVI values accumulated in different corn phenologic stages showed a positive association with yield, and this relationship was modified in function of sowing date. The NDVI value during the reproductive stage, for any sowing date, always expressed a high association with corn yield, reaching significant correlation values (P < 0.05 in all cases, and even higher (P < 0.01 for some evaluated dates. The higher sensitivity showed by the reproductive stage confirms that it is a critical period. Starting from this information, a prediction model was obtained that explains around 80% of corn yield variability of Marcos Juárez Department in Córdoba Province, Argentina.

Antonio de la Casa

2007-12-01

136

Evaluation of Landsat Archive for Global and Time Series Validation of AVHRR-MODIS Vegetation Index Data Records  

Science.gov (United States)

Spectral vegetation indices (VIs) derived from satellite images are useful in land surface phenology studies. These time series portray seasonal and annual changes to vegetation globally. Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) are two satellite sensors which provide daily global VIs. AVHRR and MODIS time series could be used together to assess longer-term changes in global phenological and climate change studies. Inherent differences of sensor characteristics potentially lead to inconsistencies between these two sensor time series, which needs to be evaluated. Landsat provides the longest data record; i.e., Landsat-5 Thematic Mapper had been acquiring data since 1984. The Landsat dataset could provide an opportunity to evaluate multi-sensor continuity of these global datasets. The objective of this study was to evaluate the availability of low cloud coverage or cloud-free Landsat scenes at the United States Geological Survey (USGS) for validating data consistency and continuity of AVHRR-MODIS global vegetation index datasets over an 18-year time period, from 1984 to 2002. The USGS Landsat Global Archive file was obtained from the USGS Landsat website, which provided a graphic view of the geographic and temporal acquisition of Landsat data from 1972 to 2011. International Geosphere-Biosphere Programme (IGBP) land cover data were extracted from the 2002 MODIS land cover product (MYC12C1) to stratify available scenes for land cover types. Archived scene metadata were used to find Landsat scenes with less than 25% cloud cover. The most comprehensive data were available over the conterminous United States, the southern part of Canada, and the northern part of Mexico, where full 18-year time series of Landsat-5 TM image stack (10 - 20 image per year) could be generated at many PATH/ROW locations. Outside of North America, no single region had sufficient data archived for all years of the 1984 to 2002 time period to allow for a continuous time-series to be generated. However, occasional regional coverage of Landsat data were observed for South America, Europe, Southeast Asia, Austraia, and Africa, which could be used to assess global consistency of AVHRR and MODIS datasets, with the exception of a few years with insufficient data collection. We conclude that the USGS EROS Landsat-5 TM archive can provide a useful temporal and spatial coverage to validate data consistency and continuity of AVHRR-MODIS global vegetation index time series.

Connor, W.; Miura, T.

2012-12-01

137

Optimización del índice espectral de la vegetación NDVIcp / Optimization of the spectral vegetation index NDVIcp  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish La optimización de los índices espectrales de la vegetación para reducir el efecto del suelo y de la atmósfera, requiere hipótesis fuertes cuando no hay conocimiento relacionado con las variables atmosféricas y sólo información contenida en las imágenes satelitales. La optimización del índice NDVIcp [...] , diseñado para minimizar el efecto del suelo, es analizada con una perspectiva de su factibilidad y de las restricciones asociadas a este objetivo. Para explicar la problemática de la optimización del índice espectral de la vegetación NDVIcp, se analizó la estructura matemática de los efectos atmosféricos y se formuló el NDVIcp en función de esta estructura para analizar el problema de minimización de los efectos conjuntos del suelo y de la atmósfera. Los análisis mostraron que sin el conocimiento del tipo de aerosol (espesor óptico de la atmósfera) y modelo atmosférico, los intentos de reducción o eliminación de los efectos atmosféricos son indeterminados (implican soluciones múltiples al problema). Si se conocen la atmósfera y el aerosol, pero no el espesor óptico atmosférico, es posible minimizar los efectos atmosféricos y del suelo usando un esquema de aproximación de las constantes del índice NDVIcp al caso sin atmósfera. Abstract in english The optimization of the spectral vegetation indices to reduce the effects of soil and atmosphere, requires strong hypotheses when there is no knowledge related to the atmospheric variables and only information contained in the satellite images. The optimization of the index NDVIcp, designed to minim [...] ize the effect of soil, is analyzed under a perspective of its viability and of the restrictions associated with this objective. To explain the problematic of the optimization of the spectral vegetation index NDVIcp, an analysis was made of the mathematical structure of the atmospheric effects, and the NDVIcp was formulated as a function of this structure to analyze the problem of minimization of the joint effects of soil and of the atmosphere. The analyses showed that without the knowledge of the type of aerosol (optical thickness of the atmosphere) and atmospheric model, the attempts at reduction or elimination of the atmospheric effects are indetermined (imply multiple solutions to the problem). If the atmosphere and aerosol are known, but not the atmospheric optical thickness, it is possible to minimize the atmospheric effects and of the soil using a scheme of approximation of the constants of the NDVIcp index to the case without atmosphere.

Fernando, Paz-Pellat; Martín, Bolaños-González; Enrique, Palacios-Vélez; Luís A., Palacios-Sánchez; Mario, Martínez-Menes; Alfredo, Huete.

2008-12-01

138

[A novel vegetation index (MPRI) of corn canopy by vehicle-borne dynamic prediction].  

Science.gov (United States)

Ground-based remote sensing system is a significant way to understand the growth of corn and provide accurate and scientific data for precision agriculture. The vehicle-borne system is one of the most important tools for corn canopy monitoring. However, the vehicle-borne growth monitoring system cannot maintain steady operations due to the row spacing of corn. The reflectance of corn canopy, which was used to construct the model for the chlorophyll content, was disturbed by the reflectance of soil background. The background interference with the reflectance could not be removed effectively, which would result in a deviation in the growth monitoring. In order to overcome this problem, a novel vegetation index named MPRI was developed in the present paper. The tests were carried out by the vehicle-borne system on the cornfield. The sensors which configured the vehicle-borne system had 4 bands, being respectively 550, 650, 766 and 850 nm. It would obtain the spectral data while the vehicle moved along the row direction. The sampling rate was about 1 point per second. The GPS receiver obtained the location information at the same rate. MPRI was made up by the reflectance ratio of 660 and 550 nm. It was very effective to analyze the information about the reflectance of the canopy. The results of experiments showed that the MPRI of soil was the positive value and the MPRI of canopy was the negative value. So it is easier to distinguish the spectral information about soil and corn canopy by MPRI. The results indicated that: it had satisfactory forecasting accuracy for the chlorophyll content by using the MPRI on the moving monitoring. The R2 of the prediction model was about 0.72. The R2 Of the model of NDVI, which was used to represent the chlorophyll content, was only 0.24. It indicates that MPRI had good measurement results for the dynamic measurement process. It provided the novel measurement way to get the canopy reflectance spectra and the better vegetation index to construct the prediction model of the contents of chlorophyll. PMID:25358172

Li, Shu-qiang; Li, Min-zan; Sun, Hong

2014-06-01

139

Scaling the h-index for different scientific ISI fields  

CERN Document Server

We propose a simple way to put in a common scale the h values of researchers working in different scientific ISI fields, so that the previsible misuse of this index for inter-areas comparison might be prevented, or at least, alleviated.

Iglesias, J E; Iglesias, Juan E.; Pecharroman, Carlos

2006-01-01

140

Effects of N fertilization on the relationship between photosynthetic light use efficiency and photochemical reflectance index of wetland vegetation  

Science.gov (United States)

Monitoring of light use efficient (LUE) over space and time is a critical component of climate change research as it is a major determinant of the amount of carbon accumulated by terrestrial ecosystems. PRI (Photochemical reflectance index) has provide a fast and reliable method for estimating photosynthetic light use efficiency across species. The aim of this study was to evaluate the use of ground-based canopy reflectance measurements to detect changes in physiology of wetland vegetation in response to experimental nitrogen (N) treatment. In this paper, Bulrush with different nitrogen fertilization were selected to research the influence of varied fertilization levels on the relationship between PRI and LUE. The results proved that leaf chlorophyll contents as well as canopy PRI increased with the increase in nitrogen fertilization. For different nitrogen fertilization of Bulrush, the regression coefficients R2 varied respectively. Therefore, PRI not only can be a reliable indicator of LUE but also can reflect the growing situation of Bulrush with different precisions of LUE assessment.

Cheng, Qian; Wu, Xiuju

2010-11-01

 
 
 
 
141

A simple interpretation of the surface temperature/vegetation index space for assessment of surface moisture status  

DEFF Research Database (Denmark)

A simplified land surface dryness index (Temperature-Vegetation Dryness Index, TVDI) based on an empirical parameterisation of the relationship between surface temperature (T-s) and vegetation index (NDVI) is suggested. The index is related to soil moisture and, in comparison to existing interpretations of the T-s/NDVI space, the index is conceptually and computationally straightforward. It is based on satellite derived information only, and the potential for operational application of the index is therefore large. The spatial pattern and temporal evolution in TVDI has been analysed using 37 NOAA-AVHRR images from 1990 covering part of the Ferlo region of northern, semiarid Senegal in West Africa. The spatial pattern in TVDI has been compared with simulations of soil moisture from a distributed hydrological model based on the MIKE SHE code. The spatial variation in TVDI reflects the variation in moisture on a finer scale than can be derived from the hydrological model in this case. (C) 2002 Elsevier Science Inc. All rights reserved.

Sandholt, Inge; Rasmussen, Kjeld

2002-01-01

142

Genotypic variations in the accumulation of Cd exhibited by different vegetables.  

Science.gov (United States)

It is an important approach to use the Cd-contaminated soils properly by growing low accumulator or excluder plants for Cd to produce safe foods. To find the suitable vegetable species for growing in Cd-contaminated soils, in the present study the variations in the Cd accumulation for twenty eight vegetable species and several cultivars of five common vegetables (cowpea, kidney pea, bitter gourd, cucumber and squash) were investigated in two soil Cd levels (1 and 2 mg/kg Cd). Experimental results showed that highly significant differences in Cd concentration were evident among 28 vegetables. For example, spinach Cd concentrations were 110-fold and 175-fold higher than that of sweet pea under the 1 and 2 mg/kg Cd exposures, respectively. For Cd accumulation, the order of vegetable species was: leafy vegetables > solanaceous vegetables > kale vegetables > root vegetables > allimus > melon vegetables > legumes. Distinctive differences were also identified when comparing different cultivars of the five common vegetables with an average range of 0.003-0.094 mg/kg Cd. Our results indicated that a large genotypic variation existed among vegetable species or cultivars when subjected to Cd exposure. Therefore, it is important and feasible to elect/breed vegetable species/cultivars with low accumulation of Cd, especially in mildly Cd-contaminated soils. PMID:21179965

Yang, Junxing; Guo, Haitao; Ma, Yibing; Wang, Liqun; Wei, Dongpu; Hua, Luo

2010-01-01

143

Remote sensing of temperate coniferous forest lead area index - The influence of canopy closure, understory vegetation and background reflectance  

Science.gov (United States)

Consideration is given to the effects of canopy closure, understory vegetation, and background reflectance on the relationship between Landsat TM data and the leaf area index (LAI) of temperate coniferous forests in the western U.S. A methodology for correcting TM data for atmospheric conditions and sun-surface-sensor geometry is discussed. Strong inverse curvilinear relationships were found between coniferous forest LAI and TM bands 3 and 5. It is suggested that these inverse relationships are due to increased reflectance of understory vegetation and background in open stands of lower LAI and decreased reflectance of the overstory in closed canopy stands with higher LAI.

Spanner, Michael A.; Pierce, Lars L.; Running, Steven W.; Peterson, David L.

1990-01-01

144

Comparative evaluation of the Vegetation Dryness Index (VDI), the Temperature Vegetation Dryness Index (TVDI) and the improved TVDI (iTVDI) for water stress detection in semi-arid regions of Iran  

Science.gov (United States)

This study aims at developing appropriate methods to detect water stress in the semi-arid regions of Iran. To do this, the Vegetation Dryness Index (VDI) concept, originally developed for forest fire detection, was applied to detect vegetation/soil water stress. A modified approach towards the Temperature Vegetation Dryness Index (TVDI) concept, incorporating air temperature and a Digital Elevation Model (DEM) to develop the improved TVDI (iTVDI) is also introduced and the results are compared with the original TVDI and VDI through verification by precipitation and soil moisture data. Evaluation of the VDI in the study area showed that there was no significant relationship between the VDI values and precipitation or soil moisture indicating its inappropriateness to be used for water stress detection. Compared with the TVDI, results indicated that there were more statistically significant relationships between the iTVDI and recent precipitation and soil moisture in the four land cover types in the study area. This indicates that the iTVDI is highly influenced by recent precipitation during the summer and can therefore estimate water status. It is concluded that the iTVDI can be successfully used for vegetation/soil water stress monitoring in the semi-arid regions of Iran.

Rahimzadeh-Bajgiran, Parinaz; Omasa, Kenji; Shimizu, Yo

2012-03-01

145

Comparing forest measurements from tree rings and a space-based index of vegetation activity in Siberia  

International Nuclear Information System (INIS)

Different methods have been developed for measuring carbon stocks and fluxes in the northern high latitudes, ranging from intensively measured small plots to space-based methods that use reflectance data to drive production efficiency models. The field of dendroecology has used samples of tree growth from radial increments to quantify long-term variability in ecosystem productivity, but these have very limited spatial domains. Since the cambium material in tree cores is itself a product of photosynthesis in the canopy, it would be ideal to link these two approaches. We examine the associations between the normalized differenced vegetation index (NDVI) and tree growth using 19 pairs of tree-ring widths (TRW) and maximum latewood density (MXD) across much of Siberia. We find consistent correlations between NDVI and both measures of tree growth and no systematic difference between MXD and TRW. At the regional level we note strong correspondence between the first principal component of tree growth and NDVI for MXD and TRW in a temperature-limited bioregion, indicating that canopy reflectance and cambial production are broadly linked. Using a network of 21 TRW chronologies from south of Lake Baikal, we find a similarly strong regional correspondence with NDVI in a markedly drier region. We show that tree growth is dominated by variation at decadal and multidecadal time periods, which the satellite record is incapable of recording given its relatively short record. (letter)

146

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences  

Energy Technology Data Exchange (ETDEWEB)

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differences are discussed.

Beck, Pieter S A; Goetz, Scott J, E-mail: pbeck@whrc.org [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 (United States)

2011-10-15

147

Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences  

International Nuclear Information System (INIS)

To assess ongoing changes in high latitude vegetation productivity we compared spatiotemporal patterns in remotely sensed vegetation productivity in the tundra and boreal zones of North America and Eurasia. We compared the long-term GIMMS (Global Inventory Modeling and Mapping Studies) NDVI (Normalized Difference Vegetation Index) to the more recent and advanced MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI data set, and mapped circumpolar trends in a gross productivity metric derived from the former. We then analyzed how temporal changes in productivity differed along an evergreen-deciduous gradient in boreal Alaska, along a shrub cover gradient in Arctic Alaska, and during succession after fire in boreal North America and northern Eurasia. We find that the earlier reported contrast between trends of increasing tundra and decreasing boreal forest productivity has amplified in recent years, particularly in North America. Decreases in boreal forest productivity are most prominent in areas of denser tree cover and, particularly in Alaska, evergreen forest stands. On the North Slope of Alaska, however, increases in tundra productivity do not appear restricted to areas of higher shrub cover, which suggests enhanced productivity across functional vegetation types. Differences in the recovery of post-disturbance vegetation productivity between North America and Eurasia are described using burn chronosequences, and the potential factors driving regional differenotential factors driving regional differences are discussed.

148

Comparison and Intercalibration of Vegetation Indices from Different Sensors for Monitoring Above-Ground Plant Nitrogen Uptake in Winter Wheat  

Directory of Open Access Journals (Sweden)

Full Text Available Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from three ground-based sensors (ASD Field Spec Pro spectrometer, CropScan MSR 16 and GreenSeeker RT 100 in six winter wheat field experiments were compared. Then, the best sensor (ASD and its normalized difference vegetation index (NDVI (807, 736 for estimating above-ground plant N uptake were determined (R2 of 0.885 and RMSE of 1.440 g·N·m?2 for model calibration. In order to better utilize the spectral reflectance from the three sensors, intercalibration models for vegetation indices based on different sensors were developed. The results indicated that the vegetation indices from different sensors could be intercalibrated, which should promote application of data fusion and make monitoring of above-ground plant N uptake more precise and accurate.

Yan Zhu

2013-03-01

149

Soil moisture status estimation over Three Gorges area with Landsat TM data based on temperature vegetation dryness index  

Science.gov (United States)

Soil moisture is the important indicator of climate, hydrology, ecology, agriculture and other parameters of the land surface and atmospheric interface. Soil moisture plays an important role on the water and energy exchange at the land surface/atmosphere interface. Remote sensing can provide information on large area quickly and easily, so it is significant to do research on how to monitor soil moisture by remote sensing. This paper presents a method to assess soil moisture status using Landsat TM data over Three Gorges area in China based on TVDI. The potential of Temperature- Vegetation Dryness Index (TVDI) from Landsat TM data in assessing soil moisture was investigated in this region. After retrieving land surface temperature and vegetation index a TVDI model based on the features of Ts-NDVI space is established. And finally, soil moisture status is estimated according to TVDI. It shows that TVDI has the advantages of stability and high accuracy to estimating the soil moisture status.

Xu, Lina; Niu, Ruiqing; Li, Jiong; Dong, Yanfang

2011-12-01

150

Combining vegetation index and model inversion methods for theextraction of key vegetation biophysical parameters using Terra and Aqua MODIS reflectance data  

DEFF Research Database (Denmark)

Accurate estimates of vegetation biophysical variables are valuable as input to models describing the exchange of carbon dioxide and energy between the land surface and the atmosphere and important for a wide range of applications related to vegetation monitoring, weather prediction, and climate change. The present study explores the benefits of combining vegetation index and physically based approaches for the spatial and temporal mapping of green leaf area index (LAI), total chlorophyll content (TCab), and total vegetation water content (VWC). A numerical optimization method was employed for the inversion of a canopy reflectance model using Terra and Aqua MODIS multi-spectral, multi-temporal, and multi-angle reflectance observations to aid the determination of vegetation-specific physiological and structural canopy parameters. Land cover and site-specific inversion modeling was applied to a restricted number of pixels to build multiple species- and environmentally dependent formulations relating the three biophysical properties of interest to a number of selected simpler spectral vegetation indices (VI). While inversions generally are computationally slow, the coupling with the simple and computationally efficient VI approach makes the combined retrieval scheme for LAI, TCab, and VWC suitable for large-scale mapping operations. In order to facilitate application of the canopy reflectance model to heterogeneous forested areas, a simple correction scheme was elaborated, which was found to improve forest LAI predictions significantly and also provided more realistic values of leaf chlorophyll contents. The inversion scheme was designed to enable biophysical parameter retrievals for land cover classes characterized by contrasting canopy architectures, leaf inclination angles, and leaf biochemical constituents without utilizing calibration measurements. Preliminary LAI validation results for the Island of Zealand, Denmark (57°N, 12°E) provided confidence in the approach with root mean square (RMS) deviations between estimates and in-situ measurements of 0.62, 0.46, and 0.63 for barley, wheat, and deciduous forest sites, respectively. Despite the independence on site-specific in-situ measurements, the RMS deviations of the automated approach are in the same range as those established in other studies employing field-based empirical calibration. Being completely automated and image-based and independent on extensive and impractical surface measurements, the retrieval scheme has potential for operational use and can quite easily be implemented for other regions. More validation studies are needed to evaluate the usefulness and limitations of the approach for other environments and species compositions.

Houborg, Rasmus MØller; SØgaard, Henrik

2007-01-01

151

Effect of three different nitrogen fertilizers on several vegetable crops  

Directory of Open Access Journals (Sweden)

Full Text Available Applications of three different sources of N fertilizers (urea, compost from slaughter house and chicken manure compost on vegetable crops (tomato, okra and spinach were conducted in the green house of Research Institute for Food Crop Biotechnology, Bogor from August of 1999 to April of 2000. Treatments consisted of: (i without fertilizer, (ii 5 g N/pot of urea, (iii 10 g N/pot of slaughter house compost, (iv 10 g N/pot of chicken manure compost, (v 5 g N/pot of urea + 10 g N/pot of slaughter house compost, and (vi 5 g N/pot of urea + 10 g N/pot of chicken manure compost. Completely Randomized Design with 3 replicates was used in the experiments. In the first experiment, tomatoes were planted in the first season, following by okra in the second season. In the second experiment, spinach was planted for 6 times. Urea and compost were applied only once at the beginning of the experiment. Results of the experiments showed that for the first experiment

WIDIATI HADI ADIL

2006-01-01

152

Fruit and Vegetable Intake and Body Mass Index in a Large Sample of Middle-Aged Australian Men and Women  

Directory of Open Access Journals (Sweden)

Full Text Available Dietary guidelines around the world recommend increased intakes of fruits and non-starchy vegetables for the prevention of chronic diseases and possibly obesity. This study aimed to describe the association between body mass index (BMI and habitual fruit and vegetable consumption in a large sample of 246,995 Australian adults aged 45 + year who had been recruited for the “45 and Up” cohort study. Fruit and vegetable intake was assessed using validated short questions, while weight and height were self-reported. Multinomial logistic regression was used, by sex, to assess the association between fruit and vegetable intake and BMI. Compared to the referent normal weight category (BMI 18.5 to 24.9, the odds ratio (OR of being in the highest vegetable intake quartile was 1.09 (95% confidence interval (CI 1.04–1.14 for overweight women (BMI 25.0–29.9 and 1.18 (95% CI 1.12–1.24 for obese women. The association was in the opposite direction for fruit for overweight (OR 0.85; 95% CI 0.80–0.90 and obese women (OR 0.75; 95% CI 0.69–0.80. Obese and overweight women had higher odds of being in the highest intake quartile for combined fruit and vegetable intake, and were more likely to meet the “2 and 5” target or to have five or more serves of fruit and vegetables per day. In contrast, overweight men were less likely to be in high intake quartiles and less likely to meet recommended target of 5 per day, but there was no consistent relationship between obesity and fruit and vegetable intake. Underweight women and underweight men were less likely to be in the highest intake quartiles or to meet the recommended targets. These data suggest that improving adherence to dietary targets for fruit and vegetables may be a dietary strategy to overcome overweight among men, but that overweight and obese women are already adhering to these targets. The association between fruit and vegetable intake and underweight in adults suggests that improving fruit and vegetables intakes are important for the overall dietary patterns of people in this group.

Karen Charlton

2014-06-01

153

Accuracy of the Temperature-Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions  

DEFF Research Database (Denmark)

Water deficit indices based on the spatial relationship between surface temperature (Ts) and NDVI, known as triangle approaches, are widely used for drought monitoring. However, their application has been recently questioned when the main factor limiting evapotranspiration is energy. Even though water is the main control in dryland ecosystems, these can also undergo periods of energy and temperature limitation. In this paper we aimed to: (i) evaluate the TVDI (Temperature-Vegetation Dryness Index) to estimate water deficits (e.g. ratio between actual and potential evapotranspiration), and heat surface fluxes using MODIS data; and (ii) provide insights about the factors most affecting the accuracy of results. Factors considered included the type of climatic control on evapotranspiration, ?E, (i.e. water-limited vs. energy-limited), the quality of Tair estimates, the heterogeneity of land cover types and climatic variables in the region, or the algorithm to extract hydrological boundaries from the images. The TVDI was compared with eddy covariance (EC) data from two shrublands with different climatic controls for ?E in South Spain. Evaluations showed that it could be used to estimate the water deficit when water was the main limiting factor (R=0.81-0.88; Mean Average Error, MAE=0.16-0.17) but not in energy-limited situations (R

Garcia, Monica; Sandholt, Inge

2014-01-01

154

Seasonal analysis of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data  

Science.gov (United States)

Paddy field is important agriculture crop in Indonesia. Rice is a food staple for 237,6 million Indonesian people. Paddy field growth is strongly influenced by water, but the amount of precipitation is unpredictable. Annual and interannual climate variability in Indonesia is unusual. In recent years remote sensing data has been used for measurement and monitoring of precipitation, drought and Vegetation index such as Global Satellite Mapping of Precipitation (GSMaP), Multi-purpose Transmission SATellite (MTSAT) and Moderate Resolution Imaging Spectroradiometer (MODIS). The objective of this research is to investigate seasonal variability of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data. The methodology consists of collecting of enhanced vegetation index (EVI) from MODIS data, mosaicking of image, collecting of region of interest of paddy field, collecting of precipitation and drought index based on Keetch Bryam Drought Index (KBDI) from GSMaP and MTSAT, and seasonal analysis. The result of this research has showed seasonal variability of precipitation, KBDI and EVI on Indonesia paddy field from 2007 until 2012. Precipitation begins from January until May and October until December, and KBDI begins to increase from June and peak in September only in South Sumatera precipitation almost in all month. Seasonal analysis has showed precipitation and KBDI affect on EVI that can indicate variety phenology of Indonesian paddy field. Peak of EVI occurs before peak of KBDI occurs and increasing of KBDI followed by decreasing of EVI. In 2010 all province got higher precipitation and smaller KBDI so EVI has three peaks such as in West Java that can indicated increasing of rice production.

Darmawan, S.; Takeuchi, W.; Shofiyati, R.; Sari, D. K.; Wikantika, K.

2014-06-01

155

Impact of the construction of a large dam on riparian vegetation cover at different elevation zones as observed from remotely sensed data  

Science.gov (United States)

The impact of the construction of a large dam on riparian vegetation cover can be multifold. How the riparian vegetation cover changes at different elevation zones in response to the construction of a large dam and the subsequent impound of reservoir water is still an open question. In this study, we used satellite remote sensing data integrated with geographic information system (GIS) to monitor vegetation cover change at different riparian elevation zones on a large spatial scale, taking the Three Gorges Dam in China as an example. Due to the large scale of this newly formed reservoir, it is expected to impact the riparian vegetation canopy both directly and indirectly. We chose to monitor vegetation cover changes along the 100 km riparian stretch of river directly upstream of the Three Gorges Dam site, over the construction period of eleven years (2000-2010), using MODIS vegetation indices products, digital elevation model (DEM) data from ASTER, and the time series water level data of the Three Gorges reservoir as the data sources. Results show that non-vegetated area increased in the inundated zone (below 175 m), as expected; area of densely vegetated land cover increased within the elevation zone of 175-775 m and no change in vegetation cover was observed above 775 m in elevation. Regression analysis between the vegetation index data and the reservoir water level shows that increasing water levels have had a negative impact on vegetation cover below 175 m, a positive impact on vegetation cover is limited to the region between 175 and 775 m, and no significant impact was observed above 775 m. MODIS EVI product is less sensitive in mapping non-vegetated land cover change, but more sensitive in mapping vegetated land cover change, caused by the reservoir water level variation; both products are similar in effectively tracking a trend between land cover change in each elevation zone with time or with reservoir water level.

Kellogg, Christopher H.; Zhou, Xiaobing

2014-10-01

156

Analysis of dynamic thresholds for the normalized difference water index  

Science.gov (United States)

The normalized difference water index (NDWI) has been successfully used to delineate surface water features. However, two major problems have been often encountered: (a) NDWIs calculated from different band combinations [visible, nearinfrared, or shortwave-infrared (SWIR)] can generate different results, and (b) NDWI thresholds vary depending on the proportions of subpixel water/non-water components. We need to evaluate all the NDWIS for determining the best performing index and to establish appropriate thresholds for clearly identifying water features. We used the spectral data obtained from a spectral library to simulate the satellite sensors Landsat ETM+, SPOT-5, ASTER, and MODIS, and calculated the simulated NDWI in different forms. We found that the NDWI calculated from (green - swm)/(green + SWIR), where SWIR is the shorter wavelength region (1.2 to 1.8 ??m), has the most stable threshold. We recommend this NDWI be employed for mapping water, but adjustment of the threshold based on actual situations is necessary. ?? 2009 American Society for Photogrammetry and Remote Sensing.

Ji, L.; Zhang, Li; Wylie, B.

2009-01-01

157

Indexed  

CERN Document Server

Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

Hagy, Jessica

2008-01-01

158

Differences between Sand and Gravel Bars of Streams in Patterns of Vegetation Succession  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We analyzed the factors driving succession and the structure, and dynamics of vegetation on sandand gravel bars in order to clarify the differences in vegetation succession in rivers with different river bed substrates.Woody plant communities (dominated by Salix), perennial herb communities (dominated by Miscanthus),and annual plant communities (dominated by Persicaria) appeared in that order from upstream to downstreamon the sandbar. The results of DCA ordination based on vegetation data ref...

Lee, Chang-seok; Yong-Chan Cho; Hyun-Cheol Shin; Sung-Ae Park

2009-01-01

159

Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Some vegetable oils contains natural antioxidants such as beta carotene and vitamin E namely tocopherol and tocotrienol. Different vegetable oils contained different amount of vitamin E and ?-carotene. Approach: Study was carried out to investigate the natural antioxidants (vitamin E and beta carotene composition in four different vegetable oils [Red Palm Olein (RPO, palm plein (PO, Corn Oil (CO and Coconut Oil (COC]. Results: The results showed that RPO contained the highest amount of vitamin E and ?-carotene compared to the other three types of vegetable oils studied. Conclusion: The RPO can be considered as a good source of natural antioxidant (tocopherol, tocotrienol and ?-carotene.

Ab. G.M. Top

2011-01-01

160

DEVELOPMENT OF AN INDEX OF ALIEN SPECIES INVASIVENESS: AN AID TO ASSESSING RIPARIAN VEGETATION CONDITION  

Science.gov (United States)

Many riparian areas are invaded by alien plant species that negatively affect native species composition, community dynamics and ecosystem properties. We sampled vegetation along reaches of 31 low order streams in eastern Oregon, and characterized species assemblages at patch an...

 
 
 
 
161

Plasma Electrophoresis and Phagocytic Index Screening of Some Indigenous Vegetables Subjected to Preclinical Models  

Directory of Open Access Journals (Sweden)

Full Text Available

50 % of methanolic extract Colocasia esculenta, Moringa oliefera, Luffa cylindrica, and Hibiscus esculentus were subjected to immunomodulatory activity in Swiss albino mice either sex. Mice were treated with five days of dosing of Colocasia esculenta 50 mg/kg bw, Colocasia esculenta 100 mg/kg bw, Moringa oliefera 200mg/kg bw, Moringa oleifera 400 mg/kg bw, Luffa cylindrica 100 mg/kg bw, Luffa cylindrica 200 mg/kg bw, Hibiscus esculentus 100 mg/kg bw, and Hibiscus esculentus 200 mg/kg bw. Cyclosporine (2.5 mg/kg used as a standard reference drug for 5 days. Investigation of immunomodulator activity of these 50 % of methanolic extract of drugs to parentage of yeast digestion form 24 hours the peritoneal fluid culture and electrophoretic plasma protein band albumin, alpha 1, alpha 2, beta and gamma respectively from blood plasma were observed using parameters phagocytosis and plasma electrophoresis. Also investigated the ulcerogenic effect or any toxic effect of plant extract by histopathology study of crypt, villi and goblet cells with reference to standard drug cyclosporine. As regards these parameters, Hibiscus esculentus 100 and 200 mg/ kg bw dose, Moringa oleifera 200 and 400 mg/ kg bw dose and Luffa cylindrica 200mg/kg bw elicited a moderately significant increase in the % of yeast digestion (P < 0.001 respectively and Luffa cylindrica 100mg/kg bw significant increase in the % of yeast digestion (P < 0.01. Hibiscus esculentus showed significant dose dependent increase and Moringa oleifera decrease phagocytic activity of macrophages. Hibiscus esculentus 200 mg/ kg bw dose and Moringa oleifera 200 significantly increased (P < 0.01 the Gamma globulin.However, our present study revealed and signatured for their immunomodulator enhancing property. As in Asian subcontinent daily there vegetables are cooked and served with know and unknown of its potential function against different diseases. If there vegetables properly ruled out for their pharmacological aspect then it may add diamond in the crown of dietician which has been bother every day today life but over looked exponetentially.

Keywords:- Colocasia esculenta, Moringa oliefera, Luffa cylindrica, and Hibiscus esculentus

Vikas Sharma

2011-04-01

162

A survey of drought and Variation of Vegetation by statistical indexes and remote sensing (Case study: Jahad forest in Bandar Abbas)  

Science.gov (United States)

The damages of drought as a climatic and creeping phenomenon are very enormous specially in deserts. Necessity of management and conflict with it is clear. In this case vegetation are damaged too, and even are changed faster. This paper describes the process of vegetation changes and surveys it with drought indexes such as statistical and remote sensing indexes and correlation between temperature and relative humidity by Geographical Information System (GIS) and Remote Sensing (RS) in forest park of Bandar Abbas in successive years. At the end the regression and determination-coefficient for showing the importance of droughts survey are computed. Results revealed that the correlation between vegetation and indexes was 0.5. The humidity had maximum correlation and when we close to 2009 the period of droughts increase and time intervals decrease that influence vegetation enormously and cause the more area lost its vegetation.

Tamassoki, E.; Soleymani, Z.; Bahrami, F.; Abbasgharemani, H.

2014-06-01

163

Study of a Vegetation Index Based on HJ CCD Data's top-of-atmosphere reflectance and FPAR Inversion  

Science.gov (United States)

The Fraction of Photosynthetically Active Radiation (FPAR)absorbed by plant canopies is a key parameter for monitoring crop condition and estimating crop yield. In general, it is necessary to obtain Top of Canopy (TOC) reflectance from optical remote sensing data in digital number through atmospheric correction procedures before retrieving FPAR. However, there are a few of uncertainties that existe in the process of atmosphere correction and reduced the quality of TOC. This paper presents a vegetation index based on Top-of-Atmosphere (TOA) reflectance derived from HJ-1 CCD satellite for estimating direct crop FPAR. The vegetation index (HJVI) was designed based on the simulated results of a canopy-atmosphere radiative transfer model, including TOA reflectance and corresponded FPAR. The HJVI had taken the advantages of information in the green, the red and the near-infrared spectral domainswith with a aim of reducing the atmospheric effect and enhancing the sensitive to green vegetation. The HJVI was used to estimate soybean FPAR directly and validated using field measurements. The result indicated that the inversion algorithm produced a good relationship between the prediction and measurement (R2 = 0.546, RMSE = 0.083) and the HJVI showed high potential for estimating FPAR based on the HJ-1 TOA reflectance directly.

Dong, Taifeng; Wu, Bingfang; Meng, Jihua

2014-03-01

164

Properties of starch from potatoes differing in glycemic index.  

Science.gov (United States)

Potatoes are a popular source of dietary carbohydrate worldwide and are generally considered to be a high glycemic index (GI) food. Potato starch characteristics play a key role in determining their rate of digestion and resulting glycemic response. Starches isolated from seven potato cultivars with different GI values, including a low GI cultivar (Carisma), were examined for relative crystallinity, granule size distribution, amylopectin chain length, and thermal and pasting properties. Starch from the Carisma cultivar was more thermally stable and more resistant to gelatinization, with significantly higher (p differential scanning calorimetry (DSC) gelatinization onset, peak and conclusion temperatures, compared to the other cultivars. Differences between the potatoes in the other properties measured did not align with the GI ranking. Thermal analysis and starch pasting properties may be useful indicators for preliminary identification of potato cultivars that are digested slowly and have a lower GI. PMID:25124366

Lin Ek, Kai; Wang, Shujun; Brand-Miller, Jennie; Copeland, Les

2014-10-24

165

Efficient retrieval of vegetation leaf area index and canopy clumping factor from satellite data to support pollutant deposition assessments.  

Science.gov (United States)

Canopy leaf area index (LAI) is an important structural parameter of the vegetation controlling pollutant uptake by terrestrial ecosystems. This paper presents a computationally efficient algorithm for retrieval of vegetation LAI and canopy clumping factor from satellite data using observed Simple Ratios (SR) of near-infrared to red reflectance. The method employs numerical inversion of a physics-based analytical canopy radiative transfer model that simulates the bi-directional reflectance distribution function (BRDF). The algorithm is independent of ecosystem type. The method is applied to 1-km resolution AVHRR satellite images to retrieve a geo-referenced data set of monthly LAI values for the conterminous USA. Satellite-based LAI estimates are compared against independent ground LAI measurements over a range of ecosystem types. Verification results suggest that the new algorithm represents a viable approach to LAI retrieval at continental scale, and can facilitate spatially explicit studies of regional pollutant deposition and trace gas exchange. PMID:16343718

Nikolov, Ned; Zeller, Karl

2006-06-01

166

The study of vegetation indices for the monitoring of differences in chlorophyll and carotenoid composition in green vegetables  

Science.gov (United States)

In this paper we studied the reflectance spectra of different green vegetables. The main objective was to identify the wavelength(s)(areas) that are the most sensitive to variations in pigment composition. With this we try to meet the ever growing demand from society to classify food products on their quality which is related to the state of ripening and degradation. The group of investigated samples consisted of a group of seven different green vegetables. Because these products have different pigment compositions they formed the ideal test samples for our research. For each product type we measured the reflectance spectra between 400 and 800 nm for 30 samples. From these spectra we investigated three different types of measurands: the measurands that are nowadays commonly used to monitor color differences, the vegetation indices that are defined to monitor plant leaves and measurands that are taking into account the entire reflectance spectrum in the visible part of the electromagnetic spectrum. The main conclusion of our research was that a combination of the first two mentioned types of indices allowed us to identify the different product groups in an optical way.

Meulebroeck, Wendy; Thienpont, Hugo

2012-04-01

167

Satellite-derived leaf-area-index and vegetation maps as input to global carbon cycle models - A hierarchical approach  

Science.gov (United States)

A hierarchical procedure for developing a leaf area index (LAI) map of deciduous boreal forests is studied. The collection of spectral reflectance data from the Boundary Waters Canoe area in Minnesota using helicopter-, high-altitude aircraft-, and Landsat-mounted spectral sensors is described. The relationship between LAI and biomass and the reflectance ratio is analyzed. The sensitivity of canopy reflectance in the visible and infrared to the LAI of the canopy for various boreal forest species is evaluated. The data reveal that Landsat data are useful for producing LAI maps of deciduous forest areas and the maps provide data which clarifies the function of vegetation in the global carbon cycle models.

Badhwar, G. D.; Macdonald, R. B.; Mehta, N. C.

1986-01-01

168

Reactivity indexes for different geometries of palladium leads  

Science.gov (United States)

Electronic transport through metallic break junctions or molecules is clearly dependent not only on the electronic structure of the central nanodevice connecting the leads, but also the shape and crystalline orientation of the contacts which can define the possible conduction channels. In this work we examine different geometries of contacts of palladium characterizing them through global and local reactivity indexes as electrophilicity, chemical hardness and Fukui functions. In molecules, these indicators are essentially defined by the energies of the frontier molecular orbitals and in solids they are related with the local and partial density of states. We use for this purpose an ab-initio based code (FIREBALL), applied to plane contacts with (001) fcc faces and also pyramidal tips grown following a (001) and (111) packaging. The results allow us to have an insight about the chemical features of this type of nanojunctions.

Gómez-Carrillo, S. C.; Ortega, J.; Bolcatto, P. G.

2009-05-01

169

Diseño de índices espectrales de la vegetación usando curvas iso-suelo / Design of spectral vegetation indexes using iso-soil curves  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El diseño de índices espectrales de la vegetación (IV) basados en las líneas iso-índice de área foliar (misma cantidad de vegetación y propiedades ópticas diferentes de los suelos debajo de la vegetación) en el ancho de banda del rojo (R) e infrarrojo cercano (IRC) del espectro electromagnético, res [...] ulta complejo por el patrón expo-lineal con cambio de pendiente, entre los parámetros que definen estas líneas. Una alternativa de diseño es considerar los patrones de las curvas iso-suelo (mismo suelo y cantidad variable de vegetación), usando el IRC como banda de saturación más lenta posible. El índice IVIS (IV basado en las curvas iso-suelo) introducido permite este tipo de aproximación, al usar una transformación del espacio de R para hacerlo coincidir con la línea del suelo y una estructura matemática similar a índices uni-banda espectral. La validación de IVIS usando simulaciones radiativas y de experimentos con cultivos generó resultados aceptables, particularmente con una óptica de minimización del efecto del suelo en escala píxel por píxel. La transformación de IVIS permite la parametrización de la curva de crecimiento en formato lineal, simple de implementar en términos algorítmicos. Abstract in english The design of spectral vegetation indexes (VI) based on the lines iso-leaf area index (same amount of vegetation and different optical properties of the soils under the vegetation) in two bands of the electromagnetic spectrum, the red (R) and near-infrared (NIR), is complicated because of the expoli [...] near pattern with change of slope, among the parameters that define these lines. An alternative design is to consider the patterns of iso-soil curves (same soil, and varying amounts of vegetation), using the NIR as a saturation band as slow as possible. The introduced index ISVI (VI based on the iso-soil curves) allows this type of approach, by using a transformation of the space of R to make it coincide with the soil line and a mathematical structure similar to uni-band spectral indexes. ISVI validation using radiative simulations and crop experiments produced acceptable results, particularly with a perspective of minimizing the soil effect at píxel by píxel scale. The transformation of the ISVI allows parameterization of the growth curve in a linear format, simple to implement in algorithmic terms.

Fernando, Paz-Pellat; Marisol, Reyes; Edgardo, Mediano.

170

Diseño de índices espectrales de la vegetación usando curvas iso-suelo / Design of spectral vegetation indexes using iso-soil curves  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El diseño de índices espectrales de la vegetación (IV) basados en las líneas iso-índice de área foliar (misma cantidad de vegetación y propiedades ópticas diferentes de los suelos debajo de la vegetación) en el ancho de banda del rojo (R) e infrarrojo cercano (IRC) del espectro electromagnético, res [...] ulta complejo por el patrón expo-lineal con cambio de pendiente, entre los parámetros que definen estas líneas. Una alternativa de diseño es considerar los patrones de las curvas iso-suelo (mismo suelo y cantidad variable de vegetación), usando el IRC como banda de saturación más lenta posible. El índice IVIS (IV basado en las curvas iso-suelo) introducido permite este tipo de aproximación, al usar una transformación del espacio de R para hacerlo coincidir con la línea del suelo y una estructura matemática similar a índices uni-banda espectral. La validación de IVIS usando simulaciones radiativas y de experimentos con cultivos generó resultados aceptables, particularmente con una óptica de minimización del efecto del suelo en escala píxel por píxel. La transformación de IVIS permite la parametrización de la curva de crecimiento en formato lineal, simple de implementar en términos algorítmicos. Abstract in english The design of spectral vegetation indexes (VI) based on the lines iso-leaf area index (same amount of vegetation and different optical properties of the soils under the vegetation) in two bands of the electromagnetic spectrum, the red (R) and near-infrared (NIR), is complicated because of the expoli [...] near pattern with change of slope, among the parameters that define these lines. An alternative design is to consider the patterns of iso-soil curves (same soil, and varying amounts of vegetation), using the NIR as a saturation band as slow as possible. The introduced index ISVI (VI based on the iso-soil curves) allows this type of approach, by using a transformation of the space of R to make it coincide with the soil line and a mathematical structure similar to uni-band spectral indexes. ISVI validation using radiative simulations and crop experiments produced acceptable results, particularly with a perspective of minimizing the soil effect at píxel by píxel scale. The transformation of the ISVI allows parameterization of the growth curve in a linear format, simple to implement in algorithmic terms.

Fernando, Paz-Pellat; Marisol, Reyes; Edgardo, Mediano.

2011-02-01

171

Differences in the dry deposition of gaseous elemental I-131 to several leafy vegetable species  

Energy Technology Data Exchange (ETDEWEB)

The height of the dry deposition of gaseous elemental {sup 131}I to leafy vegetable is quite uncertain because of the different habit, surface texture and leaf uptake of the different plant species. There is no comparative data on the deposition to various species, but leafy vegetables are taken as reference plants for the estimation of the height of contamination of vegetable foods after a nuclear accident. Therefore new chamber experiments were performed to determine under homogeneous and controlled conditions the dry deposition of gaseous elemental {sup 131}I on mature leafy vegetable. The simultaneous exposition of endive, head lettuce, red oak leaf lettuce and spinach (spring leafy vegetable) rsp. curly kale, white cabbage and spinach (summer leafy vegetable) was arranged. The sample collective of each species was such large that for the expected variation of the results a statistically firm analysis was possible. Significant differences were observed for the {sup 131}I deposition on spring vegetable: the deposition on spinach was roughly 3 times that on leaf lettuce, 4 times that on endive and 9 times that on head lettuce. All summer vegetables showed differences in deposition. For Iodine, the deposition on spinach was roughly 3 times (6 times) that on curly kale and 35 times (100 times) that on white cabbage in the 2 experiments. Washing by deionised water could reduce the contamination only by about 10% for {sup 131}I. (author)

Shinonaga, T.; Heuberger, H.; Tschiersch, J. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, Neuherberg, Germany, IAEA Laboratories, Seibersdorf (Austria)

2004-07-01

172

Efficient retrieval of vegetation leaf area index and canopy clumping factor from satellite data to support pollutant deposition assessments  

International Nuclear Information System (INIS)

Canopy leaf area index (LAI) is an important structural parameter of the vegetation controlling pollutant uptake by terrestrial ecosystems. This paper presents a computationally efficient algorithm for retrieval of vegetation LAI and canopy clumping factor from satellite data using observed Simple Ratios (SR) of near-infrared to red reflectance. The method employs numerical inversion of a physics-based analytical canopy radiative transfer model that simulates the bi-directional reflectance distribution function (BRDF). The algorithm is independent of ecosystem type. The method is applied to 1-km resolution AVHRR satellite images to retrieve a geo-referenced data set of monthly LAI values for the conterminous USA. Satellite-based LAI estimates are compared against independent ground LAI measurements over a range of ecosystem types. Verification results suggest that the new algorithm represents a viable approach to LAI retrieval at continental scale, and can facilitate spatially explicit studies of regional pollutant deposition and trace gas exchange. - The paper presents a physics-based algorithm for retrieval of vegetation LAI and canopy-clumping factor from satellite data to assist research of pollutant deposition and trace-gas exchange. The method is employed to derive a monthly LAI dataset for the conterminous USA and verified at a continental scale

173

Comparative analysis of different uni- and multi-variate methods for estimation of vegetation water content using hyper-spectral measurements  

Science.gov (United States)

Assessment of vegetation water content is critical for monitoring vegetation condition, detecting plant water stress, assessing the risk of forest fires and evaluating water status for irrigation. The main objective of this study was to investigate the performance of various mono- and multi-variate statistical methods for estimating vegetation water content (VWC) from hyper-spectral data. Hyper-spectral data is influenced by multi-collinearity because of a large number of (independent) spectral bands being modeled by a small number of (dependent) biophysical variables. Therefore, some full spectrum methods that are known to be suitable for analyzing multi-collinear data set were chosen. Canopy spectral reflectance was obtained with a GER 3700 spectro-radiometer (400-2400 nm) in a laboratory setting and VWC was measured by calculating wet/dry weight difference per unit of ground area (g/m2) of each plant canopy (n = 95). Three multivariate statistical methods were applied to estimate VWC: (1) partial least square regression, (2) artificial neural network and (3) principal component regression. They were selected to minimize the problem related to multi-collinearity. For comparison, uni-variate techniques including narrow band ratio water index (RWI), normalized difference water index (NDWI), second soil adjusted vegetation index (SAVI2) and transferred soil adjusted vegetation index (TSAVI) were applied. For each type of vegetation index, all two-band combinations were evaluated to determine the best band combination. Validation of the methods was based on the cross validation procedure and using three statistical indicators: R2, RMSE and relative RMSE. The cross-validated results identified PLSR as the regression model providing the most accurate estimates of VWC among the various methods. The result revealed that this model is highly recommended for use with multi-collinear datasets (RCV2=0.94, RRMSECV = 0.23). Principal component regression exhibited the lowest accuracy among the multivariate models (RCV2=0.78, RRMSECV = 0.41).

Mirzaie, M.; Darvishzadeh, R.; Shakiba, A.; Matkan, A. A.; Atzberger, C.; Skidmore, A.

2014-02-01

174

Analysis of Leaf Area Index and Fraction of PAR Absorbed by Vegetation Products from the Terra MODIS Sensor: 2000-2005  

Science.gov (United States)

The analysis of two years of Collection 3 and five years of Collection 4 Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) data sets is presented in this article with the goal of understanding product quality with respect to version (Collection 3 versus 4), algorithm (main versus backup), snow (snow-free versus snow on the ground), and cloud (cloud-free versus cloudy) conditions. Retrievals from the main radiative transfer algorithm increased from 55% in Collection 3 to 67% in Collection 4 due to algorithm refinements and improved inputs. Anomalously high LAI/FPAR values observed in Collection 3 product in some vegetation types were corrected in Collection 4. The problem of reflectance saturation and too few main algorithm retrievals in broadleaf forests persisted in Collection 4. The spurious seasonality in needleleaf LAI/FPAR fields was traced to fewer reliable input data and retrievals during the boreal winter period. About 97% of the snow covered pixels were processed by the backup Normalized Difference Vegetation Index-based algorithm. Similarly, a majority of retrievals under cloudy conditions were obtained from the backup algorithm. For these reasons, the users are advised to consult the quality flags accompanying the LAI and FPAR product.

Yang, Wenze; Huang, Dong; Tan, Bin; Stroeve, Julienne C.; Shabanov, Nikolay V.; Knyazikhin, Yuri; Nemani, Ramakrishna R.; Myneni, Ranga B.

2006-01-01

175

Differences between Sand and Gravel Bars of Streams in Patterns of Vegetation Succession  

Directory of Open Access Journals (Sweden)

Full Text Available We analyzed the factors driving succession and the structure, and dynamics of vegetation on sandand gravel bars in order to clarify the differences in vegetation succession in rivers with different river bed substrates.Woody plant communities (dominated by Salix, perennial herb communities (dominated by Miscanthus,and annual plant communities (dominated by Persicaria appeared in that order from upstream to downstreamon the sandbar. The results of DCA ordination based on vegetation data reflected a successional trend. Thisresult suggests that sandbars grow in a downstream direction. Various vegetation types different in successionalstage, such as grassland, young stands of Korean red pine (Pinus densiflora, two-layered stands of young andmature pines, and mature pine stands also occurred on gravel bars, but the vegetation in earlier successionalstage was established upstream, which is the opposite to the direction found on sandbars. Those resultsdemonstrate that the dynamics of the bed load itself could be a factor affecting vegetation succession in rivers.In fact, sands suspended by running water were transported downstream over the vegetated area of sand barand thereby created new areas of sandbar on the downstream end of the sandbar. Meanwhile, gravel, whichis heavy and thereby is shifted by strong water currents, accumulated on the upstream end of the vegetatedarea, and thus created new areas of gravel bar in that direction. These results showed that allogenic processesdrive vegetation succession on sand and gravel bars in streams and rivers.

Lee, Chang-Seok

2009-02-01

176

Experiments of hydraulics mechanics through different arrangement of submerged bending vegetation  

Science.gov (United States)

Laboratory experiments are used to explore the effect of different arrangement of submerged bending vegetation in the fixed bed on flow field around vegetation and area downstream. The two simulated bending vegetation were composed of pipe curved to 90 degree for stems and P.P.C films for blades. The two bending vegetation were arranged in alignment and paralleled with flow direction. The test arrangement was distinguished by different overlap rate of vegetation. Overlap rate of vegetation were defined that percentage of blades of bending vegetation overlap the other one. Overlap rate is greater than zero and it means that vegetation overlap the other one. On the other hand, overlap rate is smaller than zero and it means that two plants were separated in percentage of total length of vegetation The experiments were carried out 10 test in forms of overlap rate of vegetation (50%, 25%, 0%,-25%,-50%) by blades of 20cm and 25cm.Velocity and turbulence intensity around the vegetation (u, v, w and urms, vrms, wrms) were acquired by Ultrasound Velocity Profiler (UVP). Furthermore, to elaborate variation of the flow field, the swinging motion of vegetation was recorded by digital camera. Three arrangement types (overlapped, continuous and isolated) were concluded from the 10 tests. In case of isolated vegetation, it could be observed that there was a better effect on slowing flow velocity in x direction in case of the tests with -25% overlap rate due to a discontinuous shear layer between two plants which induced wake interference. It also showed that turbulence intensity was significant between two plants. Two plants disturbed rarely each other in the tests of isolated vegetation with -50% overlap rate .Flow was disturbed by swinging of blades only and returned to stable quickly. In 25% and 50% tests, two plants were overlapped and their behavior was similar to a longer blades plant. Its blades swinging were not obvious result as low effect on slowing velocity in x direction. It means that the characteristic of overlapped vegetation is good for stabilizing the flow field. The research helped to realize influence between two plants on flow field in order to apply river system management strategies.

Chen, Ye-Hong; Chen, Su Chun

2014-05-01

177

Multi-scale approach of the surface temperature/vegetation index triangle method for estimating evapotranspiration over heterogeneous landscapes  

Science.gov (United States)

Remote sensing has proved to be a powerful tool for estimating evapotranspiration at regional scales. Yet, the estimation accuracy not only depends on the calculation method, but also on the temporal and spatial resolution, often inversely related, of the dataset used. In order to analyse these influences, the triangle method has been tested over several satellite imagery, including MSG-SEVIRI, ENVISAT-AATSR/MERIS, NOAA-AVHRR, Landsat5-TM and Landsat7-ETM+, and compared to field site scintillometer measurements. The triangle method assumes a triangular space formed between the surface temperature (Ts) and a vegetation index. When the edges of the triangle are estimated, the evaporative fraction (EF) is computed for all cloud-free pixels through an interpolation method, based on the Priestley-Taylor method. Once evaporative fraction maps are computed, daily evapotranspiration rates can be obtained by combining EF with the available daily net energy (Rn-G). The highly frequent acquisitions (15 minutes) of the MSG-SEVIRI data provides the possibility of expressing Ts in the triangle method as an increase over time, by using what it is known as thermal inertia (dTs). As it includes more information on sensible heating than Ts alone, better estimates of daily evapotranspiration can be made than the ones obtained from instantaneous Ts as in helisynchronous satellites. In addition, the use of a time-difference temperature allows to minimize possible systematic errors in Ts estimation. However, due to the SEVIRI coarse resolution (3 km at nadir) it is difficult to achieve good results over scattered and heterogeneous areas. In this work, we have compared the evaporative fraction retrieved from SEVIRI to the one from NOAA and Landsat, both with higher spatial resolution. The main hypothesis of the study is that although the high temporal resolution of SEVIRI would lead to better estimates of surface fluxes, its coarser spatial resolution could lead to greater uncertainties in fragmented and heterogeneous landscapes. This study has been carried out during two consecutive campaigns over an experimental agricultural site near Madrid, Spain. The landscape is considered heterogeneous due to the high presence of urban areas surrounded by different types of crops. Sensible heat flux was continuously measured with a scintillometer, while a meteorological station registered the available net energy required for estimating the latent heat flux, and afterwards the evaporative fraction. Preliminary results show good correlation between the high spatial resolution Landsat data and the ground measurements, decreasing as the resolution lowers with NOAA and SEVIRI. However, despite the coarse resolution of the latter, daily variations of surface fluxes remain well represented and further improvements are expected by using dTs instead of Ts.

de Tomás, A.; Nieto, Héctor; Guzinski, Radoslaw; Mendiguren, Gorka; Sandholt, Inge; Berline, Pedro

2012-04-01

178

Territorial Differences of Human Development Index in Romania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The measuring of human capital, human development from both a quantitative and a qualitative point of view is difficult, the problem being further complicated if we consider regional and territorial approaches as well. At an international level, the Human Development Index is usually used for measuring and comparing these issues. This index addresses the most complex level of development of a region through the aggregation of the three indices from demographic (life expectancy at birth), soci...

IBOLYA KURKÓ

2011-01-01

179

A 30-Year Multi-Sensor Vegetation Index and Land Surface Phenology Data Record: Methods Challenges and Potentials  

Science.gov (United States)

During the last five years the Vegetation Index and Phenology Lab. (vip.arizona.edu) embarked on an effort to process a global multi-sensor Earth Science Data Record of NDVI, EVI2, and land surface Phenology. Data from AVHRR, MODIS, and SPOT-VGT, covering the period 1981 to present, were processed into a seamless and sensor independent record using a suite of community algorithms for data filtering, across-sensor continuity, Vegetation Index (NDVI and EVI2), land surface Phenology, and spatial and temporal gap filling. Currently at Version 3.0 these ESDRs are suitable for the study of land surface vegetation dynamics, long term change and trends, anomalies, and can support various ecosystem and climate modeling efforts by providing key parameters. While adapting the various algorithms to processing this new data record many challenges emerged, ranging from excessive missing and poor quality data to complex and temporally dependent divergence across the various sensors making continuity quite difficult. The first step to addressing these challenges was the adoption of very strict and low tolerance to noise data filters, where the intrinsic input data quality is used along with the long term expected dynamic range to screen for outliers and poor quality. A sophisticated and explicit per-pixel and seasonally dependent across-sensor translation algorithm was developed to address the continuity more properly. To generate the land surface phenology we adapted various community algorithms to work with and take advantage of this new record. Both the standard MODIS Vegetation dynamic algorithm and an in-house homogeneous cluster algorithm were applied to the data. We've also completed a spatially and temporally explicit error and uncertainty characterization of this record. Results indicate a VI error in the range of 5-10% VI units and a 5-40 days error in the date dependent phenology parameters, with an average error of 15 days. This VIP record accounts now for more than 30 years of Earth surface observation. Now in its third generation (V3) this record is capable of supporting environmental, resources management and climate studies as well provide for the parameterization of various ecosystem and climate models. All data are public and are available via a highly interactive online tool, the VIP Data Explorer (vip.arizona.edu/viplab_data_explorer.php) and concurrently via the LP-DAAC.

Didan, K.; Barreto-munoz, A.; Miura, T.; Tsend-Ayush, J.

2013-12-01

180

A New Equation for Deriving Vegetation Phenophase from Time Series of Leaf Area Index (LAI Data  

Directory of Open Access Journals (Sweden)

Full Text Available Accurately modeling the land surface phenology based on satellite data is very important to the study of vegetation ecological dynamics and the related ecosystem process. In this study, we developed a Sigmoid curve (S-curve function by integrating an asymmetric Gaussian function and a logistic function to fit the leaf area index (LAI curve. We applied the resulting asymptotic lines and the curvature extrema to derive the vegetation phenophases of germination, green-up, maturity, senescence, defoliation and dormancy. The new proposed S-curve function has been tested in a specific area (Shangdong Province, China, characterized by a specific pattern in leaf area index (LAI time course due to the dominant presence of crops. The function has not yet received any global testing. The identified phenophases were validated against measurement stations in Shandong Province. (i From the site-scale comparison, we find that the detected phenophases using the S-curve (SC algorithm are more consistent with the observations than using the logistic (LC algorithm and the asymmetric Gaussian (AG algorithm, especially for the germination and dormancy. The phenological recognition rates (PRRs of the SC algorithm are obviously higher than those of two other algorithms. The S-curve function fits the LAI curve much better than the logistic function and asymmetric Gaussian function; (ii The retrieval results of the SC algorithm are reliable and in close proximity to the green-up observed data whether using the AVHRR LAI or the improved MODIS LAI. Three inversion algorithms shows the retrieval results based on AVHRR LAI are all later than based on improved MODIS LAI. The bias statistics reveal that the retrieval results based on the AVHRR LAI datasets are more reasonable than based on the improved MODIS LAI datasets. Overall, the S-curve algorithm has the advantage of deriving vegetation phenophases across time and space as compared to the LC algorithm and the AG algorithm. With the SC algorithm, the vegetation phenophases can be extracted more effectively.

Mingliang Che

2014-06-01

 
 
 
 
181

An Empirical Algorithm for Estimating Agricultural and Riparian Evapotranspiration Using MODIS Enhanced Vegetation Index and Ground Measurements of ET. I. Description of Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We used the Enhanced Vegetation Index (EVI) from MODIS to scale evapotranspiration (ETactual) over agricultural and riparian areas along the Lower Colorado River in the southwestern US. Ground measurements of ETactual by alfalfa, saltcedar, cottonwood and arrowweed were expressed as fraction of potential (reference crop) ETo (EToF) then regressed against EVI scaled between bare soil (0) and full vegetation cover (1.0) (EVI*). EVI* values were calculated based on maximum and minimum EVI values...

Glenn, Edward P.; John Osterberg; Scott Murray, R.; Kiyomi Morino; Nagler, Pamela L.

2009-01-01

182

Modifying SEBAL Model Based on the Trapezoidal Relationship between Land Surface Temperature and Vegetation Index for Actual Evapotranspiration Estimation  

Directory of Open Access Journals (Sweden)

Full Text Available The Surface Energy Balance Algorithm for Land (SEBAL is widely used to estimate actual evapotranspiration (ETa. One major limitation of the SEBAL model is the subjectiveness in selecting extreme cold/hot pixels. In the present study, the SEBAL model is modified by determining the extreme cold/hot status, based on the theoretical trapezoidal relationship between land surface temperature (Ts and Enhanced Vegetation Index (EVI, which is established for each pixel. In this way, the dependence of SEBAL model on the existence of extreme cold/hot status and the subjectiveness in selecting cold/hot pixels with SEBAL model are eliminated. The performance of the classical SEBAL model and the modified version, T-SEBAL, are compared for estimating ETa for a semi-arid catchment, and the result showed that the accuracy of ETa estimation is improved by the T-SEBAL model compared with the classical SEBAL model.

Xiao-Gang Wang

2014-06-01

183

Variation of MODIS reflectance and vegetation indices with viewing geometry and soybean development  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Directional effects introduce a variability in reflectance and vegetation index determination, especially when large field-of-view sensors are used (e.g., Moderate Resolution Imaging Spectroradiometer - MODIS). In this study, we evaluated directional effects on MODIS reflectance and four vegetation indices (Normalized Difference Vegetation Index - NDVI; Enhanced Vegetation Index - EVI; Normalized Difference Water Index - NDWI1640 and NDWI2120) with the soybean development in two growing seaso...

Breunig, Fa?bio M.; Galva?o, Le?nio S.; Formaggio, Anto?nio R.; Epiphanio, Jose? C. N.

2012-01-01

184

Territorial Differences of Human Development Index in Romania  

Directory of Open Access Journals (Sweden)

Full Text Available The measuring of human capital, human development from both a quantitative and a qualitative point of view is difficult, the problem being further complicated if we consider regional and territorial approaches as well. At an international level, the Human Development Index is usually used for measuring and comparing these issues. This index addresses the most complex level of development of a region through the aggregation of the three indices from demographic (life expectancy at birth, social (education level and the economic sphere (GDP per capita with which we can have a much more complex picture about living standards of the population as well as the development level of a country. Because the applicability of this index has caused serious debates since its introduction, this study also focuses on selecting the right indicators for measuring human development.

IBOLYA KURKÓ

2011-01-01

185

Reestablishment of wetland vegetation on gas pipeline rights-of-way in six different wetland ecosystems  

Energy Technology Data Exchange (ETDEWEB)

Vegetational surveys were carried out to compare reestablished vegetation on pipeline rights-of-way (ROWS) with that in adjacent natural ecosystems undisturbed by pipeline installation. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the ROW approximated or exceeded those in the adjacent natural area. In four ecosystems, the vegetation on the ROW was limited to a herbaceous layer by ROW maintenance; thus, the ROWs often involved a complex of species quite different from that found in the adjacent ecosystems.

Zimmerman, R.E. Shem, L.; Wilkey, P.L. [Argonne National Lab., IL (United States); Van Dyke, G.D. [Trinity Christian Coll. Palos Heights, IL (United States); Hackney, C. [North Carolina Univ., Wilmington, NC (United States); Gowdy, M. [Institute of Technology, Chicago, IL (United States)

1992-05-01

186

Exact analytical solution for fields in gradient index metamaterials with different loss factors in negative and positive refractive index segments  

Science.gov (United States)

Gradient refractive index metamaterials are of interest for various applications of transformation optics. Wave propagation through gradient index metamaterials using an exact analytical approach is investigated. Composite materials containing constituents with negative real and positive real indexes of refraction are considered. An exact analytical solution for the field distribution is obtained for the sinusoidal spatial variation of complex effective permittivity and permeability along a fixed direction, under the assumption that the wave impedance remains spatially uniform across the structure. Loss factors in the constituent materials can be different from each other corresponding to the realistic situations. Temporal dispersion can be arbitrary subject to the physical limitations imposed by the Kramers-Kronig relations. A numerical model based on the Z-transform is developed to verify the analytical results. The approach can be applied to arbitrary periodic refractive index profiles using the Fourier series method.

Dalarsson, Mariana; Norgren, Martin; Asenov, Tatjana; Don?ov, Nebojša; Jakši?, Zoran

2013-01-01

187

Different index contrast silica-on-silicon waveguides by PECVD  

DEFF Research Database (Denmark)

Ge-doped silica-on-silicon waveguides with index steps of 0.01 and 0.02 were fabricated by a combination of plasma enhanced chemical vapour deposition (PECVD) and reactive ion etching (RIE) techniques, and their characteristics, including propagation loss, coupling loss with standard singlemode fibres, minimal bend radius, and birefringence, were investigated. The waveguides have good propagation properties and small birefringence, compared to using flame hydrolysis deposition (FHD).

Ou, Haiyan

2003-01-01

188

Radiometric quality and performance of TIMESAT for smoothing moderate resolution imaging spectroradiometer enhanced vegetation index time series from western Bahia State, Brazil  

Science.gov (United States)

The launch of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra and Aqua platforms in 1999 and 2002, respectively, with temporal resolutions of 1 to 2 days opened the possibility of using a longtime series of satellite images to map land use and land cover classes from different regions of the Earth, to study vegetation phenology, and to monitor regional and global climate change, among other applications. The main objectives of this study were twofold: to analyze the radiometric quality of the time series of enhanced vegetation index (EVI) products derived from the Terra MODIS sensor in western Bahia State, Brazil, and to identify the most appropriate filter to smooth MODIS EVI time series of the study area among those available in the public domain, the TIMESAT algorithm. The 2000 to 2011 time period was considered (a total of 276 scenes). The radiometric quality was analyzed based on the pixel reliability data set available in the MOD13Q1 product. The performances of the three smoothing filters available within TIMESAT (double logistic, Savitzky-Golay, and asymmetric Gaussian) were analyzed using the Graybill's F test and Willmott statistics. Five percent of the MODIS pixels from the study area were cloud-affected, almost all of which were from the rainy season. The double logistic filter presented the best performance.

Borges, Elane F.; Sano, Edson E.; Medrado, Euzébio

2014-01-01

189

Índices de área verde e cobertura vegetal para as praças do Municipio de Vinhedo, SP / Green area and vegetation cover indexes for commos in the city of Vinhedo, SP  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Neste estudo, objetivou-se a obtenção, para o Município de Vinhedo (SP), de índices que auxiliem a indicação da ocupação dos espaços urbanos pela vegetação. Foi realizado o levantamento das praças localizadas dentro dos bairros e das árvores (altura, diâmetro da copa e circunferência à altura do pei [...] to) contidas nessas praças. Os índices de área verde calculados foram: Índice de Áreas Verdes Total (IAVT), Índice de Áreas Verdes para Parque da Vizinhança (IAVPV), Índice de Áreas Verdes para Parque de Bairro (IAVPB), Índice de Áreas Verdes Utilizáveis (IAVU), Índice de Área Verde por Bairro (AVB) e Índice de Cobertura Vegetal (ICV). O Município de Vinhedo apresentou pouca variação entre os índices IAVT = 2,19 m² e IAVU = 1,95 m², indicando que a maioria das áreas verdes era utilizável. O IAVT de Vinhedo estava abaixo do mínimo de 15 m²/habitante para áreas verdes públicas destinadas à recreação, sugerido pela Sociedade Brasileira de Arborização Urbana. Abstract in english This research was carried out to study, in the city of Vinhedo (SP), indexes that indicate the vegetation occupation in urban spaces. Data were collected by locating the commons in the neighborhoods and the tree measures (height, diameter and circumference at breast height), in those commons. The ca [...] lculated indexes were Total Green Area Index (IAVT), Green Area Index for Near Neighborhood Park (IAVPV), Green Area Index for Neighborhood Park (IAPVPB), Usable Green Area Index (IAVU), Green Area Index for Neighborhoods (AVB) and Vegetation Cover Index (ICV). The city of Vinhedo showed few variation between the indexes IAVT = 2.19 m² and IAVU = 1.95 m² indicating that most of the green areas are usable. Vinhedo's IAVT is below the minimum of 15m²/inhabitant for public recreation in green areas, suggested by the Brazilian Society for Urban Forestation.

Isabel Cristina Fialho, Harder; Roberval de Cássia Salvador, Ribeiro; Armando Reis, Tavares.

190

Índices de área verde e cobertura vegetal para as praças do Municipio de Vinhedo, SP / Green area and vegetation cover indexes for commos in the city of Vinhedo, SP  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Neste estudo, objetivou-se a obtenção, para o Município de Vinhedo (SP), de índices que auxiliem a indicação da ocupação dos espaços urbanos pela vegetação. Foi realizado o levantamento das praças localizadas dentro dos bairros e das árvores (altura, diâmetro da copa e circunferência à altura do pei [...] to) contidas nessas praças. Os índices de área verde calculados foram: Índice de Áreas Verdes Total (IAVT), Índice de Áreas Verdes para Parque da Vizinhança (IAVPV), Índice de Áreas Verdes para Parque de Bairro (IAVPB), Índice de Áreas Verdes Utilizáveis (IAVU), Índice de Área Verde por Bairro (AVB) e Índice de Cobertura Vegetal (ICV). O Município de Vinhedo apresentou pouca variação entre os índices IAVT = 2,19 m² e IAVU = 1,95 m², indicando que a maioria das áreas verdes era utilizável. O IAVT de Vinhedo estava abaixo do mínimo de 15 m²/habitante para áreas verdes públicas destinadas à recreação, sugerido pela Sociedade Brasileira de Arborização Urbana. Abstract in english This research was carried out to study, in the city of Vinhedo (SP), indexes that indicate the vegetation occupation in urban spaces. Data were collected by locating the commons in the neighborhoods and the tree measures (height, diameter and circumference at breast height), in those commons. The ca [...] lculated indexes were Total Green Area Index (IAVT), Green Area Index for Near Neighborhood Park (IAVPV), Green Area Index for Neighborhood Park (IAPVPB), Usable Green Area Index (IAVU), Green Area Index for Neighborhoods (AVB) and Vegetation Cover Index (ICV). The city of Vinhedo showed few variation between the indexes IAVT = 2.19 m² and IAVU = 1.95 m² indicating that most of the green areas are usable. Vinhedo's IAVT is below the minimum of 15m²/inhabitant for public recreation in green areas, suggested by the Brazilian Society for Urban Forestation.

Isabel Cristina Fialho, Harder; Roberval de Cássia Salvador, Ribeiro; Armando Reis, Tavares.

2006-04-01

191

Antioxidant Contents (Vitamin C of Raw and Blanched Different Fresh Vegetable Samples  

Directory of Open Access Journals (Sweden)

Full Text Available The study was aimed to determine the antioxidant contents and the effect of different blanching times (5 min, 10 min, 15 min and 20 min on antioxidant contents of three different selected fresh vegetables. Three different types of vegeta- ble were used namely Amaranthus specie locally known as spinach, namely “tete”, (Celosia argentea, soko, (Solonum nodifiorum and odu, (Telfeira occidentalis were analyzed for their antioxidant contents. The analysis revealed that raw vegetables have the highest amount of antioxidant contents. Telferia occidentalis had the highest antioxidant content followed by Solonum nodifiorum. It was observed that blanching time had an adverse effect on the antioxidant contents of the blanched vegetables. The antioxidant contents of tete, soko and odu were significantly decreased (p < 0.05 after blanching.

Isaac B. Ariyo

2012-01-01

192

A Method for Application of Classification Tree Models to Map Aquatic Vegetation Using Remotely Sensed Images from Different Sensors and Dates  

Science.gov (United States)

In previous attempts to identify aquatic vegetation from remotely-sensed images using classification trees (CT), the images used to apply CT models to different times or locations necessarily originated from the same satellite sensor as that from which the original images used in model development came, greatly limiting the application of CT. We have developed an effective normalization method to improve the robustness of CT models when applied to images originating from different sensors and dates. A total of 965 ground-truth samples of aquatic vegetation types were obtained in 2009 and 2010 in Taihu Lake, China. Using relevant spectral indices (SI) as classifiers, we manually developed a stable CT model structure and then applied a standard CT algorithm to obtain quantitative (optimal) thresholds from 2009 ground-truth data and images from Landsat7-ETM+, HJ-1B-CCD, Landsat5-TM and ALOS-AVNIR-2 sensors. Optimal CT thresholds produced average classification accuracies of 78.1%, 84.7% and 74.0% for emergent vegetation, floating-leaf vegetation and submerged vegetation, respectively. However, the optimal CT thresholds for different sensor images differed from each other, with an average relative variation (RV) of 6.40%. We developed and evaluated three new approaches to normalizing the images. The best-performing method (Method of 0.1% index scaling) normalized the SI images using tailored percentages of extreme pixel values. Using the images normalized by Method of 0.1% index scaling, CT models for a particular sensor in which thresholds were replaced by those from the models developed for images originating from other sensors provided average classification accuracies of 76.0%, 82.8% and 68.9% for emergent vegetation, floating-leaf vegetation and submerged vegetation, respectively. Applying the CT models developed for normalized 2009 images to 2010 images resulted in high classification (78.0%–93.3%) and overall (92.0%–93.1%) accuracies. Our results suggest that Method of 0.1% index scaling provides a feasible way to apply CT models directly to images from sensors or time periods that differ from those of the images used to develop the original models.

Jiang, Hao; Zhao, Dehua; Cai, Ying; An, Shuqing

2012-01-01

193

Interannual variations and trends in global land surface phenology derived from enhanced vegetation index during 1982-2010  

Science.gov (United States)

Land surface phenology is widely retrieved from satellite observations at regional and global scales, and its long-term record has been demonstrated to be a valuable tool for reconstructing past climate variations, monitoring the dynamics of terrestrial ecosystems in response to climate impacts, and predicting biological responses to future climate scenarios. This study detected global land surface phenology from the advanced very high resolution radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) data from 1982 to 2010. Based on daily enhanced vegetation index at a spatial resolution of 0.05 degrees, we simulated the seasonal vegetative trajectory for each individual pixel using piecewise logistic models, which was then used to detect the onset of greenness increase (OGI) and the length of vegetation growing season (GSL). Further, both overall interannual variations and pixel-based trends were examined across Koeppen's climate regions for the periods of 1982-1999 and 2000-2010, respectively. The results show that OGI and GSL varied considerably during 1982-2010 across the globe. Generally, the interannual variation could be more than a month in precipitation-controlled tropical and dry climates while it was mainly less than 15 days in temperature-controlled temperate, cold, and polar climates. OGI, overall, shifted early, and GSL was prolonged from 1982 to 2010 in most climate regions in North America and Asia while the consistently significant trends only occurred in cold climate and polar climate in North America. The overall trends in Europe were generally insignificant. Over South America, late OGI was consistent (particularly from 1982 to 1999) while either positive or negative GSL trends in a climate region were mostly reversed between the periods of 1982-1999 and 2000-2010. In the Northern Hemisphere of Africa, OGI trends were mostly insignificant, but prolonged GSL was evident over individual climate regions during the last 3 decades. OGI mainly showed late trends in the Southern Hemisphere of Africa while GSL was reversed from reduced GSL trends (1982-1999) to prolonged trends (2000-2010). In Australia, GSL exhibited considerable interannual variation, but the consistent trend lacked presence in most regions. Finally, the proportion of pixels with significant trends was less than 1 % in most of climate regions although it could be as large as 10 %.

Zhang, Xiaoyang; Tan, Bin; Yu, Yunyue

2014-05-01

194

Índice de vegetação do sensor MODIS na estimativa da produtividade agrícola da cana-de-açúcar / Vegetation index from MODIS sensor to estimate sugarcane yield  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A participação da cultura da cana-de-açúcar no fornecimento de matéria prima para produção de açúcar e também de álcool, como fonte alternativa de energia, tem sido relevante para o crescimento econômico do Brasil. Consequentemente, a disponibilidade de informações precisas sobre a produção agrícola [...] dessa cultura é importante para auxiliar no planejamento e na tomada de decisões em toda a cadeia produtiva. O presente trabalho teve como objetivo estimar a produtividade agrícola de talhões de cana-de-açúcar para as safras 2004/2005 e 2005/2006, a partir de um modelo agronômico ajustado com dados orbitais. A inovação deste modelo consiste no uso do índice de área foliar (IAF) estimado a partir do produto índice de vegetação NDVI (Normalized Difference Vegetation Index) do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) a bordo do satélite Terra da NASA (National Aeronautics Space Administration). O modelo agronômico explicou 31% e 25% da variação da produtividade observada entre talhões nos anos safra 2004/2005 e 2005/2006, respectivamente, o que se deve fundamentalmente ao uso das imagens NDVI do MODIS. O resultado do modelo pode ser usado para auxiliar e aprimorar a previsão da estimativa da produtividade feita in loco. Abstract in english The contribution of sugarcane crop to provide raw material to produce sugar and also alcohol as an alternative energy source has been relevant to the economic growth of Brazil. Therefore, the availability of precise agricultural production information about this crop is important for planning and de [...] cision-making in the entire productive chain. The present work has the objective to estimate sugarcane yield in crop fields during the crop years 2004/2005 and 2005/2006, based on an agronomic model fit with orbital data. The innovation of this model consists in the use of the leaf area index (LAI) estimated from the NDVI (Normalized Difference Vegetation Index) produced by the MODIS sensor (Moderate Resolution Imaging Spectroradiometer) on board of the Terra satellite from NASA (National Aeronautics Space Administration). The agronomic model explained 31% and 25% of the yield variability among crop fields for the crop years 2004/2005 and 2005/2006, respectively, which is mainly attributed to use of NDVI images from MODIS. The model output should be useful to improve the precision of the crop yield estimation forecast performed in loco.

Michelle Cristina Araujo, Picoli; Bernardo Friedrich Theodor, Rudorff; Rodrigo, Rizzi; Angélica, Giarolla.

195

Índice de vegetação do sensor MODIS na estimativa da produtividade agrícola da cana-de-açúcar / Vegetation index from MODIS sensor to estimate sugarcane yield  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A participação da cultura da cana-de-açúcar no fornecimento de matéria prima para produção de açúcar e também de álcool, como fonte alternativa de energia, tem sido relevante para o crescimento econômico do Brasil. Consequentemente, a disponibilidade de informações precisas sobre a produção agrícola [...] dessa cultura é importante para auxiliar no planejamento e na tomada de decisões em toda a cadeia produtiva. O presente trabalho teve como objetivo estimar a produtividade agrícola de talhões de cana-de-açúcar para as safras 2004/2005 e 2005/2006, a partir de um modelo agronômico ajustado com dados orbitais. A inovação deste modelo consiste no uso do índice de área foliar (IAF) estimado a partir do produto índice de vegetação NDVI (Normalized Difference Vegetation Index) do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) a bordo do satélite Terra da NASA (National Aeronautics Space Administration). O modelo agronômico explicou 31% e 25% da variação da produtividade observada entre talhões nos anos safra 2004/2005 e 2005/2006, respectivamente, o que se deve fundamentalmente ao uso das imagens NDVI do MODIS. O resultado do modelo pode ser usado para auxiliar e aprimorar a previsão da estimativa da produtividade feita in loco. Abstract in english The contribution of sugarcane crop to provide raw material to produce sugar and also alcohol as an alternative energy source has been relevant to the economic growth of Brazil. Therefore, the availability of precise agricultural production information about this crop is important for planning and de [...] cision-making in the entire productive chain. The present work has the objective to estimate sugarcane yield in crop fields during the crop years 2004/2005 and 2005/2006, based on an agronomic model fit with orbital data. The innovation of this model consists in the use of the leaf area index (LAI) estimated from the NDVI (Normalized Difference Vegetation Index) produced by the MODIS sensor (Moderate Resolution Imaging Spectroradiometer) on board of the Terra satellite from NASA (National Aeronautics Space Administration). The agronomic model explained 31% and 25% of the yield variability among crop fields for the crop years 2004/2005 and 2005/2006, respectively, which is mainly attributed to use of NDVI images from MODIS. The model output should be useful to improve the precision of the crop yield estimation forecast performed in loco.

Michelle Cristina Araujo, Picoli; Bernardo Friedrich Theodor, Rudorff; Rodrigo, Rizzi; Angélica, Giarolla.

2009-09-01

196

Índice de vegetação do sensor MODIS na estimativa da produtividade agrícola da cana-de-açúcar Vegetation index from MODIS sensor to estimate sugarcane yield  

Directory of Open Access Journals (Sweden)

Full Text Available A participação da cultura da cana-de-açúcar no fornecimento de matéria prima para produção de açúcar e também de álcool, como fonte alternativa de energia, tem sido relevante para o crescimento econômico do Brasil. Consequentemente, a disponibilidade de informações precisas sobre a produção agrícola dessa cultura é importante para auxiliar no planejamento e na tomada de decisões em toda a cadeia produtiva. O presente trabalho teve como objetivo estimar a produtividade agrícola de talhões de cana-de-açúcar para as safras 2004/2005 e 2005/2006, a partir de um modelo agronômico ajustado com dados orbitais. A inovação deste modelo consiste no uso do índice de área foliar (IAF estimado a partir do produto índice de vegetação NDVI (Normalized Difference Vegetation Index do sensor MODIS (Moderate Resolution Imaging Spectroradiometer a bordo do satélite Terra da NASA (National Aeronautics Space Administration. O modelo agronômico explicou 31% e 25% da variação da produtividade observada entre talhões nos anos safra 2004/2005 e 2005/2006, respectivamente, o que se deve fundamentalmente ao uso das imagens NDVI do MODIS. O resultado do modelo pode ser usado para auxiliar e aprimorar a previsão da estimativa da produtividade feita in loco.The contribution of sugarcane crop to provide raw material to produce sugar and also alcohol as an alternative energy source has been relevant to the economic growth of Brazil. Therefore, the availability of precise agricultural production information about this crop is important for planning and decision-making in the entire productive chain. The present work has the objective to estimate sugarcane yield in crop fields during the crop years 2004/2005 and 2005/2006, based on an agronomic model fit with orbital data. The innovation of this model consists in the use of the leaf area index (LAI estimated from the NDVI (Normalized Difference Vegetation Index produced by the MODIS sensor (Moderate Resolution Imaging Spectroradiometer on board of the Terra satellite from NASA (National Aeronautics Space Administration. The agronomic model explained 31% and 25% of the yield variability among crop fields for the crop years 2004/2005 and 2005/2006, respectively, which is mainly attributed to use of NDVI images from MODIS. The model output should be useful to improve the precision of the crop yield estimation forecast performed in loco.

Michelle Cristina Araujo Picoli

2009-09-01

197

Estimating evapotranspiration using remote sensing: A hybrid approach between MODIS derived enhanced vegetation index, Bowen ratio system, and ground based micro-meteorological data  

Science.gov (United States)

We investigated water loss by evapotranspiration (ET) from the Palo Verde Irrigation District (PVID) and the Cibola National Wildlife Refuge (CNWR) in southern California bordering the Colorado River collaborating with the United States Bureau of Reclamation (U.S.B.R.). We developed an empirical model to estimate ET for the entire PVID using satellite derived MODIS enhanced vegetation index (EVI), and ground based measurements of solar radiation and vapor pressure. We compared our predictions with U.S.B.R. estimates through statistical cross validation and showed they agree with an error less than 8%. We tested the same model for an alfalfa field inside PVID to check its applicability at a smaller spatial scale. We showed that the same model developed for PVID is the best model for estimating ET for the alfalfa field. We collected data from three Bowen ratio energy balance (BREB) towers installed in the invasive saltcedar (Tamarix spp) dominated riparian zone in the CNWR and a fourth tower in the alfalfa field in PVID. The riparian sites were selected according to different densities of vegetation. We collected data from these sites at various intervals during the period between June 2006 to November 2008. We reduced the errors associated with the Bowen ratio data using statistical procedures taking into account occasional instrument failures and problems inherent in the BREB method. Our results were consistent with vegetation density and estimates from MODIS EVI images. To estimate ET for larger patches of mixed vegetation we modified the crop coefficient equation and represented it in terms of EVI. Using this approach, we scaled the alfalfa field data to the entire PVID and compared the results with U.S.B.R. (2001-2007) estimates. We predicted ET well within the acceptable range established in the literature. We empirically developed ET models for the riparian tower sites to provide accurate point scale ET estimation and scaled for the entire riparian region in CNWR with our modified crop coefficient approach. We investigated the assumptions upon which the Bowen ratio equation is developed. In the presence of turbulence some of the assumptions may not be valid, and the final data may require correction factors.

Chatterjee, Sumantra

198

Evaluation of Extraction Methods for the Analysis of Carotenoids for Different Vegetable Matrix  

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Full Text Available In this study, different solvents were used to achieve the maximum extractibility of total carotenoids. The extracted total carotenoids were estimated using UV- visible spectrophotometer. Carotenoids from vegetable matrix can be used as a food colorant, food additive, cosmetics, antioxidants and nutraceuticals.

Stancuta Scrob

2013-11-01

199

The Impact of an Elementary After-School Nutrition and Physical Activity Program on Children's Fruit and Vegetable Intake, Physical Activity, and Body Mass Index: Fun 5  

Science.gov (United States)

Objective This study evaluated the impact of the Fun 5 program on fruit and vegetable intake, physical activity, and body mass index (BMI) percentile of overweight and obese children in Hawai'i's A+ After-School Program. Methods Children in 4th – 6th grades (n=119, 55% female) from six randomly selected schools participated in this longitudinal study. Time 1 (T1) measures were taken October 2007 and time 2 (T2) measures April 2008. Height and weight along with a self-report survey were used to measure fruit and vegetable intake, physical activity, and BMI. Results The “at risk” population, defined as fruit and vegetable intake 85th percentile (n=48) at T1, showed a significant increase in fruit and vegetable intake, from 2.97 (±1.16) servings per day at T1 to 5.60 (±3.93) servings per day at T2 (P=<0.01) and physical activity, from 125.26 (±76.03) minutes per week of physical activity at T1 to 222.18 (±180.90) minutes per week at T2 (P=<0.01) and no change in Body Mass Index. Conclusion The Fun 5 program had an impact on improving fruit and vegetable intake and physical activity on the at risk population. PMID:21886292

Iversen, Cara S Sandoval; Titchenal, C Alan

2011-01-01

200

The frailty phenotype and the frailty index: different instruments for different purposes.  

Science.gov (United States)

The integration of frailty measures in clinical practice is crucial for the development of interventions against disabling conditions in older persons. The frailty phenotype (proposed and validated by Fried and colleagues in the Cardiovascular Health Study) and the Frailty Index (proposed and validated by Rockwood and colleagues in the Canadian Study of Health and Aging) represent the most known operational definitions of frailty in older persons. Unfortunately, they are often wrongly considered as alternatives and/or substitutables. These two instruments are indeed very different and should rather be considered as complementary. In the present paper, we discuss about the designs and rationals of the two instruments, proposing the correct ways for having them implemented in the clinical setting. PMID:24132852

Cesari, Matteo; Gambassi, Giovanni; van Kan, Gabor Abellan; Vellas, Bruno

2014-01-01

 
 
 
 
201

Soil phosphorus forms as quality indicators of soils under different vegetation covers.  

Science.gov (United States)

The type of vegetation cover determines the physicochemical and biological properties of the soil over which they are developing. The objective of this study was to determine the effect of different vegetation covers on the forms of soil phosphorus, in order to know which of these forms can be used as a soil quality indicator. The experimental area was located on the acidic plateau at the North of Palencia (North Spain), where an area was selected vegetation covers very close to each other: pine (Pinus sylvestris), oak (Quercus pyrenaica), and three different shrub species (Arctostaphylos uva-ursi, Erica australis and Halimium alyssoides). The Ah horizon was sampled and pH, total organic C (C(org)), total N (N), cationic exchange capacity (CEC), sum of bases (S) and P forms by a sequential fractionation were analysed. Results showed that oak and A. uva-ursi improve the considered soil parameters (pH, C(org)/N ratio, CEC, and S) and provide soils of better quality. Inorganic soil P forms were influenced in greater extent by the vegetation cover than were P organic forms. Labile inorganic P forms could be used as indicators of soil quality. The organic P forms were less sensitive than inorganic ones to the indicated improvements. PMID:17307240

Turrión, María-Belén; López, Olga; Lafuente, Francisco; Mulas, Rafael; Ruipérez, César; Puyo, Alberto

2007-05-25

202

Description of psychophysiological indexes of students of different sporting specializations  

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Full Text Available Information of the psychophysiological testing of students of technical institute of higher of different sporting specializations is considered. In research took part 159 students of specialization football, sambo, volleyball, basketball, aerobics, boxing, heavy athletics. The psychophysiological testing is given by possibility to choose the proper sporting specialization students for the best realization of the personality qualities. Positive attitude of students is marked toward employments on physical education. The increase of self-appraisal and improvement of health of students is also marked.

Barybina L.N.

2010-08-01

203

Analysing and Quantifying Vegetation Responses to Rainfall with High Resolution Spatio-Temporal Time Series Data for Different Ecosystems and Ecotones in Queensland  

Science.gov (United States)

Vegetation responses and ecosystem function are spatially variable and influenced by climate variability. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was used to combine MODIS (Moderate Resolution Imaging Spectrometer) and Landsat TM/ETM+ (Thematic Mapper/ Enhanced Thematic Mapper plus) imagery for an 8 year dataset (2000-2007) at 30m spatial resolution with 8 day intervals. This dataset allows for a functional analysis of ecosystem responses, suitable for heterogeneous landscapes. Derived vegetation index information in form of the NDVI (Normalised Difference Vegetation Index) was used to investigate the relationship between vegetation responses and gridded rainfall data for regional ecosystems. A hierarchical decomposition of the time series has been carried out in which relationships among the time-series were individually assessed for deterministic time-series components (trend component and seasonality) as well as for the stochastic seasonal anomalies. While no common long-term trends in NDVI and rainfall data in the time period considered exist, there is however, a strong concurrence in the seasonally of NDVI and rainfall data. This component accounts for the majority of variability in the time-series. On the level of seasonal anomalies, these relationships are more subtle. The statistical analysis required, among others, the removal of temporal autocorrelation for an unbiased assessment of significance. Significant lagged correlations between rainfall and NDVI were found in complex Queensland savannah vegetation communities. For grasslands and open woodlands, significant relationships with lag times between 8 and 16 days were found. For denser, evergreen vegetation communities greater lag times of up to 2.5 months were found. The derived distributed lag models may be used for short-term NDVI and biomass predictions on the spatial resolution scale of Landsat (30m).

Schmidt, M.; Udelhoven, T.

2012-07-01

204

Evaluation of the data of vegetable covering using fraction images and multitemporal vegetation index, derived of orbital data of moderate resolution of the sensor MODIS  

International Nuclear Information System (INIS)

The objective was to evaluate the data obtained by sensor MODIS onboard the EOS terra satellite land cover units. The study area is the republic of Colombia in South America. The methodology consisted of analyzing the multitemporal (vegetation, soil and shade-water) fraction images and vegetation indices (NDVI) apply the lineal spectral mixture model to products derived from derived images by sensor MODIS data obtained in years 2001 and 2003. The mosaics of the original and the transformed vegetation (soil and shade-water) bands were generated for the whole study area using SPRING 4. 0 software, developed by INPE then these mosaics were segmented, classified, mapped, and edited to obtain a moderate resolution land cover map. The results derived from MODIS analysis were compared with Landsat ETM+ data acquire for a single test site. The results of the project showed the usefulness of MODIS images for large-scale land cover mapping and monitoring studies

205

The Effect of SCENAR-therapy on Dynamics of Clinic and Endoscopic Vegetative Indexes in Young Children and Preschool Children with Gastroduodenal Diseases  

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Full Text Available The aim of the study is to assess the dynamics of clinical and endoscopic indexes of gastric and duodenal mucus, as well as vegetative regulation after complex therapy of gastrointestinal pathology including SCENAR-therapy in young children and preschool children.Materials and methods. 44 children aged 2—5 years with chronic duodenitis and gastroduodenitis were examined. Half of them had traditional treatment, while the therapy of others included SCENAR-therapy.Conclusion. SCENAR-therapy included into complex therapy of duodenites and gastroduodenites in young children and preschool children is marked by evident positive clinical dynamics and improvement of vegetative nervous system indexes enhancing adaptive possibilities of the body.

?.?. Zhukova

2011-06-01

206

Environmental quality evaluation. Indexing tools to evaluate environmental quality from biological data, floristic and vegetational data in Ponte Galeria (Rome, Italy)  

International Nuclear Information System (INIS)

In the present work the study of indexing tools to evaluate environmental quality from biological data has been performed using a certain number of floristic and vegetational indices near Macchia Grande of Ponte Galeria (Rome, Italy). The indices have been applied on the basis of the data coming from a phyto sociological study of the area. Multivariate statistics methodologies have been utilized to obtain a synthetic evaluation of the indices

207

Estimating the Maximal Light Use Efficiency for Different Vegetation through the CASA Model Combined with Time-Series Remote Sensing Data and Ground Measurements  

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Full Text Available Maximal light use efficiency (LUE is an important ecological index of a vegetation essential attribute, and a key parameter of the LUE-based model for estimating large-scale vegetation productivity by remote sensing technology. However, although currently used in different models there still exists extensive controversy. This paper takes the Zoige Plateau in China as a case area to develop a new approach for estimating the maximal LUEs for different vegetation. Based on an existing land cover map and MODIS NDVI product, the linear unmixing method with a moving window was adopted to estimate the time-series NDVI for different end members in a MODIS NDVI pixel; then Particle Swarm Optimizer (PSO was applied to search for the optimization of LUE retrievals through the CASA (Carnegie-Ames-Stanford Approach model combined with time-series NDVI and ground measurements. The derived maximal LUEs present significant differences among various vegetation types. These are 0.669 gC·MJ?1, 0.450 gC·MJ?1 and 0.126 gC·MJ?1 for the xerophilous grasslands with high, moderate and low vegetation fraction respectively, 0.192 gC·MJ?1 for the hygrophilous grasslands, and 0.125 gC·MJ?1 for the helobious grasslands. The field validation shows that the estimated net primary productivity (NPP by the derived maximal LUE is closely related to the ground references, with R2 of 0.8698 and root-mean-square error (RMSE of 59.37 gC·m?2·a?1. This indicates that the default set in the CASA model is not suitable for NPP estimation for the regional mountain area. The derived maximal LUEs can significantly improve the capability of NPP mapping, and open up the perspective for long-term monitoring of vegetation ecological health and ecosystem productivity by combining the LUE-based model with remote sensing observations.

Ainong Li

2012-12-01

208

Recovery of a soil under different vegetation one year after a high intensity wildfire  

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Full Text Available Studies on soil recovery in fragile ecosystems following high intensity wildfires are scarce. The aim of the present investigation is to evaluate the impact of a high intensity wildfire in an ecosystem under different vegetation (shrubland and pinewood located at Vilardevós (Galicia, NW Spain and highly susceptible to suffer soil erosion due to the steep relief and high erositivity of the rainfall. Soil samples were collected from the A horizon (0-5 cm 1 year after the fire and soil quality was evaluated by analysis of several physical, chemical and biochemical properties measured in the fraction chemical properties > physical properties. The data also showed that the fire impact was different depending on the soil vegetation considered (shrubland and pinewood. Moreover, the data confirmed the slow soil recovery in this fragile ecosystem and, therefore, the need of adopting post-fire stabilisation and rehabilitation treatments in order to minimize the post-fire erosion and soil degradation.

A. Martín

2013-05-01

209

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ISSN: 2255-2863 is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence, and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.

Antonio Juan Sánchez

2012-09-01

210

Constructed wetland systems vegetated with different plants applied to the treatment of tannery wastewater  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wastewaters from leather processing are very complex and lead to water pollution if discharged untreated, especially due to its high organic loading. In this study the survival of different plant species in subsurface horizontal flow constructed wetlands receiving tannery wastewater was investigated. Five pilot units were vegetated with Canna indica, Typha latifolia, Phragmites australis, Stenotaphrum secundatum and Iris pseudacorus, and a sixth unit was left as an unvegetated control. The...

Calheiros, Cristina S. C.; Rangel, Anto?nio O. S. S.; Castro, Paula M. L.

2007-01-01

211

Complex role of monoacylglycerols in the oxidation of vegetable oils: different behaviors of soybean monoacylglycerols in different oils.  

Science.gov (United States)

The relationship between fatty acid composition of oils and their oxidative stability in the presence of monoacylglycerols was investigated. Purified vegetable oils were added at increasing amounts (0.5, 1, 2, and 3%) of monoacylglycerols obtained from purified soybean oil and submitted to an oven test (60 °C for 18 days). The obtained results showed a generally antioxidant effect of monoacylglycerols, with remarkable differences among oils. The antioxidant effect was significantly higher in less unsaturated oils, such as palm and olive oils. Among the more unsaturated vegetable oils, peanut and sunflower oils showed an almost linear slowdown of oxidation, slightly less pronounced in sunflower oil, which was the most susceptible to oxidation due to its high content of linoleic acid. A peculiar trend was highlighted for soybean oil, where the antioxidant effect of high amounts of monoacylglycerols was opposed to a pro-oxidant effect observed up to 1%. PMID:25310182

Paradiso, Vito Michele; Caponio, Francesco; Bruno, Giuseppina; Pasqualone, Antonella; Summo, Carmine; Gomes, Tommaso

2014-11-01

212

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan Sánchez

2013-11-01

213

Index  

Directory of Open Access Journals (Sweden)

Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

Antonio Juan SÁNCHEZ

2012-07-01

214

Water regime of soils under the different vegetative cover, the Giant Mountains, Czech Republic.  

Science.gov (United States)

Several monitored plots, located in the Giant Mountains in different positions (valley, slope), are covered by different vegetation (dwarf pine forest, spruce forest, meadow). Soil moisture properties in relation to vegetative cover (dwarf pine versus grassland stands) were studied from the year 2000 to 2006. The main goal was to analyse chosen rainfall-runoff periods with respect to diferent vegetative cover. Every plot was arranged by automatic station for continual soil moisture measurements by VIRRIB sensors (Phase Transmition) in depth of 15 and 45 cm, tensiometer suction presure in depth of 15, 30, 45 and 60 cm and temperature of soil and air. Three plots were also arranged by rain gauges for precipitation measurements in the vegetation season. To complete the characteristics of the unsaturated zone the particle-size analysis and retention curves for depths of 15, 30, 45 and 60 cm were done. Four groups of three rod probes (0.3, 0.6 and 0.9 m) for TDR (Time Domain Reflectometry) soil moisture measurements for seven plots were installed. The irregular measurements were done during 2000, 2001, 2002 and 2003 vegetation seasons. The values of soil moisture for depth intervals of 0-30 cm, 30-60 cm and 60-90 cm were computed for each plot. The TDR values of soil moisture are generally lower than the results obtained from VIRRIB sensors. The explanation of this fact should be that the used TDR measurements involve bigger interval of soil profile than VIRRIB sensors which measure smaller area of soil. The other reason could be the diferent way of probe instalation for each method. The results were compared with the data obtained from VIRRIB sensors, and where possible, the TDR data was used for giving precision to the VIRRIB data. Significant influence of diferent vegetative cover on water regime in soils of tundra area of the Giant Mountains was determined but not sufficiently explained yet. Surprisingly the water regime under the grassland showed similar behavior as a forest area against the dwarf pine stands during the most rainfall-runoff periods studied. The research is supported by the Czech Science Foundation (Projects No. 205/08/1174 and 526/08/1016).

Dvorak, I. J.; Tesar, M.; M., Sir; Dohnal, J.

2009-04-01

215

Comparative study of trace element levels in some local vegetable varieties and irrigation waters from different locations in Ilorin, Nigeria  

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Full Text Available The level of heavy metals in two varieties of vegetables harvested during the dry and wet seasons from seven different locations in Ilorin, Nigeria, were determined. The correlation between the level of metals in the vegetables and the irrigation water was also studied. Vegetables harvested during the dry season were found to contain higher level of toxic metals. Low water quality, accumulation of particulate after rainless period and nearness of some vegetable gardens to major and well travelled roads appeared to be the major contributory factors. Amaranthus hybridus seemed to have higher metal accumulation capacity compared to Corchorus olitorius mannii.

O.O. Dosumu

2003-06-01

216

IDENTIFYING RECENT SURFACE MINING ACTIVITIES USING A NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI) CHANGE DETECTION METHOD  

Science.gov (United States)

Coal mining is a major resource extraction activity on the Appalachian Mountains. The increased size and frequency of a specific type of surface mining, known as mountain top removal-valley fill, has in recent years raised various environmental concerns. During mountainto...

217

Bandwidth optimization for filter-based fatigue index in different inter-electrode distances.  

Science.gov (United States)

In this study, the bandwidth of the filter-based fatigue index was determined by the comparison of optimized cut-off frequencies in different inter-electrode distances. Sixty-one subjects participated in isometric knee extension, isotonic ankle dorsiflexion, and isotonic elbow extension exercises. Electromyography (EMG) signals were obtained from right rectus femoris, triceps brachii, and tibialis anterior muscles during exercises. The filter-based fatigue index was compared with mean root-mean-square values, median frequency, Dimitrov spectral index, and Gonzalez-Izal wavelet index. Optimized cut-off frequencies of the high-pass filter for three different exercises and three different inter-electrode distances were about 350 Hz. Results from this study support that around 350 Hz high-pass filter could be useful to determine cut-off frequency for fatigue prediction in general purposes. PMID:25227085

Kim, Jungyoon; Son, Jongsang; Kim, Youngho

2014-01-01

218

Effect of Different Phases of Menstrual Cycle on Reflection Index, Stiffness index and Pulse wave velocity in Healthy subjects  

Science.gov (United States)

Introduction: Arterial compliance will result in stabilizing the fluctuations in arterial pressure and blood flow. So arterial stiffness can be a good indicator for monitoring the cardiovascular system. Arterial stiffness can be measured using indices like reflection index (RI), stiffness index (SI) and Brachial Finger Pulse Wave Velocity (BFPWV). Objectives: Aim of our study was to evaluate the changes in RI, SI and BFPWV during different phases of the menstrual cycle and to correlate RI with SI in healthy female subjects between the age group of 18-30 years from Bangalore, India. Materials and Methods: Basal recordings of RI and SI were determined by Photo Pulse Plethysmography (PPG) picked up from the fingertip using BIOPAC system and BFPWV was obtained using Doppler. Recordings were obtained at three different time points during the menstrual cycle. Analysis was done using repeated measures ANOVA with Bonferroni correction. Result: There was a significant decrease in above parameters p <0.05 during the mid-cycle. Correlation between RI and SI was also significant p<0.05. Conclusion: These findings suggests that the menstrual cycle affects the arterial stiffness and one of the factor is oestrogen. Hence, women are less prone to the incidence of cardiovascular diseases before menopause. Screening for arterial stiffness in a general population, using these indices is valid, economical and reliable. PMID:25386420

TA, Sandhya

2014-01-01

219

Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs), from the high resolution Advanced Thermal Emission and Reflection Radiometer ...

Hirokazu Yamamoto; Kayo Fujiwara; Hiroki Yoshioka; Tomoaki Miura

2008-01-01

220

H-Index of Astrophysicists at Raman Research Institute: Performance of Different Calculators  

Science.gov (United States)

H-index, a single number proposed by J. E. Hirsch in 2005 has gained popularity as an index number to measure the research performance of individuals, institutions, universities, etc. There are many calculators to derive the h-in dex number, such as Google Scholar, Web of Science, Scopus, etc. However, h-index can be calculated manually, provided we have access to a complete list of publications of a scientist and the number of citations received by them. It is observed that h-index for a given scientist at a ny given point of time differs from one calculator to the other. Here is an attempt to calculate the H-index of scientists of the Astronomy and Astrophysics Group at Raman Research Institute using Google Scholar Free calculator, Web of Science Paid calculator and The SAO/NASA As trophysics Data System manual calculation and comparison of the results. Application of this h- index phenomenon to the research output of RRI scientists in a group is done while keeping in mi nd Hirsch's systematic in vestigation to predict the position of a scientist using h-index in physics. It is believed that the higher the academic age of a scientist, the higher will be the h-index. An attempt is made to find whether this assumption is true with respect to the sample studied by including the superannuated scientists from Astronomy and Astrophysics Group at Raman Research Institute under the purview of this study.

Meera, B. M.; Manjunath, M.

2012-08-01

 
 
 
 
221

Diseño de un índice espectral de la vegetación desde una perspectiva conjunta de los patrones exponenciales y lineales del crecimiento / Design of a spectral vegetation index under the joint perspective of exponential and linear growth patterns  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish En este trabajo se analizan diferentes experimentos con mediciones de reflectancia para revisar los patrones de las primeras dos constantes de los modelos de interacciones radiativas en el espacio del rojo (R) e infrarrojo cercano (IRC), concluyéndose de la evidencia experimental que el modelo de in [...] teracciones de orden uno es suficiente para este fin. En segundo lugar se desarrolla el algoritmo del índice espectral IV_CIMAS y se aplica a experimentos de cultivos, concluyéndose que este índice sólo tiene una relativa mejoría en relación con el índice NDVIcp, y que ambos describen bien la fase expo-lineal de la etapa vegetativa de la vegetación. La fase reproductiva no es modelada en forma adecuada por ninguno de los índices espectrales. Finalmente, se revisan los modelos de la geometría sol-sensor propuestos, y se concluye que éstos tienen buenos ajustes experimentales, permitiendo estandarizar esta geometría. La modelación de los patrones asociados a las constantes de las curvas espectrales de igual vegetación es muy difícil de realizar por las propiedades de los espacios usados. El problema del diseño de índices de vegetación es todavía un problema abierto. Abstract in english This study analyzes different experiments with reflectance measurements to review the patterns of the first two constants of the models of radiative interaction in the red (R) and near infrared (NIR) space. From experimental evidence, it is concluded that the first order model of interactions is suf [...] ficient for this aim. Secondly, the algorithm of the spectral index IV_CIMAS is developed and applied to crop experiments, concluding that this index is only a relative improvement over the NDVIcp index and that the expo-linear phase of the vegetative growth stage of the vegetation are well-described by both. The reproductive phase is not adequately modeled by either of the spectral indexes. Finally, the models of sun-sensor geometry proposed are reviewed, and it is concluded that these have good experimental fit, allowing this geometry to be standardized. Modeling of the associated patterns to the spectral curve constants of equal vegetation is very difficult to do because of properties of the spaces used. The problem of designing vegetation indexes is still open.

Enrique, Romero-Sánchez; Fernando, Paz-Pellat; Enrique, Palacios-Vélez; Martín, Bolaños-González; René, Valdez-Lazalde; Arnulfo, Aldrete.

222

Diseño de un índice espectral de la vegetación desde una perspectiva conjunta de los patrones exponenciales y lineales del crecimiento / Design of a spectral vegetation index under the joint perspective of exponential and linear growth patterns  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish En este trabajo se analizan diferentes experimentos con mediciones de reflectancia para revisar los patrones de las primeras dos constantes de los modelos de interacciones radiativas en el espacio del rojo (R) e infrarrojo cercano (IRC), concluyéndose de la evidencia experimental que el modelo de in [...] teracciones de orden uno es suficiente para este fin. En segundo lugar se desarrolla el algoritmo del índice espectral IV_CIMAS y se aplica a experimentos de cultivos, concluyéndose que este índice sólo tiene una relativa mejoría en relación con el índice NDVIcp, y que ambos describen bien la fase expo-lineal de la etapa vegetativa de la vegetación. La fase reproductiva no es modelada en forma adecuada por ninguno de los índices espectrales. Finalmente, se revisan los modelos de la geometría sol-sensor propuestos, y se concluye que éstos tienen buenos ajustes experimentales, permitiendo estandarizar esta geometría. La modelación de los patrones asociados a las constantes de las curvas espectrales de igual vegetación es muy difícil de realizar por las propiedades de los espacios usados. El problema del diseño de índices de vegetación es todavía un problema abierto. Abstract in english This study analyzes different experiments with reflectance measurements to review the patterns of the first two constants of the models of radiative interaction in the red (R) and near infrared (NIR) space. From experimental evidence, it is concluded that the first order model of interactions is suf [...] ficient for this aim. Secondly, the algorithm of the spectral index IV_CIMAS is developed and applied to crop experiments, concluding that this index is only a relative improvement over the NDVIcp index and that the expo-linear phase of the vegetative growth stage of the vegetation are well-described by both. The reproductive phase is not adequately modeled by either of the spectral indexes. Finally, the models of sun-sensor geometry proposed are reviewed, and it is concluded that these have good experimental fit, allowing this geometry to be standardized. Modeling of the associated patterns to the spectral curve constants of equal vegetation is very difficult to do because of properties of the spaces used. The problem of designing vegetation indexes is still open.

Enrique, Romero-Sánchez; Fernando, Paz-Pellat; Enrique, Palacios-Vélez; Martín, Bolaños-González; René, Valdez-Lazalde; Arnulfo, Aldrete.

2009-05-01

223

Radium and uranium levels in vegetables grown using different farming management systems  

International Nuclear Information System (INIS)

Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of 238U, 226Ra and 228Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for 226Ra, 0.55 for 228Ra and 0.24 for 238U (Bq kg-1 dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10-4 to 10-2 for 238U and from 10-2 to 10-1 for 228Ra

224

Radium and uranium levels in vegetables grown using different farming management systems  

Energy Technology Data Exchange (ETDEWEB)

Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of {sup 238}U, {sup 226}Ra and {sup 228}Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for {sup 226}Ra, 0.55 for {sup 228}Ra and 0.24 for {sup 238}U (Bq kg{sup -1} dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10{sup -4} to 10{sup -2} for {sup 238}U and from 10{sup -2} to 10{sup -1} for {sup 228}Ra.

Lauria, D.C. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Recreio dos Bandeirantes, Rio de Janeiro, RJ, CEP 22780-160 (Brazil)], E-mail: dejanira@ird.gov.br; Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN), Av. Prof. Luiz Freire 200, Cidade Universitaria Recife, PE, CEP 50740-540 (Brazil); Conti, C.C. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Recreio dos Bandeirantes, Rio de Janeiro, RJ, CEP 22780-160 (Brazil); Loureiro, F.A. [Estacao Experimental de Nova Friburgo, Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro, Pesagro (Brazil)

2009-02-15

225

Economic Study on Winter Vegetables Produced by Different Categories of Farms  

Directory of Open Access Journals (Sweden)

Full Text Available The study was designed to assess the comparative profitability of selected winter vegetables like potato, cauliflower and tomato. To achieve this objective, total of 75 farmers, 25 producing potato, 25 producing cauliflower and 25 producing tomato were selected. For this purpose, Cobb-douglas production function model was used. Per hectare total cost of production of potato, cauliflower and tomato were 51396.79, 64406.06 and 61663.87 TK., respectively and the corresponding gross incomes were 99401.44, 119165.12 and 93442.24 TK., respectively. The estimated net return of producing potato, cauliflower and tomato were 48004.65, 54759.06 and 31778.37 TK., respectively. For producing the three alternate winter vegetables net return was the highest for cauliflower followed by potato and tomato. It was also found that there was a large variation of yield in producing these winter vegetables among different categories of farms. In the case producing potato and cauliflower, per hectare yield was the highest for small farms followed by medium and large farms. On the other hand in the case of tomato per hectare yield was the highest (48164.50 kg for large farms followed by medium (47444.10 kg and small farms (46143.00 kg. It is concluded that production of cauliflower is more profitable than that of others.

M.S. Sultana

2005-01-01

226

A Preliminary Study on Genetic Variation of Arsenic Concentration in 32 Different Genotypes of Leafy Vegetable  

Directory of Open Access Journals (Sweden)

Full Text Available Leafy vegetables are a food crop with higher protein and are also important source of minerals which are essential for good health. Due to the large consumption, it is necessary to decrease the arsenic (As concentration in leafy vegetable to avoid the potential risk to human health. The current study is aimed at assessing arsenic (As accumulation ability and identification of cultivars with less As concentration that could be grown in As contaminated farmland for food safety. A set of thirty two leafy vegetable cultivars from 5 species were compared in hydroponics for 2 weeks having moderate level of 0- control and 6 mg As L-1. At harvest, plants were sampled and analyzed for As concentration. Significant genotypic variations were observed in the shoots As concentration, translocation and bioaccumulation factors revealing more than 8 and 25 times cultivar differences in shoot As concentration, and in translocation factors respectively. This result revealed that As concentration in shoot was in part governed by the greater ability of root-shoot translocation. Cultivar Sijibaiye (SJBY had the lowest shoot As concentration while the highest was detected in Dayekongxincai (DYKXC. The average As concentration in roots were found to be ten to twenty times higher than those observed in shoots, indicating that there is restricted transport of As from the root system to the shoot of cultivars. Therefore, it has been suggested that there is possibility to lower the As concentration in leafy vegetables by selecting and breeding cultivars with less As concentration that can be safely grown in contaminated soils with the slight and moderate levels of As for safe consumption.

Mathieu Nsenga Kumwimba

2014-04-01

227

[Study on nutrient and salinity in soil covered with different vegetations in Shuangtaizi estuarine wetlands].  

Science.gov (United States)

Nutrient elements and salinity in soil covered by different vegetations including Phragmites australis (Clay.) Trin., Typha orientalis Presl., Puccinellia distans Parl, and Suaeda salsa in Shuangtaizi estuarine wetlands were investigated to study their distribution characteristics and to reveal the nutrient element variation during the vegetation succession processes. Results indicated that total potassium, total phosphorus and salinity were different significantly in soil between different plant communities while available phosphorus, total nitrogen, available nitrogen, available potassium, total sulfur, iron and soil organic carbon were different insignificantly. Correlation analysis suggested that soil organic carbon were related significantly to total nitrogen, available phosphorus, available potassium, which implied that decomposition of plant litter might be the mail source of soil nitrogen and available nutrient. Salinity was significantly related to total phosphorus and iron in soil. In Shuangtaizi estuarine wetland soil, ratios of carbon to nitrogen (R(C/N)) was in the range of 12.21-26.33 and the average value was 18.21, which was higher than 12.0. It indicated that soil organic carbon in Shuangtaizi estuarine mainly came from land but not ocean and plants contributed the most of soil organic matters. There was no significant difference in R(C/N) between soil from the four plant communities (F = 1.890, p = 0.151). R(C/N) was related significantly to sol salinity (r = 0.346 3, p = 0.035 8) and was increasing with soil salinity. PMID:22165232

Song, Xiao-Lin; Lü, Xian-Guo; Zhang, Zhong-Sheng; Chen, Zhi-Ke; Liu, Zheng-Mao

2011-09-01

228

Manufacture of Cheese from Skim Milk with Addition of Different Levels of Vegetable Oil  

Directory of Open Access Journals (Sweden)

Full Text Available The experiment was conducted to manufacture cheese from skim milk with 30, 40 and 50 g kg-1 soybean oil and whole milk and to monitor the quality of different types of prepared cheese. It was observed that the flavour, taste, colour and appearance, body and texture, overall acceptability and final score were significantly higher in whole milk cheese than that of other types of vegetable oil based (30, 40 and 50 g kg-1 skim milk cheese. Chemical analysis showed that there were significant differences (P<0.01 incase of protein and fat contents of different types of cheeses. On the other hand there were no significant differences in moisture, total solids, ash and acidity content of different types of cheese. Although some chemical parameters showed that the quality of soybean oil based (30, 40 and 50 g kg-1 skim milk cheeses were better than the whole milk cheese but expert judges gave their opinion in favour of whole milk cheese, on the basis of organoleptic evaluation. It may be concluded that cheese could be manufactured successfully from skim milk with 30, 40 and 50 g kg-1 soyabean oil and it will open a new door in business sector and experiment also could solve the protein deficiency of Bangladesh. According to panelists score 50 g vegetable oil based skim milk cheese was better than other types of skim milk cheese.

A. Ara

2002-01-01

229

Sacrum Index in Children Suffering from Different Grades of Vesicoureteral Reflux  

Directory of Open Access Journals (Sweden)

Full Text Available This study aimed at evaluating the sacrum index in children suffering from different grades of vesicoureteral reflux. In this case-control study, according to VCUG results, children with grade III, IV and V refluxes entered the study. There were 76 children with history of urinary canal infection and normal VCUG. Sacrum index was measured in both groups and compared. There was a meaningful relationship between these two groups considering abnormality rate of the index (p = 0.001. The factor can be used as a predictive factor in determining prognosis of medical treatment and selecting those children candidate to surgery.

Farnaz Hafez Qoran

2013-01-01

230

An Empirical Algorithm for Estimating Agricultural and Riparian Evapotranspiration Using MODIS Enhanced Vegetation Index and Ground Measurements of ET. II. Application to the Lower Colorado River, U.S.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Large quantities of water are consumed by irrigated crops and riparian vegetation in western U.S. irrigation districts. Remote sensing methods for estimating evaporative water losses by soil and vegetation (evapotranspiration, ET) over wide river stretches are needed to allocate water for agricultural and environmental needs. We used the Enhanced Vegetation Index (EVI) from MODIS sensors on the Terra satellite to scale ET over agricultural and riparian areas along the Lower Colorado River in ...

Glenn, Edward P.; Kiyomi Morino; Scott Murray, R.; Nagler, Pamela L.

2009-01-01

231

Global vegetation-fire pattern under different land use and climate conditions  

Science.gov (United States)

Fire is a process of global significance in the Earth System influencing vegetation dynamics, biogeochemical cycling and biophysical feedbacks. Naturally ignited wildfires have long history in the Earth System. Humans have been using fire to shape the landscape for their purposes for many millenia, sometimes influencing the status of the vegetation remarkably as for example in Mediterranean-type ecosystems. Processes and drivers describing fire danger, ignitions, fire spread and effects are relatively well-known for many fire-prone ecosystems. Modeling these has a long tradition in fire-affected regions to predict fire risk and behavior for fire-fighting purposes. On the other hand, the global vegetation community realized the importance of disturbances to be recognized in their global vegetation models with fire being globally most important and so-far best studied. First attempts to simulate fire globally considered a minimal set of drivers, whereas recent developments attempt to consider each fire process separately. The process-based fire model SPITFIRE (SPread and InTensity of FIRE) simulates these processes embedded in the LPJ DGVM. Uncertainties still arise from missing measurements for some parameters in less-studied fire regimes, or from broad PFT classifications which subsume different fire-ecological adaptations and tolerances. Some earth observation data sets as well as fire emission models help to evaluate seasonality and spatial distribution of simulated fire ignitions, area burnt and fire emissions within SPITFIRE. Deforestation fires are a major source of carbon released to the atmosphere in the tropics; in the Amazon basin it is the second-largest contributor to Brazils GHG emissions. How ongoing deforestation affects fire regimes, forest stability and biogeochemical cycling in the Amazon basin under present climate conditions will be presented. Relative importance of fire vs. climate and land use change is analyzed. Emissions resulting from wildfires, agricultural and woodfuel burning will be quantified and drivers identified. Future projections of climate and land use change are applied to the model to investigate joint effects on future changes in fire, deforestation and vegetation dynamics in the Amazon basin.

Thonicke, K.; Poulter, B.; Heyder, U.; Gumpenberger, M.; Cramer, W.

2008-12-01

232

A Vegetation Index to Estimate Terrestrial Gross Primary Production Capacity for the Global Change Observation Mission-Climate (GCOM-C/Second-Generation Global Imager (SGLI Satellite Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available To estimate global gross primary production (GPP, which is an important parameter for studies of vegetation productivity and the carbon cycle, satellite data are useful. In 2014, the Japan Aerospace Exploration Agency (JAXA plans to launch the Global Change Observation Mission-Climate (GCOM-C satellite carrying the second-generation global imager (SGLI. The data obtained will be used to estimate global GPP. The rate of photosynthesis depends on photosynthesis reduction and photosynthetic capacity, which is the maximum photosynthetic velocity at light saturation under adequate environmental conditions. Photosynthesis reduction is influenced by weather conditions, and photosynthetic capacity is influenced by chlorophyll and RuBisCo content. To develop the GPP estimation algorithm, we focus on photosynthetic capacity because chlorophyll content can be detected by optical sensors. We hypothesized that the maximum rate of low-stress GPP (called “GPP capacity” is mainly dependent on the chlorophyll content that can be detected by a vegetation index (VI. The objective of this study was to select an appropriate VI with which to estimate global GPP capacity with the GCOM-C/SGLI. We analyzed reflectance data to select the VI that has the best linear correlation with chlorophyll content at the leaf scale and with GPP capacity at canopy and satellite scales. At the satellite scale, flux data of seven dominant plant functional types and reflectance data obtained by the Moderate-resolution Imaging Spectroradiometer (MODIS were used because SGLI data were not available. The results indicated that the green chlorophyll index, CIgreen(?NIR/?green-1, had a strong linear correlation with chlorophyll content at the leaf scale (R2 = 0.87, p < 0.001 and with GPP capacity at the canopy (R2 = 0.78, p < 0.001 and satellite scales (R2 = 0.72, p < 0.01. Therefore, CIgreen is a robust and suitable vegetation index for estimating global GPP capacity.

Juthasinee Thanyapraneedkul

2012-11-01

233

Interpersonal Reactivity Index: Analysis of Invariance and Gender Differences in Spanish Youths  

Science.gov (United States)

Empathy is understood as a multidimensional construct involving both cognitive and emotional factors for which, traditionally, gender differences have been reported. The Interpersonal Reactivity Index (Davis in Catalog Sel Documents Psychol 10:1-19, 1980) is an instrument made up of four subscales, each measuring a different dimension of the…

Holgado Tello, Francisco Pablo; Delgado Egido, Begona; Carrasco Ortiz, Miguel A.; Del Barrio Gandara, M. V.

2013-01-01

234

Phenolic profile evolution of different ready-to-eat baby-leaf vegetables during storage.  

Science.gov (United States)

Ready-to-eat baby-leaf vegetables market has been growing and offering to consumers convenient, healthy and appealing products, which may contain interesting bioactive compounds. In this work, the composition and the evolution of the phenolic compounds from different baby-leaf vegetables during refrigerated storage was studied. The phenolic compounds were extracted using pressurized liquid extraction (PLE) and the phenolic profile of each sample was analyzed and quantified by using LC-MS and LC-DAD methods, respectively, at the beginning and at the end of a 10-day storage period. The baby-leaf vegetables studied included green lettuce, ruby red lettuce, swiss chard, spinach, pea shoots, watercress, garden cress, mizuna, red mustard, wild rocket and spearmint samples and a total of 203 phenolic compounds were tentatively identified and quantified. The main naturally phenolic compounds identified correspond to glycosylated flavonoids, with exception of green lettuce and spearmint leaves which had a higher content of hydroxycinnamic acids. Quantification of the main compounds showed a 10-fold higher content of total phenolic content of ruby red lettuce (483mgg(-1)) in relation to the other samples, being the lowest values found in the garden cress (12.8mgg(-1)) and wild rocket leaves (8.1mgg(-1)). The total phenolic content only showed a significant change (pgreen lettuce (+17.5%), mizuna (+7.8%), red mustard (-23.7%) and spearmint (-13.8%) leaves. Within the different classes of phenolic compounds monitored, the flavonols showed more stable contents than the hydroxycinnamic and hydroxybenzoic acids, although the behavior of each compound varied strongly among samples. PMID:24438834

Santos, J; Oliveira, M B P P; Ibáñez, E; Herrero, M

2014-01-31

235

Active layer thermal regime at different vegetation covers at Lions Rump, King George Island, Maritime Antarctica  

Science.gov (United States)

Climate change impacts the biotic and abiotic components of polar ecosystems, affecting the stability of permafrost, active layer thickness, vegetation, and soil. This paper describes the active layer thermal regimes of two adjacent shallow boreholes, under the same soil but with two different vegetations. The study is location in Lions Rump, at King George Island, Maritime Antarctic, one of the most sensitive regions to climate change, located near the climatic limit of Antarctic permafrost. Both sites are a Turbic Cambic Cryosol formed on andesitic basalt, one under moss vegetation (Andreaea gainii, at 85 m a.s.l.) and another under lichen (Usnea sp., at 86 m a.s.l.), located 10 m apart. Ground temperature at same depths (10, 30 and 80 cm), water content at 80 cm depth and air temperature were recorded hourly between March 2009 and February 2011. The two sites showed significant differences in mean annual ground temperature for all depths. The lichen site showed a higher soil temperature amplitude compared to the moss site, with ground surface (10 cm) showing the highest daily temperature in January 2011 (7.3 °C) and the lowest daily temperature in August (- 16.5 °C). The soil temperature at the lichen site closely followed the air temperature trend. The moss site showed a higher water content at the bottommost layer, consistent with the water-saturated, low landscape position. The observed thermal buffering effect under mosses is primarily associated with higher moisture onsite, but a longer duration of the snowpack (not monitored) may also have influenced the results. Active layer thickness was approximately 150 cm at low-lying moss site, and 120 cm at well-drained lichen site. This allows to classify these soils as Cryosols (WRB) or Gelisols (Soil Taxonomy), with evident turbic features.

Almeida, Ivan C. C.; Schaefer, Carlos Ernesto G. R.; Fernandes, Raphael B. A.; Pereira, Thiago T. C.; Nieuwendam, Alexandre; Pereira, Antônio Batista

2014-11-01

236

Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure  

Science.gov (United States)

We examined sexual differences in patterns of vegetation structure selection in the sexually dimorphic little bustard. Differences in vegetation structure between male, female and non-used locations during reproduction were examined and used to build a presence/absence model for each sex. Ten variables were measured in each location, extracting two PCA factors (PC1: a visibility-shelter gradient; PC2: a gradient in food availability) used as response variables in GLM explanatory models. Both factors significantly differed between female, male and control locations. Neither study site nor phenology was significant. Logistic regression was used to model male and female presence/absence. Female presence was positively associated to cover of ground by vegetation litter, as well as overall vegetation cover, and negatively to vegetation density over 30 cm above ground. Male presence was positively related to litter cover and short vegetation and negatively to vegetation density over 30 cm above ground. Models showed good global performance and robustness. Female microhabitat selection and distribution seems to be related to the balance between shelter and visibility for surveillance. Male microhabitat selection would be related mainly to the need of conspicuousness for courtship. Accessibility to food resources seems to be equally important for both sexes. Differences suggest ecological sexual segregation resulting from different ecological constraints. These are the first detailed results on vegetation structure selection in both male and female little bustards, and are useful in designing management measures addressing vegetation structure irrespective of landscape composition. Similar microhabitat approaches can be applied to manage the habitat of many declining farmland birds.

Morales, M. B.; Traba, J.; Carriles, E.; Delgado, M. P.; de la Morena, E. L. García

2008-11-01

237

Performance Test of CI Engine with Different Vegetable Oil as a Fuel  

Directory of Open Access Journals (Sweden)

Full Text Available Today, the diesel engine is still capable of running on “biodiesel” fuel, which can be produced from a variety of renewable sources, including soyabean oil, canola oil, sunflower oil, cottonseed oil, and animal fats. These sources can be obtained from agricultural feedstocks or by recycling used oil such as cooking grease. Biodiesel is usable in it’s pure form known as “neat biodiesel” or B100. In addition, it is available in various blends with petrodiesel, the most common of which is known as B20(20 percent biodiesel and 80 percent petrodiesel.it is also used in smaller percentage as a lubricating fuel additives.Copious resource of vegetable oil in India and its ease of translation to biodiesel help to save large expenses done on import of petroleum products and monetary growth of country. Biodiesel also generates enormous rural employment and degraded lands can be restored due to plantation of oil plants which help in reducing greenhouse gasses. in this paper we discuss & compare different performance parameters of C.I. engine with different vegetable oil as a fuel

Mr.Paresh K. Kasundra ¹ *, Prof. Ashish V. Gohil²

2011-12-01

238

Woody and grassy vegetation development in different landscape elements of the Curonian spit  

Directory of Open Access Journals (Sweden)

Full Text Available The species of woody and grassy establish on seashore sands and wastes. These plants are adapted for less favorable existence conditions some of them growing in littoral habitats of excessive moisture and salinity. Other tolerates infertile and dry sand. The purpose of the study have been analyzed the dispersion vegetation in different relief elements of the coastal protective dune look for a relation between woody and grassy plant species to foresee the tendencies of further seashore landscape development. It has been established that in locations with intensive flow of visitors a net of trodden paths is formed where the plants cover is disappearing very fast as there are suitable conditions for the springtime and autumn winds to erode the coastal protective dune of the seashore of the Curonian spit. The trodden path in a couple of years turn into 2 – 3 m. vides sand drifting corridors, but the lies of the holiday makers become there 4 – 5 m. wide pit and hollow. After these formations have interconnected they shape deflations of different size. The drifting sand carried by the prevailing western direction winds swamp the beyond coastal dune plains and the outskirts of the forest and sandy meadows. The statistical analysis of projection cover of plant shows that during the last 27 years (from 1982 the conditions for vegetation survival on the Curonian spit seashore sand dunes are gradually deteriorating.

Algimantas Me?islovas Olšausaks

2009-12-01

239

Fiber Bragg Grating Modeling, Characterization and Optimization with different index profiles  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the modeling and characterization of an optical fiber grating for maximum reflectivity, minimum side lobe power wastage. Grating length and refractive index profile are the critical parameters in contributing to performance of fiber Bragg grating. The reflection spectra and side lobes strength were analyzed with different lengths and different refractive index profiles. podization techniques are used to get optimized reflection spectra. The simulations are based on solving coupled mode equations by transfer matrix method that describes the interaction of guided modes.

SUNITA UGALE

2010-09-01

240

Different techniques for the production of biodiesel from waste vegetable oil  

Energy Technology Data Exchange (ETDEWEB)

The production of biodiesel from waste vegetable oil offers a triple-facet solution: economic, environmental and waste management. The new process technologies developed during the last years made it possible to produce biodiesel from recycled frying oils comparable in quality to that of virgin vegetable oil biodiesel with an added attractive advantage of being lower in price. Thus, biodiesel produced from recycled frying oils has the same possibilities to be utilized. Producing biodiesel from used frying oil is environmentally beneficial since it provides a cleaner way for disposing these products, and can yield valuable cuts in carbon dioxide (CO{sub 2}), the main contributor of global warming and climate change. While transesterification is well-established and becoming increasingly important, there remains considerable inefficiencies in existing transesterification processes. There is an imperative need to improve the existing biodiesel production methods from both economic and environmental viewpoints and to investigate alternative and innovative production processes. This study highlights the main changes occurring in the oil during frying in order to identify the characteristics of oil after frying and the anticipated effects of the products formed in the frying process on biodiesel quality and attempts to review the different techniques used in the production of biodiesel from recycled oils, stressing the advantages and limitations of each technique and the optimization conditions for each process. The emerging technologies which can be utilized in this field are also investigated. The quality of biodiesel produced from waste vegetable oil in previous studies is also reviewed and the performance of engines fueled with this biodiesel and the characteristics of the exhaust emissions resulting from it are highlighted. The overarching goal is to stimulate further activities in the field.

Refaat, A.A. [Cairo Univ. (Egypt). Dept. of Chemical Engineering

2010-01-01

 
 
 
 
241

Exploiting the MODIS albedos with the Two-stream Inversion Package (JRC-TIP): 1. Effective leaf area index, vegetation, and soil properties  

Science.gov (United States)

This contribution illustrates results from a large-scale application of the Joint Research Centre Two-stream Inversion Package (JRC-TIP), using MODIS broadband visible and near-infrared white sky surface albedos as inputs. The discussion focuses on products (based on the mean and one-sigma values of the probability distribution functions (PDFs)) obtained during the summer and winter. This paper discusses the retrieved model parameters including the effective leaf area index (LAI), the background brightness, and the scattering efficiency of the vegetation elements. The similarity between the derived LAI seasonal maps and earlier distributions of this variable comforts us in the quality of the albedo products as well as in the ability of the JRC-TIP to interpret the latter meaningfully. The opportunity to generate global maps of new products, such as the background albedo, underscores the advantages of using state of the art algorithmic approaches capable of fully exploiting accurate satellite remote sensing data sets. The detailed analyses of the retrieval uncertainties highlight the central role and contribution of the LAI, the main process parameter to interpret radiation transfer observations over vegetated surfaces. The estimation of the radiation fluxes that are absorbed, transmitted, and scattered by the vegetation layer and its background is achieved on the basis of the retrieved PDFs of the model parameters. Results from this latter step are discussed in a companion paper.

Pinty, B.; Andredakis, I.; Clerici, M.; Kaminski, T.; Taberner, M.; Verstraete, M. M.; Gobron, N.; Plummer, S.; Widlowski, J.-L.

2011-05-01

242

An Empirical Algorithm for Estimating Agricultural and Riparian Evapotranspiration Using MODIS Enhanced Vegetation Index and Ground Measurements of ET. I. Description of Method  

Directory of Open Access Journals (Sweden)

Full Text Available We used the Enhanced Vegetation Index (EVI from MODIS to scale evapotranspiration (ETactual over agricultural and riparian areas along the Lower Colorado River in the southwestern US. Ground measurements of ETactual by alfalfa, saltcedar, cottonwood and arrowweed were expressed as fraction of potential (reference crop ETo (EToF then regressed against EVI scaled between bare soil (0 and full vegetation cover (1.0 (EVI*. EVI* values were calculated based on maximum and minimum EVI values from a large set of riparian values in a previous study. A satisfactory relationship was found between crop and riparian plant EToF and EVI*, with an error or uncertainty of about 20% in the mean estimate (mean ETactual = 6.2 mm d?1, RMSE = 1.2 mm d?1. The equation for ETactual was: ETactual = 1.22 × ETo-BC × EVI*, where ETo-BC is the Blaney Criddle formula for ETo. This single algorithm applies to all the vegetation types in the study, and offers an alternative to ETactual estimates that use crop coefficients set by expert opinion, by using an algorithm based on the actual state of the canopy as determined by time-series satellite images.

Edward P. Glenn

2009-12-01

243

Vegetational Succession on Different Age Series Sponge Iron Solid Waste Dumps with Respect to Top Soil Application  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Vegetation composition of different age series sponge iron solid w aste dumps was analyzed with respect to the impact of top soil application on vegetation succession. Study revealed that freshly laid dump, without top soil cover was devoid of any vegetation. However, 1, 3 and 5 year old dumps were colonized by grasses, sedges, forbs and shrubs. Tree species could be recorded in 3 and 5 year old dumps, but were absent in 1 year old dump. In all the dumps, species belonging to forbs showed the...

Kullu, B.; Behera, N.

2011-01-01

244

Accuracy of the Temperature–Vegetation Dryness Index using MODIS under water-limited vs. energy-limited evapotranspiration conditions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water deficit indices based on the spatial relationship between surface temperature (Ts) and NDVI, known as triangle approaches, are widely used for drought monitoring. However, their application has been recently questioned when the main factor limiting evapotranspiration is energy. Even though water is the main control in dryland ecosystems, these can also undergo periods of energy and temperature limitation. In this paper we aimed to: (i) evaluate the TVDI (Temperature–Vegetation Dryness...

Garci?a, M.; Ferna?ndez, Ne?stor; Villagarci?a, L.; Domingo, F.; Puigdefa?bregas, Juan; Sandhold, I.

2014-01-01

245

Profitability and morphological characters of inter-cropping of different vegetables in tea  

International Nuclear Information System (INIS)

A field experiment was conducted at National Tea Research Institute, Shinkiari, Mansehra, during 2006-07 to find out the most productive and profitable tea-based intercropping system with different vegetable crops. The vegetables included were brinjal solanum melongena , chilies Capsicum annum, okra Ahle moselous, potato Solanum tuberosum, spinach Spinacia oleracea, garlic Allium sativum, onion Allium cepa, peas Pisum sativum and tomato Lycopersicon esculentum, as intercrop combination in newly planted tea. Intercropping of peas showed up poorest among all other treatments, in net income of Rs. 4,800.0, whereas intercrops significantly affected no. of branches, leaves, fresh and dry weight/plant of tea crop respectively. Considering the net return and total expenditure incurred on raising of intercrops, the highest net profit of Rs. 6,669.0/acre was obtained from potato, followed by garlic at Rs. 6,200.0. All treatments combination is more or less similar in net return, except T/sub 5/. Yield and yield-attributes in all treatments were significantly affected. Whereas branches and fresh weight remained significant among each other except sole tea crop. Agronomic data showed that the cropping days were also varies from 45 to 150 days in all treatments. Therefore it might be more economically viable than sole tea crop, upto complete bush formation. (author)

246

The Influence of Different Vegetable Oils on Some ?-3 Polyunsaturated Fatty Acids in Broiler Chickens Breast  

Directory of Open Access Journals (Sweden)

Full Text Available Taking into consideration that the vegetable oils added to the combined fodder can significantly modify the fatty acids profile in broiler food, through its redirection even the fatty acids profile of carcasses can be modified through enrichment in certain fatty acids and obtaining functional foods. Therefore an experiment was conduced on broilers, made up of three experimental groups, fed with a combined base fodder in which 2% of different fat sources have been incorporated (sunflower oil, soybean oil, linseed oil. After the 42 days growth period, the fatty acids profile, % of fatty acids in 100 g product (EPA, DPA, DHA, ? SFA, ? MUFA, ? PUFA of the chicken from the experimental groups, were determined. Fatty acids were determined using gascromatography. The data obtained after statistic processing and interpretation have highlighted the fact that, concerning the fatty acids profile in the chickens breast, we can observe variations of the determined fatty acids content, what shows us that they can be influenced through dietary factors, but there quantity being determined by the participation % of the energy sources (vegetable oils, but also by the fatty acids content of the participating raw materials.

Drago?-Sorin Fota

2011-05-01

247

Outcome prediction of advanced mantle cell lymphoma by international prognostic index versus different mantle cell lymphoma indexes: one institution study.  

Science.gov (United States)

The aim of this study was to evaluate the prognostic significance of international prognostic index (IPI), mantle cell lymphoma IPI (MIPI), simplified MIPI (sMIPI), and MIPI biological (MIPIb), as well as their correlation with immunophenotype, clinical characteristics, and overall survival (OS), in a selected group of 54 patients with advanced-stage mantle cell lymphoma (MCL), treated uniformly with CHOP. Seventeen patients had IV clinical stage (CS), while other 37 had leukemic phase at presentation. Diffuse type of marrow infiltration was verified in 68.5% and nodular in remainder patients. Extranodal localization (25.9%) included bowel (20.4%), pleural effusion, sinus, and palpebral infiltration. All of analyzed patients expressed typical MCL immunophenotypic profile: CD19(+)CD20(+)CD22(+)CD5(+)Cyclin-D1(+)FMC7(+)CD79b(+)smIg(+)CD38(+/-)CD23(-)CD10(-). Median OS of the whole group was 23 months, without significant differences between IV CS and leukemic phase patients. Thirty-two patients (59.3%) responded to initial treatment, 9 (16.7%) with complete and 23 (42.6%) with partial remission. Negative prognostic influence on OS had high IPI (P 80%) (P < 0.01). Using univariate Cox regression, we proved that IPI, sMIPI, MIPI, and MIPIb had an independent predictive importance (P < 0.01) for OS in uniformly treated advanced MCL patients, although sMIPI prognostic significance was the highest (P < 0.001). PMID:22170090

Todorovic, Milena; Balint, Bela; Andjelic, Bosko; Stanisavljevic, Dejana; Kurtovic, Nada Kraguljac; Radisavljevic, Ziv; Mihaljevic, Biljana

2012-09-01

248

Sensitivity study of land biosphere CO2 exchange through an atmospheric tracer transport model using satellite-derived vegetation index data  

International Nuclear Information System (INIS)

We develop a simple, globally uniform model of CO2 exchange between the atmosphere and the terrestrial biosphere by coupling the model with a three-dimensional atmospheric tracer transport model using observed winds, and checking results against observed concentrations of CO2 at various monitoring sites. CO2 fluxes are derived from observed greenness using satellite-derived Global Vegetation Index data, combined with observations of temperature, radiation, and precipitation. We explore a range of CO2 flux formulations together with some modifications of the modelled atmospheric transport. We find that while some formulations can be excluded, it cannot be decided whether or not to make CO2 uptake and release dependent on water stress. It appears that the seasonality of net CO2 fluxes in the tropics, which would be expected to be driven by water availability, is small and is therefore not visible in the seasonal cycle of atmospheric CO2. The latter is dominated largely by northern temperate and boreal vegetation, where seasonality is mostly temperature determined. We find some evidence that there is still considerable CO2 release from soils during northern-hemisphere winter. An exponential air temperature dependence of soil release with a Q10 of 1.5 is found to be most appropriate, with no cutoff at low freezing temperatures. This result is independent of the year from which observed winds were taken. This is remarkable insofar as year-to-year changes in modelled CO2 concentrations caused by changes in the wind data clearly outweigh those caused by year-to-year variability in the climate and vegetation index data. (orig.)

249

Effects of vegetation structure on biomass accumulation in a Balanced Optimality Structure Vegetation Model (BOSVM v1.0  

Directory of Open Access Journals (Sweden)

Full Text Available A myriad of interactions exist between vegetation and local climate for arid and semi-arid regions. Vegetation function, structure and individual behavior have large impacts on carbon–water–energy balances, which consequently influence local climate variability that, in turn, feeds back to the vegetation. In this study, a conceptual vegetation structure scheme is formulated and tested in the new Balanced Optimality Structure Vegetation Model (BOSVM to explore the importance of vegetation structure and vegetation adaptation to water stress on equilibrium biomass states. Surface energy, water and carbon fluxes are simulated for a range of vegetation structures across a precipitation gradient in West Africa and optimal vegetation structures that maximize biomass for each precipitation regime are determined. Two different strategies of vegetation adaptation to water stress are included. Under dry conditions vegetation tries to maximize the water use efficiency and leaf area index as it tries to maximize carbon gain. However, a negative feedback mechanism in the vegetation–soil water system is found as the vegetation also tries to minimize its cover to optimize the surrounding bare ground area from which water can be extracted, thereby forming patches of vertical vegetation. Under larger precipitation, a positive feedback mechanism is found in which vegetation tries to maximize its cover as it then can reduce water loss from bare soil while having maximum carbon gain due to a large leaf area index. The competition between vegetation and bare soil determines a transition between a "survival" state to a "growing" state.

Z. Yin

2014-05-01

250

Fourier Transform Infrared Spectroscopy (FTIR) and Multivariate Analysis for Identification of Different Vegetable Oils Used in Biodiesel Production  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main objective of this study was to use infrared spectroscopy to identify vegetable oils used as raw material for biodiesel production and apply multivariate analysis to the data. Six different vegetable oil sources—canola, cotton, corn, palm, sunflower and soybeans—were used to produce biodiesel batches. The spectra were acquired by Fourier transform infrared spectroscopy using a universal attenuated total reflectance sensor (FTIR-UATR). For the multivariate analysis principal compon...

Rosana de Cássia de Souza Schneider; Adilson Ben da Costa; Luciano Marder; Marco Flôres Ferrão; Daniela Mueller

2013-01-01

251

Features of development speed - power capabilities with different anthropometric indexes for boys 10 - 11 years.  

Directory of Open Access Journals (Sweden)

Full Text Available The aspects of development speed - power capabilities for the boys of middle school ages are considered. 88 boys of sixth classes of basic medical group took part in research (age 10 - 11???. Facilities of development of the indicated capabilities on gymnastic shells with the use of own weight body were exercises. Experimental groups were completed taking into account a difference between the indexes of growth and weight after the index of Brok. Distinctive features of development speed - power capabilities between children appeared in support on the squared beams and in climb on a rope on speed.

Kamaev O.I.

2012-04-01

252

On the evaluation of vegetation resilience in Southern Italy by using VEGETATION, MODIS, TM satellite time series  

Science.gov (United States)

Satellite technologies can be profitably used for investigating the dynamics of vegetation re-growth after disturbance at different temporal and spatial scales. Nevertheless, disturbance -induced dynamical processes are very difficult to study since they affect the complex soil-surface-atmosphere system, due to the existence of feedback mechanisms involving human activity, ecological patterns and different subsystems of climate. The remote sensing of vegetation has been traditionally carried out by using vegetation indices, which are quantitative measures, based on vegetation spectral properties, that attempt to measure biomass or vegetative vigor. The vegetation indices operate by contrasting intense chlorophyll pigment absorption in the red against the high reflectance of leaf mesophyll in the near infrared. The simplest form of vegetation index is simply a ratio between two digital values from these two spectral bands. The most widely used index is the well-known normalized difference vegetation index NDVI = [NIR-R]/ [NIR+R]. The normalization of the NDVI reduces the effects of variations caused by atmospheric contaminations. High values of the vegetation index identify pixels covered by substantial proportions of healthy vegetation. NDVI is indicative of plant photosynthetic activity and has been found to be related to the green leaf area index and the fraction of photosynthetically active radiation absorbed by vegetation. Variations in NDVI values become indicative of variations in vegetation composition and dynamics. In this study, we analyze the mutiscale satellite temporal series ( 2000 to 2008) of NDVI and other vegetation indices from SPOT VEGETATION, MODIS and Landsat TM data acquired for some significant test areas affetced and unaffected (Southern Italy) by different types of environmental diturbances (drought, salinity, pollution, etc). Our objective was to characterize quantitatively the resilient effect of vegetation cover at differen temporal and spatial scales.

Didonna, I.; Coluzzi, R.

2009-04-01

253

[Energy/protein index: its use in the diagnosis of different forms of malnutrition].  

Science.gov (United States)

The applicability of the energy/protein index (the ratio between the logarithmic transformation of tricipital skin fold and the brachial muscular circumference) is studied. Results obtained in a group of preschool children exhibiting different clinical-anthropometric forms of malnutrition led us to use this index not only for differentiating well-nourished from malnourished children, but also as a criterion for classifying energy malnutrition (including desnutrition and overweight) as well as protein malnutrition and assessing their magnitude. Mean values--with a 95% confidence interval for energy/protein index--were respectively 1,477 +/- 0.029 and 1,324 +/- 0,124 in children with moderate or severe energy denutrition; 1,836 +/- 0,028 in children with kwashiokor; and 1,683 +/- 0,019 in overweight children. PMID:830049

Amador, M; Bacallao, J; Hermelo, M; Fernández-Regalado, R; Tolon, C

1976-01-01

254

STUDY OF SACRAL INDEX: COMPARISON BETWEEN DIFFERENT REGIONAL POPULATIONS OF INDIA AND ABROAD  

Directory of Open Access Journals (Sweden)

Full Text Available Identification of sex by human skeletal remains is a critical problem and is very important in anthropological and medico legal works. Bones often survive the process of decay and therefore provide the major evidence of human age and sex after death. Over the years different authors had carried various types of measurements on human sacra of different races and regions. The present study carried out 81 sacra of unknown sex contains 45 male and 36 female sacra identified by physical characteristics. They were collected from Telangana and Andhra Pradesh region. India may be divided into four regions like North part, South part, West part, and East part for different study purpose on local population. In the present study mean sacral index in males is 104.08 and females are 115.72. The male mean sacral index value of present study is more than the values of Eastern part, north part, other worker of Southern part of India and western part except in Western part in Western Rajasthan population. The female mean sacral index value of present study is higher than the observation of Eastern part, other workers of Southern part of India, Varanasi and Jammu of north part of India and Saurashtra region of western region of India. Observations of the workers from remaining areas of Western part of India and Agra region of North India is higher than the present study. The studies on Indian population suggest that mean sacral index in females is higher than that of males.

Poornima Janipati

2014-10-01

255

Recovery of different waste vegetable oils for biodiesel production: a pilot experience in Bahia State, Brazil.  

Science.gov (United States)

In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH. The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated. PMID:23993759

Torres, Ednildo Andrade; Cerqueira, Gilberto S; Tiago, M Ferrer; Quintella, Cristina M; Raboni, Massimo; Torretta, Vincenzo; Urbini, Giordano

2013-12-01

256

Cholesterol levels and nutritional composition of commercial layers eggs fed diets with different vegetable oils  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english This experiment aimed at evaluating the effects of the supplementation of different vegetable oils at different levels to the diet of commercial layers on egg cholesterol levels and nutritional composition (proteins, total solids, lipids, and ashes) for 112 days. Birds were distributed according to [...] a completely randomized experimental design with 10 treatments (T1 - control; T2 - inclusion of 2.5% rapeseed oil; T3 - inclusion of 2.5% canola oil; T4 - inclusion of 2.5% soybean oil; T5 - inclusion of 5% rapeseed oil; T6 - inclusion of 5% canola oil; T7 - inclusion of 5% soybean oil; T8 - inclusion of 2.5% rapeseed oil + 2.5% soybean oil; T9 - inclusion 2.5% canola oil + 2.5% soybean oil; T10 - inclusion of 2.5% rapeseed oil + 2.5% canola oil) of six replicates of eight birds each, totaling 480 birds. Yolk cholesterol levels and nutritional composition were determined on days 20, 60 and 112 days of the experimental period. Data obtained during the experimental period were submitted to analysis of variance. Egg yolks produced by layer fed oils presented lower cholesterol levels after 20 days of inclusion in the experimental diets. On days 60 and 112, cholesterol levels were higher. It was concluded that supplementing layer diets with vegetable oils rich in polyunsaturated fatty acids does not change the nutritional composition of egg yolks. The supply of diets containing oils rich in polyunsaturated fatty acids does not reduce yolk cholesterol content.

ABG, Faitarone; EA, Garcia; R de O, Roça; H de A, Ricardo; E N de, Andrade; K, Pelícia; F, Vercese.

2013-03-01

257

Analyzing the vegetation response under different treatments after wildfires in NE Spain  

Science.gov (United States)

Fire is a natural factor of landscape evolution in Mediterranean ecosystems. The socio-economic changes that occurred in the last decades have contributed to an increase in forest fires (Shakesby, 2011). There was found a change in the fire regimes in terms of frequency, size, seasonality, recurrence as well as fire intensity and severity (Keeley, 2009), which resulted in severe effects on soils, water and vegetation (Guénon et al., 2013). Fire affects soil properties directly by the heat impact (Aznar et al., 2013), and the ash cover (Cerdà and Doerr, 2008) and the reduction of the plant cover (Neary et al., 1999). The lack of vegetation and the heating promotes changes in the soil organic matter content (González-Pérez et al., 2004), on the structural stability (Mataix-Solera et al., 2011), on the hydrophobic response (Bodí et al., 2012), and on the infiltration capacity (Cerdà, 1998a). This is why the vegetation cover and the litter are key factors on soil erosion after forest fires (Prats et al., 2013). Besides, the ash plays an important paper in the soil protection after the forest fire and after the first storms and winds (León et al., 2013; Pereira et al., 2013). The objective of this experiment is to asses the vegetation response after a forest fire and the impact of vegetation recovery on soil erosion. The experiment consisted in a sampling of a linear transect of 10 m with samples each 2 m, under different slope position and aspect. To measure the soil erosion rates we used rainfall simulation experiments (León et al., 2013). The experiments were carried in Castejón (UTM 30T, X671106, Y4644584) in a forest burned in 2008, in the Zuera Mountains, both located in the north of Zaragoza province (NE Spain). The soils on limestone parent material are Rendzic Phaeozem (IUSS, 2007) and the texture of Ah horizons of soils developed on limestone is sandy-loam (Badía et al., 2013). The result shows fast and successful vegetation regeneration in the north-facing slopes, and a delayed recovery on the south-facing slopes. The soil erosion control treatments shown a very efficient response when Chipped branches covered the soil. References Aznar, J.M., González-Pérez, J.A., Badía, D., Martí, C. 2013. At what depth are the properties of a Gypseous forest topsoil affected by burning?. Land Degradation and Development, DOI: 10.1002/ldr.2258 Badía, D., Martí, C., Aznar, J.M., León, J. 2013. Influence of slope and parent rock on soil genesis and classification in semiarid mountainous environments. Geoderma 193-194: 13-21, doi: http://dx.doi.org/10.1016/j.geoderma.2012.10.020. Bodí, M.B., Doerr, S.H., Cerdà, A., and Mataix-Solera, J. 2012. Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soil. Geoderma, 191: 14-23. Cerdà, A. 1998a. Postfire dynamics of erosional processes under mediterranean climatic conditions. Zeitschrift für Geomorphologie, 42 (3) 373-398. Cerdà, A. 1998b. The influence of aspect and vegetation on seasonal changes in erosion under rainfall simulation on a clay soil in Spain. Canadian Journal of Soil Science 78, 321-330. Cerdà, A., Doerr, S.H., 2008. The effect of ash and needle cover on surface runoff and ersion in the inmediate post-fire period. Catena 74, 256-263. González-Pérez, J.A., González-Vila, F.J., Almendros, G., Knicker, H. 2004. The effect of fire on soil organic matter - a review. Enviroment International, 30: 855-870. Guénon, R., Vennetier, M., Dupuy, N., Roussos, S., Pailler, A., Gros, R. 2013. Trends in recovery of Mediterranean soil chemical properties and microbial activities after infrequent and frequent wildfires. Land Degradation & Development, 24: 115-128, DOI: 10.1002/ldr.1109. Keeley, J.E. 2009. Fire intensity, fire severity and burn severity: a brief review and suggests usage. International Journal of Wildland Fire, 18: 116-126. León, J., Bodí, M.B., Cerdà, A., Badía, D., 2013. The contrasted response of ash to wetting: The effects of ash type, thickness and rainfall events. Geoderma 209-210, 143-152. Mataix

León, Javier; Cerdà, Artemi; Badía, David; Echeverría, Maite; Martí, Clara

2014-05-01

258

Relationships between ambient ozone regimes and white clover forage production using different ozone exposure indexes  

Science.gov (United States)

Plant responses to seasonal exposure to tropospheric ozone (O 3) are mediated by interactions with physical and genetic factors that complicate attempts to develop a measure of O 3 exposure (exposure index) that best relates to plant response. Dozens of exposure indexes have been tested for best fit to yield response data from open-top chamber studies. These tests have limited applicability because of possible confounding caused by variability in experimental protocols used in chamber dose-response studies. A 2-yr study in ambient air at eight locations in the USA measured relative effects of ambient O 3 on forage weight of a sensitive (NC-S) and a resistant (NC-R) clone of white clover. Protocols included uniform growth medium, irrigation, exposure duration and genetics (clones). Plants were harvested to determine NC-S/NC-R forage biomass ratios after each of four 28-day periods. High ratios indicated low O 3 concentrations, and low ratios indicated high concentrations. We used these results in attempts to identify the relative suitability of several exposure indexes in defining O 3 exposure-forage biomass relationships. Indexes were calculated using combinations of O 3 exposure forms (SUM00, SUM06, W95, W126, and AOT04), diurnal and seasonal accumulating times and harvests. Squared correlations ( r2's) between the index and biomass ratio were used as a general indication of relative suitability of the different indexes. Squared correlations were much higher for indexes coupled with harvests 2, 3 and 4, than for harvest 1. Even higher r2's occurred for indexes coupled with the combined mean forage ratio for harvests 2, 3 and 4. Squared correlations were most sensitive to the choice of hourly averaging times. Lowest r2's occurred for the 24 h accumulating period, much higher r2's occurred for the 12 h daylight period, and the highest r2's occurred for periods of 6 h or less during midday, regardless of all other factors. The exposure form was important only for 24 h indexes for which SUM00 gave the lowest r2's. All forms, including SUM00, produced similarly high r2's for 6, 5, and 4 h midday accumulating times.

Heagle, Allen S.; Stefanski, Leonard A.

259

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Blood pressure (BP variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM. We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI. Methods and Results In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time, standard deviation (SD of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (? 0.90 or ? 1.40 was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007. In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04. In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P Conclusion Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

Moreira Leila B

2010-11-01

260

Composition, peat-forming vegetation and kerogen paraffinicity of Cenozoic coals: Relationship to variations in the petroleum generation potential (Hydrogen Index)  

Energy Technology Data Exchange (ETDEWEB)

Coals with similar thermal maturity and from the same deposit normally show a considerable range in petroleum generation potential as measured by the Hydrogen Index (HI). This variation may partly be related to variations in plant input to the precursor mires and organic matter preservation. It is widely accepted that some Cenozoic coals and coaly sediments have the potential to generate oil, which is related to the coal's paraffinicity. Coal paraffinicity is not readily reflected in the bulk HI. In this paper, the relationships between measured HI and coal composition, coal kerogen paraffinicity and floral input have been investigated in detail for three sets of coals from Colombia/Venezuela, Indonesia, and Vietnam. The samples in each coal set are largely of iso-rank. The petroleum generation potential was determined by Rock-Eval pyrolysis. Reflected light microscopy was used to analyse the organic matter (maceral) composition and the thermal maturity was determined by vitrinite reflectance (VR) measurements. The botanical affinity of pollen and spores was analysed by palynology. Coal kerogen paraffinicity was determined by ruthenium tetroxide-catalysed oxidation (RTCO) followed by chain length analysis and quantification (mg/g TOC) of the liberated aliphatic chains. The coals are dominated by huminite, in particular detrohuminite. Only the Vietnamese coals are rich in microscopically visible liptinite. The pollen and spores suggest that the coals were derived principally from complex angiosperm mire vegetations, with subordinate proportions of ferns that generally grew in a subtropical to tropical climate. Measured HI values vary considerably, but for the majority of the coals the values lie between approximately 200 mg HC/g TOC and 300 mg HC/g TOC. Aliphatics yielding monocarboxylic acids dominate in the coal kerogen, whereas aliphatics yielding dicarboxylic acids are secondary. However, the dicarboxylic acids show that cross-linking long-chain aliphatics are present in the kerogen structure. All studied coals are paraffinic with C{sub 19-35} aliphatic chains in the kerogen, and the aliphatics in the range C{sub 25-35} show that the coals may have the potential to generate waxy crude oil. The Indonesian coals are richest in long-chain aliphatics and are thus potentially most oil-prone. Multivariate statistical analysis shows that for the present three sample sets variations in HI are positively correlated to different combinations of the C{sub 10+} aliphatic chains in the kerogen and the amount of detrohuminite + liptodetrinite and liptinite. Furthermore, part of the HI can be attributed to hydrogen in compounds with less than 10 carbon atoms, which is the lowest alkyl detected by RTCO analysis, thus representing a potential for generation of gas and light liquid hydrocarbons. The measured HI is therefore not always a good indicator for humic coal's potential to source waxy oil. Vegetational influence (palynology) on the variation of HI cannot be shown within the investigated span of variance and for the present coals. However, it is likely that some of the range in measured HI values is caused by floral vairiations not revealed by the palynological analysis and to variations in the preservation of the organic matter. (author)

Petersen, H.I.; Lindstroem, S.; Nytoft, H.P.; Rosenberg, P. [Geological Survey of Denmark and Greenland (GEUS), Oester Voldgade 10, DK-1350 Copenhagen (Denmark)

2009-04-01

 
 
 
 
261

A STUDY ON VARIATION IN BIOCHEMICAL ASPECTS OF DIFFERENT TREE SPECIES WITH TOLERANCE AND PERFORMANCE INDEX  

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Full Text Available The present study was undertaken to evaluate the variation between biochemical characteristics and air pollution tolerance index (APTI of 6 different plant species. The results of the present study indicate that APTI was significantly correlated with total chlorophyll, ascorbic acid, leaf pH for all species and are the most significant and determining factors on which the tolerance depends. The order of tolerance index of plant species is as follows Saraca indica (13.71, Azadirachta indica (12.98, Shorea robusta (12.64, Eucalyptus sp. (12.61, Ficus religiosa (12.61 and Tectona grandis (13.33. According to anticipated performance index (API all species were tolerant i.e. Azadirachta indica, Ficus religiosa, Saraca indica, Tectona grandis (75%, Shorea robusta and Tectona grandis (68%. The present study suggests that evaluation of plant tolerance and performance index might be very useful in the selection of appropriate species which can be expected to perform well for the development of green environment.

MEHA BORA

2014-03-01

262

Measuring the Human Development or Deprivation : A Review of (Different Composite Index) Methods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present paper reviews the different methods in practice to measure the human development or deprivation, which, in fact, is an emerging part of the development discourse. Specifically it deals with the problems of comparability, aggregation and weighing the dimension/indicators in composite index. The essential part of reporting human development involves a normalization of selected indicators by setting the goal posts of minimum and maximum values of the selected indicator that facilitat...

Motkuri, Venkatanarayana

2007-01-01

263

ADAPTABILITY OF STUDENTS WITH DIFFERENT INDIVIDUAL AND TYPOLOGICAL PECULIARITIES OF VEGETATIVE FUNCTIONS REGULATION  

Directory of Open Access Journals (Sweden)

Full Text Available In the last decade the health of young people inUkraineas well as in many other countries of the world significantly deteriorated according to the results of screening tests. Because of this the main task of prophylactic medicine is development and introduction of new methods of early diagnostics of diseases. The aim of the work to assess the peculiarities of adaptation of students with different types of vegetative regulation.Material and methods: 415 second year students ofLuganskStateMedicalUniversitywere tested. The mechanisms of physiological functions of the body regulation were assessed by registration of cardiac rhythm variability (CRV. Analysis of CRV was performed by three methods: statistical, geometrical, and spectral analysis. The express method proposed by Shlyk, N.I. (2009 was later used to determine the prevailing type of vegetative regulation. To assess adaptability the method of R.M. Baevskij (1979 was used.Results: In the result of investigation 4 types of functional states of regulatory systems were determined: I type – 295 (71 % of tested, II – in 14 (3 %, III – in 96 (23 % and IV – only in 10 (2%. I type of functional state of regulatory systems in the wakeful state at rest was characterized by moderate prevalence of central regulation of heart rhythm (MPCR, decreased activity of autonomic regulation. It was noticed that some of the parameters of CRV (like R-R, SDNN, RMSSD and pNN50 which characterize autonomic regulation, were statistically lowere (??0.01 compared to type III, and some (like AMo and SI higher, in both female and male students. Summarized spectrum capacity and components of its wave structure (HF, LF, VLF which characterize central regulation were statistically significantly lower (??0.01 for the I type of regulation compared to the III one which is characterized by moderate prevalence of autonomic regulation of the heart rhythm. In female students with type I autonomic regulation compared to male students such CRV parameters as R-R and A?o were statistically significantly lower (??0.05, while the parameters of total potency (TP and high frequency waves (HF were higher (??0.05, which could point to more centralized heart rhythm regulation in male compared to female. The evaluation of regulatory systems overstress allowed to determine the state of adaptation and risk of overstress or breakdown in students with different types of autonomic regulation.Conclusions: Thus, evaluation of adaptation state in students with different types of autonomic regulation allows to characterize the current functional state and uncover the risk of disease development.

Tatiana Tananakina

2014-04-01

264

An evaluation of multiple trauma severity indices created by different index development strategies.  

Science.gov (United States)

Evaluation of the effectiveness of emergency trauma care systems is complicated by the need to adjust for the widely variable case mix found in trauma patient populations. Several strategies have been advanced to construct the severity indices that can control for these population differences. This article describes a validity and reliability comparison of trauma severity indices developed under three different approaches: 1) use of a multi-attribute utility (MAU) model; 2) an actuarial approach relying on empirical data bases; and 3) an "ad hoc" approach. Seven criteria were identified to serve as standards of comparison for four different indices. The study's findings indicate that the index developed using the MAU theory approach associates most closely with physician judgments of trauma severity. When correlated with a morbidity outcome measure, the MAU-based index shows higher levels of agreement than the other indices. The index development approach based on the principles of MAU theory has several advantages and it appears to be a powerful tool in the creation of effective severity indices. PMID:6888025

Gustafson, D H; Fryback, D G; Rose, J H; Prokop, C T; Detmer, D E; Rossmeissl, J C; Taylor, C M; Alemi, F; Carnazzo, A J

1983-07-01

265

Limitaciones en la estimación de variables biofísicas en cultivos usando índices de vegetación espectrales: efecto de la densidad del follaje / Limitations in the estimation of biophysical variables in crops using spectral vegetation indexes: foliage density effect  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish En cultivos con una densidad alta del follaje, se produce la saturación rápida de la banda del rojo y la reducción de las variaciones en las pendientes de las curvas de igual vegetación (iso-IAF), en las que están basados muchos índices de vegetación (IV). Por ello, es importante el desarrollo de ín [...] dices alternativos que no presenten problemas de saturación y sean fácilmente parametrizados con información de campo. Con este fin se evalúan los patrones temporales (modelo expo-lineal como referencia) de índices espectrales basados en las pendientes de las líneas iso-IAF, así como los de variables biofísicas: biomasa aérea (Bm), cobertura aérea (fv) y altura (h) de dos cultivos con diferente densidad del follaje, alta (sorgo) y media (algodón). Al aplicar un modelo expo-lineal se espera que presenten un patrón bilineal siempre que exista coincidencia de las variables en las fases de inicio y final. En general, las fases exponencial y lineal de la Bm no coinciden con las de fv y h, mostrando diferencias entre las características estructurales y de distribución espacial de la vegetación (fv y h) y la función fotosintética (follaje y biomasa). El cultivo de densidad media presenta patrones bilineales bien caracterizados; en cambio, el de alta densidad muestra una rápida saturación en la fase exponencial de la Bm. Para reducir el problema de saturación, se exploró el uso de la constante aditiva a0 como alternativa de los índices basados en la pendiente. La relación entre la constante aditiva y Bm presentó patrones de tipo expo-lineal doble con problemas en la definición de sus transiciones; las relaciones con la variable fv fueron bilineales, tanto para el cultivo de densidad media como para el de densidad alta, permitiendo una parametrización fácil en campo de los índices de vegetación (uso de fv); con la altura la relación fue lineal-exponencial. Abstract in english High density foliage crops produce the rapid saturation of the red band and reduction of variations in curve slopes of the same vegetation (iso-LAI), on which many vegetation indexes (VI) are based. For this reason, it is important to develop alternative indexes that do not become saturated and that [...] are easily parameterized with information from the field. To this end, temporal patterns of spectral indexes (expo-linear model as reference) were evaluated based on the slopes of the iso-LAI lines, as well as the biophysical variables aerial biomass (Bm), aerial cover (fv) and height (h) of two crops with different foliage density: high (sorghum) and medium (cotton). When an expo-linear model is applied, it is expected that it would have a bi-linear pattern, as long as the variables coincide in their initial and end phases. In general, the Bm exponential and linear phases do not coincide with those of fv and h; this shows that there are differences among the structural characteristics, those of spatial vegetation distribution (fv and h), and photosynthetic function (foliage and biomass). The medium density crop exhibited well-characterized bilinear patterns. In contrast, the high density crop saturated rapidly in the exponential phase of Bm. To reduce the problem of saturation, the use of the additive constant a0 was explored as an alternative to the indexes based on slope. The relationship between the additive constant and Bm exhibited patterns of the double expo-linear type with problems in the definition of its transitions; the relationship with the variable fv were bi-linear, both for the medium density crop and for the high density crop, thus facilitating parameterization the vegetation indexes (use of fv) in the field; with height, the relationship was linear-exponential.

Magali, Odi-Lara; Fernando, Paz-Pellat; Ramón, López-Urrea; José, González-Piqueras.

266

Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles  

International Nuclear Information System (INIS)

Different vegetable oils including soy oil, high-oleic sunflower oil, corn oil, castor oil (CO), rapeseed oil, and hydrogenated CO were added to the imidization reaction of poly(styrene–maleic anhydride) or SMA, with ammonium hydroxide in aqueous medium. The oils favorably reduce viscosity during ammonolysis of the anhydride moieties and increase the maximum solid content of the dispersed imidized SMA to at least 50 wt%, compared to a maximum of 35 wt% for pure imidized SMA. The viscosity of imidized SMA with polyunsaturated oils was generally larger than for monosaturated oils, but it was highest for COs due to high contents of hydroxyl groups. Depending on the oil reactivity, homogeneous or core–shell nanoparticles with 20–60 nm diameters formed. The interactions of oil and organic phase were studied by Fourier-transform infrared spectroscopy, indicating qualitative variances between different oils, the fraction imidized SMA and remaining fraction of ammonolyzed SMA without leakage of oil upon diluting the dispersion and precipitation at low pH. A quantitative analysis with calculation of imide contents, amounts of reacted oil and chemical interactions was made by Fourier-transform-Raman spectroscopy suggesting that most interactions take place around the unsaturated oil moieties and ammonolyzed anhydride.

267

Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

Different vegetable oils including soy oil, high-oleic sunflower oil, corn oil, castor oil (CO), rapeseed oil, and hydrogenated CO were added to the imidization reaction of poly(styrene-maleic anhydride) or SMA, with ammonium hydroxide in aqueous medium. The oils favorably reduce viscosity during ammonolysis of the anhydride moieties and increase the maximum solid content of the dispersed imidized SMA to at least 50 wt%, compared to a maximum of 35 wt% for pure imidized SMA. The viscosity of imidized SMA with polyunsaturated oils was generally larger than for monosaturated oils, but it was highest for COs due to high contents of hydroxyl groups. Depending on the oil reactivity, homogeneous or core-shell nanoparticles with 20-60 nm diameters formed. The interactions of oil and organic phase were studied by Fourier-transform infrared spectroscopy, indicating qualitative variances between different oils, the fraction imidized SMA and remaining fraction of ammonolyzed SMA without leakage of oil upon diluting the dispersion and precipitation at low pH. A quantitative analysis with calculation of imide contents, amounts of reacted oil and chemical interactions was made by Fourier-transform-Raman spectroscopy suggesting that most interactions take place around the unsaturated oil moieties and ammonolyzed anhydride.

Samyn, Pieter, E-mail: Pieter.Samyn@fobawi.uni-freiburg.de [Albert-Luedwigs-University Freiburg, Institute for Forest Utilization (Germany); Schoukens, Gustaaf [Ghent University, Department of Textiles (Belgium); Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk [Topchim N.V. (Belgium)

2012-08-15

268

Mercury concentration in vegetables of Pakistan irrigated by different water sources  

International Nuclear Information System (INIS)

Mercury levels were determined in twenty samples of each vegetable i.e., Spinach (Spinacia oleracea), Lettuce (Lactuca sativa), Carrot (Daucus cariota), Capsicum (Capsicum fistulosus), Sweet pea (Lathyrus Odoratus), Potato (Solanum tuberosum) and Cabbage (Brassica oleracea), with a special reference of source of water of irrigation, i.e., tube well water, canal water and municipal sewage water. All the samples of vegetables were collected during the year 2006, 2007 and 2008 from the five districts of Pakistan viz Lahore, Kasur, Multan, Bahawalpur and R.Y. Khan. Statistical analysis such as Test of significance and multiple comparison were applied on the data obtained. The results showed that the concentration of Mercury in vegetables irrigated by canal water, sewage water and tube well water was in the range of 3.1-88.9 ppb and 9.0-130.6 ppb. It can be concluded from this study that the uptake of mercury by vegetables collected from above five districts of Pakistan was in the following order. Leafy vegetables > Root vegetables > seedy vegetables. (author)

269

How does feed with different levels of vegetable origin affect the sensory quality of ice storage Rainbow trout (Oncorhynchus mykiss)?  

DEFF Research Database (Denmark)

Background Fish from the aquaculture sector make up a steep raising share of the total fish consumed and play in that respect an essential role. The most important farmed fish in Denmark is rainbow trout (Oncorhynchus mykiss). However the aquaculture sector, raising fish species which are primarily carnivores, is facing major challenges as a consequence of the limited access in future sustainable resources of wild fish or other sea living organisms from a lower trophic level for feed production. Consequently, alternative feeding regimes are now considered e.g. use of components of vegetable origin such as soy oil or rapeseed oil combined with vegetable proteins. Such a change in feeding regime will result in a “green fish” and may affect flesh quality and eating quality. The objective was to study the effect of vegetable based feed on sensory of ice storage farmed rainbow trout. Experimental design and methods Feed trials Rainbow trout were farmed in tanks at Biomar A/S, Hirtshals and fed on six different diets covering only marine, only vegetables and mixture of marine and vegetable feeds. Trout for the quality study were slaughtered, vacuum-packed and stored at -80°C until analysis. Sensory Quality Changes in sensory quality were determined by objective descriptive sensory methods using profiling carried out by a trained panel. The fish samples were thawed and ice storage for 3, 5, 7 and 12 days. Results The sensory characterization of the trout feed with 100% marine and 100% vegetable feed showed after 3 days of ice storage that the trout feed with marine fed were more firm, juicy and the texture was more flacky that trout feed with vegetable feed. This sensory difference increased with increasing ice storage.

Hyldig, Grethe; Nielsen, Henrik Hauch

270

Caracterização da fauna edáfica em diferentes coberturas vegetais na região norte Fluminense Characterization of soil fauna in different vegetation covers in the northern Fluminense region (RJ  

Directory of Open Access Journals (Sweden)

Full Text Available O sistema solo-serapilheira é o habitat natural para grande variedade de organismos, que diferem em tamanho e metabolismo, responsáveis por inúmeras funções. O monitoramento dos grupos de fauna no sistema solo-serapilheira permite não só uma inferência sobre a funcionalidade destes organismos, mas também uma indicação simples da complexidade ecológica dessas comunidades. O presente trabalho teve como objetivo caracterizar a distribuição da fauna edáfica nos compartimentos solo e serapilheira em duas épocas do ano e em cinco diferentes coberturas vegetais (eucalipto, floresta não preservada, floresta preservada, capoeira, pasto no Norte Fluminense. As coberturas de floresta natural, especialmente das florestas preservadas e não preservadas, mostraram, de maneira geral, valores de densidade e riqueza de fauna superiores aos de eucalipto e pasto, tanto no solo quanto na serapilheira, nas duas épocas de coleta. Em geral, não houve preferência dos grupos de fauna pelos compartimentos solo e serapilheira. A densidade de fauna, riqueza de espécies, índice de Shannon e índice de Pielou também variaram conforme a época de coleta, sendo, no verão, estabelecidas maiores diferenças entre as diferentes coberturas vegetais estudadas do que no inverno. O índice de Pielou foi a variável mais estável e, portanto, mais apropriada para o estudo da dissimilaridade entre as coberturas vegetais em termos de distribuição dos grupos de fauna.The soil-litter system is a natural habitat for a great variety of organisms that differ in size and metabolism and are responsible for numerous functions. The study of groups of organism in the soil-litter system allows not only to make inferences on the functionality of these organisms, but also is a simple indication of the ecological complexity in these communities. Our study aimed at characterizing the distribution of groups of organism in soil and litter compartments in two seasons of the year (wet summer and dry winter under five different vegetation covers (eucalyptus, non-preserved forest, preserved forest, regenerating forest ('capoeira', and pasture in the northern Fluminense region (RJ, Brazil. Both soil and litter under the natural forest covers, in particular the preserved and non- preserved forest, generally showed higher organism density and abundance values than eucalyptus and pasture for in both collecting seasons. In general, there was no preference of organism groups for soil or litter. The organisms density and abundance, Shannon's index and Pielou's index also varied according to the season of the year and the differences among vegetation covers were more distinct in the summer than in the winter season. The Pielou's index was the most stable variable and, therefore, the most appropriate to study the dissimilarities among the vegetation covers in terms of distribution of groups of organisms.

Maria Kellen da S. Moço

2005-07-01

271

Caracterización del efecto de estrés usando índices espectrales de la vegetación para la estimación de variables relacionadas con la biomasa del área / Characterization of stress effect using spectral vegetation indexes for the estimate of variables related to aerial biomass  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El uso de índices espectrales o IV de la vegetación, basados en las líneas iso-IAF en el espacio espectral del rojo (R) e infrarrojo cercano (IRC), plantea relaciones diferentes en las etapas vegetativas y de senescencia con variables biofísicas como la biomasa aérea o Bm, el índice de área foliar o [...] IAF o la cobertura aérea de la vegetación o fv. Con el índice FVIS basado en las líneas iso-suelo del espacio R-IRC, los patrones temporales pueden identificarse mediante un modelo expo-lineal y exponencial. Así, las pendientes para la etapa vegetativa y de senescencia pueden usarse para cuantificar el nivel de estrés utilizando el concepto de equivalencia ambiental. Este esquema de caracterización fue analizado con mediciones radiométricas y de fv en cultivos de fríjol (Phaseolus vulgaris L.), garbanzo (Cicer arietinum L.), cártamo (Carthamus tinctorius, L.), sorgo (Sorghum bicolor, L. Moench) y trigo (Triticum spec. L.), del Valle del Yaqui, estado de Sonora, México. Los resultados obtenidos soportan la aproximación de caracterización planteada para el nivel de estrés. Abstract in english The use of spectral indexes or vegetation VI, based on iso-LAI lines in the spectral space of red (R) and near infrared (NIR), presents different relations in vegetative and senescence periods with biophysical variables such as aerial biomass or Bm, the index of foliar area or LAI, or aerial vegetat [...] ion cover or fv. With the ISVI index based on iso-soil lines of the R-NIR space, the temporal patterns may be identified by an expo-linear and exponential model. Thus, the slopes for the vegetative phase and for senescence can be used to quantify the stress level utilizing the concept of environmental equivalence. This scheme of characterization was analyzed with radiometric and fv measurements in crops of bean (Phaseolus vulgaris L.), chickpea (Cicer arietinum. L.), safflower (Carthamus tinctorius L.), sorghum (Sorghum bicolor, L. Moench), and wheat (Triticum spec. L.) of the Valle del Yaqui, State of Sonora, México. The obtained results support the approximation of the characterization proposed for the stress level.

Marisol, Reyes; Fernando, Paz; Marcos, Casiano; Fermín, Pascual; M. Isabel, Marín; Enrique, Rubiños.

2011-03-01

272

COMPARISON OF BIODIESEL PRODUCTIVITIES OF DIFFERENT VEGETABLE OILS BY ACIDIC CATALYSIS  

Directory of Open Access Journals (Sweden)

Full Text Available Biodiesel has become a subject which increasingly attracts worldwide attention because of its environmental benefits, biodegradability and renewability. Biodiesel production typically involves the transesterification of a triglyceride feedstock with methanol or other short-chain alcohols. This paper presents a study of transesterification of various vegetable oils, sunflower, safflower, canola, soybean, olive, corn, hazelnut and waste sunflower oils, with the acidic catalyst. Under laboratory conditions, fatty acid methyl esters (FAME were prepared by using methanol in the presence of 1.85% hydrochloric acid at 100 °C for 1 h and 25 °C for 3 h. The analyses of biodiesel were carried out by gas chroma¬tography and thin layer chromatography. Also, biodiesel productivities (% were determined on basis of the ratio of ester to oil content (w/w. The biodiesel productivities for all oils were found to be about 80% and about 90% at 25 and 100 °C, respectively. Also, the results showed that the yield of biodiesel depended on temperature for some oils, including canola, sunflower, safflower oils, but it was not found significant differences among all of the oil types on biodiesel productivities.

AYTEN SAGIROGLU

2011-03-01

273

Influence of different planting seasons of six leaf vegetables on residues of five pesticides.  

Science.gov (United States)

To investigate the influence of different planting seasons on the dissipation of pesticides, field experiments of thiophanate-methyl, metalaxyl, fluazifop-P-butyl, chlorpyrifos, and ?-cyhalothrin on six crops including pakchoi, rape, crown daisy, amaranth, spinach, and lettuce were designed and conducted. In this study, a high-performance liquid chromatography and electrospray ionization-tandem mass spectrometer with multiple reaction monitoring was used to simultaneously determine thiophanate-methyl and its metabolite carbendazim, metalaxyl, and fluazifop-P-butyl in various samples; gas chromatography with an electron capture detector was used to detect chlorpyrifos and ?-cyhalothrin. The limits of quantitation (LOQs) of these six pesticides were in the range of 0.001-0.01 mg kg(-1) for all samples, and the average recoveries of all pesticides ranged from 60.1 to 119.1% at 0.01 and 0.1 mg kg(-1) spiked levels. The relative standard deviation (RSD) ranged from 1.1 to 13.9%. All maximal concentrations of the six pesticides in six leaf vegetables in autumn were higher than in summer in Beijing. For most pesticides half-lives in autumn were longer than in summer. The results showed that the initial concentration, maximal concentration, and half-lives of pesticides were influenced not only by environmental factors such as light, heat, moisture, and rainy climate but also by plant matrices. PMID:23978278

Fan, Sufang; Deng, Kailin; Yu, Chuanshan; Zhao, Pengyue; Bai, Aijuan; Li, Yanjie; Pan, Canping; Li, Xuesheng

2013-09-25

274

Summary of the especies of Spanish vegetation sensitive to different pollutants  

International Nuclear Information System (INIS)

A detail literature review of the sensitivity of the species of Spanish vegetation to various pollutants was made. An impact scale was created to describe the qualitative degree of sensitivity to which each specie is affected by major atmospheric pollutants: very sensitive, sensitive, intermediate sensitive and resistent. This type of study, combined with studies of emission, concentration and dispersion of air pollution, is of great interest to evaluate the environmental impact to the vegetation community. (author) 45 refs

275

Evaluation of Effluent Quality Used for Irrigation of Vegetable Production in Different Districts of Potowar, Pakistan  

Directory of Open Access Journals (Sweden)

Full Text Available A study was conducted in different districts of Potowar region to evaluate the quality of sewage for irrigation purposes and heavy metal contents in sewage water. Sewage samples were collected from 25 sewage irrigated farms around Rawalpindi, Attock and Abotabad districts. Electrical conductivity of the samples ranged from 0.55-2.36 dS m-1. Sixty percent of the samples did not pose salinity hazard while forty percent were marginally fit for irrigation. Sodium adsorption ratio ranged from 0.24 to 4.36 showing that all the samples were low in Na contents. RSC varied from 0.0-8.1 mmol L-1 in the sewage samples under study; 59% of the samples had < 2.0 mmol L-1 of RSC showing that sewage represented by these samples had no risk of NaHCO3 hazard when applied to soils. Chloride contents in the samples were in the range of 0.5 to 4.7 mmol L-1 and were within safe limits. Zn and Pb contents in the sewage of various locations were found within safe limits (< 2.0 and 5.0 mg L-1, respectively while Cu, Cd, Ni and Cr concentrations were found to exceed the maximum permissible limits. The effluent of areas under investigation are mixture of both domestic and industrial wastewater, high levels of HCO3- from washing soaps and detergents and excess of heavy metals from different industrial sources were present in the effluent. Therefore, sewage irrigation may cause deterioration of soil quality by causing salinity and introducing excessive contents of HCO3- in soils and poses health hazards by increasing heavy metal contents in vegetables and crops.

Tahir Hussain Chattha

2005-01-01

276

Índice de seleção e estimativa de parâmetros genéticos e fenotípicos para características relacionadas com a produção de milho-verde / Index of selection and estimation of genetic and phenotypical parameters for traits related with the production of vegetable corn  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O Brasil é um dos maiores produtores de milho do mundo e possui grande potencial para a produção de milho verde. Além de agregar valor ao produto, a comercialização de milho verde cresceu muito nos últimos anos. Há escassez de informações sobre a avaliação e a obtenção de cultivares destinadas à pro [...] dução de milho-verde e também sobre estudos genéticos das características envolvidas nessa produção. Objetivou-se, neste trabalho, estimar parâmetros genéticos e fenotípicos, a correlação genética, classificar e identificar híbridos de milho verde promissores ao mercado consumidor e avaliar a eficiência dos pesos econômicos atribuídos. Os resultados determinaram que a seleção terá sucesso, para as diferentes características de milho-verde, pois, a herdabilidade foi de alta magnitude para as características avaliadas. A avaliação da produtividade de espigas empalhadas (PEE) é suficiente para definir quais os híbridos apresentam o melhor desempenho para a produtividade de espigas comerciais (PEC), diâmetro (DIAM) e comprimento de espigas (COMP). Isso indica que as características PEC, DIAM e COMP podem ser descartadas da avaliação em programas de melhoramento de milho-verde. Os híbridos HS48, HS27, HS24, HS25, HS12 e HS45 acumularam um maior número de características desejadas em um único genótipo, com base no índice de seleção baseado na soma de postos, sendo os mais promissores para a produção de milho-verde. Os pesos econômicos utilizados foram capazes de distinguir e identificar os híbridos mais promissores para a produção de milho- verde e podem ser utilizados como critério de seleção em programas de melhoramento de milho-verde. Abstract in english Brazil is one of the largest producers of corn of the world and it possesses great potential for vegetable corn production. Besides adding value to the product, the commercialization of vegetable corn increased in the last years. There is shortage of information about the evaluation and the acquisit [...] ion of genotypes destined to the production of vegetable corn and also on genetic studies of the traits involved in this production. The objective of this work was to estimate the genetic and phenotypic parameters, and the genetic correlation, and to classify and identify hybrids of promising vegetable corn to the consumer market and to evaluate the efficiency of the attributed economical weights. The results determined that the selection will succeed, for the different traits of vegetable corn, because the heritability was of high magnitude to the appraised traits. Evaluation of husked ears yield (PEE) was enough to define which hybrid presents better commercial ear productivity, diameter and corn ear length. This indicates that those traits could be discarded in the selection process of genotypes of breeding programs for vegetable corn production. The hybrids HS48, HS27, HS24, HS25 and HS12 accumulated the largest number of desirable traits in a single genotype based on the sum of rank index. The used economical weights were efficient to distinguish and identify the most promising hybrid for vegetable corn production and they can be used as a selection criterion in programs of breeding of vegetable corn.

Fabricio, Rodrigues; Renzo Garcia, Von Pinho; Carlos Juliano Brant, Albuquerque; Édila Vilela Resende, Von Pinho.

277

Bacterial diversity in the saliva of patients with different oral hygiene indexes  

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Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo do presente estudo foi avaliar a diversidade bacteriana da saliva de pacientes com diferentes índices de higiene bucal através da construção de duas bibliotecas do gene 16S rRNA. Cada biblioteca foi composta por amostras de saliva de pacientes com índice de biofilme dental de Silness-Löe [...] diferenciado, sendo a primeira (A) com índice de 1,0 a 3,0 (denominada de alto índice) e a segunda (B), entre 0 a 0,5 (denominada de baixo índice). O DNA da saliva foi extraído e o gene 16S rRNA foi amplificado, clonado e sequenciado. As sequências obtidas foram comparadas com aquelas armazenadas no GenBank do NCBI e RDP. A saliva de pacientes com alto índice de biofilme dental apresentou cinco gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella e Peptostreptococcus e 33,3% de bactérias não-cultivadas, agrupados em 23 unidades taxonômicas operacionais (UTOs). A saliva de pacientes com baixo índice de biofilme dental, foi diferente significativamente da primeira (p=0,000) e foi composta de 42 UTOs, distribuídas em 11 gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces, além de 24,87% de bactérias não-cultivadas. Pode-se concluir que existe maior diversidade bacteriana na saliva de pacientes com baixo índice de biofilme dental em relação a pacientes com alto índice de biofilme dental Abstract in english The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: t [...] he first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

Juliana Vianna, Pereira; Luciana, Leomil; Fabíola, Rodrigues-Albuquerque; José Odair, Pereira; Spartaco, Astolfi-Filho.

278

The Millon Index of Personality Styles Revised (MIPS-R) in Portugal: Gender Differences  

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This study aims to determine whether males and females differ in the personality styles mesured with the Portuguese version of the Millon Index of Personality Styles Revised, MIPS-R (Millon, 2004). The MIPS-R is a 180-item, True/False inventory designed to measure personality styles of normally functioning adults between the ages of 18 and 65+. It is a theory-based inventory, grounded in biosocial and evolutionary theory, and comprises 12 pairs of scales organized into three main areas: Motiv...

Pires, Rute; Fagulha, Teresa; Silva, Danilo R.

2007-01-01

279

Multi-scale mapping and accuracy assessment of leaf area index for vegetation study in southern Illinois  

Science.gov (United States)

The increasing interest of modeling global carbon cycling during the past two decades has driven this research to map leaf area index (LAI) at multiple spatial resolutions by combining LAI field observations with various sensor images at local, regional, and global scale. This is due to its important role in process based models that are used to predict carbon sequestration of terrestrial ecosystems. Although a substantial research has been conducted, there are still many challenges in this area. One of the challenges is that various images with spatial resolutions varying from few meters to several hundred meters and even to 1 km have been used. However, a method that can be used to collect LAI field measurements and further conduct multiple spatial resolution mapping and accuracy assessment of LAI is not available. In this study, a pilot study in a complex landscape located in the Southern Illinois was carried out to map LAI by combining field observations and remotely sensed images. Multi-scale mapping and accuracy assessment of LAI using aerial photo, Landsat TM and MODIS images were explored by developing a multi-scale sampling design. The results showed that the sampling design could be used to collect LAI observations to create LAI products at various spatial resolutions and further conduct accuracy assessment. It was also found that the TM derived LAI maps at the original and aggregated spatial resolutions successfully characterized the heterogeneous landscape and captured the spatial variability of LAI and were more accurate than those from the aerial photo and MODIS. The aerial photo derived models led to not only over- and under-estimation, but also pixilated maps of LAI. The MODIS derived LAI maps had an acceptable accuracy at various spatial resolutions and are applicable to mapping LAI at regional and global scale. Thus, this study overcame some of the significant gaps in this field.

Shah, Kushendra Narayan

280

Independent control of differently-polarized waves using anisotropic gradient-index metamaterials  

Science.gov (United States)

We propose a kind of anisotropic gradient-index (GRIN) metamaterials, which can be used to control differently-polarized waves independently. We show that two three- dimensional (3D) planar lenses made of such anisotropic GRIN metamaterials are able to make arbitrary beam deflections for the vertical (or horizontal) polarization but have no response to the horizontal (or vertical) polarization. Then the vertically- and horizontally-polarized waves are separated and controlled independently to deflect to arbitrarily different directions by designing the anisotropic GRIN planar lenses. We make experimental verifications of the lenses using such a special metamaterial, which has both electric and magnetic responses simultaneously to reach approximately equal permittivity and permeability. Hence excellent impedance matching is obtained between the GRIN planar lenses and the air. The measurement results demonstrate good performance on the independent controls of differently-polarized waves, as observed in the numerical simulations.

Ma, Hui Feng; Wang, Gui Zhen; Jiang, Wei Xiang; Cui, Tie Jun

2014-09-01

 
 
 
 
281

Independent control of differently-polarized waves using anisotropic gradient-index metamaterials.  

Science.gov (United States)

We propose a kind of anisotropic gradient-index (GRIN) metamaterials, which can be used to control differently-polarized waves independently. We show that two three- dimensional (3D) planar lenses made of such anisotropic GRIN metamaterials are able to make arbitrary beam deflections for the vertical (or horizontal) polarization but have no response to the horizontal (or vertical) polarization. Then the vertically- and horizontally-polarized waves are separated and controlled independently to deflect to arbitrarily different directions by designing the anisotropic GRIN planar lenses. We make experimental verifications of the lenses using such a special metamaterial, which has both electric and magnetic responses simultaneously to reach approximately equal permittivity and permeability. Hence excellent impedance matching is obtained between the GRIN planar lenses and the air. The measurement results demonstrate good performance on the independent controls of differently-polarized waves, as observed in the numerical simulations. PMID:25231412

Ma, Hui Feng; Wang, Gui Zhen; Jiang, Wei Xiang; Cui, Tie Jun

2014-01-01

282

A tobacco cDNA reveals two different transcription patterns in vegetative and reproductive organs  

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Full Text Available In order to identify genes expressed in the pistil that may have a role in the reproduction process, we have established an expressed sequence tags project to randomly sequence clones from a Nicotiana tabacum stigma/style cDNA library. A cDNA clone (MTL-8 showing high sequence similarity to genes encoding glycine-rich RNA-binding proteins was chosen for further characterization. Based on the extensive identity of MTL-8 to the RGP-1a sequence of N. sylvestris, a primer was defined to extend the 5' sequence of MTL-8 by RT-PCR from stigma/style RNAs. The amplification product was sequenced and it was confirmed that MTL-8 corresponds to an mRNA encoding a glycine-rich RNA-binding protein. Two transcripts of different sizes and expression patterns were identified when the MTL-8 cDNA insert was used as a probe in RNA blots. The largest is 1,100 nucleotides (nt long and markedly predominant in ovaries. The smaller transcript, with 600 nt, is ubiquitous to the vegetative and reproductive organs analyzed (roots, stems, leaves, sepals, petals, stamens, stigmas/styles and ovaries. Plants submitted to stress (wounding, virus infection and ethylene treatment presented an increased level of the 600-nt transcript in leaves, especially after tobacco necrosis virus infection. In contrast, the level of the 1,100-nt transcript seems to be unaffected by the stress conditions tested. Results of Southern blot experiments have suggested that MTL-8 is present in one or two copies in the tobacco genome. Our results suggest that the shorter transcript is related to stress while the larger one is a flower predominant and nonstress-inducible messenger.

Silva I. da

2002-01-01

283

A tobacco cDNA reveals two different transcription patterns in vegetative and reproductive organs  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In order to identify genes expressed in the pistil that may have a role in the reproduction process, we have established an expressed sequence tags project to randomly sequence clones from a Nicotiana tabacum stigma/style cDNA library. A cDNA clone (MTL-8) showing high sequence similarity to genes e [...] ncoding glycine-rich RNA-binding proteins was chosen for further characterization. Based on the extensive identity of MTL-8 to the RGP-1a sequence of N. sylvestris, a primer was defined to extend the 5' sequence of MTL-8 by RT-PCR from stigma/style RNAs. The amplification product was sequenced and it was confirmed that MTL-8 corresponds to an mRNA encoding a glycine-rich RNA-binding protein. Two transcripts of different sizes and expression patterns were identified when the MTL-8 cDNA insert was used as a probe in RNA blots. The largest is 1,100 nucleotides (nt) long and markedly predominant in ovaries. The smaller transcript, with 600 nt, is ubiquitous to the vegetative and reproductive organs analyzed (roots, stems, leaves, sepals, petals, stamens, stigmas/styles and ovaries). Plants submitted to stress (wounding, virus infection and ethylene treatment) presented an increased level of the 600-nt transcript in leaves, especially after tobacco necrosis virus infection. In contrast, the level of the 1,100-nt transcript seems to be unaffected by the stress conditions tested. Results of Southern blot experiments have suggested that MTL-8 is present in one or two copies in the tobacco genome. Our results suggest that the shorter transcript is related to stress while the larger one is a flower predominant and nonstress-inducible messenger.

I. da, Silva; P.C.S., Angelo; J.B., Molfetta; M.T., Ferraz; L.L.P. da, Silva; G.H., Goldman; M.H.S., Goldman.

2002-08-01

284

A COMPARISON OF THE SALINITY REGIME ALONG THE TEXAS COAST WITH TERRESTRIAL VEGETATION GREENNESS AND WATER USE IN THE GALVESTON BAY WATERSHED USING REMOTING SENSING  

Science.gov (United States)

Variability in vegetation greenness was determined for the Galveston Bay watershed using biweekly Normalized Difference Vegetation Index (NDVI) data derived from the Advanced Very High Resolution Radiometer (A VHRR) flown on NOAA satellites. NDVI variability was compared with reg...

285

Yield Characteristics of Moringa oleifera Across Different Ecologies in Nigeria as an Index of Its Adaptation to Climate Change  

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Full Text Available The pod and yield characteristics of Moringa oleifera plants grown in Ibadan (Rainforest vegetation, Nsukka (Forest-derived savannah vegetation and Jos (arid derived savannah vegetation were evaluated from 2007- 2009 to assess adaptability of the plant to climate change threats. The rainfall and temperature distribution in the three locations varied over the years. The Moringa oleifera plants grown at Ibadan had the greatest pod and seed yield followed by those at Nsukka and Jos in that order. The annual pod and seed production capacities of the plants differed significantly (p < 0.05 in the different locations. The overall annual pod and seed production per location, including yield characteristics, did not differ significantly throughout the years of study. Moringa oleifera was therefore found to be a suitable crop adaptable to various environmental and climatic changes in Nigeria.

Ndubuaku U. M.

2013-11-01

286

THE INFLUENCE OF NAPHTHALENE ACETIC ACID (NAA IN ROOTING OF THE DIFFERENT VEGETATIVE CUTTINGS OF THUYA OCCIDENTALIS “EMERAUD”  

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Full Text Available Thuya occidentalis “Emeraud” (Thuya ssp, is one of the most used evergreen ornamental plants for decoration of parks and gardens with very slow growth. They form few seeds with relatively low germination. This is the cause of the continuous efforts to find efficient ways of vegetative propagation, which influence the increase of the coefficient of thuya’s propagation. The paper presents the influence of the naphthalene acetic acid (NAA 4000 ppm in the rooting of one year vegetative cuttings of Thuya occidentalis “Emeraud”, with and without biennial wood. The experiment was carried out during three consecutive years, 2008-2010, in the flower’s greenhouse of the Experimental Centre of the Department of Horticulture at Agricultural University of Tirana. The one year vegetative cuttings were prepared as simple cuttings (cuttings without bark or biennial wood and cuttings with the scion (cuttings with bark or biennial wood. Vegetative cuttings of thuya were sown in the perlite band. Control for the final rooted seedlings and/or rooting percentage was carried out 60 days after sowing of the vegetative cuttings in the perlite band. There was calculated the rooting percentage of the vegetative cuttings treated and untreated with NAA 4000 ppm. The results show that the average rooting percentage of the simple untreated cuttings was 20%, while the average rooting percentage of the untreated cuttings with a scion was 45%. Total rooting percentage of the untreated cuttings was 32.5%. So, cuttings with a scion (the cuttings with bark and biennial wood, have a higher rooting percentage even when they are not treated with NAA. There were observed significant differences of the results in the case of treating cuttings with the rooting hormone NAA, 4000 ppm. These differences consisted in increasing the rooting ability and the rooting percentage of the cuttings. The average rooting percentage of the simple untreated cuttings with NAA was 51%, while the mean percentage of the cuttings with a scion treated with NAA was 80%. The total rooting percentage of the untreated cuttings was 65.5%. The use of the rooting hormone NAA, 4000 ppm, for the treatment of the one year vegetative cuttings of thuya was followed by the significant increases the rooting percentage in total from 32.5% to 65.5%. The three-year-results showed that the use of the rooting hormone NAA, 4000 ppm, does affect significantly in the increase of the rooting percentage of the vegetative cuttings, up to 30%, as well as in doubling the quantity of the seedling produced for each planting season, which was confirmed by ANOVA.

Esmeralda Sherko

2011-12-01

287

Bacteriological quality of vegetables from organic and conventional production in different areas of Korea.  

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Foods grown in organic production systems have been described as representing an increased risk to public health compared with foods from conventional production. Leafy vegetables (spinach, romaine lettuce, and green sesame leaves) grown in organic and conventional systems were collected from various areas in Korea and examined using standard culture methods to compare the microbiological quality of the produce grown in the two agricultural systems. The 354 samples of these leafy vegetables were analyzed for levels of indicator bacteria (aerobic bacteria, coliforms, and Escherichia coli) and the prevalence of the pathogens Staphylococcus aureus, E. coli O157:H7, Listeria monocytogenes, Bacillus cereus, and Salmonella. Aerobic bacteria and coliforms were detected in all vegetable types, but nonpathogenic E. coli was below the limit of detection in all samples. B. cereus was the most prevalent pathogen, found on 7 (11.1%) of the 63 organic spinach samples. The prevalence of S. aureus was highest in organic sesame leaves; it was found on 5 (8.0%) of the 63 samples. The prevalence of L. monocytogenes was highest on organic romaine lettuce and spinach; it was found in 4 (6.4%) of 63 samples of each type of vegetable. E. coli O157:H7 found on only 1 (1.58%) of 55 conventional spinach samples. These results suggest that farming type at most only slightly affects the hygienic quality of leafy vegetables, and no effect was found for sample collection area. Salmonella was not isolated from any of the conventional or organic leafy vegetables. These results do not support the hypothesis that organic produce poses a substantially greater risk of pathogen contamination than does conventional produce. PMID:25198606

Tango, Charles Nkufi; Choi, Na-Jung; Chung, Myung-Sub; Oh, Deog Hwan

2014-08-01

288

The influence of different environmental and climatic conditions on vegetated aeolian dune landscape development and response  

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Aeolian dune field development in coastal and semi-arid environments is a function of complex ecogeomorphic interactions which are sensitive to fluctuations in climatic and environmental conditions. We explore the relationships between ecological and geomorphic processes in the development of these landscape patterns and speculate on their response to variations in vegetation vitality and sediment transport capacity, indicating possible consequences of climate and land use change, using the Discrete ECogeomorphic Aeolian Landscape (DECAL) cellular automaton algorithm. This algorithm models dune field behaviour that reflects long-term trends prevalent in palaeo-records, but also elucidates possible evolutionary progressions, relaxation period sequences and threshold sensitivities. The landscape response is sensitive both to the perturbation itself and the state of the system when the disturbance occurs. Response amplitude decreases in simulated systems with reduced mobility unless an external disturbance mimicking fire or land clearance is applied concurrently with a reduction in growth vigour triggering a threshold type response when sufficient vegetation is removed. The model demonstrates that the relative response characteristics of the multiple vegetation types and their mutual feedback with geomorphic processes impart a significant influence on landscape equilibrium or attractor states. Fast growing vegetation enables the formation of hairpin (long-walled) parabolic dune systems, which eventually become sediment starved and stabilise, whereas inhospitable conditions inhibiting vegetation growth contribute to the development of active transgressive transverse dune fields. This simple vegetated dune model illustrates the power and versatility of a cellular automaton approach for exploring thresholds, sensitivities and possible evolutionary trajectories associated with the interactions between ecology, geomorphology and climatic conditions in complex earth surface systems.

Nield, Joanna M.; Baas, Andreas C. W.

2008-11-01

289

Spatial and temporal distribution of litter arthropods in different vegetation covers of Porto Santo Island (Madeira Archipelago, Portugal)  

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The main objective of this study is to assess the soil diversity and temporal and spatial distribution of litter macro-arthropods, captured with pitfall traps, on different vegetation covers from Porto Santo Island (Portugal) with different soil physical and chemical characteristics. The PCA clearly separated sampling areas geographically more exposed to winds and solar radiation, from the others that were not. In this analysis, seasons seemed to have no influence on this distribution. Non-ex...

Antunes, S. C.; Pereira, R.; Sousa, J. P.; Santos, M. C.; Gonc?alves, F.

2008-01-01

290

Vegetative compatibility and heterokaryon formation between different isolates of Colletotrichum lindemuthianum by using the nit mutant system  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Colletotrichum lindemuthianum, the causative agent of bean anthracnose, is one of the most common pathogens leading to expressive damage to plants beyond presenting noticeable variability. The knowledge on vegetative compatibility groups (VCGs) is of particular interest in asexual fungi as they subd [...] ivide the population in groups that can exchange genetic information via heterokaryosis and the parasexual cycle. Among the techniques used in studies about vegetative compatibility groups, the obtainment of nit mutants is apparent. This paper is aimed at obtaining heterokaryons between different isolates of C. lindemuthianum, grouping them in VCGs and evaluating their genetic variability by using the nit mutants system. Nit mutants were obtained from 20 single spore isolates. The mutants were phenotypically classified and paired for complementation and formation of heterokaryons so as to group them in VCGs. Seventeen mutants from the different phenotypic-rates were recovered: nit1, nit2, nit3 and nitM. At the same time, 10 mutants were selected for pairing and division of the anastomosis groups. Nine heterokaryons were obtained and the isolates were divided into 9 vegetative compatibility groups. In the combinations for the formation of anastomosis, 31 compatible combinations and 24 incompatible combinations were observed. It was concluded that the methodology used to select nit mutants in C. lindemuthianum made it possible to determine the vegetative compatibility groups and that such a technique was adequate to prove genetic variability.

Camila Rodrigues de, Carvalho; Maria Cristina, Mendes-Costa.

291

Analysis of Spatio-Temporal Patterns of Leaf Area Index in Different Forest Types of India Using High Temporal Remote Sensing Data  

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Knowledge of temporal variations of Leaf Area Index (LAI) aids in understanding the climate-vegetation interaction of different vegetative systems. This information is amenable from high temporal remote sensing data. India has around 78.37 million hectare, accounting for 23.84% of the geographic area of the country under forest/tree cover. India has a diverse set of vegetation types ranging from tropical evergreen to dry deciduous. We present a detailed spatio-temporal and inter-seasonal analysis of LAI patterns in different forest types of India using MODIS 8-day composites global LAI/fPAR product for the year 2005 at 1-km spatial resolution. A forest cover mask was generated using SPOT 1-km landuse/landcover classification over the Indian region. The range of estimated LAI varied from 0.1-6.9 among the different forest types. Maximum LAI was observed in tropical evergreen forests in North-Eastern region and Western Ghats. Low LAI was observed in Central Indian region due to predominance of dry deciduous forests. The spatial patterns of seasonal variations detected that for most of the forest types, the peak LAI values were observed during September and October months of the autumn season in contrast to minimum LAI during summer season. The mean LAI and standard deviation for each 8-day LAI composite were also computed and mean monthly LAI profiles were derived for each forest type classified on the basis of their geographical locations. These results are useful indicators for detailed understanding of phenological sequence and may also serve as important inputs for deriving bioclimatic indices for different forest types of India.

Chhabra, A.; Panigrahy, S.

2011-08-01

292

Directional Difference of Patterns Printed by Scan-Projection Lithography Using a Gradient Index Lens Array  

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Peculiar patterning characteristics of scan projection lithography using a gradient index lens array were investigated. When a lens array with two-line lenses was used, pattern widths of line-and-space patterns differed according to the pattern directions. Parts of the light rays diffracted in the direction perpendicular to the lens line are lost without passing through the lenses, because only two lenses are available in that direction. As a result, the resolution of patterns parallel to the lens line slightly degrades. On the other hand, light rays parallel to the lens line are sufficiently used for imaging. For this reason, the widths of line patterns printed in a positive resist slightly decrease. However, if the two-line lens array was replaced by a four-line lens array, the peculiar patterning characteristics were almost lost, and patterns were printed almost without directional differences. This is because the lens array width becomes sufficient.

Horiuchi, Toshiyuki; Suzuki, Takeru; Kobayashi, Hiroshi

2013-06-01

293

Índices de vegetação simulados de diferentes sensores na estimativa das variáveis biofísicas do feijoeiro / Vegetation indices simulated from different sensors for the estimation of biophysical variables of common bean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar os índices de vegetação e bandas do vermelho e do infravermelho próximo, gerados a partir dos sensores HRVIR, ETM+ e Modis, nas estimativas de índice de área foliar e produtividade da cultura do feijoeiro. O experimento foi realizado em blocos ao acaso, com parc [...] elas subdivididas, com quatro lâminas de irrigação (179,5, 256,5, 357,5 e 406,2 mm), três doses de N (0,0, 80,0 e 160,0 kg ha-1) e quatro repetições. As medidas de reflectância foram obtidas com o Spetron SE-590, no estádio R6 da cultura, nas 48 parcelas. Foram testados: a razão simples, o índice de vegetação por diferença normalizada, índice de vegetação ajustado ao solo e índice de vegetação realçado. Os índices de vegetação foram eficientes na estimativa do índice de área foliar (IAF) e da produtividade da cultura do feijoeiro. Os índices de vegetação e a banda do infravermelho apresentam o mesmo potencial na estimativa do IAF, quando se considera a resolução espectral dos sensores Modis, ETM+ e HRVIR. Abstract in english The objective of this work was to evaluate the vegetation indices and red and infrared bands of the HRVIR, ETM+ and Modis sensors, in the estimations of leaf area index and grain yield of common bean. The experiment was carried out in a randomized block design, with split plots and four irrigation l [...] evels (179.5, 256.5, 357.5, and 406.2 mm), three N rates (0.0, 80.0 and 160.0 kg ha-1), and four replicates. The reflectance measurements were obtained through the Spectron SE-590, at R6 stage, on 48 plots. Simple ratio, normalized difference vegetation index, soil-adjusted vegetation index, and enhanced vegetation index were tested. The vegetation indices were efficient to estimate the leaf area index (LAI) and grain yield. The vegetation indices and infrared band show the same potential to estimate LAI, when considering the spectral resolution of Modis, ETM+ and HRVIR.

Priscylla Ferraz Câmara, Monteiro; Rubens, Angulo Filho; Alexandre Cândido, Xavier; Rodrigo Otávio Câmara, Monteiro.

2013-04-01

294

Correlação espacial do índice de vegetação (NDVI) de imagem Landsat/ETM+ com atributos do solo / Spatial correlation of the vegetation index (NDVI) of a Landsat/ETM+ images with soil attributes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese As tecnologias de agricultura de precisão, como o uso da variabilidade espacial dos atributos do solo, vêm sendo muito estudadas para a cultura de cana-de-açúcar. Dentre essas tecnologias se destaca o uso de índices de vegetação derivados de produtos de sensoriamento remoto, como poderosas ferrament [...] as indicadoras do desenvolvimento da vegetação. Objetivou-se, neste estudo, analisar a variabilidade espacial dos teores de argila, fósforo e o pH de um Latossolo Vermelho-amarelo em área com produção de cana-de-açúcar e correlacioná-los com o índice espectral de vegetação (NDVI). Foram estudados, a partir de uma malha georreferenciada, os atributos do solo (argila, fósforo e pH) e gerados mapas de variabilidade espacial. Para esses mesmos locais calculou-se o NDVI possibilitando, além do mapeamento deste índice, a avaliação da correlação espacial entre este e as demais propriedades em estudo. A argila e o teor de fósforo apresentaram correlação espacial positiva com o NDVI enquanto nenhuma correlação espacial foi observada com o pH. A imagem do sensor ETM+ do satélite Landsat 5 utilizada neste estudo em relação ao NDVI, apresentou boa aplicação para observar a variabilidade espacial dos atributos estudados. Abstract in english The precision agriculture technologies such as the spatial variability of soil attributes have been widely studied mostly with sugarcane. Among these technologies have been recently highlighted the use of the vegetation index derived from remote sensing products, such as powerful tools indicating th [...] e development of vegetation. This study aimed to analyze the spatial variability of clay content, pH and phosphorus in an Oxisol in an area with sugarcane production, and correlate with the Normalized Difference Vegetation Index (NDVI). The georeferenced grid was created for the soil properties (clay, phosphorus and pH) and generated the maps of spatial variability. For these same sites were calculated the NDVI, in addition to mapping of this ratio, the evaluation of the spatial correlation between this and other studied properties. The clay and phosphorus content showed positive spatial correlation with the NDVI, while no spatial correlation was observed between NDVI and pH. The satellite images from the sensor ETM + Landsat were used to correlate to NDVI to observe the spatial variability of the studied attributes.

Fabricio V., Zanzarini; Teresa C. T., Pissarra; Flavia J. C., Brandão; Daniel D. B., Teixeira.

2013-06-01

295

Correlação espacial do índice de vegetação (NDVI de imagem Landsat/ETM+ com atributos do solo Spatial correlation of the vegetation index (NDVI of a Landsat/ETM+ images with soil attributes  

Directory of Open Access Journals (Sweden)

Full Text Available As tecnologias de agricultura de precisão, como o uso da variabilidade espacial dos atributos do solo, vêm sendo muito estudadas para a cultura de cana-de-açúcar. Dentre essas tecnologias se destaca o uso de índices de vegetação derivados de produtos de sensoriamento remoto, como poderosas ferramentas indicadoras do desenvolvimento da vegetação. Objetivou-se, neste estudo, analisar a variabilidade espacial dos teores de argila, fósforo e o pH de um Latossolo Vermelho-amarelo em área com produção de cana-de-açúcar e correlacioná-los com o índice espectral de vegetação (NDVI. Foram estudados, a partir de uma malha georreferenciada, os atributos do solo (argila, fósforo e pH e gerados mapas de variabilidade espacial. Para esses mesmos locais calculou-se o NDVI possibilitando, além do mapeamento deste índice, a avaliação da correlação espacial entre este e as demais propriedades em estudo. A argila e o teor de fósforo apresentaram correlação espacial positiva com o NDVI enquanto nenhuma correlação espacial foi observada com o pH. A imagem do sensor ETM+ do satélite Landsat 5 utilizada neste estudo em relação ao NDVI, apresentou boa aplicação para observar a variabilidade espacial dos atributos estudados.The precision agriculture technologies such as the spatial variability of soil attributes have been widely studied mostly with sugarcane. Among these technologies have been recently highlighted the use of the vegetation index derived from remote sensing products, such as powerful tools indicating the development of vegetation. This study aimed to analyze the spatial variability of clay content, pH and phosphorus in an Oxisol in an area with sugarcane production, and correlate with the Normalized Difference Vegetation Index (NDVI. The georeferenced grid was created for the soil properties (clay, phosphorus and pH and generated the maps of spatial variability. For these same sites were calculated the NDVI, in addition to mapping of this ratio, the evaluation of the spatial correlation between this and other studied properties. The clay and phosphorus content showed positive spatial correlation with the NDVI, while no spatial correlation was observed between NDVI and pH. The satellite images from the sensor ETM + Landsat were used to correlate to NDVI to observe the spatial variability of the studied attributes.

Fabricio V. Zanzarini

2013-06-01

296

Effect of Different Sowing Dates on Seed Index, Lint and Ginning Out-turn of Various Cotton Varieties  

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Full Text Available The field experiment was conducted to study the effects of sowing dates on seed index, lint index and ginning out-turn of three cotton varieties. The study revealed that the sowing dates produced significant difference in above parameters. The sowing on 10th May produced heavier seed index (8.21g, maximum lint index (4.04 g and high ginning Out-turn percent (33.98. Among the genotypes, Rehmani performed better in seed index (8.48g, lint index (4.04g and G.O.T. percent (33.71. It is recommended that for lower part of Sindh, Pakistan, the cotton crop may be planted in early to mid of May month. Very early and delayed sowings reduces cotton crop yield due to change in environmental factors of the region, which in turn affects plant`s life cycle and vigorous growth.

F. C. Oad

2002-01-01

297

Oxidative changes during ice storage of rainbow trout (Oncorhynchus mykiss) fed different ratios of marine and vegetable feed ingredients.  

Science.gov (United States)

Recently fish meal and oil have increasingly been replaced with proteins and oils from vegetable sources in the diets of farmed salmonids, but the consequences for the oxidative stability of the resulting fish products have not been investigated. The aim of the present study was to evaluate the influence of feeding regime on composition of rainbow trout fillets, as well as on lipid and protein oxidation during storage on ice. Rainbow trout were fed six different diets, which differed in their levels of marine oil and proteins vs. vegetable oil and protein. Fish fillets were characterised by measurement of fatty acid and amino acid composition, primary and secondary lipid oxidation products, astaxanthin and tocopherol content. Protein oxidation was assessed by measuring protein carbonyl content, oxidised amino acids, sulfhydryl groups and immuno-blotting against carbonyl groups. Feeding regimes significantly influenced fatty acid composition. Replacement of fish oil with vegetable oil reduced formation of primary oxidation products, but the effect on secondary oxidation products differed between different types of volatiles. The differences in protein and amino acid composition were not significant, and there were no clear effects of diets on protein oxidation, but data indicated that compounds present in the marine ingredients might have had an effect on protein oxidation. PMID:23194517

Timm-Heinrich, Maike; Eymard, Sylvie; Baron, Caroline P; Nielsen, Henrik Hauch; Jacobsen, Charlotte

2013-02-15

298

Oxidative changes during ice storage of rainbow trout (Oncorhynchus mykiss) fed different ratios of marine and vegetable feed ingredients  

DEFF Research Database (Denmark)

Recently fish meal and oil have increasingly been replaced with proteins and oils from vegetable sources in the diets of farmed salmonids, but the consequences for the oxidative stability of the resulting fish products have not been investigated. The aim of the present study was to evaluate the influence of feeding regime on composition of rainbow trout fillets, as well as on lipid and protein oxidation during storage on ice. Rainbow trout were fed six different diets, which differed in their levels of marine oil and proteins vs. vegetable oil and protein. Fish fillets were characterised by measurement of fatty acid and amino acid composition, primary and secondary lipid oxidation products, astaxanthin and tocopherol content. Protein oxidation was assessed by measuring protein carbonyl content, oxidised amino acids, sulfhydryl groups and immuno-blotting against carbonyl groups. Feeding regimes significantly influenced fatty acid composition. Replacement of fish oil with vegetable oil reduced formation of primary oxidation products, but the effect on secondary oxidation products differed between different types of volatiles. The differences in protein and amino acid composition were not significant, and there were no clear effects of diets on protein oxidation, but data indicated that compounds present in the marine ingredients might have had an effect on protein oxidation.

Timm Heinrich, Maike; Baron, Caroline P.

2013-01-01

299

Heavy Metals Levels in Soil and Vegetables in Different Growing Systems  

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Full Text Available The current project deals with an issue of actuality and scientific/technical necessity and aims to assess the factors contributing to the vulnerability of ecological systems and therefore endangering/compromising food safety. The goals of this ongoing study are to address the main risk factors on ecological system with particular regards to fresh growing vegetables and to establish technical monitoring system(s with a view to increase food safety. Herein, the authors present the research results obtained in 2011 in SIECOLEG Project regarding the assessment of some heavy metals (mainly lead, cadmium, cooper, and manganese of 80 samples soils and 25 samples vegetables from some ecological system. The concentrations of heavy metals were measured by Atomic absorption spectrometer (AAS Schimadzu 6300 - with graphite furnace atomizer and autosampler. In soil: lead and cadmium concentrations ranged from 4.51 to 6.58 mg/kg and from 0.14 to 0.4 mg/kg, respectively. Cooper and manganese concentrations ranged from 20.73 to 6.58 mg/kg and from 218.1 to 298.3 mg/kg, respectively. In vegetables (tomatoes, cucumber, peppers, eggplant, cabbage: lead concentrations ranged from 0.0 (tomatoes to 4.35 mg/kg (cabbage; cooper concentrations ranged from 0.2 mg/kg (cucumber to 0.80 mg/kg (eggplant; manganese concentrations ranged from 0.0 mg/kg (tomatoes to 0.60 mg/kg (eggplant. Cadmium was not detected in any of analysed vegetable samples. Under these circumstances, the project intends to demonstrate the extent of this vulnerability and to elaborate measures for controlling and diminishing the effects of the involved factors in order to increase food safety and security for ecological fresh vegetables

Hura C.

2013-04-01

300

LEAF AREA INDEX CHANGE DETECTION OF UNDERSTORY VEGETATION IN THE ALBEMARLE-PAMLICO BASIN USING IKOMOS AND LANDSAT ETM+ SATELLITE DATA  

Science.gov (United States)

The advent of remotely sensed data from satellite platforms has enabled the research community to examine vegetative spatial distributions over regional and global scales. This assessment of ecosystem condition through the synoptic monitoring of terrestrial vegetation extent, bio...

 
 
 
 
301

LEAF AREA INDEX (LAI) CHANGES DETECTION OF UNDERSTORY VEGETATION IN THE ALBEMARLE-PAMLICO BASIN IKONOS AND LANDSAT ETM+ SATELLITE DATA  

Science.gov (United States)

The advent of remotely sensed data from satellite platforms has enabled the research community to examine vegetative spatial distributions over regional and global scales. This assessment of ecosystem condition through the synoptic monitoring of terrestrial vegetation extent, bio...

302

Comparison of different dispersion models for single layer optical thin film index determination  

Energy Technology Data Exchange (ETDEWEB)

We here determine the optical properties of different single-layer thin films containing Ta{sub 2}O{sub 5}, Si, Indium Tin Oxide and Au in the ultraviolet-visible and near infrared ranges. More specifically, we deduce the complex refractive index and thickness from the reflectance and transmittance measured using a spectrophotometer at normal incidence. One major difficulty is to find an appropriate selection of dispersion laws for various types of material (dielectric, semiconductors, and metals). For this purpose, a number of models have been investigated from a theoretical point of view in consideration of the Kramers-Kronig relation. These include the Forouhi-Bloomer model, combined with the modified Drude, Tauc-Lorentz and multiple-oscillator Tauc-Lorentz models. A global optimization procedure had to be employed because of the large number of parameters (from 3 to 15) required to describe the optical dispersion laws. The calculated reflectance and transmittance are in good agreement with experimental data and the complex refractive index is consistent with our knowledge and that already reported.

Gao Lihong; Lemarchand, Fabien, E-mail: fabien.lemarchand@fresnel.fr; Lequime, Michel

2011-10-31

303

Perfusion index variability in preterm infants treated with two different natural surfactants for respiratory distress syndrome.  

Science.gov (United States)

Objective?The objective of this study was to compare the perfusion index (PI) variability in premature infants with respiratory distress syndrome (RDS) following administration of two different natural surfactant preparations. Study design?This was a prospective study on 92 preterm infants with RDS. Patients were randomized into two groups. Group 1 (n?=?46) received beractant; Group 2 (n?=?46) received poractant alfa. Oxygen saturation, PI, and heart rate were measured by Masimo Rainbow SET Radical-7 pulse oximeter (Masimo Corp., Irvine, CA) before and after surfactant. The effects of the two treatment regimens on PI and oxygenation were compared. Results?Repeated doses were more needed in beractant group (p?=?0.04). Median oxygenation index (OI) before surfactant were similar, but improvement in OI was more prominent at 6th hour of surfactant in Group 2 (p?=?0.001). Both groups had similar preductal PI values before surfactant. PI was higher at 6th hour of surfactant in Group 2 (p?=?0.001). Pulmonary hemorrhage, intraventricular hemorrhage, patent ductus arteriosus, necrotizing enterocolitis, and mortality were more frequent in infants whose PI values lower than 0.7 within the first 5 days of life (p?=?0.001). Conclusion?Poractant alfa resulted in more prominent improvement in PI and OI. Low PI values measured at early postnatal period may predict poor clinical outcome in preterm infants with RDS. PMID:24566756

Karadag, Nilgun; Dilli, Dilek; Zenciroglu, Aysegul; Aydin, Banu; Beken, Serdar; Okumus, Nurullah

2014-11-01

304

Analysis of Vegetation Behavior in a North African Semi-Arid Region, Using SPOT-VEGETATION NDVI Data  

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Full Text Available The analysis of vegetation dynamics is essential in semi-arid regions, in particular because of the frequent occurrence of long periods of drought. In this paper, multi-temporal series of the Normalized Difference of Vegetation Index (NDVI, derived from SPOT-VEGETATION satellite data between September 1998 and June 2010, were used to analyze the vegetation dynamics over the semi-arid central region of Tunisia. A study of the persistence of three types of vegetation (pastures, annual agriculture and olive trees is proposed using fractal analysis, in order to gain insight into the stability/instability of vegetation dynamics. In order to estimate the state of vegetation cover stress, we propose evaluating the properties of an index referred to as the Vegetation Anomaly Index (VAI. A positive VAI indicates high vegetation dynamics, whereas a negative VAI indicates the presence of vegetation stress. The VAI is tested for the above three types of vegetation, during the study period from 1998 to 2010, and is compared with other drought indices. The VAI is found to be strongly correlated with precipitation.

Abdelghani Chehbouni

2011-11-01

305

How do sink and source activities influence the reproduction and vegetative growth of spring ephemeral herbs under different light conditions?  

Science.gov (United States)

Spring ephemeral herbs inhabiting deciduous forests commonly complete reproduction and vegetative growth before canopy closure in early summer. Effects of shading by early canopy closure on reproductive output and vegetative growth, however, may vary depending on the seasonal allocation patterns of photosynthetic products between current reproduction and storage for future growth in each species. To clarify the effects of sink-source balance on seed production and bulb growth in a spring ephemeral herb, Gagea lutea, we performed a bract removal treatment (source reduction) and a floral-bud removal treatment (sink reduction) under canopy and open conditions. Leaf carbon fixations did not differ between the forest and open sites and among treatments. Bract carbon fixations were also similar between sites but tended to decrease when floral buds were removed. Seed production was higher under open condition but decreased by the bract-removal treatment under both light conditions. In contrast, bulb growth was independent of light conditions and the bract-removal treatment but increased greatly by the bud-removal treatment. Therefore, leaves and bracts acted as specialized source organs for vegetative and reproductive functions, respectively, but photosynthetic products by bracts were flexibly used for bulb growth when plants failed to set fruits. Extension of bright period was advantageous for seed production (i.e., source limited) but not for vegetative growth (i.e., sink limited) in this species. PMID:24879401

Sunmonu, Ninuola; Kudo, Gaku

2014-07-01

306

Vegetational Succession on Different Age Series Sponge Iron Solid Waste Dumps with Respect to Top Soil Application  

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Full Text Available Vegetation composition of different age series sponge iron solid w aste dumps was analyzed with respect to the impact of top soil application on vegetation succession. Study revealed that freshly laid dump, without top soil cover was devoid of any vegetation. However, 1, 3 and 5 year old dumps were colonized by grasses, sedges, forbs and shrubs. Tree species could be recorded in 3 and 5 year old dumps, but were absent in 1 year old dump. In all the dumps, species belonging to forbs showed the highest percentage contribution to species composition which was followed by grasses. Common occurrence of certain plant species in all the dumps indicated their greater adaptability to the adverse condition of waste material. IVI of herbaceous plants gradually decreased with dump age which was replaced by occupation of shrub and tree species in older dump. Among the families, Poaceae dominated in all the dumps. Species richness and diversity showed increasing trend, where as dominance showed decreasing trend with increasing dump age. Patch with top soil cover always showed highest species richness, follow ed by mixed patch and lowest by the patch only with waste material. The study revealed that top soil acted as seed bank and its application on sponge iron solid waste dump positively contributed towards species richness and vegetation growth.

B. Kullu

2011-01-01

307

Health status of birds fed diets containing three differently processed discarded vegetable-bovine blood-rumen content mixtures.  

Science.gov (United States)

This study was conducted to determine the effect of feeding three differently processed mixtures on health status of broilers. A total of 1080 day-old Marshal broilers were fed; discarded vegetable-fresh bovine blood-fresh rumen digesta (P1), discarded vegetable-ensiled bovine blood-fresh rumen digesta (P2) and discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3) at three levels of inclusion (0, 3 and 6%). Data on blood parameters was taken and were subjected to 3 x 3 factorial arrangements in a completely randomized design. Birds fed P1 had least values (p glucose, total protein, globulin, uric acid and creatinine at starter phase. Birds fed diets containing 3 and 6% level of inclusion recorded the highest (p level of inclusion recorded the highest albumin value. At finisher phase, birds fed P2 and P3 had the highest glucose, uric acid and creatinine values. 6% level of inclusion significantly (p broiler chickens could be fed diets containing discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3) up to 6% level of inclusion. PMID:24498799

Ekunseitan, D A; Balogun, O O; Sogunle, O M; Yusuf, A O; Ayoola, A A; Egbeyale, L T; Adeyemi, O A; Allison, I B; Iyanda, A I

2013-04-01

308

Health Status of Birds Fed Diets Containing Three Differently Processed Discarded Vegetable-bovine Blood-rumen Content Mixtures  

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Full Text Available This study was conducted to determine the effect of feeding three differently processed mixtures on health status of broilers. A total of 1080 day-old Marshal broilers were fed; discarded vegetable-fresh bovine blood-fresh rumen digesta (P1, discarded vegetable-ensiled bovine blood-fresh rumen digesta (P2 and discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3 at three levels of inclusion (0, 3 and 6%. Data on blood parameters was taken and were subjected to 3x3 factorial arrangements in a completely randomized design. Birds fed P1 had least values (p<0.05 of serum glucose, total protein, globulin, uric acid and creatinine at starter phase. Birds fed diets containing 3 and 6% level of inclusion recorded the highest (p<0.05 Packed cell volume, Haemoglobin, White blood cell and Red blood cell values. However, those fed at 0% level of inclusion recorded the highest albumin value. At finisher phase, birds fed P2 and P3 had the highest glucose, uric acid and creatinine values. 6% level of inclusion significantly (p<0.05 increased the total protein and albumin values. Therefore, for enhanced performance and without comprising the health condition of birds; broiler chickens could be fed diets containing discarded vegetable-fresh bovine blood-ensiled rumen digesta (P3 up to 6% level of inclusion.

O.A. Adeyemi

2013-01-01

309

Sensitivity Analysis of Remote Sensing Data: Comparing the Response of Vegetation Indices in Tropical Areas.  

Science.gov (United States)

During the past two decades, satellite remote sensing systems possessing high temporal resolution, but typically moderate or coarse spatial resolution, have increasingly been used to characterize and map vegetation dynamics. Assessing the seasonality of tropical vegetation has, however, been especially challenging. Tropical regimes of temperature and precipitation are generally less variable and pronounced than those in other biomes, and variations in plant growth are often more subtle. Using samples from selected tropical land cover types (tropical rain forest, tropical grasses, tropical deciduous forest, mixed forest and agricultural areas), sensitivity analysis will be carried out comparing different 'greenness' indices such as the Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI) and the Wide Dynamic Range Vegetation Index (WDRVI) derived from the MODIS/TERRA sensor. This analysis will potentially allow the selection of the best index to describe the particular behavior of tropical vegetation for further characterization of seasonal changes of such areas.

Bonifaz, R.

2005-12-01

310

The effects of different irrigation levels on vegetative growth of young dwarf cherry trees in a sub-humid climate  

International Nuclear Information System (INIS)

In this study, the effects of different irrigation treatments on evapotranspiration and vegetative growth parameters such as plant height, trunk cross-sectional area, volume of trees and branch cross-sectional area of 'Z-900'/Gisela-5 young dwarf cherry trees were investigated in a sub-humid climate during 2001-2002. Four irrigation treatments (T1, T2, T3 and T4) were applied based on different percentages of Class A Pan evaporation (50%, 75%, 100% and 125%). Seasonal crop evapotranspiration (ETc) values at applied irrigation water levels varied from 327 to 656 mm and from 354 to 733 mm for 2001 and 2002, respectively. While the difference between water levels was 25%, the difference in evapotranspiration for water levels was found to be 21-30%. Maximum average values of vegetative growth parameters area were obtained in T4 treatment in each experimental year. Although the amount of irrigation water for treatments increased, values of vegetative growth parameters didn't indicate a proportional change. (author)

311

Neighbourhood differences in objectively measured physical activity, sedentary time and body mass index  

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Full Text Available Background: There is limited Canadian research examining whether directly measured physical activity (PA and body mass index (BMI differ between neighbourhoods with different objectively measured socioeconomic (SES and recreation (REC environments. Purpose: To determine whether mean adult PA levels, sedentary time and BMIs were different across four neighbourhoods with contrasting SES and REC environments in Ottawa, Canada. Methods: This study employed a cross-sectional design to collect pilot data of objectively measured height, weight and PA (using accelerometry and self-reported covariates in 113 adults (?18 years. Four contrasting neighbourhoods (high REC/high SES, high REC/low SES, low REC/high SES, and low REC/low SES were selected based on data collected as part of the Ottawa Neighbourhood Study. Analysis of covariance and logistic regression were used to perform neighbourhood comparisons for PA, sedentary time and BMI, adjusting for age, sex and household income and possible interactions. Post-hoc comparisons using Tukey’s test were performed. Results: Significant neighbourhood-group effects were observed for light intensity PA and sedentary time. Post-hoc tests identified that the low REC/high SES neighbourhood had significantly more minutes of light PA than the low REC/low SES (Mdiff = 56.05 minutes·day, Tukey p = 0.01. Unadjusted BMI differed between the four neighbourhoods, but the differences were not significant after controlling for age, sex and household income. Conclusions: This study demonstrates that light PA and sedentary time differ between neighbourhoods of varying REC and SES environments after controlling for differences in age, sex and household income. Findings also suggest that other area-level factors may explain these neighbourhood differences.

Stephanie A. Prince

2011-11-01

312

Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found ...

Koci?-Tanackov Sun?ica D.; Dimi? Gordana R.; Levi? Jelena T.; Pejin Dušanka J.; Pejin Jelena D.; Jaji? Igor M.

2010-01-01

313

Economic Study on Winter Vegetables Produced by Different Categories of Farms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The study was designed to assess the comparative profitability of selected winter vegetables like potato, cauliflower and tomato. To achieve this objective, total of 75 farmers, 25 producing potato, 25 producing cauliflower and 25 producing tomato were selected. For this purpose, Cobb-douglas production function model was used. Per hectare total cost of production of potato, cauliflower and tomato were 51396.79, 64406.06 and 61663.87 TK., respectively and the corresponding gross incomes were ...

Sultana, M. S.; Kabir, F.; Islam, M. S.; Rashid, M. M.; Akon, A. I.

2005-01-01

314

[Soil microbial properties under different vegetation types in Loess hilly region].  

Science.gov (United States)

By using fumigation-extract (FE) method and Biolog Ecoplate, this paper investigated the microbial biomass and diversity in 0-20 cm soil layer under five vegetation types, including artificial woodland, shrubland, cropland, abandoned farmland, and natural grassland, in Dingxi of Gansu Province. In the meanwhile, the relationships between soil microbes and soil nutrients were studied by path analysis, and the five typical vegetation types were evaluated from the aspect of soil microbes. Relative to cropland, "grain for green" project played a key role in improving soil microbial resources. Microbial biomass carbon was the highest in ridge grassland, abandoned farmland, and pine woodland, followed by in Caragana korshinskii land, Medicago sativa land, restored land, and roadside land, and in wheat field and potato field. Microbial biomass nitrogen was the highest in ridge land, abandoned farmland, Pinus tabulaeformis woodland, Caragana korshinskii land, and Medicago sativa land, followed by in restored land and roadside land, and in wheat field and potato field. Caragana korshinskii land and Medicago sativa land, due to the existence of N-fixing rhizobium, had the highest ratio of soil microbial biomass nitrogen to soil total nitrogen. Owing to the continual biomass loss and rare feedback, cropland had the lowest quantity and activity of soil microbes. Through planting trees, shrubs and grasses or through fallowing, soil microbial biomass and activity were recovered, and the effect was increased with time. In 20-year old Caragana korshinskii land, the quantity and activity of soil microbes were similar to those in 50-year old Pinus tabulaeformis woodland, and the microbial community catabolic activity and soil nutrient use efficiency were higher. Considering the features of soil microbes under test vegetation types, Caragana korshinskii would be a good choice for local vegetation restoration. PMID:20387439

Zhang, Yan-Yan; Qu, Lai-Ye; Chen, Li-Ding; Wei, Wei

2010-01-01

315

Study of Heavy Metal Accumulation in Sewage Irrigated Vegetables in Different Regions of Agra District, India  

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Full Text Available Heavy metal contamination of soil resulting from sewage irrigation is a cause of serious concern due to the potential health impacts of consuming contaminated products. In this study an assessment made of the impact of sewage irrigation on heavy metal contamination of Spinach, Cabbage, Beetroot, Reddish, Okra, Tomato, and Cucumber is widely cultivated and consumed in urban India, particularly by the poor. A field study was conducted at seven major sites that were irrigated by either treated, (Dhandupura or untreated wastewater in the suburban areas of Agra, India. Samples of irrigation water, soil, and the edible portion of all the vegetables were collected monthly during the winter seasons and were analyzed for Fe, Cd, Cu, Zn, and Pb. Heavy metals in irrigation water were below the internationally recom- mended (WHO maximum permissible limits set for agricultural use for all heavy metals except Cd at all the sites. Similarly, the mean heavy metal concentrations in soil were below the Indian standards for all heavy metals, but the maximum value of Cd recorded during January was higher than the standard. However, in the edible portion of spinach, the Cd concentration was higher than the permissible limits of the Indian standard during summer, whereas Pb concentrations were higher in winter seasons. Results of correlation analysis were computed to assess the relationship between individual heavy metal concentration in the vegetable samples. The study concludes that the use of treated and untreated wastewater for irrigation has increased the contamination of Cd, Pb in edible portion of vegetables causing potential health risk in the long term from this practice. The study also points to the fact that adherence to standards for heavy metal contamination of soil and irrigation water does not ensure safe food. Fe was measured abundant in soil whereas Pb and Cd were found more in untreated sites as compared to treated site. Correlation, paired T-test and ANOVA were also carried out for pre post harvested soil and vegetables.

Fazal Masih Prasad

2013-03-01

316

Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia  

Science.gov (United States)

Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating the model results, and (iii) the methods used to compare simulated and observed vegetation. We use vegetation simulated for Asia by the equilibrium vegetation model BIOME4 as a typical example of vegetation model output. BIOME4 was run using 19 different climatologies and their associated atmospheric CO2 concentrations. The Kappa statistic, Fuzzy Kappa statistic and a newly developed map-comparison method, the Nomad index, were used to quantify the agreement between the biomes simulated under each scenario and the observed vegetation from three different global land- and tree-cover data sets: the global Potential Natural Vegetation data set (PNV), the Global Land Cover Characteristics data set (GLCC), and the Global Land Cover Facility data set (GLCF). The results indicate that the 30-year mean climatology (and its associated atmospheric CO2 concentration) for the time period immediately preceding the collection date of the observed vegetation data produce the most accurate vegetation simulations when compared with all three observed vegetation data sets. The study also indicates that the BIOME4-simulated vegetation for Asia more closely matches the PNV data than the other two observed vegetation data sets. Given the same observed data, the accuracy assessments of the BIOME4 simulations made using the Kappa, Fuzzy Kappa and Nomad index map-comparison methods agree well when the compared vegetation types consist of a large number of spatially continuous grid cells. The results of this analysis can assist model users in designing experimental protocols for simulating vegetation.

Tang, Guoping; Shafer, Sarah L,; Barlein, Patrick J.; Holman, Justin O.

2009-01-01

317

Relationships between vegetation indices and different burn and vegetation ratios: a multi-scale approach applied in a fire affected area  

Science.gov (United States)

Vegetation indices have been widely used in remote sensing literature for burned land mapping and monitoring. In the present study we used satellite data (IKONOS, LANDSAT, ASTER, MODIS) of multiple spectral (visible, near, shortwave infrared) and spatial (1-500 meters) resolutions, acquired shortly after a very destructive fire occurred in the mountain of Parnitha in Attica, Greece the summer of 2007. The aim of our study is to examine and evaluate the performance of some vegetation indices for burned land mapping and also to characterize the relationships between vegetation indices and the percent of fire-scorched (burned) and non fire-scorched (vegetated) areas. The available satellite images were processed geometrically, radiometrically and atmospherically. The very high resolution IKONOS imagery was served as a base to estimate the percent of cover of burned areas, bare soil and vegetation by applying the maximum likelihood classification algorithm. The percent of cover for each type was then correlated to vegetation indices for all the satellite images, and regression models were fit to characterize those relationships. In total 57 versions of some classical vegetation indices were computed using LANDSAT, ASTER and MODIS data. Most of them were modified by replacing Red with SWIR channel, as the latter has been proved sensitive to burned area discrimination. IPVI and NDVI showed a better performance among the indices tested to estimate the percent of vegetation, while most of the modified versions of the indices showed highest performance to estimate the percent of burned areas.

Pleniou, M.; Koutsias, N.

2013-08-01

318

Effects of Pansharpening on Vegetation Indices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study evaluated the effects of image pansharpening on Vegetation Indices (VIs), and found that pansharpening was able to downscale single-date and multi-temporal Landsat 8 VI data without introducing significant distortions in VI values. Four fast pansharpening methods—Fast Intensity-Hue-Saturation (FIHS), Brovey Transform (BT), Additive Wavelet Transform (AWT), and Smoothing Filter-based Intensity Modulation (SFIM)—and two VIs—Normalized Difference Vegetation Index (NDVI) and Simp...

Brian Johnson

2014-01-01

319

“The Potential Pozzolanic Activity of Different Ceramic Waste Powder as Cement Mortar Component (Strength Activity Index  

Directory of Open Access Journals (Sweden)

Full Text Available Under the strong contemporary demand for modern and environmental friendly materials, natural pozzolan can be proved to be such material and several researchers have focused their research efforts in using it as a partial substitute in the manufacture of concrete and mortar. Pozzolans are divided into two categories, namely the natural and the artificial, as metakaoline and silica fume (SF. In recent years, the industry has shifted to using natural pozzolans because of their lower cost and accessibility. A pozzolan is a siliceous material that can be used as an inexpensive Substitute for cement in mortar mixtures. The objective of this experimental study was to examine the possibility of reusing ceramic materials waste from ceramic industry as partial cement replacement in mortar and concrete. The different types of ceramic waste were finely ground to specific sizes (0–45 lm, 45–75 lm and 75–150 lm from different industries and its pozzolanic activity was determined. The compressive strength activity index at 7, 28 days and accelerated curing was determined in mortars produced with each finely grounded waste ceramics and different percentages of partial cement replacement. As per Indian standard mortar bar tests on 70.6*70.6*70.6 mm3 size mortar specimens were performed and results concluded with comparison to nominal mix specimen. own text.

Jay Patel

2014-03-01

320

THE EFFECT OF STORAGE TIME IN DIFFERENT TEMPERATURE ON NATIVE CHICKEN EGG HAUGH UNIT AND YOLK INDEX  

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Full Text Available Three hundred sixty native chicken eggs was test on the effect of storage time in different temperature on haugh unit and yolk index. The aim of this research is to get the effect of storage time in different temperatures : 300 – 32oC (RH 54%, 280 – 290 C (RH 58% and 150 – 180 C (RH 80%; on native chicken eggs haugh unit and yolk index. This experiment used Completely Randomized Design (CRD on three different temperatures (30-320C, 28-290C and 15­180C and each treatment was repeated six times. Results indicated that the lowest temperature (15-180C has the highest haugh unit (89.96 and yolk index (0.45; and when the temperature raised (28-290C and 30-320C the haugh unit and yolk index was lower (72.80 and 0.29; 73.15 and 0.30 respectively.

Hendronoto Arnoldus W. Lengkey

2012-01-01

 
 
 
 
321

Satellite-based analysis of clouds and radiation properties of different vegetation types in the Brazilian Amazon region  

Science.gov (United States)

Land-use changes impact the energy balance of the Earth system, and feedbacks in the Earth system can dampen or amplify this perturbation. We analyze here from satellite data the response of clouds and subsequently radiation to a change of land use for the example of deforestation in the Amazon Basin. In this region, the characteristics of different cloud types over two vegetation types (forest and crop-/grasslands) were calculated for a time period of five years by using satellite data from the instruments MODIS and CERES. The cloud types are defined according to height, optical thickness, and fraction of cloud cover. For calculating the radiative forcing caused by deforestation, the dependency of spatial and temporal averages for the reflected shortwave and outgoing longwave radiation of the top of the atmosphere on vegetation types were determined as well. The results show distinct differences in cloud cover and radiative forcing over crop-/grasslands and forests for the two vegetation regimes, implying a potentially significant positive cloud feedback to deforestation.

Schneider, Nadine; Quaas, Johannes; Claussen, Martin; Reick, Christian

2013-05-01

322

Influence of Paclobutrazol and Ethephon on Vegetative Growth of Guava (Psidium guajava L. Plants at Different Spacing  

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Full Text Available To ascertain the growth retarding potential of Paclobutrazol (PBZ and Ethephon on guava plants at different spacing viz 6?2 m, 6?3 m, 6?4 m and 6?5 m; both were applied at 500 ppm, 1000 ppm as a foliar spray. Investigation revealed that all treatments influence the vegetative growth of plants compared to untreated plants at all spacing levels. However, paclobutrazol considerably restrict the overall vegetative growth of trees. Stock and scion girth was found to be increased with ethephon treatments. The tree height and E-W tree spread was found to increased with increasing plant density. Similarly, trunk girth in terms of stock and scion girth was also increased with increase in plant spacing. Although, the PBZ 500 ppm markedly restrict the plant growth but it may be further investigated for managing the guava tree canopies under high density planting systems, taking the fruit quality and economic aspects into consideration.

Jaswinder Singh BRAR

2010-09-01

323

Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.  

Energy Technology Data Exchange (ETDEWEB)

A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4

Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

2005-05-01

324

Age and gender differences in disabling foot pain using different definitions of the manchester foot pain and disability index  

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Full Text Available Abstract Background The Manchester Foot Pain and Disability Index (MFPDI has been used to determine the prevalence of disabling foot pain in several studies, however there is some debate as to which case definition is most appropriate. The objective of this study was to explore age and gender differences in the proportion of people with disabling foot pain using three different case definitions of the MFPDI and for each individual MFPDI item. Methods A random sample of 223 participants aged 27 to 90 years (88 males and 135 females from the North West Adelaide Health Study, who reported having pain, aching or stiffness in either of their feet on most days in the last month, completed the MFPDI by telephone interview. The proportion of people with disabling foot pain was determined using three definitions: (i Definition A-at least one of the 17 items documented on at least some days in the last month; (ii Definition B-at least one of the 17 items documented on most/every day(s in the last month, and; (iii Definition C-at least one of the ten functional limitation items documented on most/every day(s in the last month. Cross-tabulations and chi-squared statistics were used to explore differences in responses to the MFPDI items according to age and gender. Results The proportion of people with disabling foot pain according to each definition was as follows: Definition A (100%, Definition B (95.1% and Definition C (77.6%. Definition C was most sensitive to age and gender differences. Exploration of individual MFPDI items indicated that age significantly affected both the pain intensity and functional limitation items, with younger people more likely to report their foot pain being worse in the morning, and older people more likely to report functional limitations. Although gender did not influence responses to the personal appearance items, women were more likely report functional limitations than men. Conclusions Definition C of the MFPDI is more sensitive to age and gender differences in the proportion of people with disabling foot pain, and would therefore seem to be the most appropriate case definition to use in epidemiological studies involving a broad age range of participants.

Taylor Anne W

2011-10-01

325

The just noticeable difference of center time and clarity index in large reverberant spaces.  

Science.gov (United States)

Just noticeable difference (JND) values are available for most acoustical parameters currently used in practice. However, they have been determined with reference to conditions typically encountered in concert halls and in rooms for speech, covering a range of reverberation times (T) spanning from 0.5 s to 2 s. When reverberation gets longer, the relationship between measured parameters describing acoustic clarity may change significantly and subjective perception might also be different. The proposed research investigates the influence of reverberation time on JND for clarity measures taking into account three reference cases having T values varying from 2 s to 6 s. Measured B-format impulse responses were properly modified to introduce the desired changes and then auralized with two music motifs for presentation on a 4-channel playback system. Listening tests based on paired comparisons were carried out to determine subjective limens. The results proved to be independent of music motifs and showed that JND in the clarity index is almost independent of T, while JND in the center time is significantly related to T and can be assumed as the 8.5% of the reference T(S) value. PMID:20707435

Martellotta, F

2010-08-01

326

Kinetics of soil enzyme activities under different ecosystems: An index of soil quality  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Soil microbial activity plays an important role in regulating biotransformation, nutrient cycling and hence the microbiological processes are at the center of many ecological functions. The kinetic parameters (Vmax and KmMichaelis constant) of different enzymes (amylase, invertase, protease, urease, [...] and dehydrogenase) were determined in order to assess the metabolic response of soil. The maximum reaction velocity (Vmax) represents a maximum rate of activity when all enzymes are saturated, which markedly increased in forest soil as compared to fresh mine spoil due to the gradual accumulation of soil organic matter. Smaller Km value was estimated in forest soil (FS) as compared to fresh mine spoil (FMS), suggesting the greater affinity of soil enzymes for substrate in FS. The catalytic efficiency (Vmax /Km) reflects an impression on microbial community composition with a change in soil enzymes. These enzyme characters (activities and kinetic parameters) have greater significance as early and sensitive indicators of the changes in soil properties induced by different management systems. These parameters (Vmax and Km) can be useful markers to assess changes in microbial activity of soil, since they represent quantity and affinity of enzymes respectively. The metabolic index (dehydrogenase activity/organic carbon (OC)) was found to be correlated with Vmax of dehydrogenase (r = 0.953; p

Monty, Kujur; Amiya, Kumar Patel.

327

Kinetics of soil enzyme activities under different ecosystems: An index of soil quality  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Soil microbial activity plays an important role in regulating biotransformation, nutrient cycling and hence the microbiological processes are at the center of many ecological functions. The kinetic parameters (Vmax and KmMichaelis constant) of different enzymes (amylase, invertase, protease, urease, [...] and dehydrogenase) were determined in order to assess the metabolic response of soil. The maximum reaction velocity (Vmax) represents a maximum rate of activity when all enzymes are saturated, which markedly increased in forest soil as compared to fresh mine spoil due to the gradual accumulation of soil organic matter. Smaller Km value was estimated in forest soil (FS) as compared to fresh mine spoil (FMS), suggesting the greater affinity of soil enzymes for substrate in FS. The catalytic efficiency (Vmax /Km) reflects an impression on microbial community composition with a change in soil enzymes. These enzyme characters (activities and kinetic parameters) have greater significance as early and sensitive indicators of the changes in soil properties induced by different management systems. These parameters (Vmax and Km) can be useful markers to assess changes in microbial activity of soil, since they represent quantity and affinity of enzymes respectively. The metabolic index (dehydrogenase activity/organic carbon (OC)) was found to be correlated with Vmax of dehydrogenase (r = 0.953; p

Monty, Kujur; Amiya, Kumar Patel.

2014-03-01

328

Geostatistical estimation of signal-to-noise ratios for spectral vegetation indices  

Science.gov (United States)

In the past 40 years, many spectral vegetation indices have been developed to quantify vegetation biophysical parameters. An ideal vegetation index should contain the maximum level of signal related to specific biophysical characteristics and the minimum level of noise such as background soil influences and atmospheric effects. However, accurate quantification of signal and noise in a vegetation index remains a challenge, because it requires a large number of field measurements or laboratory experiments. In this study, we applied a geostatistical method to estimate signal-to-noise ratio (S/N) for spectral vegetation indices. Based on the sample semivariogram of vegetation index images, we used the standardized noise to quantify the noise component of vegetation indices. In a case study in the grasslands and shrublands of the western United States, we demonstrated the geostatistical method for evaluating S/N for a series of soil-adjusted vegetation indices derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The soil-adjusted vegetation indices were found to have higher S/N values than the traditional normalized difference vegetation index (NDVI) and simple ratio (SR) in the sparsely vegetated areas. This study shows that the proposed geostatistical analysis can constitute an efficient technique for estimating signal and noise components in vegetation indices.

Ji, Lei; Zhang, Li; Rover, Jennifer; Wylie, Bruce K.; Chen, Xuexia

2014-01-01

329

A systematic review of socio-economic differences in food habits in Europe: consumption of fruit and vegetables  

DEFF Research Database (Denmark)

Objective: To evaluate the differences in the consumption of fruit and vegetables between groups with different socio-economic status (SES) in the adult population of European countries. Design: A systematic review of published and unpublished surveys of food habits conducted between 1985 and 1999 in 15 European countries. Educational level and occupational status were used as indicators of SES. a pooled estimate of the mean difference between the highest and the lowest level of education and occupation was calculated separately for men and women, using DerSimonian and Laird's random effects model. Setting: The inclusion criteria of studies were: use of a validated method for assessing intake at the individual level; selection of a nationwide sample or a representative sample of a region; and providing the mean and standard deviation of overall fruit and vegetable consumption for each level of education or occupation, and separately for men and women. Subjects: Participants in the individual surveys had to be adults (18 - 85 y). Results: Eleven studies from seven countries met the criteria for being included in the meta-analysis. A higher SES was associated with a greater consumption of both fruit and vegetables. The pooled estimate of the difference in the intake of fruit was 24.3 g/person/day (95% confidence interval (CI) 14.0-34.7) between men in the highest level of education and those in the lowest level of education. Similarly, this difference was 33.6g/person/day for women (95% CI 22.5-44.8). The differences regarding vegetables were 17.0g/person/day (95% CI 8.6-25.5) for men and 13.4g/person/day (95% CI 7.1-19.7) for women. The results were in the same direction when occupation instead of education was used as an indicator of SES. Conclusions: Although we cannot exclude over-reporting of intake by those with highest SES, it is unlikely that this potential bias could fully explain the differences we have found. Our results suggest that an unhealthier nutrition pattern may exist among adults belonging to lower socio-economic levels in Europe.

Groth, Margit Velsing

2000-01-01

330

Análise espacial de atributos do solo e cobertura vegetal em diferentes condições de pastagem / Spatial analysis of soil attributes and cover vegetation under different grazing conditions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese As áreas destinadas à pecuária têm-se expandido sobre áreas de vegetação nativa promovendo transformações na qualidade do solo. O objetivo foi avaliar os atributos de um Neossolo Quartzarênico sob diferentes coberturas vegetais para saber se a degradação do pasto representa a degradação do solo. As [...] áreas avaliadas foram: floresta nativa; capoeira; pastagem sem controle de lotação animal; pastagem em pousio; pastagem com invasoras; pastagem degradada com solo descoberto e invasoras, pastagem degradada com invasoras e espécies arbóreas e pastagem com baixa produção de forragem. Todas as pastagens eram formadas pela gramínea Brachiaria brizantha cv. Marandu. Realizaram-se 128 amostras de solo nas profundidades de 0-5 e 5-10 cm, dentro de cada área de manejo considerada como parcela experimental e a cobertura do solo foi quantificada. Foram mensuradas propriedades químicas e físicas do solo. Os dados foram submetidos a estudo geoestatístico. Foram constatados aumento na resistência mecânica à penetração e diminuição nos teores de matéria orgânica nas áreas mais degradadas. Pasto degradado não representa necessariamente solo degradado enquanto solo degradado está relacionado a pastagem degrada. Abstract in english The areas for livestock raising have expanded into areas of native vegetation, promoting changes in soil quality. The objective of this study was to evaluate the attributes of a Entisol under different vegetation covers to whether the pasture degradation represents soil degradation. The areas evalua [...] ted were: native forest, shrub, uncontrolled grazing animal stocking, grazing in fallow pasture with weeds; degraded pasture with bare soil and weeds, degraded pasture with weeds and tree species and grassland with low forage production. All pastures were formed by Brachiaria brizantha cv. Marandu. Hundred and twenty eight soil samples were collected in 0-5 and 5-10 cm, within each management area, considered as an experimental plot and soil cover was quantified. The chemical and physical properties of the soil were measured. Data were subjected to geoestatistical study. Increase in penetration resistance and decrease in the levels of organic matter were observed in the most degraded areas. Degraded pasture is not necessarily degraded land while degraded soil is related to grazing degrades.

Durval N., Neves Neto; Antonio C. dos, Santos; Perlon M., Santos; Jonahtan C., Melo; Josemara S., Santos.

331

Evaluation of Eucalyptus clones in different places seeking to the production of vegetal charcoal Avaliação de clones de Eucalyptus em diferentes locais visando à produção de carvão vegetal  

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This research aim to evaluate the wood and charcoal quality of three Eucalyptus clones planted at different places and to verify the existent functional relations between the basic density and the depth of penetration of the Pilodyn pin. Three Eucalyptus clones were evaluated and four trees were sample for each clone and place. It was determined the depth of penetration of a Pilodyn pin at 1.30 m of height of the soil (DBH, average basic density (DBm, the basic density at DBH, the calorific value, lignin, total extractive, ashes and holocellulose contents and elemental chemical analysis (C, H, N and O. The wood was carbonized and the charcoal produced was evaluated quantitatively and qualitatively. In the evaluation of the wood characteristics a completely randomized design disposed in a factorial scheme 3 x 2 was used. A linear model was adjusted between DBm and the depth of penetration of the Pilodyn pin. It was possible to conclude that the clones present potential to be used for energy. The charcoal produced may be used in siderurgy. The linear model adjusted between DBm and the penetration of the Pilodyn pin was satisfactory.

doi: 10.4336/2011.pfb.31.68.319

Os objetivos desse trabalho foram avaliar a qualidade da madeira e do carvão vegetal de três clones de Eucalyptus plantados em diferentes locais e verificar a relação funcional existente entre a densidade básica e a profundidade de penetração do pino do Pilodyn. Foram avaliados três clones de Eucalyptus e amostradas quatro árvores por clone em cada local. Determinou-se a profundidade de penetração de um pino de aço do Pilodyn a 1,30 m de altura do solo (DAP, a densidade básica média (DBm, a densidade básica no DAP, o poder calorífico superior e os teores de lignina, extrativos totais, cinzas, holocelulose e a análise química elementar (C, H, N e O. A madeira foi carbonizada e o carvão produzido foi avaliado quantitativamente e qualitativamente. Na avaliação das características da madeira, utilizou-se um DIC em um esquema fatorial 3 x 2. Foi ajustado um modelo linear entre a DBm e a profundidade de penetração do pino do Pilodyn. Foi possível concluir que os clones apresentaram potencial para o uso energético. O carvão vegetal produzido pode ser utilizado na siderurgia. O modelo linear ajustado entre a DBm e a penetração do pino do Pilodyn mostrou-se satisfatório.

doi: 10.4336/2011.pfb.31.68.319

Thiago Andrade Neves

2011-12-01

332

Influence of different solvents in extraction of phenolic compounds from vegetable residues and their evaluation as natural sources of antioxidants.  

Science.gov (United States)

Dried residues from four different vegetables, viz. pea pod (pp), cauliflower waste (CW), potato peel (PP) and tomato peel (TP) were extracted using four solvents i.e., hexane, chloroform, ethyl acetate and methanol. Among the four solvents, methanolic extracts showed the highest total phenolic content (TPC) for all the four vegetable residues. Methanolic extracts were evaluated for antioxidant activities using diphenylpicryl-hydrazyl (DPPH) and reducing power assay. Tomato peel extract showed highest phenolic content of 21.0 mg GAE/g-dw and 80.8 % DPPH free radical scavenging ability, whereas potato peel extract had a low phenolic content, and it also showed the least antioxidant activity among the residues examined in this study. Total phenolic content and DPPH free radical scavenging activity in pea pods and cauliflower waste were 13.6 mg GAE/g-dw and 72 % and 9.2 mg GAE/g-dw and 70.7 %, respectively. The coefficient of determination (r(2)) for correlation between TPC and reducing power, DPPH and TPC, DPPH and reducing power for all extracts was 0.85, 0.91and 0.87, respectively, suggesting an important role of phenolics in imparting antioxidant ability. Extracts from vegetables residues therefore represent a significant source of phenolic antioxidants for use as nutraceuticals or biopreservatives. PMID:25328197

Babbar, Neha; Oberoi, Harinder Singh; Sandhu, Simranjeet Kaur; Bhargav, Vinod Kumar

2014-10-01

333

Comparing Different Approaches for Mapping Urban Vegetation Cover from Landsat ETM+ Data: A Case Study on Brussels  

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Full Text Available Urban growth and its related environmental problems call for sustainable urban management policies to safeguard the quality of urban environments. Vegetation plays an important part in this as it provides ecological, social, health and economic benefits to a city’s inhabitants. Remotely sensed data are of great value to monitor urban green and despite the clear advantages of contemporary high resolution images, the benefits of medium resolution data should not be discarded. The objective of this research was to estimate fractional vegetation cover from a Landsat ETM+ image with sub-pixel classification, and to compare accuracies obtained with multiple stepwise regression analysis, linear spectral unmixing and multi-layer perceptrons (MLP at the level of meaningful urban spatial entities. Despite the small, but nevertheless statistically significant differences at pixel level between the alternative approaches, the spatial pattern of vegetation cover and estimation errors is clearly distinctive at neighbourhood level. At this spatially aggregated level, a simple regression model appears to attain sufficient accuracy. For mapping at a spatially more detailed level, the MLP seems to be the most appropriate choice. Brightness normalisation only appeared to affect the linear models, especially the linear spectral unmixing.

Frank Canters

2008-06-01

334

Fourier Transform Infrared Spectroscopy (FTIR and Multivariate Analysis for Identification of Different Vegetable Oils Used in Biodiesel Production  

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Full Text Available The main objective of this study was to use infrared spectroscopy to identify vegetable oils used as raw material for biodiesel production and apply multivariate analysis to the data. Six different vegetable oil sources—canola, cotton, corn, palm, sunflower and soybeans—were used to produce biodiesel