WorldWideScience

Sample records for difference vegetation index

  1. Portable Instrument for Normalized Difference Vegetation Index

    Institute of Scientific and Technical Information of China (English)

    ZHOU Han-chang; ZHAO Chun-jiang; XUE Xu-zhang; HAO Xiao-jian

    2004-01-01

    By using four specially designed narrow bandpass filters and photodetectors in the instrument, the incident and reflected radiances of sun light on the vegetation are optically sensed, at the red and near infrared bands, then the normalized difference vegetation index(NDVI) is processed by a microprocessor. Compared with conventional spectrometer measuring method of NDVI, the instrument is easy to be used, compact, light and low-cost.

  2. Bi-directional normalized difference vegetation index: concept and application

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The data products of land surface bi-directional reflectance distribution function (BRDF) from the space-borne Polarization and Directionality of the Earth Reflectance (POLDER) of France and the Moderate Resolution Imaging Spectroradiometer (MODIS)of USA are available recently, but the atmospheric correction for meeting the requirement of quantitative remote sensing is still a very dfficult problem. This paper presents a concept: bi-directional normalized difference vegetation index (Bi-NDVI), in order to consider simul taneously the effects of both land surface BRDF and atmospheric path scattering. An atmospheric quality index is thus defined for satellite multi-angular observations. The quality of MODIS/BRDF data products can be improved notably through iterative inversion weighed by this index.

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

    Directory of Open Access Journals (Sweden)

    Tamara Bellone

    2009-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Gabriela Camargos Lima

    2013-08-01

    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.

  5. Principle and application of three-band gradient difference vegetation index

    Institute of Scientific and Technical Information of China (English)

    TANG; Shihao; ZHU; Qijiang; WANG; Jindi; ZHOU; Yuyu; ZHAO

    2005-01-01

    Vegetation index is a simple, effective and experiential measurement of terrestrial vegetation activity, and plays a very important role in qualitative and quantitative remote sensing. Aiming at shortages of current vegetation indices, and starting from the analysis of vegetation spectral characteristics, we put forward a new vegetation index, the three-band gradient difference vegetation index (TGDVI), and established algorithms to inverse crown cover fraction and leaf area index (LAI) from it. Theoretical analysis and model simulation show that TGDVI has high saturation point and the ability to remove the influence of background to some degree, and the explicit functional relation with crown cover fraction and LAI can be established. Moreover, study shows that TGDVI also has the ability to partly remove the influence of thin cloud. Experiment in the Shunyi District, Beijing, China shows that reasonable result can be reached using the vegetation index to retrieve LAI. We also theoretically analyzed the reason why the normalized difference vegetation index (NDVI) owns the low saturation point, and show that it is determined by the definition of NDVI and the characteristic of vegetation spectra, and is unavoidable to some degree. Meanwhile, through model simulation, we also indicate that the relationship between simple ratio vegetation index (SR) and LAI closes to a piecewise linear one instead of a linear one, which is mainly caused by the influence of background and different change rates of reflectance in red and infrared bands with LAI increasing.

  6. NOAA Climate Data Record (CDR) of Normalized Difference Vegetation Index (NDVI), Version 4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains gridded daily Normalized Difference Vegetation Index (NDVI) derived from the NOAA Climate Data Record (CDR) of Advanced Very High Resolution...

  7. Vegetation extraction from high-resolution satellite imagery using the Normalized Difference Vegetation Index (NDVI)

    Science.gov (United States)

    AlShamsi, Meera R.

    2016-10-01

    Over the past years, there has been various urban development all over the UAE. Dubai is one of the cities that experienced rapid growth in both development and population. That growth can have a negative effect on the surrounding environment. Hence, there has been a necessity to protect the environment from these fast pace changes. One of the major impacts this growth can have is on vegetation. As technology is evolving day by day, there is a possibility to monitor changes that are happening on different areas in the world using satellite imagery. The data from these imageries can be utilized to identify vegetation in different areas of an image through a process called vegetation detection. Being able to detect and monitor vegetation is very beneficial for municipal planning and management, and environment authorities. Through this, analysts can monitor vegetation growth in various areas and analyze these changes. By utilizing satellite imagery with the necessary data, different types of vegetation can be studied and analyzed, such as parks, farms, and artificial grass in sports fields. In this paper, vegetation features are detected and extracted through SAFIY system (i.e. the Smart Application for Feature extraction and 3D modeling using high resolution satellite ImagerY) by using high-resolution satellite imagery from DubaiSat-2 and DEIMOS-2 satellites, which provide panchromatic images of 1m resolution and spectral bands (red, green, blue and near infrared) of 4m resolution. SAFIY system is a joint collaboration between MBRSC and DEIMOS Space UK. It uses image-processing algorithms to extract different features (roads, water, vegetation, and buildings) to generate vector maps data. The process to extract green areas (vegetation) utilize spectral information (such as, the red and near infrared bands) from the satellite images. These detected vegetation features will be extracted as vector data in SAFIY system and can be updated and edited by end-users, such as

  8. Elk Distributions Relative to Spring Normalized Difference Vegetation Index Values

    Directory of Open Access Journals (Sweden)

    Samuel T. Smallidge

    2010-01-01

    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.

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

    Science.gov (United States)

    Hirani, Hanisha K.

    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.

  10. Desertification Risk Monitoring for North Shaanxi Province, China, Using Normalized Difference Vegetation Index (NDVI)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this study, the remote sensing is applied to the examination of the relationship between desertification and normalized difference vegetation index (NDVI) in the context of northern Shaanxi Province. This relationship is also examined using spatial analysis methods. A strong negative correlation is found in the largest area desert, indicating that the relationship between desert and NDVI is not a simple linear one and that the correlation coefficient between NDVI and vegetation abundance is significant.The normalized difference vegetation index (NDVI) was compared with other vegetation index-based methodologies. NDVI is a valuable first-cut indicator for such systems, although the analysis and interpretation of its relationship to desertification are complex and also based on the detailed analysis of its reiationship to ecological zone, vegetation type and season. Conclusions thus made would help to upgrade the methodology as an effective tool for early-warning desertification in the northern Shaanxi Province where a drought is a recurring threat. This methodology includes the integration of NDVI with other socio-economic and bio-physical indicators in GIS, the complementation of desert area data with satellite data, and the analysis of the relationship between NDVI and specific climatic zones, for each season and vegetation type.

  11. Spatiotemporal variability and predictability of Normalized Difference Vegetation Index (NDVI) in Alberta, Canada.

    Science.gov (United States)

    Jiang, Rengui; Xie, Jiancang; He, Hailong; Kuo, Chun-Chao; Zhu, Jiwei; Yang, Mingxiang

    2016-09-01

    As one of the most popular vegetation indices to monitor terrestrial vegetation productivity, Normalized Difference Vegetation Index (NDVI) has been widely used to study the plant growth and vegetation productivity around the world, especially the dynamic response of vegetation to climate change in terms of precipitation and temperature. Alberta is the most important agricultural and forestry province and with the best climatic observation systems in Canada. However, few studies pertaining to climate change and vegetation productivity are found. The objectives of this paper therefore were to better understand impacts of climate change on vegetation productivity in Alberta using the NDVI and provide reference for policy makers and stakeholders. We investigated the following: (1) the variations of Alberta's smoothed NDVI (sNDVI, eliminated noise compared to NDVI) and two climatic variables (precipitation and temperature) using non-parametric Mann-Kendall monotonic test and Thiel-Sen's slope; (2) the relationships between sNDVI and climatic variables, and the potential predictability of sNDVI using climatic variables as predictors based on two predicted models; and (3) the use of a linear regression model and an artificial neural network calibrated by the genetic algorithm (ANN-GA) to estimate Alberta's sNDVI using precipitation and temperature as predictors. The results showed that (1) the monthly sNDVI has increased during the past 30 years and a lengthened growing season was detected; (2) vegetation productivity in northern Alberta was mainly temperature driven and the vegetation in southern Alberta was predominantly precipitation driven for the period of 1982-2011; and (3) better performances of the sNDVI-climate relationships were obtained by nonlinear model (ANN-GA) than using linear (regression) model. Similar results detected in both monthly and summer sNDVI prediction using climatic variables as predictors revealed the applicability of two models for

  12. Spatiotemporal variability and predictability of Normalized Difference Vegetation Index (NDVI) in Alberta, Canada

    Science.gov (United States)

    Jiang, Rengui; Xie, Jiancang; He, Hailong; Kuo, Chun-Chao; Zhu, Jiwei; Yang, Mingxiang

    2016-09-01

    As one of the most popular vegetation indices to monitor terrestrial vegetation productivity, Normalized Difference Vegetation Index (NDVI) has been widely used to study the plant growth and vegetation productivity around the world, especially the dynamic response of vegetation to climate change in terms of precipitation and temperature. Alberta is the most important agricultural and forestry province and with the best climatic observation systems in Canada. However, few studies pertaining to climate change and vegetation productivity are found. The objectives of this paper therefore were to better understand impacts of climate change on vegetation productivity in Alberta using the NDVI and provide reference for policy makers and stakeholders. We investigated the following: (1) the variations of Alberta's smoothed NDVI (sNDVI, eliminated noise compared to NDVI) and two climatic variables (precipitation and temperature) using non-parametric Mann-Kendall monotonic test and Thiel-Sen's slope; (2) the relationships between sNDVI and climatic variables, and the potential predictability of sNDVI using climatic variables as predictors based on two predicted models; and (3) the use of a linear regression model and an artificial neural network calibrated by the genetic algorithm (ANN-GA) to estimate Alberta's sNDVI using precipitation and temperature as predictors. The results showed that (1) the monthly sNDVI has increased during the past 30 years and a lengthened growing season was detected; (2) vegetation productivity in northern Alberta was mainly temperature driven and the vegetation in southern Alberta was predominantly precipitation driven for the period of 1982-2011; and (3) better performances of the sNDVI-climate relationships were obtained by nonlinear model (ANN-GA) than using linear (regression) model. Similar results detected in both monthly and summer sNDVI prediction using climatic variables as predictors revealed the applicability of two models for

  13. Higher northern latitude normalized difference vegetation index and growing season trends from 1982 to 1999

    Science.gov (United States)

    Tucker, C. J.; Slayback, D. A.; Pinzon, J. E.; Los, S. O.; Myneni, R. B.; Taylor, M. G.

    2001-01-01

    Normalized difference vegetation index data from the polar-orbiting National Oceanic and Atmospheric Administration meteorological satellites from 1982 to 1999 show significant variations in photosynthetic activity and growing season length at latitudes above 35 degrees N. Two distinct periods of increasing plant growth are apparent: 1982-1991 and 1992-1999, separated by a reduction from 1991 to 1992 associated with global cooling resulting from the volcanic eruption of Mt. Pinatubo in June 1991. The average May to September normalized difference vegetation index from 45 degrees N to 75 degrees N increased by 9% from 1982 to 1991, decreased by 5% from 1991 to 1992, and increased by 8% from 1992 to 1999. Variations in the normalized difference vegetation index were associated with variations in the start of the growing season of -5.6, +3.9, and -1.7 days respectively, for the three time periods. Our results support surface temperature increases within the same period at higher northern latitudes where temperature limits plant growth.

  14. Multifractal Downscaling of Rainfall Using Normalized Difference Vegetation Index (NDVI) in the Andes Plateau

    Science.gov (United States)

    Posadas, A. N.; Carbajal, M.; Quiroz, R.

    2017-01-01

    In this paper, a multifractal downscaling technique is applied to adequately transformed and lag corrected normalized difference vegetation index (NDVI) in order to obtain daily estimates of rainfall in an area of the Peruvian Andean high plateau. This downscaling procedure is temporal in nature since the original NDVI information is provided at an irregular temporal sampling period between 8 and 11 days, and the desired final scale is 1 day. The spatial resolution of approximately 1 km remains the same throughout the downscaling process. The results were validated against on-site measurements of meteorological stations distributed in the area under study. PMID:28125607

  15. Trends in normalized difference vegetation index (NDVI) associated with urban development in northern West Siberia

    Science.gov (United States)

    Esau, Igor; Miles, Victoria V.; Davy, Richard; Miles, Martin W.; Kurchatova, Anna

    2016-08-01

    Exploration and exploitation of oil and gas reserves of northern West Siberia has promoted rapid industrialization and urban development in the region. This development leaves significant footprints on the sensitive northern environment, which is already stressed by the global warming. This study reports the region-wide changes in the vegetation cover as well as the corresponding changes in and around 28 selected urbanized areas. The study utilizes the normalized difference vegetation index (NDVI) from high-resolution (250 m) MODIS data acquired for summer months (June through August) over 15 years (2000-2014). The results reveal the increase of NDVI (or "greening") over the northern (tundra and tundra-forest) part of the region. Simultaneously, the southern, forested part shows the widespread decrease of NDVI (or "browning"). These region-wide patterns are, however, highly fragmented. The statistically significant NDVI trends occupy only a small fraction of the region. Urbanization destroys the vegetation cover within the developed areas and at about 5-10 km distance around them. The studied urbanized areas have the NDVI values by 15 to 45 % lower than the corresponding areas at 20-40 km distance. The largest NDVI reduction is typical for the newly developed areas, whereas the older areas show recovery of the vegetation cover. The study reveals a robust indication of the accelerated greening near the older urban areas. Many Siberian cities become greener even against the wider browning trends at their background. Literature discussion suggests that the observed urban greening could be associated not only with special tending of the within-city green areas but also with the urban heat islands and succession of more productive shrub and tree species growing on warmer sandy soils.

  16. Temperature Vegetation Dryness Index Estimation of Soil Moisture under Different Tree Species

    Directory of Open Access Journals (Sweden)

    Shulin Chen

    2015-08-01

    Full Text Available The Laoshan forest is the largest forest in Nanjing, and it plays an important role in water resource management in Nanjing. The objectives of this study are to determine if the temperature vegetation dryness index (TVDI is suitable to estimate the soil moisture and if soil moisture is significantly affected by tree species in the Laoshan forest. This paper calculated the spatial distribution of TVDI using LANDSAT-5 TM data. Sixty-two observation points of in situ soil moisture measurements were selected to validate the effectiveness of the TVDI as an index for assessing soil moisture in the Laoshan forest. With the aid of the three different temporal patterns, which are 10 January 2011, 18 May 2011 and 23 September 2011, this paper used the TVDI to investigate the differences of soil moisture under four kinds of mono-species forests and two kinds of mixed forests. The results showed that there is a strong and significant negative correlation between the TVDI and the in situ measured soil moisture (R2 = 0.15–0.8, SE = 0.015–0.041 cm3/cm3. This means that the TVDI can reflect the soil moisture status under different tree species in the Laoshan forest. The soil moisture under these six types of land cover from low to high is listed in the following order: Eucommia ulmoides, Quercus acutissima, broadleaf mixed forest, Cunninghamia lanceolata, coniferous and broadleaf mixed forest and Pinus massoniana.

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

    Science.gov (United States)

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

    2011-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Andrew K Skidmore

    2011-01-01

    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.

  19. Estimating Sugarcane Yield Potential Using an In-Season Determination of Normalized Difference Vegetative Index

    Directory of Open Access Journals (Sweden)

    Howard Viator

    2012-06-01

    Full Text Available Estimating crop yield using remote sensing techniques has proven to be successful. However, sugarcane possesses unique characteristics; such as, a multi-year cropping cycle and plant height-limiting for midseason fertilizer application timing. Our study objective was to determine if sugarcane yield potential could be estimated using an in-season estimation of normalized difference vegetative index (NDVI. Sensor readings were taken using the GreenSeeker® handheld sensor from 2008 to 2011 in St. Gabriel and Jeanerette, LA, USA. In-season estimates of yield (INSEY values were calculated by dividing NDVI by thermal variables. Optimum timing for estimating sugarcane yield was between 601–750 GDD. In-season estimated yield values improved the yield potential (YP model compared to using NDVI. Generally, INSEY value showed a positive exponential relationship with yield (r2 values 0.48 and 0.42 for cane tonnage and sugar yield, respectively. When models were separated based on canopy structure there was an increase the strength of the relationship for the erectophile varieties (r2 0.53 and 0.47 for cane tonnage and sugar yield, respectively; however, the model for planophile varieties weakened slightly. Results of this study indicate using an INSEY value for predicting sugarcane yield shows potential of being a valuable management tool for sugarcane producers in Louisiana.

  20. Estimating sugarcane yield potential using an in-season determination of normalized difference vegetative index.

    Science.gov (United States)

    Lofton, Josh; Tubana, Brenda S; Kanke, Yumiko; Teboh, Jasper; Viator, Howard; Dalen, Marilyn

    2012-01-01

    Estimating crop yield using remote sensing techniques has proven to be successful. However, sugarcane possesses unique characteristics; such as, a multi-year cropping cycle and plant height-limiting for midseason fertilizer application timing. Our study objective was to determine if sugarcane yield potential could be estimated using an in-season estimation of normalized difference vegetative index (NDVI). Sensor readings were taken using the GreenSeeker® handheld sensor from 2008 to 2011 in St. Gabriel and Jeanerette, LA, USA. In-season estimates of yield (INSEY) values were calculated by dividing NDVI by thermal variables. Optimum timing for estimating sugarcane yield was between 601-750 GDD. In-season estimated yield values improved the yield potential (YP) model compared to using NDVI. Generally, INSEY value showed a positive exponential relationship with yield (r(2) values 0.48 and 0.42 for cane tonnage and sugar yield, respectively). When models were separated based on canopy structure there was an increase the strength of the relationship for the erectophile varieties (r(2) 0.53 and 0.47 for cane tonnage and sugar yield, respectively); however, the model for planophile varieties weakened slightly. Results of this study indicate using an INSEY value for predicting sugarcane yield shows potential of being a valuable management tool for sugarcane producers in Louisiana.

  1. Interannual Variability of the Normalized Difference Vegetation Index on the Tibetan Plateau and Its Relationship with Climate Change

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dingwen; FAN Guangzhou; HUANG Ronghui; FANG Zhifang; LIU Yaqin; LI Hongquan

    2007-01-01

    The Qinghai-Xizang Plateau, or Tibetan Plateau, is a sensitive region for climate change, where the manifestation of global warming is particularly noticeable. The wide climate variability in this region significantly affects the local land ecosystem and could consequently lead to notable vegetation changes. In this paper, the interannual variations of the plateau vegetation are investigated using a 21-year normalized difference vegetation index (NDVI) dataset to quantify the consequences of climate warming for the regional ecosystem and its interactions. The results show that vegetation coverage is best in the eastern and southern plateau regions and deteriorates toward the west and north. On the whole, vegetation activity demonstrates a gradual enhancement in an oscillatory manner during 1982-2002. The temporal variation also exhibits striking regional differences: an increasing trend is most apparent in the west, south, north and southeast, whereas a decreasing trend is present along the southern plateau boundary and in the central-east region. Covariance analysis between the NDVI and surface temperature/precipitation suggests that vegetation change is closely related to climate change. However, the controlling physical processes vary geographically. In the west and east, vegetation variability is found to be driven predominantly by temperature, with the impact of precipitation being of secondary importance. In the central plateau, however, temperature and precipitation factors are equally important in modulating the interannual vegetation variability.

  2. Effects of Normalized Difference Vegetation Index and Related Wavebands' Characteristics on Detecting Spatial Heterogeneity Using Variogram-based Analysis

    Institute of Scientific and Technical Information of China (English)

    WEN Zhaofei; ZHANG Ce; ZHANG Shuqing; DING Changhong; LIU Chunyue; PAN Xin; LI Huapeng; SUN Yan

    2012-01-01

    Spatial heterogeneity is widely used in diverse applications,such as recognizing ecological process,guiding ecological restoration,managing land use,etc.Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables.How these variables affect their corresponding spatial heterogeneities,however,have received little attention.In this paper,we examined the effects of characteristics of normalized difference vegetation index (NDVI) and its related bands variable images,namely red and near infrared (NIR),on their corresponding spatial heterogeneity detection based on variogram models.In a coastal wetland region,two groups of study sites with distinct fractal vegetation cover were tested and analyzed.The results show that:1) in high fractal vegetation cover (H-FVC) area,NDVI and NIR variables display a similar ability in detecting the spatial heterogeneity caused by vegetation growing status structure; 2) in low fractal vegetation cover (L-FVC) area,the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3) generally,NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers.Moreover,as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account,the proposed variogram analysis method can make the variable selection objectively and scientifically,especially in studies related to spatial heterogeneity using remotely sensed data.

  3. Spectra and vegetation index variations in moss soil crust in different seasons, and in wet and dry conditions

    Science.gov (United States)

    Fang, Shibo; Yu, Weiguo; Qi, Yue

    2015-06-01

    Similar to vascular plants, non-vascular plant mosses have different periods of seasonal growth. There has been little research on the spectral variations of moss soil crust (MSC) over different growth periods. Few studies have paid attention to the difference in spectral characteristics between wet MSC that is photosynthesizing and dry MSC in suspended metabolism. The dissimilarity of MSC spectra in wet and dry conditions during different seasons needs further investigation. In this study, the spectral reflectance of wet MSC, dry MSC and the dominant vascular plant (Artemisia) were characterized in situ during the summer (July) and autumn (September). The variations in the normalized difference vegetation index (NDVI), biological soil crust index (BSCI) and CI (crust index) in different seasons and under different soil moisture conditions were also analyzed. It was found that (1) the spectral characteristics of both wet and dry MSCs varied seasonally; (2) the spectral features of wet MSC appear similar to those of the vascular plant, Artemisia, whether in summer or autumn; (3) both in summer and in autumn, much higher NDVI values were acquired for wet than for dry MSC (0.6 ∼ 0.7 vs. 0.3 ∼ 0.4 units), which may lead to misinterpretation of vegetation dynamics in the presence of MSC and with the variations in rainfall occurring in arid and semi-arid zones; and (4) the BSCI and CI values of wet MSC were close to that of Artemisia in both summer and autumn, indicating that BSCI and CI could barely differentiate between the wet MSC and Artemisia.

  4. Correlation analysis of Normalized Different Vegetation Index (NDVI)difference series and climate variables in the Xilingole steppe,China from 1983 to 1999

    Institute of Scientific and Technical Information of China (English)

    GU Zhihui; CHEN Jin; SHI Peijun; XU Ming

    2007-01-01

    There is a crucial need in the study of global change to understand how terrestrial ecosystems respond to the climate system.It has been demonstrated by many researches that Normalized Different Vegetation Index (NDVI)time series from remotely sensed data,which provide effective information of vegetation conditions on a large scale with highly temporal resolution,have a good relation with meteorological factors.However,few of these studies have taken the cumulative property of NDVI time series into account.In this study,NDVI difference series were proposed to replace the original NDVI time series with NDVI difference series to reappraise the relationship between NDVI and meteorological factors.As a proxy of the vegetation growing process,NDVI difference represents net primary productivity of vegetation at a certain time interval under an environment controlled by certain climatic conditions and other factors.This data replacement is helpful to eliminate the cumulative effect that exist in original NDVI time series,and thus is more appropriate to understand how climate system affects vegetation growth in a short time scale.By using the correlation analysis method,we studied the relationship between NOAA/AVHRR ten-day NDVI difference series and corresponding meteorological data from 1983 to 1999 from 11 meteorological stations located in the Xilingole steppe in Inner Mongolia.The results show that:(1)meteorological factors are found to be more significantly correlation with NDVI difference at the biomass-rising phase than that at the falling phase;(2)the relationship between NDVI difference and climate variables varies with vegetation types and vegetation communities.In a typical steppe dominated by Leymus chinensis,temperature has higher correlation with NDVI difference than precipitation does,and in a typical steppe dominated by Stipa krylovii,the correlation between temperature and NDVI difference is lower than that between precipitation and NDVI difference.In a

  5. Trends in the normalized difference vegetation index (NDVI) associated with urban development in arctic and subarctic Western Siberia

    Science.gov (United States)

    Outten, S.; Miles, V.; Ezau, I.

    2015-12-01

    Changes in normalized difference vegetation index (NDVI) in the high Arctic have been reliably documented, with widespread "greening" (increase in NDVI), specifically along the northern rim of Eurasia and Alaska. Whereas in West Siberia south of 65N, widespread "browning" (decrease in NDVI) has been noted, although the causes remain largely unclear. In this study we report results of statistical analysis of the spatial and temporal changes in NDVI around 28 major urban areas in the arctic and subarctic Western Siberia. Exploration and exploitation of oil and gas reserves has led to rapid industrialization and urban development in the region. This development has significant impact on the environment and particularly in the vegetation cover in and around the urbanized areas. The analysis is based on 15 years (2000-2014) of high-resolution (250 m) Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired for summer months (June through August) over the entire arctic and subarctic Western Siberian region. The analysis shows that the NDVI background trends are generally in agreement with the trends reported in previous coarse-resolution NDVI studies. Our study reveals greening over the arctic (tundra and tundra-forest) part of the region. Simultaneously, the southern (boreal taiga forest) part is browning, with the more densely vegetation areas or areas with highest NDVI, particularly along Ob River showing strong negative trend. The unexpected and interesting finding of the study is statistically robust indication of the accelerated increase of NDVI ("greening") in the older urban areas. Many Siberian cities become greener even against the decrease in the NDVI background. Moreover, interannual variations of urban NDVI are not coherent with the NDVI background variability. We also find that in tundra zones, NDVI values are higher in a 5-10 km buffer zone around the city edge than in rural areas (40 km distance from the city edge), and in taiga in a 5-10 km

  6. Vegetation/Soil Synthesis Water Index Using MODIS Data

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) data and the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) are deduced using one visible band (0.66μm) and two near-infrared bands (0.86μm, 1.24 μm). Vegetation canopy temperature is derived using two thermal infrared bands (8.6 μm and 11μm). Then the vegetation/soil synthesis water index (VSWI) is acquired through analyzing the coupling character of three indexes which can reflect the water condition of vegetation. Finally, the synthesis index is verified by equivalent water content of a single leaf. The matching results show that the synthesis index is directly proportional to the modeled data, which means that the vegetation water content can be reflected using the synthesis index effectively.

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

    Science.gov (United States)

    Ahmed, A.; Akhtar, A.; Khalid, B.; Shamim, A.

    2013-06-01

    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.

  8. Mapping rice cropping systems using Landsat-derived Renormalized Index of Normalized Difference Vegetation Index (RNDVI) in the Poyang Lake Region, China

    Science.gov (United States)

    Li, Peng; Jiang, Luguang; Feng, Zhiming; Sheldon, Sage; Xiao, Xiangming

    2016-06-01

    Mapping rice cropping systems with optical imagery in multiple cropping regions is challenging due to cloud contamination and data availability; development of a phenology-based algorithm with a reduced data demand is essential. In this study, the Landsat-derived Renormalized Index of Normalized Difference Vegetation Index (RNDVI) was proposed based on two temporal windows in which the NDVI values of single and early (or late) rice display inverse changes, and then applied to discriminate rice cropping systems. The Poyang Lake Region (PLR), characterized by a typical cropping system of single cropping rice (SCR, or single rice) and double cropping rice (DCR, including early rice and late rice), was selected as a testing area. The results showed that NDVI data derived from Landsat time-series at eight to sixteen days captures the temporal development of paddy rice. There are two key phenological stages during the overlapping growth period in which the NDVI values of SCR and DCR change inversely, namely the ripening phase of early rice and the growing phase of single rice as well as the ripening stage of single rice and the growing stage of late rice. NDVI derived from scenes in two temporal windows, specifically early August and early October, was used to construct the RNDVI for discriminating rice cropping systems in the polder area of the PLR, China. Comparison with ground truth data indicates high classification accuracy. The RNDVI approach highlights the inverse variations of NDVI values due to the difference of rice growth between two temporal windows. This makes the discrimination of rice cropping systems straightforward as it only needs to distinguish whether the candidate rice type is in the period of growth (RNDVI0).

  9. Normalized Difference Vegetation Index as a Tool for Wheat Yield Estimation: A Case Study from Faisalabad, Pakistan

    Directory of Open Access Journals (Sweden)

    Syeda Refat Sultana

    2014-01-01

    Full Text Available 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 (R2 = 0.90; R2 = 0.90; R2 = 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.

  10. Stay-green in spring wheat can be determined by spectral reflectance measurements (normalized difference vegetation index) independently from phenology.

    Science.gov (United States)

    Lopes, Marta S; Reynolds, Matthew P

    2012-06-01

    The green area displayed by a crop is a good indicator of its photosynthetic capacity, while chlorophyll retention or 'stay-green' is regarded as a key indicator of stress adaptation. Remote-sensing methods were tested to estimate these parameters in diverse wheat genotypes under different growing conditions. Two wheat populations (a diverse set of 294 advanced lines and a recombinant inbred line population of 169 sister lines derived from the cross between Seri and Babax) were grown in Mexico under three environments: drought, heat, and heat combined with drought. In the two populations studied here, a moderate heritable expression of stay-green was found-when the normalized difference vegetation index (NDVI) at physiological maturity was estimated using the regression of NDVI over time from the mid-stages of grain-filling to physiological maturity-and for the rate of senescence during the same period. Under heat and heat combined with drought environments, stay-green calculated as NDVI at physiological maturity and the rate of senescence, showed positive and negative correlations with yield, respectively. Moreover, stay-green calculated as an estimation of NDVI at physiological maturity and the rate of senescence regressed on degree days give an independent measurement of stay-green without the confounding effect of phenology. On average, in both populations under heat and heat combined with drought environments CTgf and stay-green variables accounted for around 30% of yield variability in multiple regression analysis. It is concluded that stay-green traits may provide cumulative effects, together with other traits, to improve adaptation under stress further.

  11. Vegetation Drought Response Index: 2010-Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — VegDRI, short for Vegetation Drought Response Index, is a drought-monitoring tool developed by scientists at EROS in collaboration with the National Drought...

  12. Initial Response of Normalized Difference Vegetation Index, Green Normalized Difference Vegetation Index and Soil Adjusted Vegetation Index to Infrared Warming in Highland Barley of the Tibet%西藏高原青稞三种植被指数对红外增温的初始响应

    Institute of Scientific and Technical Information of China (English)

    付刚; 沈振西; 钟志明

    2015-01-01

    Climatic warming affects the crop growth and its related vegetation indices. In order to understand the initial response of normalized difference vegetation index (NDVI), normalized green difference vegetation index (GNDVI) and soil adjusted vegetation index (SAVI) to climatic warming, a field warming experiment using infrared radiator was conducted in a highland barley located at the Dazi county of the Tibet since late May, 2015. There were three warming treatments, i.e., control, low (1000 W) and high (2000W) warming. The NDVI, GNDVI and SAVI were obtained using an agricultural digital camera during the period from June to September in 2015. Meanwhile, the soil temperature and soil moisture at depths of 5 cm and 20 cm were also obtained using HOBO microclimate observing systems. Then this study analyzed the response of NDVI, GNDVI and SAVI to infrared warming and the relationships between the three vegetation indices and soil temperature and moisture. The 1000 W and 2000 W infrared warming increased soil temperature at the depth of 5 cm (t5) by 1.62℃ and 1.77℃, and soil temperature at the depth of 20 cm (t20) by 1.16℃and 1.43℃, but decreased soil moisture at the depth of 5 cm (SM5) by 1.8% and 14.1%, and soil moisture at the depth of 20 cm (SM20) by 21.6% and 14.7%, respectively. The 1000 W infrared warming increased NDVI by 2.4%, GNDVI by 4.3% and SAVI by 0.5%, whereas the 2000 W infrared warming increased NDVI by 5.5%, GNDVI by 5.3% and SAVI by 4.8%, although these changes were non-significant. Simple regression analyses showed that (1) NDVI (r2=0.110,P=0.026) and GNDVI(r2=0.254, P=0.0004)decreased with increasingt5,whereas there was non-significant correlation between SAVI andt5 (r2=0.069,P=0.082); (2) GNDVI decreased with increasingt20, (r2=0.218,P=0.001), whereas there were non-significant relationships between NDVI (r2=0.040,P=0.190), SAVI (r2=0.014,P=0.443) andt20; (3) NDVI (r2=0.277,P=0.0002), GNDVI (r2=0.394,P=0.0000) and SAVI (r2=0.208,P=0

  13. 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)

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

    2013-01-01

    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.

  14. 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)

    Alvaro Ivanoff

    2013-08-01

    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.

  15. Human induced dryland degradation in Ordos Plateau, China, revealed by multilevel statistical modeling of normalized difference vegetation index and rainfall time-series

    Institute of Scientific and Technical Information of China (English)

    Jing ZHANG; JianMing NIU; Tongliga BAO; Alexander BUYANTUYEV; Qing ZHANG; JianJun DONG; XueFeng ZHANG

    2014-01-01

    Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index (NDVI) from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive (land restoration and re-vegetation) or negative (degradation) trends. Linear regressions were used to assess the accuracy of the multi-level statistical model. The results show that:(1) land restoration was the dominant process in the Ordos Plateau between 1998 and 2012;(2) the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man-agement in many parts of the Ordos; (3) compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi-nate some observed non-significant residual trends.

  16. 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)

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

    2014-01-01

    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.

  17. Seasonal relationship between normalized difference vegetation index and abundance of the Phlebotomus kala-azar vector in an endemic focus in Bihar, India

    Directory of Open Access Journals (Sweden)

    Gouri S. Bhunia

    2012-11-01

    Full Text Available Remote sensing was applied for the collection of spatio-temporal data to increase our understanding of the potential distribution of the kala-azar vector Phlebotomus argentipes in endemic areas of the Vaishali district of Bihar, India. We produced monthly distribution maps of the normalized difference vegetation index (NDVI based on data from the thematic mapper (TM sensor onboard the Landsat-5 satellite. Minimum, maximum and mean NDVI values were computed for each month and compared with the concurrent incidence of kala-azar and the vector density. Maximum and mean NDVI values (R2 = 0.55 and R2 = 0.60, respectively, as well as the season likelihood ratio (X2 = 17.51; P <0.001, were found to be strongly associated with kala-azar, while the correlation with between minimum NDVI values and kala-azar was weak (R2 = 0.25. Additionally, a strong association was found between the mean and maximum NDVI values with seasonal vector abundance (R2 = 0.60 and R2 = 0.55, respectively but there was only a marginal association between minimum NDVI value and the spatial distribution of kala-azar vis-à-vis P. argentipes density.

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

    Science.gov (United States)

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

    2014-06-01

    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.

  19. Vegetation

    DEFF Research Database (Denmark)

    Epstein, H.E.; Walker, D.A.; Bhatt, U.S.;

    2012-01-01

    • 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...

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

    Directory of Open Access Journals (Sweden)

    Ainong Li

    2010-06-01

    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.

  1. Leaf area index retrieval based on canopy reflectance and vegetation index in easternChina

    Institute of Scientific and Technical Information of China (English)

    JIANGJianjun; CHENSuozhong; CAOShunxian; WUHongan; ZHANGLi; ZHANGHailong

    2005-01-01

    The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index,detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (Ⅵ), such as simple ratio vegetationin dex (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDⅥ). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area.LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of TM3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR+0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future.

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

    Science.gov (United States)

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

    2012-08-01

    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.

  3. Test of multi-spectral vegetation index for floating and canopy-forming submerged vegetation.

    Science.gov (United States)

    Cho, Hyun Jung; Kirui, Philemon; Natarajan, Harene

    2008-12-01

    Remote sensing of terrestrial vegetation has been successful thanks to the unique spectral characteristics of green vegetation, low reflectance in red and high reflectance in Near-InfraRed (NIR). These spectral characteristics were used to develop vegetation indices, including Normalized Difference Vegetation Index (NDVI). However, the NIR absorption by water and light scattering from suspended particles reduces the practical application of such indices in aquatic vegetation studies, especially for the Submerged Aquatic Vegetation (SAV) that grows below water surface. We experimentally tested if NDVI can be used to depict canopies of aquatic plants in shallow waters. A 100-gallonoutdoor tank was lined with black pond liners, a black panel or SAV shoots were mounted on the bottom, and filled with water up to 0.5 m. We used a GER 1500 spectroradiometer to collect spectral data over floating waterhyacinth (Eichhornia crassipes) and also over the tanks that contain SAV and black panel at varying water depths. The measured upwelling radiance was converted to % reflectance; and we integrated the hyperspectral reflectance to match the Red and NIR bands of three satellite sensors: Landsat 7 ETM, SPOT 5 HRG, and ASTER. NDVI values ranged 0.6-0.65 when the SAV canopy was at the water level, then they decreased linearly (slope of 0.013 NDVI/meter) with water depth increases in clear water. When corrected for water attenuation using the data obtained from the black panel, the NDVI values significantly increased at all depths that we tested (0.1 - 0.5 m). Our results suggest the conventional NDVI: (1) can be used to depict SAV canopies at water surface; (2) is not a good indicator for SAV that is adapted to live underwater or other aquatic plants that are submerged during flooding even at shallow waters (0.3 m); and (3) the index values can significantly improve if information on spectral reflectance attenuation caused by water volume increases is collected simultaneously

  4. Inversion of Biochemical Parameters by Selection of Proper Vegetation Index in Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    HUANG Wen-jiang; WANG Ji-hua; LIU Liang-yun; ZHAO Chun-jiang; WANG Zhi-jie; WANG Jin-di

    2004-01-01

    Recent studies have demonstrated the application of vegetation indices from canopy reflected spectrum for inversion of chlorophyll concentration.Some indices are both response to variations of vegetation and environmental factors.Canopy chlorophyll concentration,an indicator of photosynthesis activity,is related to nitrogen concentration in green vegetation and serves as an indicator of the crop response to soil nitrogen fertilizer application.The combination of normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) can reduce the effect of leaf area index (LAI) and soil background.The canopy chlorophyll inversion index (CCII) was proved to be sensitive to chlorophyll concentration and very resistant to the other variations.This paper introduced the ratio of TCARI/OSAVI to make accurate predictions of winter wheat chlorophyll concentration under different cultivars.It indicated that canopy chlorophyll concentration could be evaluated by some combined vegetation indices.

  5. An initial assessment of Suomi NPP VIIRS vegetation index EDR

    Science.gov (United States)

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

    2013-11-01

    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.

  6. New Vegetation Index and Its Application in Estimating Leaf Area Index of Rice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Leaf area index (LAI) is an important characteristic of land surface vegetation system, and is also a key parameter for the models of global water balancing and carbon circulation. By using the reflectance values of Landsat-5 blue, green and red channels simulated from rice reflectance spectrum, the sensitivities of the bands to LAI were analyzed, and the response and capability to estimate LAI of various NDVIs (normalized difference vegetation indices), which were established by substituting the red band of general NDVI with all possible combinations of red, green and blue bands, were assessed. Finally,the conclusion was tested by rice data at different conditions. The sensitivities of red, green and blue bands to LAI were different under various conditions. When LAI was less than 3, red and blue bands were more sensitive to LAI. Though green band in the circumstances was less sensitive to LAI than red and blue bands, it was sensitive to LAI in a wider range. When the vegetation indices were constituted by all kinds of combinations of red, green and blue bands, the premise for making the sensitivity of these vegetation indices to LAI be meaningful was that the value of one of the combinations was greater than 0.024, i.e. visible reflectance (VIS)>0.024. Otherwise, the vegetation indices would be saturated, resulting in lower estimation accuracy of LAI. Comparison on the capabilities of the vegetation indices derived from all kinds of combinations of red, green and blue bands to LAI estimation showed that GNDVI (Green NDVI) and GBNDVI (Green-Blue NDVI) had the best relations with LAI. The capabilities of GNDVI and GBNDVI to LAI estimation were tested under different circumstances, and the same result was acquired. It suggested that GNDVI and GBNDVI performed better to predict LAI than the conventional NDVI.

  7. Test of Multi-spectral Vegetation Index for Floating and Canopy-forming Submerged Vegetation

    Directory of Open Access Journals (Sweden)

    Philemon Kirui

    2008-12-01

    Full Text Available Remote sensing of terrestrial vegetation has been successful thanks to the unique spectral characteristics of green vegetation, low reflectance in red and high reflectance in Near-InfraRed (NIR. These spectral characteristics were used to develop vegetation indices, including Normalized Difference Vegetation Index (NDVI. However, the NIR absorption by water and light scattering from suspended particles reduces the practical application of such indices in aquatic vegetation studies, especially for the Submerged Aquatic Vegetation (SAV that grows below water surface. We experimentally tested if NDVI can be used to depict canopies of aquatic plants in shallow waters. A 100-gallonoutdoor tank was lined with black pond liners, a black panel or SAV shoots were mounted on the bottom, and filled with water up to 0.5 m. We used a GER 1500 spectroradiometer to collect spectral data over floating waterhyacinth (Eichhornia crassipes and also over the tanks that contain SAV and black panel at varying water depths. The measured upwelling radiance was converted to % reflectance; and we integrated the hyperspectral reflectance to match the Red and NIR bands of three satellite sensors: Landsat 7 ETM, SPOT 5 HRG, and ASTER. NDVI values ranged 0.6-0.65 when the SAV canopy was at the water level, then they decreased linearly (slope of 0.013 NDVI/meter with water depth increases in clear water. When corrected for water attenuation using the data obtained from the black panel, the NDVI values significantly increased at all depths that we tested (0.1 – 0.5 m. Our results suggest the conventional NDVI: (1 can be used to depict SAV canopies at water surface; (2 is not a good indicator for SAV that is adapted to live underwater or other aquatic plants that are submerged during flooding even at shallow waters (0.3 m; and (3 the index values can significantly improve if information on spectral reflectance attenuation caused by water volume increases is

  8. Estimation of leaf area index using an angular vegetation index based on in situ measurements and CHRIS/PROBA data

    Science.gov (United States)

    Wang, Lijuan; Zhang, Guimin; Lin, Hui; Liang, Liang; Niu, Zheng

    2016-06-01

    The Normalized Difference Vegetation Index (NDVI) is widely used for Leaf Area Index (LAI) estimation. It is well documented that the NDVI is extremely subject to the saturation problem when LAI reaches a high value. A new multi-angular vegetation index, the Hotspot-darkspot Difference Vegetation Index (HDVI) is proposed to estimate the high density LAI. The HDVI, defined as the difference between the hot and dark spot NDVI, relative to the dark spot NDVI, was proposed based on the Analytical two-layer Canopy Reflectance Model (ACRM) model outputs. This index is validated using both in situ experimental data in wheat and data from the multi-angular optical Compact High-Resolution Imaging Spectrometer (CHRIS) satellite. Both indices, the Hotspot-Darkspot Index (HDS) and the NDVI were also selected to analyze the relationship with LAI, and were compared with new index HDVI. The results show that HDVI is an appropriate proxy of LAI with higher determination coefficients (R2) for both the data from the in situ experiment (R2=0.7342, RMSE=0.0205) and the CHRIS data (R2=0.7749, RMSE=0.1013). Our results demonstrate that HDVI can make better the occurrence of saturation limits with the information of multi-angular observation, and is more appropriate for estimating LAI than either HDS or NDVI at high LAI values. Although the new index needs further evaluation, it also has the potential under the condition of dense canopies. It provides the effective improvement to the NDVI and other vegetation indices that are based on the red and NIR spectral bands.

  9. Performance Indexes: Similarities and Differences

    Directory of Open Access Journals (Sweden)

    André Machado Caldeira

    2013-06-01

    Full Text Available The investor of today is more rigorous on monitoring a financial assets portfolio. He no longer thinks only in terms of the expected return (one dimension, but in terms of risk-return (two dimensions. Thus new perception is more complex, since the risk measurement can vary according to anyone’s perception; some use the standard deviation for that, others disagree with this measure by proposing others. In addition to this difficulty, there is the problem of how to consider these two dimensions. The objective of this essay is to study the main performance indexes through an empirical study in order to verify the differences and similarities for some of the selected assets. One performance index proposed in Caldeira (2005 shall be included in this analysis.

  10. Statistical analysis of land surface temperature-vegetation indexes relationship through thermal remote sensing.

    Science.gov (United States)

    Kumar, Deepak; Shekhar, Sulochana

    2015-11-01

    Vegetation coverage has a significant influence on the land surface temperature (LST) distribution. In the field of urban heat islands (UHIs) based on remote sensing, vegetation indexes are widely used to estimate the LST-vegetation relationship. This paper devises two objectives. The first analyzes the correlation between vegetation parameters/indicators and LST. The subsequent computes the occurrence of vegetation parameter, which defines the distribution of LST (for quantitative analysis of urban heat island) in Kalaburagi (formerly Gulbarga) City. However, estimation work has been done on the valuation of the relationship between different vegetation indexes and LST. In addition to the correlation between LST and the normalized difference vegetation index (NDVI), the normalized difference build-up index (NDBI) is attempted to explore the impacts of the green land to the build-up land on the urban heat island by calculating the evaluation index of sub-urban areas. The results indicated that the effect of urban heat island in Kalaburagi city is mainly located in the sub-urban areas or Rurban area especially in the South-Eastern and North-Western part of the city. The correlation between LST and NDVI, indicates the negative correlation. The NDVI suggests that the green land can weaken the effect on urban heat island, while we perceived the positive correlation between LST and NDBI, which infers that the built-up land can strengthen the effect of urban heat island in our case study. Although satellite data (e.g., Landsat TM thermal bands data) has been applied to test the distribution of urban heat islands, but the method still needs to be refined with in situ measurements of LST in future studies.

  11. Introducing a rain-adjusted vegetation index (RAVI) for improvement of long-term trend analyses in vegetation dynamics

    Science.gov (United States)

    Wessollek, Christine; Karrasch, Pierre; Osunmadewa, Babatunde

    2015-10-01

    It seems to be obvious that precipitation has a major impact on greening during the rainy season in semi-arid regions. First results1 imply a strong dependence of NDVI on rainfall. Therefore it will be necessary to consider specific rainfall events besides the known ordinary annual cycle. Based on this fundamental idea, the paper will introduce the development of a rain adjusted vegetation index (RAVI). The index is based on the enhancement of the well-known normalized difference vegetation index (NDVI2) by means of TAMSAT rainfall data and includes a 3-step procedure of determining RAVI. Within the first step both time series were analysed over a period of 29 years to find best cross correlation values between TAMSAT rainfall and NDVI signal itself. The results indicate the strongest correlation for a weighted mean rainfall for a period of three months before the corresponding NDVI value. Based on these results different mathematical models (linear, logarithmic, square root, etc.) are tested to find a functional relation between the NDVI value and the 3-months rainfall period before (0.8). Finally, the resulting NDVI-Rain-Model can be used to determine a spatially individual correction factor to transform every NDVI value into an appropriate rain adjusted vegetation index (RAVI).

  12. A PROPOSED NEW VEGETATION INDEX, THE TOTAL RATIO VEGETATION INDEX (TRVI, FOR ARID AND SEMI-ARID REGIONS

    Directory of Open Access Journals (Sweden)

    H. Fadaei

    2012-07-01

    Full Text Available Vegetation indices that provide important key to predict amount vegetation in forest such as percentage vegetation cover, aboveground biomass, and leaf-area index. Arid and semi-arid areas are not exempt of this rule. Arid and semi-arid areas of northeast Iran cover about 3.4 million ha and are populated by two main tree species, the broadleaf Pistacia vera (pistachio and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper. Natural stands of pistachio in Iran are not only environmentally important but also genetically essential as seed sources for pistachio production in orchards. We investigated the relationships between tree density and vegetation indices in the arid and semi-arid regions in the northeast of Iran by analysing Advanced Land Observing Satellite (ALOS data PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, and has one band with a wavelength of 0.52–0.77 μm (JAXA EORC. AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, and has four multispectral bands: blue (0.42–0.50 μm, green (0.52–0.60 μm, red (0.61–0.69 μm, and near infrared (0.76–0.89 μm (JAXA EORC. In this study, we estimated various vegetation indices using maximum filtering algorithm (5×5 and examined. This study carried out of juniper forests and natural pistachio stand using Advanced Land Observing Satellite (ALOS and field inventories. Have been compared linear regression model of vegetation indices and proposed new vegetation index for arid and semi-arid regions. Also, we estimated the densities of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. We present a new vegetation index for arid and semi-arid regions with sparse forest cover, the Total Ratio Vegetation Index (TRVI, and we investigate the relationship of the new index to tree density by

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

    Science.gov (United States)

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

    2011-01-01

    The spectral vegetation index (ρNIR – ρSWIR)/(ρNIR + ρSWIR), where ρNIR and ρSWIR 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.

  14. Influence of solar zenith angle on the enhanced vegetation index of a Guyanese rainforest

    NARCIS (Netherlands)

    Brede, B.; Suomalainen, J.M.; Bartholomeus, H.M.; Herold, M.

    2015-01-01

    In this study, the effect of solar zenith angle () on enhanced vegetation index (EVI) of a Guyanese tropical rainforest was studied. For this sub-crown resolution, hyperspectral data have been collected with an unmanned aerial vehicle (UAV) at five different solar zenith angles in a 1-day period. Th

  15. Validating a Dynamic Global Vegetation Model with Remotely Sensed Vegetation Index

    Directory of Open Access Journals (Sweden)

    Jiaxin Jin

    2013-02-01

    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.

  16. A special vegetation index for the weed detection in sensor based precision agriculture.

    Science.gov (United States)

    Langner, Hans-R; Böttger, Hartmut; Schmidt, Helmut

    2006-06-01

    Many technologies in precision agriculture (PA) require image analysis and image- processing with weed and background differentiations. The detection of weeds on mulched cropland is one important image-processing task for sensor based precision herbicide applications. The article introduces a special vegetation index, the Difference Index with Red Threshold (DIRT), for the weed detection on mulched croplands. Experimental investigations in weed detection on mulched areas point out that the DIRT performs better than the Normalized Difference Vegetation Index (NDVI). The result of the evaluation with four different decision criteria indicate, that the new DIRT gives the highest reliability in weed/background differentiation on mulched areas. While using the same spectral bands (infrared and red) as the NDVI, the new DIRT is more suitable for weed detection than the other vegetation indices and requires only a small amount of additional calculation power. The new vegetation index DIRT was tested on mulched areas during automatic ratings with a special weed camera system. The test results compare the new DIRT and three other decision criteria: the difference between infrared and red intensity (Diff), the soil-adjusted quotient between infrared and red intensity (Quotient) and the NDVI. The decision criteria were compared with the definition of a worse case decision quality parameter Q, suitable for mulched croplands. Although this new index DIRT needs further testing, the index seems to be a good decision criterion for the weed detection on mulched areas and should also be useful for other image processing applications in precision agriculture. The weed detection hardware and the PC program for the weed image processing were developed with funds from the German Federal Ministry of Education and Research (BMBF).

  17. Monitoring Rangeland Health With MODIS Vegetation Index Data

    Science.gov (United States)

    Brown, J. F.

    2004-12-01

    Rangelands cover approximately one third of the land area of the conterminous U.S. These lands supply much of the forage for the U.S. cattle industry. Large area monitoring of these vast expanses of range has proved challenging since most of these lands are in the western U.S., are relatively sparsely populated, and are not well covered by meteorological weather stations. Improvements in the spatial and temporal precision of rangeland health information would be useful both for the cattle industry and for scientific studies of soil erosion, water runoff, ecosystem health, and carbon cycling. Optical multispectral remote sensing data from satellites are an objective source of synoptic, timely information for monitoring rangeland health. The objective of this study is to develop and evaluate a method for measuring and monitoring rangeland health over large areas. In the past, data collected by the Advanced Very High Resolution Radiometer has proved useful for this purpose, however the basic 1 km spatial resolution is not ideal when scaling up from ground observations. This study assesses MODIS 250 meter resolution vegetation index data for this purpose. MODIS data not only have finer spatial resolution and improved geolocation, but they also exhibit enhanced vegetation sensitivity and minimized variations associated with external atmospheric and non-atmospheric effects. Ground data collected over 51 sites in western South Dakota over four years are used as training for regression tree models of range health. Range health maps for the growing season derived from the models are presented and evaluated.

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

    Science.gov (United States)

    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

    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.

  19. Consistency of vegetation index seasonality across the Amazon rainforest

    Science.gov (United States)

    Maeda, Eduardo Eiji; Moura, Yhasmin Mendes; Wagner, Fabien; Hilker, Thomas; Lyapustin, Alexei I.; Wang, Yujie; Chave, Jérôme; Mõttus, Matti; Aragão, Luiz E. O. C.; Shimabukuro, Yosio

    2016-10-01

    Vegetation indices (VIs) calculated from remotely sensed reflectance are widely used tools for characterizing the extent and status of vegetated areas. Recently, however, their capability to monitor the Amazon forest phenology has been intensely scrutinized. In this study, we analyze the consistency of VIs seasonal patterns obtained from two MODIS products: the Collection 5 BRDF product (MCD43) and the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC). The spatio-temporal patterns of the VIs were also compared with field measured leaf litterfall, gross ecosystem productivity and active microwave data. Our results show that significant seasonal patterns are observed in all VIs after the removal of view-illumination effects and cloud contamination. However, we demonstrate inconsistencies in the characteristics of seasonal patterns between different VIs and MODIS products. We demonstrate that differences in the original reflectance band values form a major source of discrepancy between MODIS VI products. The MAIAC atmospheric correction algorithm significantly reduces noise signals in the red and blue bands. Another important source of discrepancy is caused by differences in the availability of clear-sky data, as the MAIAC product allows increased availability of valid pixels in the equatorial Amazon. Finally, differences in VIs seasonal patterns were also caused by MODIS collection 5 calibration degradation. The correlation of remote sensing and field data also varied spatially, leading to different temporal offsets between VIs, active microwave and field measured data. We conclude that recent improvements in the MAIAC product have led to changes in the characteristics of spatio-temporal patterns of VIs seasonality across the Amazon forest, when compared to the MCD43 product. Nevertheless, despite improved quality and reduced uncertainties in the MAIAC product, a robust biophysical interpretation of VIs seasonality is still missing.

  20. Frontier differences and the global malmquist index

    DEFF Research Database (Denmark)

    Asmild, Mette

    2015-01-01

    This chapter reviews different ways of comparing the efficiency frontiers for subgroups within a data set, specifically program efficiency, the metatechnology (or technology gap) ratio and the global frontier difference index. The latter is subsequently used to define a global Malmquist index...

  1. [Inversion of leaf area index during different growth stages in winter wheat].

    Science.gov (United States)

    Zhao, Juan; Huang, Wen-jiang; Zhang, Yao-hong; Jing, Yuan-shu

    2013-09-01

    Being orientated to the low prescion of crop leaf area index (LAI) inversion using the same spectral vegetation index during different crop growth stages, the present paper analyzed the precision of LAI inversion by employing NDVI(normalized difference vegetation index). Ten vegetation indices were chosen including six broad-band vegetation indices and four narrow-band vegetation indices responding to vegetation cover to inverse LAI in different growth stages. Several conclusions were drawn according to the analysis. The determinant coefficient (R2) and root mean square error (RMSE) between LAI inversion value and true value were 0.5585 and 0.3209 respectively during the whole growth duraton. The mSR (modified simple ratio index) index was appropriate to inverse of LAI during earlier growth stages (before jointing stage) in winter wheat. The R2 and RMSE between LAI inversion value and true value were 0.7287 and 0.2971 respectively. The SR (simple ratio index) index was suitable enough to inverse of LAI during medium growth stages (from joingting stagess to heading stages). The R2 and RMSE between LAI inversion value and true value were 0.6546 and 0.3061 respectively. The NDVI (normalized difference vegetation index) index was proven to be fine to inverse LAI during later growth stages(from heading stage to ripening stage). The R2 and RMSE between LAI inversion value and true value were 0.6794 and 0.3164 respectively. Therefore it was indicated that the results of LAI inversion was much better inverse of winter wheat LAI choosing different vegetation indices during differen growth stages for winter wheat according to the change of vegetation cover and canopy reflectance than merely with NDVI to inverse LAI in the whole growth stages. It was concluded that the precision of LAI inversion was significantly improved with segmented models based on different vegetation indices.

  2. Monitoring Frost Disaster of Cotton Based on Difference of Vegetation Index and Canopy Temperature by Remote Sensing%基于ETM植被指数和冠层温度差异遥感监测棉花冷害

    Institute of Scientific and Technical Information of China (English)

    林海荣; 李章成; 周清波; 吕新

    2009-01-01

    大范围地、及时地遥感监测棉花的冻害状况及损失对安排救灾、灾后评估有着现实的意义.利用2001年6月7日、8月10日和2000年8月7日ETM影像,结合农业灾害和农作物生长发育统计数据,通过植被指数变化和冠层温度差异对新疆沙湾2001年8月初棉花结桃时发生的冷害进行遥感监测.结果表明:与往年未遭受冷害的同期棉花植被指数相比,棉花植被指数NDVI绝对差值降低区域占67.8%,其中下降0~0.2占51%,下降大于0.2占17%,降低百分比处于0~20%.植被指数和温度图像散点图呈现显著负相关,相关系数-0.63.其中未受冷害影响,植被指数增加,长势较好的棉花冠层温度平均为26.4℃,植被指数未变化区域为27.6℃,植被指数降低较多,冷害程度较重区域冠层温度约为29.3℃,冠层温度差异显著.基于ETM遥感影像植被指数变化幅度和冠层温度差异可用于冷害程度区域划分.%Frostbite occurrence lies mainly on condition of weather and vegetation.Frostbite can be monitored by remote sensing according to the difference of vegetation index,which has higher spatial and temporal resolution, and to the canopy temperature,which has higher precision of temperature retrieval.In addition,considering the aerosol and humidity effect on the temperature retrieval and the quality of the remote sensing image,monitoring the frostbite by remote sensing is rather complicated and difficult.North Xinjiang is the main production zone of cotton in China,where cotton is influenced seriously by later spring frost or early autumn low-temperature injury.Remote sensing is proved feasible in monitoring crop growth,especially after stresses.But monitoring frostbite of cotton with remote sensing has been rarely studied so far.So combining with the statistical data of agriculture disaster and crop development,according to the difference of NDVI and canopy temperature (CT), the remote sensing was applied to three

  3. RGB picture vegetation indexes for High-Throughput Phenotyping Platforms (HTPPs)

    Science.gov (United States)

    Kefauver, Shawn C.; El-Haddad, George; Vergara-Diaz, Omar; Araus, José Luis

    2015-10-01

    Extreme and abnormal weather events, as well as the more gradual meteorological changes associated with climate change, often coincide with not only increased abiotic risks (such as increases in temperature and decreases in precipitation), but also increased biotic risks due to environmental conditions that favor the rapid spread of crop pests and diseases. Durum wheat is by extension the most cultivated cereal in the south and east margins of the Mediterranean Basin. It is of strategic importance for Mediterranean agriculture to develop new varieties of durum wheat with greater production potential, better adaptation to increasingly adverse environmental conditions (drought) and better grain quality. Similarly, maize is the top staple crop for low-income populations in Sub-Saharan Africa and is currently suffering from the appearance of new diseases, which, together with increased abiotic stresses from climate change, are challenging the very sustainability of African societies. Current constraints in field phenotyping remain a major bottleneck for future breeding advances, but RGB-based High-Throughput Phenotyping Platforms (HTPPs) have shown promise for rapidly developing both disease-resistant and weather-resilient crops. RGB cameras have proven costeffective in studies assessing the effect of abiotic stresses, but have yet to be fully exploited to phenotype disease resistance. Recent analyses of durum wheat in Spain have shown RGB vegetation indexes to outperform multispectral indexes such as NDVI consistently in disease and yield prediction. Towards HTTP development for breeding maize disease resistance, some of the same RGB picture vegetation indexes outperformed NDVI (Normalized Difference Vegetation Index), with R2 values up to 0.65, compared to 0.56 for NDVI. . Specifically, hue, a*, u*, and Green Area (GA), as produced by FIJI and BreedPix open source software, performed similar to or better than NDVI in predicting yield and disease severity conditions

  4. Assessments of Drought Impacts on Vegetation in China with the Optimal Time Scales of the Climatic Drought Index.

    Science.gov (United States)

    Li, Zheng; Zhou, Tao; Zhao, Xiang; Huang, Kaicheng; Gao, Shan; Wu, Hao; Luo, Hui

    2015-07-08

    Drought is expected to increase in frequency and severity due to global warming, and its impacts on vegetation are typically extensively evaluated with climatic drought indices, such as multi-scalar Standardized Precipitation Evapotranspiration Index (SPEI). We analyzed the covariation between the SPEIs of various time scales and the anomalies of the normalized difference vegetation index (NDVI), from which the vegetation type-related optimal time scales were retrieved. The results indicated that the optimal time scales of needle-leaved forest, broadleaf forest and shrubland were between 10 and 12 months, which were considerably longer than the grassland, meadow and cultivated vegetation ones (2 to 4 months). When the optimal vegetation type-related time scales were used, the SPEI could better reflect the vegetation's responses to water conditions, with the correlation coefficients between SPEIs and NDVI anomalies increased by 5.88% to 28.4%. We investigated the spatio-temporal characteristics of drought and quantified the different responses of vegetation growth to drought during the growing season (April-October). The results revealed that the frequency of drought has increased in the 21st century with the drying trend occurring in most of China. These results are useful for ecological assessments and adapting management steps to mitigate the impact of drought on vegetation. They are helpful to employ water resources more efficiently and reduce potential damage to human health caused by water shortages.

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

    Directory of Open Access Journals (Sweden)

    Timothy J. Fullman

    2014-01-01

    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.

  6. Evaluating an Enhanced Vegetation Condition Index (VCI Based on VIUPD for Drought Monitoring in the Continental United States

    Directory of Open Access Journals (Sweden)

    Wenzhe Jiao

    2016-03-01

    Full Text Available Drought is a complex hazard, and it has an impact on agricultural, ecological, and socio-economic systems. The vegetation condition index (VCI, which is derived from remote-sensing data, has been widely used for drought monitoring. However, VCI based on the normalized difference vegetation index (NDVI does not perform well in certain circumstances. In this study, we examined the utility of the vegetation index based on the universal pattern decomposition method (VIUPD based VCI for drought monitoring in various climate divisions across the continental United States (CONUS. We compared the VIUPD-derived VCI with the NDVI-derived VCI in various climate divisions and during different sub-periods of the growing season. It was also compared with other remote-sensing-based drought indices, such as the temperature condition index (TCI, precipitation condition index (PCI and the soil moisture condition index (SMCI. The VIUPD-derived VCI had stronger correlations with long-term in situ drought indices, such as the Palmer Drought Severity Index (PDSI and the standardized precipitation index (SPI-3, SPI-6, SPI-9, and SPI-12 than did the NDVI-derived VCI, and other indices, such as TCI, PCI and SMCI. The VIUPD has considerable potential for drought monitoring. As VIUPD can make use of the information from all the observation bands, the VIUPD-derived VCI can be regarded as an enhanced VCI.

  7. Evaluation of NPP VIIRS Vegetation Index EDR performance using MODIS and AVHRR data records

    Science.gov (United States)

    vargas, M.; Shabanov, N.; Miura, T.

    2012-12-01

    Vegetation Index (VI) is one key parameter to specify the boundary condition in global climate models, weather forecasting models and numerous remote sensing applications for monitoring environmental state and its change. The VI Environmental Data Record (EDR), which includes the Top of Atmosphere Normalized Difference Vegetation Index (TOA NDVI) and the Top of Canopy Enhanced Vegetation Index (TOC EVI), is currently operationally generated from data delivered by the Visible Infrared Imaging radiometer Suite (VIIRS) instrument onboard the National Polar-orbiting Partnership (NPP) platform launched in October 2011. The VI EDR was implemented to provide continuity for 30+ years of historical VI records provided by MODIS and AVHRR sensors. This presentation reports on the results of the analysis performed by the JPSS VI group at NOAA-NESDIS-STAR on two major aspects of performance of the VI EDR in the early phase of the NPP mission: (1) assessment of accuracy of the VIIRS VI EDR product with respect to input data including Surface Reflectances, Cloud and Aerosol masks as function of vegetation (biome) types; (2) temporal and spatial consistency of VIIRS VI EDR with respect to heritage MODIS and AVHRR VI products. This analysis is based on data from VIIRS (daily TOA NDVI and TOC EVI, and daily surface reflectances), Terra MODIS (16 days composites of TOC EVI and TOC NDVI, and daily TOA radiances) and NOAA-18 AVHRR (7-days composites of TOA NDVI). MODIS 8-biome landcover mask was used to quantify variations in VI product performance as function of vegetation type. Best overall agreement is achieved between VIIRS and MODIS data (TOC EVI and TOC NDVI) in terms of minimum systematic discrepancy (minimum bias and STD) and highest correlation of spatial patterns (highest r^2). The agreement is highest for biomes with low vegetation cover, but degrades with increased foliage density. VIIRS cloud mask provides a fair screening of daily data over the globe. While performance of

  8. Vegetation Spatial Heterogeneity of Different Soil Regions in Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The vegetation spatial heterogeneity and ecological characteristics in different soil regions were analyzed by surveying the vegetation in 12 different soil regions of Inner Mongolia, China, including coniferous-broadleaf deciduous forests, shrub, grassland, and desert regions with 1122 large 2 cm × 2 cm quadrats (actual size 30 km × 30 km, referred to as L-quadrat hereafter) in about 1.18 million km2. Each Lquadrat was divided into four small 1 cm× 1 cm quadrats (actual size 15 km × 15 km, S-quadrat). The vegetation was analyzed based on the beta-binomial distribution to describe the frequency of occurrence and spatial heterogeneity for each kind of vegetation. The weighted average of the heterogeneity of all vegetation in the same soil region provides a measure of the soil regional landscape level heterogeneity which describes the spatial complexity of the regional landscape composition of the existing vegetation. Comparison of the vegetation characteristics in the 12 soil regions shows that, the calcic gray soil has the highest average vegetation type per quadrat. The largest soil region is calcic chestnut soil and has the most vegetation types. Every soil region has its own dominant vegetation sequence which dominates in occurrence and dominant vegetation types which dominates in spatial heterogeneity. For the Inner Mongolian vegetation, the weighted average of the heterogeneity is 0.60 and the vegetation diversity index is 4.47.

  9. Aerial image mosaics built using images with vegetation index pre-calculated

    Science.gov (United States)

    Rosendo Candido, Leandro; de Castro Jorge, Lúcio André; Luppe, Maximiliam

    2016-10-01

    Precision agriculture (PA) has offered a multitude of benefits to farmers, such as cost reduction, accuracy and speed in decision making. Among the tools that work with PA, the aerial image mosaics have key role in accurate mapping of diseases and pests in crops. A mosaic is the combination of multiple images, creating a new image that covers the property or plots accurately. One of the important analysis for farmers is based on the properties of the reflectance in each range of the electromagnetic spectrum of vegetation. Performing mathematical combinations of the different spectral bands has a better understanding of the spectral response of the vegetation. These combinations are called vegetation index (VI) and are useful for the control of the biomass, water content in leaf, chlorophyll content and others. It is usually calculated VI after the construction of the mosaic, as well the farmer has an accurate analysis of its vegetation. However, building a mosaic of images, it has a high computational cost, taking hours to complete and then apply the VI and to have the first test results. In order to reduce the computational cost of this process, this work aims to present a mosaic of images constructed from images with the VI already pre-calculated providing faster analysis to the farmer, given the fact that applying VI on the image came a this reduction in density image and thus have the gain in computational cost to build the mosaic.

  10. Assessments of Drought Impacts on Vegetation in China with the Optimal Time Scales of the Climatic Drought Index

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2015-07-01

    Full Text Available Drought is expected to increase in frequency and severity due to global warming, and its impacts on vegetation are typically extensively evaluated with climatic drought indices, such as multi-scalar Standardized Precipitation Evapotranspiration Index (SPEI. We analyzed the covariation between the SPEIs of various time scales and the anomalies of the normalized difference vegetation index (NDVI, from which the vegetation type-related optimal time scales were retrieved. The results indicated that the optimal time scales of needle-leaved forest, broadleaf forest and shrubland were between 10 and 12 months, which were considerably longer than the grassland, meadow and cultivated vegetation ones (2 to 4 months. When the optimal vegetation type-related time scales were used, the SPEI could better reflect the vegetation’s responses to water conditions, with the correlation coefficients between SPEIs and NDVI anomalies increased by 5.88% to 28.4%. We investigated the spatio-temporal characteristics of drought and quantified the different responses of vegetation growth to drought during the growing season (April–October. The results revealed that the frequency of drought has increased in the 21st century with the drying trend occurring in most of China. These results are useful for ecological assessments and adapting management steps to mitigate the impact of drought on vegetation. They are helpful to employ water resources more efficiently and reduce potential damage to human health caused by water shortages.

  11. Vegetation index methods for estimating evapotranspiration by remote sensing

    Science.gov (United States)

    Glenn, Edward P.; Nagler, Pamela L.; Huete, Alfredo R.

    2010-01-01

    Evapotranspiration (ET) is the largest term after precipitation in terrestrial water budgets. Accurate estimates of ET are needed for numerous agricultural and natural resource management tasks and to project changes in hydrological cycles due to potential climate change. We explore recent methods that combine vegetation indices (VI) from satellites with ground measurements of actual ET (ETa) and meteorological data to project ETa over a wide range of biome types and scales of measurement, from local to global estimates. The majority of these use time-series imagery from the Moderate Resolution Imaging Spectrometer on the Terra satellite to project ET over seasons and years. The review explores the theoretical basis for the methods, the types of ancillary data needed, and their accuracy and limitations. Coefficients of determination between modeled ETa and measured ETa are in the range of 0.45–0.95, and root mean square errors are in the range of 10–30% of mean ETa values across biomes, similar to methods that use thermal infrared bands to estimate ETa and within the range of accuracy of the ground measurements by which they are calibrated or validated. The advent of frequent-return satellites such as Terra and planed replacement platforms, and the increasing number of moisture and carbon flux tower sites over the globe, have made these methods feasible. Examples of operational algorithms for ET in agricultural and natural ecosystems are presented. The goal of the review is to enable potential end-users from different disciplines to adapt these methods to new applications that require spatially-distributed ET estimates.

  12. Modified soil adjusted vegetation index for the Death Valley regional flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1992 for the Death Valley...

  13. Modified soil adjusted vegetation index of the Sarcobatus Flat area of the Death Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1989 for Sarcobatus Flat. The...

  14. Global assessment of Vegetation Index and Phenology Lab (VIP and Global Inventory Modeling and Mapping Studies (GIMMS version 3 products

    Directory of Open Access Journals (Sweden)

    M. Marshall

    2015-06-01

    Full Text Available Earth observation based long-term global vegetation index products are used by scientists from a wide range of disciplines concerned with global change. Inter-comparison studies are commonly performed to keep the user community informed on the consistency and accuracy of such records as they evolve. In this study, we compared two new records: (1 Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index Version 3 (NDVI3g and (2 Vegetation Index and Phenology Lab (VIP Version 3 NDVI (NDVI3v and Enhanced Vegetation Index 2 (EVI3v. We evaluated the two records via three experiments that addressed the primary use of such records in global change research: (1 prediction of the Leaf Area Index (LAI used in light-use efficiency modeling, (2 estimation of vegetation climatology in Soil-Vegetation-Atmosphere Transfer models, and (3 trend analysis of the magnitude and phenology of vegetation productivity. Experiment one, unlike previous inter-comparison studies, was performed with a unique Landsat 30 m spatial resolution and in situ LAI database for major crop types on five continents. Overall, the two records showed a high level of agreement both in direction and magnitude on a monthly basis, though VIP values were higher and more variable and showed lower correlations and higher error with in situ LAI. The records were most consistent at northern latitudes during the primary growing season and southern latitudes and the tropics throughout much of the year, while the records were less consistent at northern latitudes during green-up and senescence and in the great deserts of the world throughout much of the year. The two records were also highly consistent in terms of trend direction/magnitude, showing a 30+ year increase (decrease in NDVI over much of the globe (tropical rainforests. The two records were less consistent in terms of timing due to the poor correlation of the records during start and end of growing season.

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

    Science.gov (United States)

    Pleniou, M.; Koutsias, N.

    2013-08-01

    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.

  16. Tree Species Richness, Diversity, and Vegetation Index for Federal Capital Territory, Abuja, Nigeria

    Directory of Open Access Journals (Sweden)

    Aladesanmi D Agbelade

    2017-01-01

    Full Text Available This study was conducted to investigate the tree species richness and diversity of urban and periurban areas of the Federal Capital Territory (FCT, Abuja, Nigeria, and produce Normalized Difference Vegetation Index (NDVI for the territory. Data were collected from urban (Abuja city and periurban (Lugbe areas of the FCT using both semistructured questionnaire and inventory of tree species within green areas. In the study location, all trees with diameter at breast height (dbh ≥ 10 cm were identified; their dbh was measured and frequency was taken. The NDVI was calculated in ArcGIS 10.3 environment using standard formula. A cumulative total of twenty-nine (29 families were encountered within the FCT, with 27 occurring in Abuja city (urban centre and 12 in Lugbe (periurban centre of the FCT. The results of Shannon-Wiener diversity index (H′ for the two centres are 3.56 and 2.24 while Shannon’s maximum diversity index (Hmax is 6.54 (Abuja city and 5.36 (Lugbe for the urban (Abuja city and periurban (Lugbe areas of the Federal Capital Territory (FCT. The result of tree species evenness (Shannon’s equitability (EH index in urban and periurban centres was 0.54 and 0.42, respectively. The study provided baseline information on urban and periurban forests in the FCT of Nigeria, which can be used for the development of tree species database of the territory.

  17. Detection of Terrestrial Ecosystem Disturbances Using Aqua/MODIS Land Surface Temperature and Enhanced Vegetation Index

    Science.gov (United States)

    Mildrexler, D. J.; Zhao, M.; Running, S. W.

    2011-12-01

    Global information on the timing, location and magnitude of large-scale ecosystem disturbance events is needed to reduce significant uncertainty in the global carbon cycle. The MODIS Global Disturbance Index (MGDI) algorithm is designed for systematic, global, disturbance mapping using Aqua/MODIS Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI) data. The MGDI uses annual maximum composite LST data to detect fundamental changes in land-surface energy partitioning, while avoiding the high natural variability associated with tracking LST at daily, weekly, or seasonal time frames. LST and EVI respond to different biophysical processes and coupling these variables together into a ratio results in a dynamic approach that measures both the energy exchange consequence and the vegetation density changes resulting from disturbance. This robust radiometric relationship is revisited for each individual pixel every year resulting in a consistent methodology that can be generalized globally to provide 1-km resolution information about the effects of major disturbance on woody ecosystems and has been validated across North America. We have now applied the full Aqua/MODIS dataset through 2010 to the MGDI algorithm across woody ecosystems globally and continue to validate the MGDI results by comparison with confirmed, historical disturbance events such as wildfire, hurricanes, insect epidemics, ice storms, and droughts.

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

    Science.gov (United States)

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

    2013-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Russell L. Scott

    2013-08-01

    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.

  20. Identification of Forest Vegetation Using Vegetation Indices

    Institute of Scientific and Technical Information of China (English)

    Yuan Jinguo; Wang Wei

    2004-01-01

    Spectral feature of forest vegetation with remote sensing techniques is the research topic all over the world, because forest plays an important role in human beings' living environment. Research on vegetation classification with vegetation index is still very little recently. This paper proposes a method of identifying forest types based on vegetation indices,because the contrast of absorbing red waveband with reflecting near-infrared waveband strongly for different vegetation types is recognized as the theoretic basis of vegetation analysis with remote sensing. Vegetation index is highly related to leaf area index, absorbed photosynthetically active radiation and vegetation cover. Vegetation index reflects photosynthesis intensity of plants and manifests different forest types. According to reflectance data of forest canopy and soil line equation NIR=1.506R+0.0076 in Jingyuetan, Changchun of China, many vegetation indices are calculated and analyzed. The result shows that the relationships between vegetation indices and forest types are that perpendicular vegetation index (PVI) identifies broadleaf forest and coniferous forest the most easily;the next is transformed soil-adjusted vegetation index(TSVI) and modified soil-adjusted vegetation index(MSVI), but their calculation is complex. Ratio vegetation index (RVT) values of different coniferous forest vary obviously, so RVI can classify conifers.Therefore, the combination of PVI and RVI is evaluated to classify different vegetation types.

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

    Science.gov (United States)

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

    2014-06-01

    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 μg 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.

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

    OpenAIRE

    Timothy J. Fullman; Erin L. Bunting

    2014-01-01

    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 as...

  3. Evaluating the quality of riparian forest vegetation: the Riparian Forest Evaluation (RFV index

    Directory of Open Access Journals (Sweden)

    Fernando Magdaleno

    2014-08-01

    Full Text Available Aim of study: This paper presents a novel index, the Riparian Forest Evaluation (RFV index, for assessing the ecological condition of riparian forests. The status of riparian ecosystems has global importance due to the ecological and social benefits and services they provide. The initiation of the European Water Framework Directive (2000/60/CE requires the assessment of the hydromorphological quality of natural channels. The Directive describes riparian forests as one of the fundamental components that determine the structure of riverine areas. The RFV index was developed to meet the aim of the Directive and to complement the existing methodologies for the evaluation of riparian forests.Area of study: The RFV index was applied to a wide range of streams and rivers (170 water bodies inSpain.Materials and methods: The calculation of the RFV index is based on the assessment of both the spatial continuity of the forest (in its three core dimensions: longitudinal, transversal and vertical and the regeneration capacity of the forest, in a sampling area related to the river hydromorphological pattern. This index enables an evaluation of the quality and degree of alteration of riparian forests. In addition, it helps to determine the scenarios that are necessary to improve the status of riparian forests and to develop processes for restoring their structure and composition.Main results: The results were compared with some previous tools for the assessment of riparian vegetation. The RFV index got the highest average scores in the basins of northernSpain, which suffer lower human influence. The forests in central and southern rivers got worse scores. The bigger differences with other tools were found in complex and partially altered streams and rivers.Research highlights: The study showed the index’s applicability under diverse hydromorphological and ecological conditions and the main advantages of its application. The utilization of the index allows a

  4. Trends in a satellite-derived vegetation index and environmental variables in a restored brackish lagoon

    Directory of Open Access Journals (Sweden)

    Ji Yoon Kim

    2015-07-01

    Full Text Available We evaluated relative influence of climatic variables on the plant productivity after lagoon restoration. Chilika Lagoon, the largest brackish lake ecosystem in East Asia, experienced severe problems such as excessive dominance of freshwater exotic plants and rapid debasement of biodiversity associated with decreased hydrologic connectivity between the lagoon and the ocean. To halt the degradation of the lagoon ecosystem, the Chilika Development Authority implemented a restoration project, creating a new channel to penetrate the barrier beach of the lagoon. Using a satellite-derived normalized difference vegetation index (NDVI dataset, we compared the trend of vegetation changes after the lagoon restoration, from April 1998 to May 2014. The time series of NDVI data were decomposed into trend, seasonal, and random components using a local regression method. The results were visualized to understand the traits of spatial distribution in the lagoon. The NDVI trend, indicative of primary productivity, decreased rapidly during the restoration period, and gradually increased (slope coefficient: 2.1×10−4, p<0.05 after two years of restoration. Level of seawater exchange had more influences on plant productivity than local precipitation in the restored lagoon. Higher El Niño/Southern Oscillation increased sea level pressure, and caused intrusion of seawater into the lagoon, and the subsequently elevated salinity decreased the annual mean NDVI. Our findings suggest that lagoon restoration plans for enhancing interconnectivity with the ocean should consider oceanographic effects due to meteorological forcing, and long-term NDVI results can be used as a valuable index for adaptive management of the restoration site.

  5. Non-Lambertian effects on remote sensing of surface reflectance and vegetation index

    Science.gov (United States)

    Lee, T. Y.; Kaufman, Y. J.

    1986-01-01

    This paper discusses the effects of non-Lambertian reflection from a homogeneous surface on remote sensing of the surface reflectance and vegetation index from a satellite. Remote measurement of the surface characteristics is perturbed by atmospheric scattering of sun light. This scattering tends to smooth the angular dependence of non-Lambertian surface reflectances, an effect that is not present in the case of Lambertian surfaces. This effect is calculated to test the validity of a Lambertian assumption used in remote sensing. For the three types of vegetations considered in this study, the assumption of Lambertian surface can be used satisfactorily in the derivation of surface reflectance from remotely measured radiance for a view angle outside the backscattering region. Within the backscattering region, however, the use of the assumption can result in a considerable error in the derived surface reflectance. Accuracy also deteriorates with increasing solar zenith angle. The angular distribution of the surface reflectance derived from remote measurements is smoother than that at the surface. The effect of surface non-Lambertianity on remote sensing of vegetation index is very weak. Since the effect is similiar in the visible and near infrared part of the solar spectrum for the vegetations treated in this study, it is canceled in deriving the vegetation index. The effect of the diffuse skylight on surface reflectance measurements at ground level is also discussed.

  6. Coastwide Reference Monitoring System (CRMS) Vegetation Volume Index: An assessment tool for marsh habitat focused on the three-dimensional structure at CRMS vegetation monitoring stations

    Science.gov (United States)

    Wood, William B.; Visser, Jenneke M.; Piazza, Sarai C.; Sharp, Leigh Anne; Hundy, Laura C.; McGinnis, Tommy E.

    2015-12-04

    A Vegetation Volume (VV) variable and Vegetation Volume Index (VVI) have been developed for the Coastwide Reference Monitoring System (CRMS). The VV is a measure of the amount of three-dimensional vegetative structure present at each CRMS site and is based on vegetation data collected annually. The VV uses 10 stations per CRMS site to quantify four vegetation layers: carpet, herbaceous, shrub, and tree. For each layer an overall live vegetation percent cover and height are collected to create a layer volume; the individual layer volumes are then summed to generate a site vegetation volume profile. The VV uses the two-dimensional area of live vegetative cover (in square meters) multiplied by the height (in meters) of each layer to produce a volume (in cubic meters) for each layer present in a 2-meter by 2-meter station. These layers are additive, yielding a total volume for each of the 10 herbaceous vegetation stations and an overall CRMS marsh site average.

  7. MODIS derived vegetation index for drought detection on the San Carlos Apache Reservation

    Science.gov (United States)

    Wu, Zhuoting; Velasco, Miguel G.; McVay, Jason; Middleton, Barry R.; Vogel, John M.; Dye, Dennis G.

    2016-01-01

    A variety of vegetation indices derived from remotely sensed data have been used to assess vegetation conditions, enabling the identification of drought occurrences as well as the evaluation of drought impacts. Moderate Resolution Imaging Spectroradiometer (MODIS) Terra 8-day composite data were used to compute the Modified Soil Adjusted Vegetation Index II (MSAVI2) of four dominant vegetation types over a 13-year period (2002 – 2014) on the San Carlos Apache Reservation in Arizona, US. MSAVI2 anomalies were used to identify adverse impacts of drought on vegetation, characterized as mean MSAVI2 below the 13-year average. In terms of interannual variability, we found similar responses between grassland and shrubland, and between woodland and forest vegetation types. We compared MSAVI2 for specific vegetation types with precipitation data at the same time step, and found a lag time of roughly two months for the peak MSAVI2 values following precipitation in a given year. All vegetation types responded to summer monsoon rainfall, while shrubland and annual herbaceous vegetation also displayed a brief spring growing season following winter snowmelt. MSAVI2 values of shrublands corresponded well with precipitation variability both for summer rainfall and winter snowfall, and can be potentially used as a drought indicator on the San Carlos Apache Reservation given its wide geographic distribution. We demonstrated that moderate temporal frequency satellite-based MSAVI2 can provide drought monitoring to inform land management decisions, especially on vegetated tribal land areas where in situ precipitation data are limited.

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

    Directory of Open Access Journals (Sweden)

    Teruel Bárbara

    2004-01-01

    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.

  9. 中国东部南北样带主要植被类型归一化植被指数对气候变化的响应及不同时间尺度的差异性%Response of normalized difference vegetation index in main vegetation types to climate change and their variations in different time scales along a North-South Transect of Eastern China

    Institute of Scientific and Technical Information of China (English)

    余振; 孙鹏森; 刘世荣

    2011-01-01

    植被的动态变化及其与环境的关系已成为全球变化研究的热点问题.陆地样带是进行全球变化驱动因素梯度分析的有效途径.该研究依托中国东部南北样带(NSTEC),对南北样带不同时问尺度的气候因子和植被活动变化特征进行了分析,并重点阐述了具有代表性的12种植被类型对气候因子的响应方式.研究结果表明:南北样带植被的归一化植被指数(NDVI)的变化同时受控十气温和降水,但是在不同的窄间和时间尺度L植被NDVI的响应方式各异.在年时间尺度上,只有温带落叶灌丛(TDS)的NDVI受气温控制;而温带禾草草原(TGS)和亚热带和热带针叶林(STCF)的NDVI同时受气温和降水调控.其他植被类型的年NDVI与年平均气温和年总降水量没有直接显著的联系,而受年内气温变化和降水分配状况的影响更大.在月时间尺度上,NDVI与气温的关系在不同类型植被之间存在很大差异.一般而言,植被NDVI与前4个月内的气温关系最为密切,并且从1月份到4月份气温的滞后时长在缩短.其中,温带针叶林(TCF)、温带落叶阔叶林(TDBF)、TDS、STCF和亚热带热带草丛(STG)等植被类型,5-8月的NDVI与气温普遍呈负相关关系.草原和灌丛植被类型当月NDVI与当月降水量主要以正相关为主.而森林类型当月NDVI与当月降水量主要以负相关为主.%Aims Climate change characterized by global wanning has posed a great threat to terrestrial ecosystems and sustainable development of human society. Our objective was to examine the response of major vegetation types to climate change.Methods We used the biweekly dataset of the National Oceanographic and Atmospheric Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR) normalized difference vegetation index (NDVI) and climatic data from 752 standard stations in China for 1982-2006 to study the responses of 12 major vegetation types to changes in air temperature

  10. Assessment of agricultural drought in Rajasthan (India using remote sensing derived Vegetation Condition Index (VCI and Standardized Precipitation Index (SPI

    Directory of Open Access Journals (Sweden)

    Dipanwita Dutta

    2015-06-01

    Full Text Available Owing to its severe effect on productivity of rain-fed crops and indirect effect on employment as well as per capita income, agricultural drought has become a prime concern worldwide. The occurrence of drought is mainly a climatic phenomenon which cannot be eliminated. However, its effects can be reduced if actual spatio-temporal information related to crop status is available to the decision makers. The present study attempts to assess the efficiency of remote sensing and GIS techniques for monitoring the spatio-temporal extent of agricultural drought. In the present study, NOAA-AVHRR NDVI data were used for monitoring agricultural drought through NDVI based Vegetation Condition Index. VCI was calculated for whole Rajasthan using the long term NDVI images which reveals the occurrence of drought related crop stress during the year 2002. The VCI values of normal (2003 and drought (2002 year were compared with meteorological based Standardized Precipitation Index (SPI, Rainfall Anomaly Index and Yield Anomaly Index and a good agreement was found among them. The correlation coefficient between VCI and yield of major rain-fed crops (r > 0.75 also supports the efficiency of this remote sensing derived index for assessing agricultural drought.

  11. Numerical Simulation of the Impact of Vegetation Index on the Interannual Variation of Summer Precipitation in the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Two sets of numerical experiments using the coupled National Center for Environmental Prediction General Circulation Model (NCEP/GCM T42L18) and the Simplified Simple Biosphere land surface scheme (SSiB) were carried out to investigate the climate impacts of fractional vegetation cover (FVC)and leaf area index (LAI) on East Asia summer precipitation, especially in the Yellow River Basin (YRB).One set employed prescribed FVC and LAI which have no interannual variations based on the climatology of vegetation distribution; the other with FVC and LAI derived from satellite observations of the International Satellite Land Surface Climate Project (ISLSCP) for 1987 and 1988. The simulations of the two experiments were compared to study the influence of FVC, LAI on summer precipitation interannual variation in the YRB. Compared with observations and the NCEP reanalysis data, the experiment that included both the effects of satellite-derived vegetation indexes and sea surface temperature (SST)produced better seasonal and interannual precipitation variations than the experiment with SST but no interannual variations in FVC and LAI, indicating that better representations of the vegetation index and its interannual variation may be important for climate prediction. The difference between 1987 and 1988indicated that with the increase of FVC and LAI, especially around the YRB, surface albedo decreased,net surface radiation increased, and consequently local evaporation and precipitation intensified. Further more, surface sensible heat flux, surface temperature and its diurnal variation decreased around the YRB in response to more vegetation. The decrease of surface-emitting longwave radiation due to the cooler surface outweighed the decrease of surface solar radiation income with more cloud coverage, thus maintaining the positive anomaly of net surface radiation. Further study indicated that moisture flux variations associated with changes in the general circulation also

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

    Directory of Open Access Journals (Sweden)

    Jan Dempewolf

    2014-10-01

    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.

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

    Science.gov (United States)

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

    2013-04-01

    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

  14. Forested floristic quality index: An assessment tool for forested wetland habitats using the quality and quantity of woody vegetation at Coastwide Reference Monitoring System (CRMS) vegetation monitoring stations

    Science.gov (United States)

    Wood, William B.; Shaffer, Gary P.; Visser, Jenneke M.; Krauss, Ken W.; Piazza, Sarai C.; Sharp, Leigh Anne; Cretini, Kari F.

    2017-02-08

    The U.S. Geological Survey, in cooperation with the Coastal Protection and Restoration Authority of Louisiana and the Coastal Wetlands Planning, Protection and Restoration Act, developed the Forested Floristic Quality Index (FFQI) for the Coastwide Reference Monitoring System (CRMS). The FFQI will help evaluate forested wetland sites on a continuum from severely degraded to healthy and will assist in defining areas where forested wetland restoration can be successful by projecting the trajectories of change. At each CRMS forested wetland site there are stations for quantifying the overstory, understory, and herbaceous vegetation layers. Rapidly responding overstory canopy cover and herbaceous layer composition are measured annually, while gradually changing overstory basal area and species composition are collected on a 3-year cycle.A CRMS analytical team has tailored these data into an index much like the Floristic Quality Index (FQI) currently used for herbaceous marsh and for the herbaceous layer of the swamp vegetation. The core of the FFQI uses basal area by species to assess the quality and quantity of the overstory at each of three stations within each CRMS forested wetland site. Trees that are considered by experts to be higher quality swamp species like Taxodium distichum (bald cypress) and Nyssa aquatica (water tupelo) are scored higher than tree species like Triadica sebifera (Chinese tallow) and Salix nigra (black willow) that are indicators of recent disturbance. This base FFQI is further enhanced by the percent canopy cover in the overstory and the presence of indicator species at the forest floor. This systemic approach attempts to differentiate between locations with similar basal areas that are on different ecosystem trajectories. Because of these varying states of habitat degradation, paired use of the FQI and the FFQI is useful to interpret the vegetative data in transitional locations. There is often an inverse relation between the health of the

  15. Dynamic Drought Monitoring in Guangxi Using Revised Temperature Vegetation Dryness Index

    Institute of Scientific and Technical Information of China (English)

    LU Yuan; TAG Heping; WU Hua

    2007-01-01

    Moderate resolution imaging spectroradiometer (MODIS) data are very suitable for vast extent, long term and dynamic drought monitoring for its high temporal resolution, high spectral resolution and moderate spatial resolution. The composite Enhanced Vegetation Index (EVI) and composite land surface temperature (Ts) obtained from MODIS data MOD11A2 and MOD13A2 were used to construct the EVI-rs space. And Temperature Vegetation Dryness Index (TVDI) was calculated to evaluate the agriculture drought in Guangxi province, China in October of 2006. The results showed that the drought area in Guangxi was evidently increasing and continuously deteriorating from the middle of September to the middle of November. The TVDI, coming from the EVI-rs space, could effectively indicate the spatial distribution and temporal evolution of drought, so that it could provide a strong technical support for the forecasting agricultural drought in south China.

  16. Comparison of the prevalence index and average wetland values for identification of wetland vegetation

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-07-01

    Prevalence index values (FICWD, 1989) and average wetland values for all species present were compared for three wetland gas pipeline rights-of-way (ROWS) and adjacent natural areas. The similarities in results using these two indicator values suggest that an average wetland value may offer a simpler, less time-consuming method of evaluating the vegetation of a study site as an indication of wetness. Both PIVs and AWVs, are presented for the ROWs and the adjacent natural area at each site.

  17. 基于冠层反射和植被指数的华东地区叶面指数反演%Leaf area index retrieval based on canopy reflectance and vegetation index in eastern China

    Institute of Scientific and Technical Information of China (English)

    蒋建军; 陈锁忠; 曹顺仙

    2005-01-01

    The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (VI), such as simple ratio vegetation index (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDVI). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area. LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of TM3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR +0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future.

  18. Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

    Directory of Open Access Journals (Sweden)

    Laura Ulsig

    2017-01-01

    Full Text Available Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI. This study investigates the potential of a Photochemical Reflectance Index (PRI, which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36–0.8, which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 > 0.6 in all cases. The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.

  19. [Kriging analysis of vegetation index depression in peak cluster karst area].

    Science.gov (United States)

    Yang, Qi-Yong; Jiang, Zhong-Cheng; Ma, Zu-Lu; Cao, Jian-Hua; Luo, Wei-Qun; Li, Wen-Jun; Duan, Xiao-Fang

    2012-04-01

    In order to master the spatial variability of the normal different vegetation index (NDVI) of the peak cluster karst area, taking into account the problem of the mountain shadow "missing" information of remote sensing images existing in the karst area, NDVI of the non-shaded area were extracted in Guohua Ecological Experimental Area, in Pingguo County, Guangxi applying image processing software, ENVI. The spatial variability of NDVI was analyzed applying geostatistical method, and the NDVI of the mountain shadow areas was predicted and validated. The results indicated that the NDVI of the study area showed strong spatial variability and spatial autocorrelation resulting from the impact of intrinsic factors, and the range was 300 m. The spatial distribution maps of the NDVI interpolated by Kriging interpolation method showed that the mean of NDVI was 0.196, apparently strip and block. The higher NDVI values distributed in the area where the slope was greater than 25 degrees of the peak cluster area, while the lower values distributed in the area such as foot of the peak cluster and depression, where slope was less than 25 degrees. Kriging method validation results show that interpolation has a very high prediction accuracy and could predict the NDVI of the shadow area, which provides a new idea and method for monitoring and evaluation of the karst rocky desertification.

  20. Assessment of Iranian Agroclimatological Zone Classification by Using TVDI (Temperature Vegetation Dryness Index)

    Science.gov (United States)

    Asadi, Ebrahim; Lopez-Baeza, Ernesto; Coll Pajaron, M. Amparo; Kouzehgaran, Saeedeh; Haghighat, Masoud

    2016-07-01

    Agricultural zoning is an important tool for authorities to plan and decide about development of the agricultural sector, environmental sustainability issues and plan and provide irrigation and rural infrastructures. Previous different methods have suggested the definition of agroclimatological zones in big areas in Iran, but most of them are not easy to be validated or there are not clear criteria to evaluate whether the zones are correctly defined or not. The current {it Iranian Meteorological Organisation} classification is composed of six significant agroclimatological zones defined using the fundamental climate elements of temperature and precipitation obtained from 30 years data from 180 synoptic stations interpolated using regression kriging methods. Elevation was derived from SRTM (Shuttle Radar Topography Mission) digital elevation model of 90 m resolution. In this paper we assess the homogeneity of each of these conventionally defined agroclimatological zones using {bf TVDI (Temperature Vegetation Dryness Index)} values obtained from MODIS land surface temperature and NDVI operational products of the last three years between 2013 and 2015.

  1. [Estimation models of vegetation fractional coverage (VFC) based on remote sensing image at different radiometric correction levels].

    Science.gov (United States)

    Gu, Zhu-Jun; Zeng, Zhi-Yuan; Shi, Xue-Zheng; Yu, Dong-Sheng; Zheng, Wei; Zhang, Zhen-Long; Hu, Zi-Fu

    2008-06-01

    The images of post atmospheric correction reflectance (PAC), top of atmosphere reflectance (TOA), and digital number (DN) of a SPOT5 HRG remote sensing image of Nanjing, China were used to derive four vegetation indices (VIs), i. e., normalized difference vegetation index (NDVI), transformed vegetation index (TVI), soil-adjusted vegetation index (SAVI), and modified soil-adjusted vegetation index (MSAVI), and 36 VI-VFC relationship models were established based on these VIs and the VFC data obtained from ground measurement. The results showed that among the models established, the cubic polynomial models based on NDVI and TVI from PAC were the best, followed by those based on SAVI and MSAVI from DN, with the accuracy being slightly higher than that of the former two models when VFC > 0.8. The accuracy of these four models was higher in middle-densely vegetated areas (VFC = 0.4-0.8) than in sparsely vegetated areas (VFC = 0-0.4). All the established models could be used in other places via the introduction of calibration models. In VI-VFC modeling, using VIs derived from different radiometric correction levels of remote sensing image could help mining valuable information from remote sensing image, and thus, improving the accuracy of VFC estimation.

  2. Spatio-temporal distribution of vegetation index and its influencing factors—a case study of the Jiaozhou Bay, China

    Science.gov (United States)

    Zheng, Yang; Yu, Ge

    2016-10-01

    The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation cover changes in coastal zones resulting from climate change and land-use change, with a lack of knowledge about the driving mechanism. Normalized difference vegetation index (NDVI) can be used as an indicator for change of the coastal environment. In this study, we analyzed the interannual changes and spatial distribution of NDVI in the coastal zone around Jiaozhou Bay in Qingdao, a coastal city undergoing rapid urbanization in northeast China. The underlying causes of NDVI variations were discussed in the context of climate change and land-use change. Results showed that the spatio-temporal distribution of NDVI displayed high spatial variability in the study area and showed a typical trend of gradually increasing from coastal to inland regions. The significant increase area of NDVI was mainly found in newly added construction land, extending along the coastline towards the inland. Land vegetation cover demonstrated a certain response relationship to sea-land climate change and land-based activities. The impact of land-based human activities was slightly greater than that of sea-land climate change for land vegetation cover. The results indicate that promoting ecological policies can build an ecological security framework of vegetation suitable for the resource characteristics of coastal cities. The framework will buffer the negative effects of sea-land climate change and land-based human activities on vegetation cover and thereby achieve the balance of regional development and ecological benefits in the coastal zone.

  3. A method for canopy water content estimation for highly vegetated surfaces-shortwave infrared perpendicular water stress index

    Institute of Scientific and Technical Information of China (English)

    GHULAM; Abduwasit; LI; Zhao-Liang; QIN; QiMing; TONG; QingXi; WANG; JiHua; KASIMU; Alimujiang; ZHU; Lin

    2007-01-01

    In this paper, a new method for canopy water content (FMC) estimation for highly vegetated surfaces- shortwave infrared perpendicular water stress index (SPSI) is developed using NIR, SWIR wavelengths of Enhanced Thematic Mapper Plus (ETM+) on the basis of spectral features and distribution of surface targets with different water conditions in NIR-SWIR spectral space. The developed method is further explored with radiative transfer simulations using PROSPECT, Lillesaeter, SailH and 6S. It is evident from the results of validation derived from satellite synchronous field measurements that SPSI is highly correlated with FMC, coefficient of determination (R squared) and root mean square error are 0.79 and 26.41%. The paper concludes that SPSI has a potential in vegetation water content estimation in terms of FMC.

  4. Normalized Difference Vegetation Index for Fanno Creek, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff...

  5. EROS MODIS Normalized Difference Vegetation Index: 2001-Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — eMODIS processes calibrated radiance data (level-1B) acquired by the MODIS sensors on the EOS Terra and Aqua satellites by combining MODIS Land Science Collection 5...

  6. [Vegetation index estimation by chlorophyll content of grassland based on spectral analysis].

    Science.gov (United States)

    Xiao, Han; Chen, Xiu-Wan; Yang, Zhen-Yu; Li, Huai-Yu; Zhu, Han

    2014-11-01

    Comparing the methods of existing remote sensing research on the estimation of chlorophyll content, the present paper confirms that the vegetation index is one of the most practical and popular research methods. In recent years, the increasingly serious problem of grassland degradation. This paper, firstly, analyzes the measured reflectance spectral curve and its first derivative curve in the grasslands of Songpan, Sichuan and Gongger, Inner Mongolia, conducts correlation analysis between these two spectral curves and chlorophyll content, and finds out the regulation between REP (red edge position) and grassland chlorophyll content, that is, the higher the chlorophyll content is, the higher the REIP (red-edge inflection point) value would be. Then, this paper constructs GCI (grassland chlorophyll index) and selects the most suitable band for retrieval. Finally, this paper calculates the GCI by the use of satellite hyperspectral image, conducts the verification and accuracy analysis of the calculation results compared with chlorophyll content data collected from field of twice experiments. The result shows that for grassland chlorophyll content, GCI has stronger sensitivity than other indices of chlorophyll, and has higher estimation accuracy. GCI is the first proposed to estimate the grassland chlorophyll content, and has wide application potential for the remote sensing retrieval of grassland chlorophyll content. In addition, the grassland chlorophyll content estimation method based on remote sensing retrieval in this paper provides new research ideas for other vegetation biochemical parameters' estimation, vegetation growth status' evaluation and grassland ecological environment change's monitoring.

  7. Analysis of relationship between meteorological and agricultural drought using standardized precipitation index and vegetation health index

    Science.gov (United States)

    Ma’rufah, U.; Hidayat, R.; Prasasti, I.

    2017-01-01

    Agricultural drought is closely related to meteorological drought in which the agricultural drought is an impact of meteorological drought. This study aim to understand the duration, spatial extent, severity and lag time of meteorological and agricultural drought during El Niño years. The data used in this study are monthly data of CHIPRS and MODIS. Meteorological drought and agricultural drought are intensified in the El Niño years. The duration of meteorological drought is different in each region but generally occurs during June to November. Agricultural drought mostly occurs from August to November. Spatially, meteorological drought and agricultural drought in 2015 has wider extent and higher severity (SPI VHI VHI is significantly correlated with SPI-3 reach 58% of the total area of Indonesia. It means rainfall deficit during three months has a significant impact on agricultural drought in Indonesia. In general, SPI-3 and VHI clearly explain the relationship between meteorological drought and agricultural drought in Indonesia.

  8. Effects of Climate Change on Normalized Difference Vegetation Index Based on the Multiple Analysis of Standardized Precipitation Evapotranspiration Index Methods in the Lancang River Basin%基于逐月标准化降水蒸散指数的多尺度方法分析气候变化对澜沧江流域归一化植被指数的影响

    Institute of Scientific and Technical Information of China (English)

    刘世梁; 田韫钰; 安南南; 赵海迪; 董世魁

    2015-01-01

    基于澜沧江流域10个气象站点1951~2012年的日降水资料的逐月标准化降水蒸散指数(SPEI)值、各站1998~2012年流域的归一化植被指数(NDVI)值,利用 SPEI 以及趋势分析法,多尺度分析了澜沧江流域干旱发生的时间和强度演变特征以及上中下游NDVI时间变化特征,探讨了气候变化对植被变化的影响,并对NDVI与SPEI的变化进行了相关性分析。结果表明,不同站点和不同时间尺度的SPEI值均呈现出干旱化逐年加强的线性趋势,上游相对于中下游干旱态势较轻,且时间尺度越大,干旱波动趋势越明显;在季节尺度上,夏、秋、冬的SPEI值均呈下降趋势,其中冬季干旱最为严重;15年来澜沧江流域各区域年平均NDVI总体表现为先降低后增加,总体植被状况得到改善,其中下游较明显。从年际变化看,对于流域的不同区域,NDVI与不同尺度的SPEI的相关性和滞后性有较大差异,年代际之间的响应规律也不同,中下游的SPEI对同年NDVI的响应比较敏感,而上游则表现出明显的滞后性。说明 NDVI 对 SPEI 的响应比较敏感,干旱程度的变化在一定程度上影响着流域的植被状况,SPEI是影响NDVI的因素之一。%The characteristics of drought variations at different timescales in the Lancang River basin from 1951 to 2012 were studied using a new drought index (standardized precipitation evapotranspiration index, SPEI). The authors calculated this level from daily precipitation data at 10 meteorological stations. Furthermore, the authors used a time series (1998–2012) data set of the normalized difference vegetation index (NDVI) and trend analysis to analyze the inter-annual variation in the valley of the Lancang River and explore the relationship between NDVI and SPEI. The results show that the SPEI values at different sites and time scales showed a significant increased trend to drought, but the

  9. An efficient unsupervised index based approach for mapping urban vegetation from IKONOS imagery

    Science.gov (United States)

    Anchang, Julius Y.; Ananga, Erick O.; Pu, Ruiliang

    2016-08-01

    Despite the increased availability of high resolution satellite image data, their operational use for mapping urban land cover in Sub-Saharan Africa continues to be limited by lack of computational resources and technical expertise. As such, there is need for simple and efficient image classification techniques. Using Bamenda in North West Cameroon as a test case, we investigated two completely unsupervised pixel based approaches to extract tree/shrub (TS) and ground vegetation (GV) cover from an IKONOS derived soil adjusted vegetation index. These included: (1) a simple Jenks Natural Breaks classification and (2) a two-step technique that combined the Jenks algorithm with agglomerative hierarchical clustering. Both techniques were compared with each other and with a non-linear support vector machine (SVM) for classification performance. While overall classification accuracy was generally high for all techniques (>90%), One-Way Analysis of Variance tests revealed the two step technique to outperform the simple Jenks classification in terms of predicting the GV class. It also outperformed the SVM in predicting the TS class. We conclude that the unsupervised methods are technically as good and practically superior for efficient urban vegetation mapping in budget and technically constrained regions such as Sub-Saharan Africa.

  10. Relationship of Remote Sensing Normalized Differential Vegetation Index to Anopheles Density and Malaria Incidence Rate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the relationship of remote sensing normalized differential vegetation index (NDVI) to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles density and malaria incidence rate, and remote sensing NDVI were collected from 27 townships of 10 counties in southeastern Yunnan Province from 1984 to 1993. The relationship of remote sensing ecological proxy index, NDVI, to Anopheles density and malaria incidence rate was studied by principal component analysis, factor analysis and grey correlation analysis. Results The correlation matrix showed that NDVI highly correlated with Anopheles density in 4 townships of Mengla, Jinghong, and Yuanjiang counties, but in other 23 townships the relationship was not clear. Principal component and factor analyses showed that remote sensing NDVI was the representative index of the first principal component and the first common factor of Anopheles density evaluation. Grey correlation analysis showed that in rainy season NDVI had a high grey correlation with Anopheles density and malaria incidence rate. The grey correlation analysis showed that in rainy season the grey degree of NDVI correlated with Anopheles. Minimus density was 0.730, and 0.713 with Anopheles sinensis density, and 0.800 with malarial incidence rate. Conclusion Remote sensing NDVI can serve as a sensitive evaluation index of Anopheles density and malaria incidence rate.

  11. Mapping paddy biomass with multiple vegetation indexes by using multispectral remotely sensed image

    Science.gov (United States)

    Gu, Xiaohe; Wang, Yancang; Song, Xiaoyu; Xu, Xingang

    2016-10-01

    Monitoring dry biomass of crop timely and accurately by remote sensing is crucial to assess crop growth, manage field water-fertilizer and predict yield. The Huaihe River Basin in China was chose as study area to map the spatial distribution of paddy biomass. The study derived 12 vegetation indexes from HJ-CCD image, which were closely related to crop growth. After screening sensitive vegetation index with in-situ samples by correlation analysis, the study developed the inversion model by single variable and multiple variables. The determination coefficient (R2) and root mean square error (RMSE) was used to evaluate the accuracy of models. Results showed that the accuracies of multivariable models were better than these of single-variable models, of which the average R2 reached 0.647 and the average RMSE was 0.059. It indicated that the multi-variable models were input in more information than those of single-variable models, which improved the accuracies of estimating paddy biomass in to a certain degree. The average overall accuracies of multi-variable models were 92.7%, while that of singe-variable models were 87.8%. The model with multiple linear regressions could be used to map the paddy biomass in the study area by using HJ-CCD image.

  12. Differences of cadmium absorption and accumulation in selected vegetable crops

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A pot experiment and a sandy culture experiment grown with three vegetable crops of Chinese cabbage (B.chinensis L.,cv.Zao-Shu 5),winter greens (B.var.rosularis Tsen et Lee,cr.Shang-Hai-Qing) and celery (A.graveolens L.var.dulce DC.,cv.Qing-Qin)were conducted,respectively.The initial soil and four incubated soils with different extractable Cd (0.15,0.89,1.38,1.84 and 2.30 mg Cd/kg soil) were used for the pot experiment.Five treatments were designed (0,0.0625,0.125,0.250 and 0.500 mg Cd/L) in nutrient solution in the sandy culture experiment.Each treatment in pot and sandy culture experiments was trireplieated.The objectives of the study were to examine Cd accumulation in edible parts of selected vegetable crops,its correlation with Cd concentrations in vegetable garden soil or in nutrient solution,and evaluate the criteria of Cd pollution in vegetable garden soil and in nutrient solution based on the hygienic limit of Cd in vegetables.Cadmium concentrations in edible parts of the three selected vegetable crops were as follows:0.01-0.15 mg/kg fresh weight for Chinese cabbage,0.02-0.17 mg/kg fresh weight for winter greens,and 0.02-0.24 rag/kg fresh weight for celery in the pot experiment,and 0.1-0.4 mg/kg fresh weight for Chinese cabbage,0.1-1.4 mg/kg fresh weight for winter greens,and 0.05-0.5 rag/kg fresh weight for celery in the pot experiment(except no-Cd treatment).The order of the three test vegetable crops for cadmium accumulation in the edible parts was celery > winter greens > Chinese cabbage in both the pot experiment and the sandy culture experiment.Cadmium accumulation in edible parts or roots of the vegetable crops increased with increasing of cadmium concentration in the medium( soil or nutrient solution).And cadmium concentrations in edible parts of the test vegetable crops were significantly linearly related to the Cd levels in the growth media (soil and antrient solution).Based on the regression equations established and the limit of cadmium

  13. Responses of grassland vegetation to climatic variations on different temporal scales in Hulun Buir Grassland in the past 30 years

    Institute of Scientific and Technical Information of China (English)

    ZHANG Geli; XU Xingliang; ZHOU Caiping; ZHANG Hongbin; OUYANG Hua

    2011-01-01

    Global warming has led to significant vegetation changes especially in the past 20 years.Hulun Buir Grassland in Inner Mongolia,one of the world's three prairies,is undergoing a process of prominent warming and drying.It is essential to investigate the effects of climatic change (temperature and precipitation) on vegetation dynamics for a better understanding of climatic change.NDVl (Normalized Difference Vegetation Index),reflecting characteristics of plant growth,vegetation coverage and biomass,is used as an indicator to monitor vegetation changes.GIMMS NDVl from 1981 to 2006 and MODIS NDVl from 2000 to 2009 were adopted and integrated in this study to extract the time series characteristics of vegetation changes in Hulun Buir Grassland.The responses of vegetation coverage to climatic change on the yearly,seasonal and monthly scales were analyzed combined with temperature and precipitation data of seven meteorological sites.In the past 30 years,vegetation coverage was more correlated with climatic factors,and the correlations were dependent on the time scales.On an inter-annual scale,vegetation change was better correlated with precipitation,suggesting that rainfall was the main factor for driving vegetation changes.On a seasonal-interannual scale,correlations between vegetation coverage change and climatic factors showed that the sensitivity of vegetation growth to the aqueous and thermal condition changes was different in different seasons.The sensitivity of vegetation growth to temperature in summers was higher than in the other seasons,while its sensitivity to rainfall in both summers and autumns was higher,especially in summers.On a monthly-interannual scale,correlations between vegetation coverage change and climatic factors during growth seasons showed that the response of vegetation changes to temperature in both April and May was stronger.This indicates that the temperature effect occurs in the early stage of vegetation growth.Correlations between

  14. 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)

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

    2011-01-01

    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.

  15. Spectral Reflectance and Vegetation Index Changes in Deciduous Forest Foliage Following Tree Removal: Potential for Deforestation Monitoring

    Science.gov (United States)

    Peng, D.; Hu, Y.; Li, Z.

    2016-05-01

    It is important to detect and quantify deforestation to guide strategic decisions regarding environment, socioeconomic development, and climate change. In the present study, we conducted a field experiment to examine spectral reflectance and vegetation index changes in poplar and locust tree foliage with different leaf area indices over the course of three sunny days, following tree removal from the canopy. The spectral reflectance of foliage from harvested trees was measured using an ASD FieldSpec Prospectroradiometer; synchronous meteorological data were also obtained. We found that reflectance in short-wave infrared and red-edge reflectance was more time sensitive after tree removal than reflectance in other spectral regions, and that the normalized difference water index (NDWI) and the red-edge chlorophyll index (CIRE) were the preferred indicators of these changes from several indices evaluated. Synthesized meteorological environments were found to influence water and chlorophyll contents after tree removal, and this subsequently changed the spectral canopy reflectance. Our results indicate the potential for such tree removal to be detected with NDWI or CIRE from the second day of a deforestation event.

  16. Scales of form roughness on riverbanks with different riparian vegetation

    Science.gov (United States)

    Konsoer, K. M.; Rhoads, B. L.; Best, J.; Langendoen, E. J.; Ursic, M.; Abad, J. D.; Garcia, M. H.

    2013-12-01

    Riverbanks often include topographic irregularities that occur over a range of scales and that are produced by interactions among erosional processes, vegetation, and the geotechnical properties of the banks and floodplains. Irregularity of the bank surface can increase form drag, affecting the overall flow resistance, near-bank shear stresses, and patterns of sediment transport. Understanding how dominant scales of form roughness influence the near-bank flow structure, and thus the shear stress partitioning, is vital for the development of accurate predictive morphodynamic models. In this paper, the scales of bank roughness are examined for two meander bends of a large alluvial river with differing riparian vegetation on the Wabash River near Grayville, Illinois. Detailed measurements of bank topography were obtained using terrestrial LiDAR during low flow events and a multibeam echo sounder (MBES) during bankfull events. These measurements yielded high spatial resolution maps (~5-10 cm) that were used to analyze scales of roughness at different elevations along the banks during both subaerial and subaqueous conditions. The results of these analyses provide insight into the influence of riparian vegetation on form roughness and patterns of near-bank flow structure as documented using acoustic Doppler current profilers (ADCP).

  17. Modelling spatial and temporal vegetation variability with the Climate Constrained Vegetation Index: evidence of CO2 fertilisation and of water stress in continental interiors

    Directory of Open Access Journals (Sweden)

    S. O. Los

    2015-06-01

    Full Text Available A model was developed to simulate spatial, seasonal and interannual variations in vegetation in response to temperature, precipitation and atmospheric CO2 concentrations; the model addresses shortcomings in current implementations. The model uses the minimum of 12 temperature and precipitation constraint functions to simulate NDVI. Functions vary based on the Köppen–Trewartha climate classification to take adaptations of vegetation to climate into account. The simulated NDVI, referred to as the climate constrained vegetation index (CCVI, captured the spatial variability (0.82 r r = 0.83 and interannual variability (median global r = 0.24 in NDVI. The CCVI simulated the effects of adverse climate on vegetation during the 1984 drought in the Sahel and during dust bowls of the 1930s and 1950s in the Great Plains in North America. A global CO2 fertilisation effect was found in NDVI data, similar in magnitude to that of earlier estimates (8 % for the 20th century. This effect increased linearly with simple ratio, a transformation of the NDVI. Three CCVI scenarios, based on climate simulations using the representative concentration pathway RCP4.5, showed a greater sensitivity of vegetation towards precipitation in Northern Hemisphere mid latitudes than is currently implemented in climate models. This higher sensitivity is of importance to assess the impact of climate variability on vegetation, in particular on agricultural productivity.

  18. Retrieval of leaf area index in different plant species using thermal hyperspectral data

    Science.gov (United States)

    Neinavaz, Elnaz; Skidmore, Andrew K.; Darvishzadeh, Roshanak; Groen, Thomas A.

    2016-09-01

    Leaf area index (LAI) is an important variable of terrestrial ecosystems because it is strongly correlated with many ecosystem processes (e.g., water balance and evapotranspiration) and directly related to the plant energy balance and gas exchanges. Although LAI has been accurately predicted using visible and short-wave infrared hyperspectral data (0.3-2.5 μm), LAI estimation using thermal infrared (TIR, 8-14 μm) measurements has not yet been addressed. The novel approach of this study is to evaluate the retrieval of LAI using TIR hyperspectral data. The leaf area indices were destructively acquired for four plant species: Azalea japonica, Buxussempervirens, Euonymus japonicus, and Ficus benjamina. Canopy emissivity spectral measurements were obtained under controlled laboratory conditions using a MIDAC (M4401-F) spectrometer. The LAI retrieval was assessed using a partial least squares regression (PLSR), artificial neural networks (ANNs), and narrow band indices calculated from all possible combinations of waveband pairs for three vegetation indices including simple difference, simple ratio, and normalized difference. ANNs retrieved LAI more accurately than PLSR and vegetation indices (0.67 retrieval did not differ significantly between the vegetation indices. The results revealed that wavebands from the 8-12 μm region contain relevant information for LAI estimation, irrespective of the chosen vegetation index. Moreover, they demonstrated that LAI may be successfully predicted from TIR hyperspectral data, even for higher values of LAI (LAI ⩾ 5.5). The study showed the significance of using PLSR and ANNs as multivariate methods compared to the univariate technique (e.g., narrow band vegetation indices) when hyperspectral thermal data is utilized. We thus demonstrated for the first time the potential of hyperspectral thermal data to accurately retrieve LAI.

  19. 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)

    Houborg, Rasmus Møller; Søgaard, Henrik; Bøgh, Eva

    2007-01-01

    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...... 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...... 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...

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

    Science.gov (United States)

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

    2014-06-01

    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

  1. Vegetation and Soil Characteristics of Different Desertification Grasslands in Northwest Sichuan

    Institute of Scientific and Technical Information of China (English)

    Wan; Ting; Tu; Weiguo; Xi; Huan; Li; Yudong; Tang; Xuefang; Yang; Yichuan

    2014-01-01

    [Objective]The paper was to study vegetation and soil characteristics of different desertification grasslands in northwest Sichuan. [Method]By taking different desertification grasslands as the research object,the characteristic factors of vegetation community,biomass,soil moisture content,volume weight and porosity were analyzed through scientific investigation,sampling and formula calculation to reveal the changes in vegetation and soil characteristics of different desertification grasslands in Northwest Sichuan. [Result]Community succession presented the pattern of " hygrophyte-mesophyte-xerophyte" with the aggravation of grassland desertification. The height and coverage of community decreased,species richness was declined by 88%,and composition of dominant species also changed greatly. The diversity index of light-desertification grassland was the highest among tested grasslands. Total biomass was decreased by 90. 4%,and the underground biomass decreased far more than aboveground biomass. In desertification progress,both soil moisture content and water holding capacity decreased,while volume weight showed upward trend and porosity showed downward trend; soil characteristics had large variation in early stage of desertification,so restoration treatment of desertification grassland should be carried out in the early stage of desertification. [Conclusion]The study provided a theoretical basis for researches on causes and management programs of desertification grassland,having an important meaning for ecological restoration of regional grassland and maintenance of ecological security.

  2. Responses of Natural Vegetation to Different Stages of Extreme Drought during 2009–2010 in Southwestern China

    Directory of Open Access Journals (Sweden)

    Xiang Zhao

    2015-10-01

    Full Text Available An extreme drought event is usually a long-term process with different stages. Although it is well known that extreme droughts that have occurred frequently in recent years can substantially affect vegetation growth, few studies have revealed the characteristics of vegetation responses for different stages of an extreme drought event. Especially, studies should address when the vegetation growth was disturbed and how it recovered through an extreme drought event. In this study, we used the Normalized Difference Vegetation Index (NDVI and Palmer Drought Severity Index (PDSI to evaluate the response of vegetation to different stages of a severe drought event during 2009–2010 throughout Southwestern China. The PDSI time series indicated that the drought can be divided into three stages, including an initial stage represented by moderate drought (S1, a middle stage represented by continual severe drought (S2, and a final recovery stage (S3. The results revealed that the drought during the initial stage inhibited the growth of grassland and woody savanna, however, forest growth did not decrease during the first stage of droughts, and there was even a trend towards higher NDVI values. The continual severe drought in the middle stage inhibited growth for all vegetation types, and the woody savanna was affected most severely. In the final stage, all vegetation types underwent recovery, including the grassland that had endured the most severe drought. This study provides observational evidence and reveals that the responses of forest to the extreme drought are different from grassland and woody savanna in the different drought stages.

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

    DEFF Research Database (Denmark)

    Westergaard-Nielsen, Andreas; Lund, Magnus; Hansen, Birger Ulf;

    2013-01-01

    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...... 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 ... 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...

  4. Comparison of sap flux, moisture flux tower and MODIS enhanced vegetation index methods for estimating riparian evapotranspiration

    Science.gov (United States)

    Nagler, Pamela L.; Glenn, Edward P.; Morino, Kiyomi; Neale, Christopher M.U; Cosh, Michael H.

    2010-01-01

    Riparian evapotranspiration (ET) was measured on a salt cedar (Tamarix spp.) dominated river terrace on the Lower Colorado River from 2007 to 2009 using tissue-heat-balance sap flux sensors at six sites representing very dense, medium dense, and sparse stands of plants. Salt cedar ET varied markedly across sites, and sap flux sensors showed that plants were subject to various degrees of stress, detected as mid-day depression of transpiration and stomatal conductance. Sap flux results were scaled from the leaf level of measurement to the stand level by measuring plant-specific leaf area index and fractional ground cover at each site. Results were compared to Bowen ratio moisture tower data available for three of the sites. Sap flux sensors and flux tower results ranked the sites the same and had similar estimates of ET. A regression equation, relating measured ET of salt cedar and other riparian plants and crops on the Lower Colorado River to the Enhanced Vegetation Index from the MODIS sensor on the Terra satellite and reference crop ET measured at meteorological stations, was able to predict actual ET with an accuracy or uncertainty of about 20%, despite between-site differences for salt cedar. Peak summer salt cedar ET averaged about 6 mm d-1 across sites and methods of measurement.

  5. Empirical Relationship Between Leaf Biomass of Red Pine Forests and Enhanced Vegetation Index in South Korea Using LANDSAT-5 TM

    Science.gov (United States)

    Gusso, A.; Lee, J.; Son, Y.; Son, Y. M.

    2016-06-01

    Research on forest carbon (C) dynamics has been undertaken due to the importance of forest ecosystems in national C inventories. Currently, the C sequestration of South Korean forests surpasses that of other countries. In South Korea, Pinus densiflora (red pine) is the most abundant tree species. Thus, understanding the growth rate and biomass evolution of red pine forest in South Korea is important for estimating the forest C dynamics. In this paper, we derived empirical relationship between foliage biomass and the no blue band enhanced vegetation index (EVI-2) profile using both field work and multi-temporal Landsat-5 TM remote sensing data to estimate the productivity of forest biomass in South Korea. Our analysis combined a set of 84 Landsat-5 TM images from 28 different dates between 1986 and 2008 to study red pine forest development over time. Field data were collected from 30 plots (0.04 ha) that were irregularly distributed over South Korea. Individual trees were harvested by destructive sampling, and the age of trees were determined by the number of tree rings. The results are realistic (R2&thinsp=&thinsp0.81, p < 0.01) and suggest that the EVI-2 index is able to adequately represent the development profile of foliage biomass in red pine forest growth.

  6. EMPIRICAL RELATIONSHIP BETWEEN LEAF BIOMASS OF RED PINE FORESTS AND ENHANCED VEGETATION INDEX IN SOUTH KOREA USING LANDSAT-5 TM

    Directory of Open Access Journals (Sweden)

    A. Gusso

    2016-06-01

    Full Text Available Research on forest carbon (C dynamics has been undertaken due to the importance of forest ecosystems in national C inventories. Currently, the C sequestration of South Korean forests surpasses that of other countries. In South Korea, Pinus densiflora (red pine is the most abundant tree species. Thus, understanding the growth rate and biomass evolution of red pine forest in South Korea is important for estimating the forest C dynamics. In this paper, we derived empirical relationship between foliage biomass and the no blue band enhanced vegetation index (EVI-2 profile using both field work and multi-temporal Landsat-5 TM remote sensing data to estimate the productivity of forest biomass in South Korea. Our analysis combined a set of 84 Landsat-5 TM images from 28 different dates between 1986 and 2008 to study red pine forest development over time. Field data were collected from 30 plots (0.04 ha that were irregularly distributed over South Korea. Individual trees were harvested by destructive sampling, and the age of trees were determined by the number of tree rings. The results are realistic (R2&thinsp=&thinsp0.81, p < 0.01 and suggest that the EVI-2 index is able to adequately represent the development profile of foliage biomass in red pine forest growth.

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

    Science.gov (United States)

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

    1990-01-01

    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.

  8. Drought Forecasting with Vegetation Temperature Condition Index Using ARIMA Models in the Guanzhong Plain

    Directory of Open Access Journals (Sweden)

    Miao Tian

    2016-08-01

    Full Text Available This paper works on the agricultural drought forecasting in the Guanzhong Plain of China using Autoregressive Integrated Moving Average (ARIMA models based on the time series of drought monitoring results of Vegetation Temperature Condition Index (VTCI. About 90 VTCI images derived from Advanced Very High Resolution Radiometer (AVHRR data were selected to develop the ARIMA models from the erecting stage to the maturity stage of winter wheat (early March to late May in each year at a ten-day interval of the years from 2000 to 2009. We take the study area overlying on the administration map around the study area, and divide the study area into 17 parts where at least one weather station is located in each part. The pixels where the 17 weather stations are located are firstly chosen and studied for their fitting models, and then the best models for all pixels of the whole area are determined. According to the procedures for the models’ development, the selected best models for the 17 pixels are identified and the forecast is done with three steps. The forecasting results of the ARIMA models were compared with the monitoring ones. The results show that with reference to the categorized VTCI drought monitoring results, the categorized forecasting results of the ARIMA models are in good agreement with the monitoring ones. The categorized drought forecasting results of the ARIMA models are more severity in the northeast of the Plain in April 2009, which are in good agreements with the monitoring ones. The absolute errors of the AR(1 models are lower than the SARIMA models, both in the frequency distributions and in the statistic results. However, the ability of SARIMA models to detect the changes of the drought situation is better than the AR(1 models. These results indicate that the ARIMA models can better forecast the category and extent of droughts and can be applied to forecast droughts in the Plain.

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

    Science.gov (United States)

    Bunn, Andrew G.; Hughes, Malcolm K.; Kirdyanov, Alexander V.; Losleben, Mark; Shishov, Vladimir V.; Berner, Logan T.; Oltchev, Alexander; Vaganov, Eugene A.

    2013-09-01

    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.

  10. 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)

    Karen Charlton

    2014-06-01

    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

  11. Fruit and vegetable intake and body mass index in a large sample of middle-aged Australian men and women.

    Science.gov (United States)

    Charlton, Karen; Kowal, Paul; Soriano, Melinda M; Williams, Sharon; Banks, Emily; Vo, Kha; Byles, Julie

    2014-06-17

    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

  12. 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)

    Yan Zhu

    2013-03-01

    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.

  13. Assessing plant senescence reflectance index-retrieved vegetation phenology and its spatiotemporal response to climate change in the Inner Mongolian Grassland.

    Science.gov (United States)

    Ren, Shilong; Chen, Xiaoqiu; An, Shuai

    2017-04-01

    Plant phenology is a key link for controlling interactions between climate change and biogeochemical cycles. Satellite-derived normalized difference vegetation index (NDVI) has been extensively used to detect plant phenology at regional scales. Here, we introduced a new vegetation index, plant senescence reflectance index (PSRI), and determined PSRI-derived start (SOS) and end (EOS) dates of the growing season using Moderate Resolution Imaging Spectroradiometer data from 2000 to 2011 in the Inner Mongolian Grassland. Then, we validated the reliability of PSRI-derived SOS and EOS dates using NDVI-derived SOS and EOS dates. Moreover, we conducted temporal and spatial correlation analyses between PSRI-derived SOS/EOS date and climatic factors and revealed spatiotemporal patterns of PSRI-derived SOS and EOS dates across the entire research region at pixel scales. Results show that PSRI has similar performance with NDVI in extracting SOS and EOS dates in the Inner Mongolian Grassland. Precipitation regime is the key climate driver of interannual variation of grassland phenology, while temperature and precipitation regimes are the crucial controlling factors of spatial differentiation of grassland phenology. Thus, PSRI-derived vegetation phenology can effectively reflect land surface vegetation dynamics and its response to climate change. Moreover, a significant linear trend of PSRI-derived SOS and EOS dates was detected only at small portions of pixels, which is consistent with that of greenup and brownoff dates of herbaceous plant species in the Inner Mongolian Grassland. Overall, PSRI is a useful and robust metric in addition to NDVI for monitoring land surface grassland phenology.

  14. Assessing plant senescence reflectance index-retrieved vegetation phenology and its spatiotemporal response to climate change in the Inner Mongolian Grassland

    Science.gov (United States)

    Ren, Shilong; Chen, Xiaoqiu; An, Shuai

    2016-08-01

    Plant phenology is a key link for controlling interactions between climate change and biogeochemical cycles. Satellite-derived normalized difference vegetation index (NDVI) has been extensively used to detect plant phenology at regional scales. Here, we introduced a new vegetation index, plant senescence reflectance index (PSRI), and determined PSRI-derived start (SOS) and end (EOS) dates of the growing season using Moderate Resolution Imaging Spectroradiometer data from 2000 to 2011 in the Inner Mongolian Grassland. Then, we validated the reliability of PSRI-derived SOS and EOS dates using NDVI-derived SOS and EOS dates. Moreover, we conducted temporal and spatial correlation analyses between PSRI-derived SOS/EOS date and climatic factors and revealed spatiotemporal patterns of PSRI-derived SOS and EOS dates across the entire research region at pixel scales. Results show that PSRI has similar performance with NDVI in extracting SOS and EOS dates in the Inner Mongolian Grassland. Precipitation regime is the key climate driver of interannual variation of grassland phenology, while temperature and precipitation regimes are the crucial controlling factors of spatial differentiation of grassland phenology. Thus, PSRI-derived vegetation phenology can effectively reflect land surface vegetation dynamics and its response to climate change. Moreover, a significant linear trend of PSRI-derived SOS and EOS dates was detected only at small portions of pixels, which is consistent with that of greenup and brownoff dates of herbaceous plant species in the Inner Mongolian Grassland. Overall, PSRI is a useful and robust metric in addition to NDVI for monitoring land surface grassland phenology.

  15. Central Amazon Forest Enhanced Vegetation Index Seasonality Driven by Strongly Seasonal Leaf Flush

    Science.gov (United States)

    Wu, J.; Nelson, B. W.; Lopes, A. P.; Graca, P. M. L. D. A.; Tavares, J. V.; Prohaska, N.; Martins, G.; Saleska, S. R.

    2015-12-01

    We used an RGB camera mounted 50m above an upland forest canopy to quantify leaf phenology during 12 months for 267 upper canopy tree crowns at the Amazon Tall Tower site (59.0005ºW, 2.1433ºS). Daily images under overcast sky were selected and radiometrically intercalibrated to remove any seasonal bias from incoming radiant color balance. Seasonality of crown color was then recovered for each individual crown by plotting its greenness timeline (green chromatic coordinate). We detected rapid large-amplitude positive and negative changes in greenness. Rapid increase was attributed to leaf flush and occurred in 85% of all crowns, with 80% showing a single flush per year. The theory of photoperiod control of equatorial tropical forest leaf phenology predicts two annual peaks of leaf flush, so is not supported. Rapid negative change occurred in 42% of individuals and was caused by massive pre-flush leaf abscission (31% of all trees) or other non-green pre-flushing states (11%). Crown flushing was concentrated in the five driest months (55% of trees) compared to the five wettest months (10%). Enhanced Vegetation Index (EVI) for each of three crown phenostages was obtained from a single high spatial resolution QuickBird satellite image.These phenostages were identified using only the visible bands of QuickBird so they could be related to the same crown stages seen in the RGB tower camera images. Relative frequencies of the three crown level phenostages were monitored with the tower camera, allowing a monthly estimate of landscape-scale EVI. Free of the seasonal effects on orbital sensors from clouds, cloud shadows, aerosols or solar illumination angle and corrected for seasonal change in light quality, the camera- and QuickBird derived EVI served as an independent verification of MODIS EVI seasonality. Camera-based EVI was highly consistent with view- and solar-angle corrected MAIAC-EVI of a 3x3 km footprint centered on the tower (R = 0.95 between the two monthly curves

  16. Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils

    OpenAIRE

    2011-01-01

    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 β-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 showe...

  17. Comparison of Different Vegetation Indices for Very High-Resolution Images, Specific Case Ultracam-D Imagery

    Science.gov (United States)

    Barzegar, M.; Ebadi, H.; Kiani, A.

    2015-12-01

    Today digital aerial images acquired with UltraCam sensor are known to be a valuable resource for producing high resolution information of land covers. In this research, different methods for extracting vegetation from semi-urban and agricultural regions were studied and their results were compared in terms of overall accuracy and Kappa statistic. To do this, several vegetation indices were first tested on three image datasets with different object-based classifications in terms of presence or absence of sample data, defining other features and also more classes. The effects of all these cases were evaluated on final results. After it, pixel-based classification was performed on each dataset and their accuracies were compared to optimum object-based classification. The importance of this research is to test different indices in several cases (about 75 cases) and to find the quantitative and qualitative effects of increasing or decreasing auxiliary data. This way, researchers who intent to work with such high resolution data are given an insight on the whole procedure of detecting vegetation species as one of the outstanding and common features from such images. Results showed that DVI index can better detect vegetation regions in test images. Also, the object-based classification with average 93.6% overall accuracy and 86.5% Kappa was more suitable for extracting vegetation rather than the pixel-based classification with average 81.2% overall accuracy and 59.7% Kappa.

  18. COMPARISON OF DIFFERENT VEGETATION INDICES FOR VERY HIGH-RESOLUTION IMAGES, SPECIFIC CASE ULTRACAM-D IMAGERY

    Directory of Open Access Journals (Sweden)

    M. Barzegar

    2015-12-01

    Full Text Available Today digital aerial images acquired with UltraCam sensor are known to be a valuable resource for producing high resolution information of land covers. In this research, different methods for extracting vegetation from semi-urban and agricultural regions were studied and their results were compared in terms of overall accuracy and Kappa statistic. To do this, several vegetation indices were first tested on three image datasets with different object-based classifications in terms of presence or absence of sample data, defining other features and also more classes. The effects of all these cases were evaluated on final results. After it, pixel-based classification was performed on each dataset and their accuracies were compared to optimum object-based classification. The importance of this research is to test different indices in several cases (about 75 cases and to find the quantitative and qualitative effects of increasing or decreasing auxiliary data. This way, researchers who intent to work with such high resolution data are given an insight on the whole procedure of detecting vegetation species as one of the outstanding and common features from such images. Results showed that DVI index can better detect vegetation regions in test images. Also, the object-based classification with average 93.6% overall accuracy and 86.5% Kappa was more suitable for extracting vegetation rather than the pixel-based classification with average 81.2% overall accuracy and 59.7% Kappa.

  19. 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...

  20. Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments

    Directory of Open Access Journals (Sweden)

    Pires Regina Célia de Matos

    2006-01-01

    Full Text Available The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene. Three water potential levels in the soil were used in order to define irrigation time, corresponding to -0.010 (N1, -0.035 (N2, and -0.070 (N3 MPa, measured through tensiometers installed at the 10 cm depth. A 2 x 3 factorial arrangement was adopted, as randomized complete block, with 5 replicates. In the protected cultivation, the irrigation levels of -0.010 and -0.035 MPa and the clear plastic mulch favored the vegetative growth, evaluated through plant height, maximum horizontal dimension of the plant, leaf area index, as well as by total marketable fruit yield and its components (mean number and weight of fruits per plant. In the open field cultivation, no effect of treatments due to rainfall were observed.

  1. Indexed

    CERN Document Server

    Hagy, Jessica

    2008-01-01

    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.

  2. Differences in hydrological responses for different vegetation types on a steep slope on the Loess Plateau, China

    Science.gov (United States)

    Duan, Liangxia; Huang, Mingbin; Zhang, Luodan

    2016-06-01

    Extensive vegetation restoration practices have been implemented to control soil erosion on the Loess Plateau, China. However, no strict guidelines are available to determine the most suitable plant species for vegetation restoration within a given area. The objective of this study was to quantify the changes of each component (soil water storage, surface runoff, and actual evapotranspiration) of a water balance model and soil loss over time under eight different vegetation types, and to further determine the optimal vegetation type for soil and water conservation and sustainable ecological restoration on the steep slopes (>25°) on the Loess Plateau. The results indicated that vegetation type substantially affected soil water storage and that the greatest soil water storage in both the shallow (0-2 m) and the deep soil layers (2-5 m) occurred under Bothriochloa ischaemum L. (BOI). Vegetation type also affected surface runoff and soil losses. The most effective vegetation types for reducing soil erosion were BOI and Sea-buckthorn (Hippophae rhamnoides L.), while Chinese pine (Pinus tabulaeformis Carr.) and Chinese pine + Black locust (Robinia pseudoacacia L.) were the most ineffective types. Soil water dynamics and evapotranspiration varied considerably among the different vegetation types. A soil water surplus was only found under BOI, while insufficient water replenishment existed under the other seven vegetation types. The higher water consumption rates of the seven vegetation types could result in soil desiccation, which could lead to severe water stresses that would adversely affect plant growth. This study suggested that both vegetation type and its effect on controlling soil erosion should be considered when implementing vegetation restoration and that BOI should be highly recommended for vegetation restoration on the steep slopes of the Loess Plateau. A similar approach to the one used in this study could be applied to other regions of the world confronted

  3. 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)

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

    2014-06-01

    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.

  4. Evaluation of habitat suitability index models by global sensitivity and uncertainty analyses: a case study for submerged aquatic vegetation.

    Science.gov (United States)

    Zajac, Zuzanna; Stith, Bradley; Bowling, Andrea C; Langtimm, Catherine A; Swain, Eric D

    2015-07-01

    Habitat suitability index (HSI) models are commonly used to predict habitat quality and species distributions and are used to develop biological surveys, assess reserve and management priorities, and anticipate possible change under different management or climate change scenarios. Important management decisions may be based on model results, often without a clear understanding of the level of uncertainty associated with model outputs. We present an integrated methodology to assess the propagation of uncertainty from both inputs and structure of the HSI models on model outputs (uncertainty analysis: UA) and relative importance of uncertain model inputs and their interactions on the model output uncertainty (global sensitivity analysis: GSA). We illustrate the GSA/UA framework using simulated hydrology input data from a hydrodynamic model representing sea level changes and HSI models for two species of submerged aquatic vegetation (SAV) in southwest Everglades National Park: Vallisneria americana (tape grass) and Halodule wrightii (shoal grass). We found considerable spatial variation in uncertainty for both species, but distributions of HSI scores still allowed discrimination of sites with good versus poor conditions. Ranking of input parameter sensitivities also varied spatially for both species, with high habitat quality sites showing higher sensitivity to different parameters than low-quality sites. HSI models may be especially useful when species distribution data are unavailable, providing means of exploiting widely available environmental datasets to model past, current, and future habitat conditions. The GSA/UA approach provides a general method for better understanding HSI model dynamics, the spatial and temporal variation in uncertainties, and the parameters that contribute most to model uncertainty. Including an uncertainty and sensitivity analysis in modeling efforts as part of the decision-making framework will result in better-informed, more robust

  5. Bioclimatic and vegetation mapping of a topographically complex oceanic island applying different interpolation techniques.

    Science.gov (United States)

    Garzón-Machado, Víctor; Otto, Rüdiger; del Arco Aguilar, Marcelino José

    2014-07-01

    Different spatial interpolation techniques have been applied to construct objective bioclimatic maps of La Palma, Canary Islands. Interpolation of climatic data on this topographically complex island with strong elevation and climatic gradients represents a challenge. Furthermore, meteorological stations are not evenly distributed over the island, with few stations at high elevations. We carried out spatial interpolations of the compensated thermicity index (Itc) and the annual ombrothermic Index (Io), in order to obtain appropriate bioclimatic maps by using automatic interpolation procedures, and to establish their relation to potential vegetation units for constructing a climatophilous potential natural vegetation map (CPNV). For this purpose, we used five interpolation techniques implemented in a GIS: inverse distance weighting (IDW), ordinary kriging (OK), ordinary cokriging (OCK), multiple linear regression (MLR) and MLR followed by ordinary kriging of the regression residuals. Two topographic variables (elevation and aspect), derived from a high-resolution digital elevation model (DEM), were included in OCK and MLR. The accuracy of the interpolation techniques was examined by the results of the error statistics of test data derived from comparison of the predicted and measured values. Best results for both bioclimatic indices were obtained with the MLR method with interpolation of the residuals showing the highest R2 of the regression between observed and predicted values and lowest values of root mean square errors. MLR with correction of interpolated residuals is an attractive interpolation method for bioclimatic mapping on this oceanic island since it permits one to fully account for easily available geographic information but also takes into account local variation of climatic data.

  6. Assessing intra-annual vegetation regrowth after fire using the pixel based regeneration index

    NARCIS (Netherlands)

    Lhermitte, S.; Verbesselt, J.; Verstraeten, W.W.; Veraverbeke, S.; Coppin, P.

    2011-01-01

    Several remote sensing studies have discussed the potential of satellite imagery as an alternative for extensive field sampling to quantify fire-vegetation impact over large areas. Most studies depend on Landsat image availability with infrequent image acquisition dates and consequently are limited

  7. Assessing agricultural drought in summer over Oklahoma Mesonet sites using the water-related vegetation index from MODIS

    Science.gov (United States)

    Bajgain, Rajen; Xiao, Xiangming; Basara, Jeffrey; Wagle, Pradeep; Zhou, Yuting; Zhang, Yao; Mahan, Hayden

    2016-08-01

    Agricultural drought, a common phenomenon in most parts of the world, is one of the most challenging natural hazards to monitor effectively. Land surface water index (LSWI), calculated as a normalized ratio between near infrared (NIR) and short-wave infrared (SWIR), is sensitive to vegetation and soil water content. This study examined the potential of a LSWI-based, drought-monitoring algorithm to assess summer drought over 113 Oklahoma Mesonet stations comprising various land cover and soil types in Oklahoma. Drought duration in a year was determined by the number of days with LSWI drought years (2001, 2006, 2011, and 2012). The DNLSWI tracked the east-west gradient of summer rainfall in Oklahoma. Drought intensity increased with increasing duration of DNLSWI, and the intensity increased rapidly when DNLSWI was more than 48 days. The comparison between LSWI and the US Drought Monitor (USDM) showed a strong linear negative relationship; i.e., higher drought intensity tends to have lower LSWI values and vice versa. However, the agreement between LSWI-based algorithm and USDM indicators varied substantially from 32 % (D 2 class, moderate drought) to 77 % (0 and D 0 class, no drought) for different drought intensity classes and varied from ˜30 % (western Oklahoma) to >80 % (eastern Oklahoma) across regions. Our results illustrated that drought intensity thresholds can be established by counting DNLSWI (in days) and used as a simple complementary tool in several drought applications for semi-arid and semi-humid regions of Oklahoma. However, larger discrepancies between USDM and the LSWI-based algorithm in arid regions of western Oklahoma suggest the requirement of further adjustment in the algorithm for its application in arid regions.

  8. Reactivity indexes for different geometries of palladium leads

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Carrillo, S C; Bolcatto, P G [Departamento de Fisica, Facultad de Ingenieria Quimica, Universidad Nacional de Litoral, Santiago del Estero 2829 S3000AOM Santa Fe Argentina (Argentina); Ortega, J, E-mail: scgomez@fiq.unl.edu.a [Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid (Spain)

    2009-05-01

    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.

  9. Assessing Land Degradation and Desertification Using Vegetation Index Data: Current Frameworks and Future Directions

    Directory of Open Access Journals (Sweden)

    Thomas P. Higginbottom

    2014-10-01

    Full Text Available Land degradation and desertification has been ranked as a major environmental and social issue for the coming decades. Thus, the observation and early detection of degradation is a primary objective for a number of scientific and policy organisations, with remote sensing methods being a candidate choice for the development of monitoring systems. This paper reviews the statistical and ecological frameworks of assessing land degradation and desertification using vegetation index data. The development of multi-temporal analysis as a desertification assessment technique is reviewed, with a focus on how current practice has been shaped by controversy and dispute within the literature. The statistical techniques commonly employed are examined from both a statistical as well as ecological point of view, and recommendations are made for future research directions. The scientific requirements for degradation and desertification monitoring systems identified here are: (I the validation of methodologies in a robust and comparable manner; and (II the detection of degradation at minor intensities and magnitudes. It is also established that the multi-temporal analysis of vegetation index data can provide a sophisticated measure of ecosystem health and variation, and that, over the last 30 years, considerable progress has been made in the respective research.

  10. Diversity and structure of woody vegetation across areas with different soils in Gonarezhou National Park, Zimbabwe

    NARCIS (Netherlands)

    Gandiwa, E.; Zisadza-Gandiwa, P.; Goza, D.; Mashapa, C.; Muboko, N.

    2014-01-01

    Despite the importance of edaphic factors in influencing woody vegetation diversity and structure in savannas, there is still limited research on the topic across most savanna ecosystems. Here we investigate the differences and/or similarities of woody vegetation diversity and structure across areas

  11. Sustainability aspects of biobased products : comparison of different crops and products from the vegetable oil platform

    NARCIS (Netherlands)

    Meesters, K.P.H.; Corré, W.J.; Conijn, J.G.; Patel, M.K.; Bos, H.L.

    2012-01-01

    This study focusses on the production of vegetable oil based products. A limited number of aspacts of the sustainability of the full chain (from agriculture to product at the factory gate) was evaluated. Three different vegetable oils were taken into account: palm oil, soy oil and rapeseed oil. Also

  12. NORMALIZED DIFFERENCE SNOW INDEX SIMULATION FOR SNOW-COVER MAPPING IN FOREST BY GEOSAIL MODEL

    Institute of Scientific and Technical Information of China (English)

    CAO Yun-gang; LIU Chuang

    2006-01-01

    The snow-cover mapping in forest area is always one of the difficult points for optical satellite remote sensing. To investigate reflectance variability and to improve the mapping of snow in forest area, GeoSail model was used to simulate the reflectance of a snow-covered forest. Using this model, the effects of varying canopy density, solar illumination and view geometry on the performance of the MODIS (Moderate-resolution Imaging Spectroradiometer)snow-cover mapping algorithm were investigated. The relationship between NDSI (Normalized Difference Snow Index), NDVI (Normalized Difference Vegetation Index) and snow fraction was discussed in detail. Results indicated that the weak performance would be achieved if fixed criteria were used for different regions especially in the complicated land cover components. Finally, some suggestions to MODIS SNOWMAP algorithm were put forward to improve snow mapping precision in forest area based on the simulation, for example, new criteria should be used in coniferous forest, that is, NDSI greater than 0.3 and NDVI greater than zero. Otherwise, a threshold on view zenith angle may be used in the criteria such as 45°.

  13. The Oslo Health Study: A Dietary Index Estimating Frequent Intake of Soft Drinks and Rare Intake of Fruit and Vegetables Is Negatively Associated with Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    Arne Torbjørn Høstmark

    2011-01-01

    Full Text Available Background. Since nutritional factors may affect bone mineral density (BMD, we have investigated whether BMD is associated with an index estimating the intake of soft drinks, fruits, and vegetables. Methods. BMD was measured in distal forearm in a subsample of the population-based Oslo Health Study. 2126 subjects had both valid BMD measurements and answered all the questions required for calculating a Dietary Index = the sum of intake estimates of colas and non-cola beverages divided by the sum of intake estimates of fruits and vegetables. We did linear regression analyses to study whether the Dietary Index and the single food items included in the index were associated with BMD. Results. There was a consistent negative association between the Dietary Index and forearm BMD. Among the single index components, colas and non-cola soft drinks were negatively associated with BMD. The negative association between the Dietary Index and BMD prevailed after adjusting for gender, age, and body mass index, length of education, smoking, alcohol intake, and physical activity. Conclusion. An index reflecting frequent intake of soft drinks and rare intake of fruit and vegetables was inversely related to distal forearm bone mineral density.

  14. The oslo health study: a dietary index estimating frequent intake of soft drinks and rare intake of fruit and vegetables is negatively associated with bone mineral density.

    Science.gov (United States)

    Høstmark, Arne Torbjørn; Søgaard, Anne Johanne; Alvær, Kari; Meyer, Haakon E

    2011-01-01

    Background. Since nutritional factors may affect bone mineral density (BMD), we have investigated whether BMD is associated with an index estimating the intake of soft drinks, fruits, and vegetables. Methods. BMD was measured in distal forearm in a subsample of the population-based Oslo Health Study. 2126 subjects had both valid BMD measurements and answered all the questions required for calculating a Dietary Index = the sum of intake estimates of colas and non-cola beverages divided by the sum of intake estimates of fruits and vegetables. We did linear regression analyses to study whether the Dietary Index and the single food items included in the index were associated with BMD. Results. There was a consistent negative association between the Dietary Index and forearm BMD. Among the single index components, colas and non-cola soft drinks were negatively associated with BMD. The negative association between the Dietary Index and BMD prevailed after adjusting for gender, age, and body mass index, length of education, smoking, alcohol intake, and physical activity. Conclusion. An index reflecting frequent intake of soft drinks and rare intake of fruit and vegetables was inversely related to distal forearm bone mineral density.

  15. The Oslo Health Study: A Dietary Index Estimating Frequent Intake of Soft Drinks and Rare Intake of Fruit and Vegetables Is Negatively Associated with Bone Mineral Density

    Science.gov (United States)

    Høstmark, Arne Torbjørn; Søgaard, Anne Johanne; Alvær, Kari; Meyer, Haakon E.

    2011-01-01

    Background. Since nutritional factors may affect bone mineral density (BMD), we have investigated whether BMD is associated with an index estimating the intake of soft drinks, fruits, and vegetables. Methods. BMD was measured in distal forearm in a subsample of the population-based Oslo Health Study. 2126 subjects had both valid BMD measurements and answered all the questions required for calculating a Dietary Index = the sum of intake estimates of colas and non-cola beverages divided by the sum of intake estimates of fruits and vegetables. We did linear regression analyses to study whether the Dietary Index and the single food items included in the index were associated with BMD. Results. There was a consistent negative association between the Dietary Index and forearm BMD. Among the single index components, colas and non-cola soft drinks were negatively associated with BMD. The negative association between the Dietary Index and BMD prevailed after adjusting for gender, age, and body mass index, length of education, smoking, alcohol intake, and physical activity. Conclusion. An index reflecting frequent intake of soft drinks and rare intake of fruit and vegetables was inversely related to distal forearm bone mineral density. PMID:21772969

  16. Vegetational Diversity Analysis across Different Habitats in Garhwal Himalaya

    Directory of Open Access Journals (Sweden)

    Vardan Singh Rawat

    2014-01-01

    Full Text Available Four forest sites varying in vegetation types were studied along an altitudinal range between 2200 and 2500 m. Maximum tree, shrub, and herb species were recorded on stream bank site (22, 25, and 54, resp.. Pteridophytes and bryophytes species richness was maximum on moist site (4 and 5, resp.. The number of climbers was greater in moist and dry habitats (7 species each. Parasitic species were restricted only on dry and stream bank habitats. Restricted tree and shrub species were greater on stream bank site and dry site, respectively. The herb and climber species were greater on moist site. The distribution and species richness pattern in this elevational range largely depend on the altitude and climatic variables. Along the entire range of Garhwal Himalaya, the overlapping among species regimes is broad; therefore, transitional communities having mixture of many species and zones are present. The present study indicates that the opening canopies increase the richness of tree, shrub, herb, and climbers.

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

    Science.gov (United States)

    Beck, Pieter S. A.; Goetz, Scott J.

    2011-12-01

    In the first paragraph of the section '2. Data sets and methods', the Normalized Difference Vegetation Index (NDVI) data set used was incorrectly referred to as GIMMS-NDVI version 3G with a 0.084° spatial resolution. This should be corrected to GIMMS-NDVI version G with a 0.07° spatial resolution. Accordingly, the acknowledgement should state 'We would like to thank ... Jim Tucker and Jorge Pinzon for providing the GIMMS version G data', instead of 'We would like to thank ... Jorge Pinzon for providing the GIMMS 3G data'.

  18. Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils

    Directory of Open Access Journals (Sweden)

    Ab. G.M. Top

    2011-01-01

    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 β-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 β-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 β-carotene.

  19. Radiation budget and soil heat fluxes in different Arctic tundra vegetation types

    Science.gov (United States)

    Juszak, Inge; Iturrate Garcia, Maitane; Gastellu-Etchegorry, Jean-Philippe; Schaepman, Michael E.; Schaepman-Strub, Gabriela

    2016-04-01

    While solar radiation is one of the primary energy sources for warming and thawing permafrost soil, the amount of shortwave radiation reaching the soil is reduced by vegetation shading. Climate change has led to greening, shrub expansion and encroachment in many Arctic tundra regions and further changes are anticipated. These vegetation changes feed back to the atmosphere and permafrost as they modify the surface energy budget. However, canopy transmittance of solar radiation has rarely been measured or modelled for a variety of tundra vegetation types. We assessed the radiation budget of the most common vegetation types at the Kytalyk field site in North-East Siberia (70.8°N, 147.5°E) with field measurements and 3D radiative transfer modelling and linked it to soil heat fluxes. Our results show that Arctic tundra vegetation types differ in canopy albedo and transmittance as well as in soil heat flux and active layer thickness. Tussock sedges transmitted on average 56% of the incoming light and dwarf shrubs 27%. For wet sedges we found that the litter layer was very important as it reduced the average transmittance to only 6%. Model output indicated that both, albedo and transmittance, also depend on the spatial aggregation of vegetation types. We found that permafrost thaw was more strongly related to soil properties than to canopy shading. The presented radiative transfer model allows quantifying effects of the vegetation layer on the surface radiation budget in permafrost areas. The parametrised model can account for diverse vegetation types and variation of properties within types. Our results highlight small scale radiation budget and permafrost thaw variability which are indicated and partly caused by vegetation. As changes in species composition and biomass increase can influence thaw rates, small scale patterns should be considered in assessments of climate-vegetation-permafrost feedbacks.

  20. CHANGES IN AMARANTH POLYPHENOL CONTENT DURING THE DIFFERENT VEGETATION PHASES

    Directory of Open Access Journals (Sweden)

    Alena Vollmannová

    2015-02-01

    Full Text Available Total content of polyphenols was investigated in different anatomical parts of amaranth during different growth periods. Five amaranth cultivars were included in the experiment (Amaranthus hypochondriacus L.: cultivars Annapurna and Koniz, Amaranthus caudatus L.: cultivar Oscar Blanco, Amaranthus cruentus L.: cultivars Golden Giant and Rawa. Analysis were done in 4 growth phases: phase I. – intensive stem growth, phase II. – formation of the flowers and pollination, phase III. – milky ripeness, phase IV. – full ripeness. Based on the determined total polyphenol content in amaranth it is possible to create this anatomical part order: leaves > flowers > seeds > stems. No statistically significant differences were confirmed between phases I., III. and IV. On the other hand the total polyphenol content in amaranth determined in growth phase II. was significantly different in comparison to other growth phases. Statistically significant differences in polyphenolic content were confirmed between all investigated anatomical parts of amaranth.

  1. Characterization of Vegetation and Soil Scattering Mechanisms across Different Biomes using P-band SAR Polarimetry

    CERN Document Server

    Alemohammad, Seyed Hamed; Jagdhuber, Thomas; Moghaddam, Mahta; Entekhabi, Dara

    2016-01-01

    A quantitative analysis of vegetation and soil scattering mechanisms retrieved from the observations of an airborne P-band Synthetic Aperture Radar (SAR) instrument across nine different biomes in North America is presented. The understanding of scattering mechanisms from the surface in the presence of different vegetation densities is necessary for the interpretation of P-band SAR observations and for the design of retrieval algorithms. Observations used here are part of the NASA Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) mission, and data have been collected between 2013 and 2015. A data-driven phase calibration technique is used to correct the phase information in the polarimetric observations. A hybrid (model- and eigen- based) three component decomposition algorithm is developed to separate the contributions of surface, double-bounce and vegetation scattering. The decomposition makes no prior assumptions about vegetation structure and is analytically tractable. Applying the retr...

  2. A Different Kind of Publishing; Subject Listings; Library Distributors; Publisher Index; Index to Advertisers; Best Sellers.

    Science.gov (United States)

    Bryant, Eric; Kim, Ann; Miller, Rebecca; Ward, Nathan

    2002-01-01

    This annual supplement discusses issues related to reference books and the publishing industry. Highlights include producing reference books for the library market; a bibliography of over 1000 titles organized by categories and indicating appropriate grade levels; a descriptive list of library distributors; a publisher's index; and a list of the…

  3. Índice de cobertura vegetal e sua modelagem para cultivares de soja no sul de Minas Gerais Index of vegetal cover and its modeling for soybean cultivars in the south of Minas Gerais

    Directory of Open Access Journals (Sweden)

    Vitor Corrêa de Mattos Barreto

    2010-10-01

    Full Text Available A cobertura vegetal do solo é decisiva para redução dos efeitos erosivos do impacto direto das gotas de chuva na superfície do solo. Desta forma, objetivou-se com este estudo determinar o índice de cobertura vegetal (CV e desenvolver modelos para sua estimativa para a cultura da soja, usando os atributos climáticos no período de chuvas intensas no Sul de Minas Gerais. As determinações da CV foram feitas semanalmente, na área experimental do Departamento de Ciência do Solo, Universidade Federal de Lavras, no período de novembro de 1999 a maio de 2000, em 28 cultivares de soja com potencial para cultivo nesta região. Para avaliação da cobertura vegetal foi utilizada a metodologia descrita por Stocking (1988. Na modelagem procurou-se relacionar a CV com os valores acumulados dos seguintes atributos climáticos: temperatura média (Tmed, precipitação (PREC e umidade relativa do ar (UR. Os valores de cobertura vegetal apresentaram uma amplitude de variação de 56 a 83%, sendo BR 162, LO 12 L e M. Soy 108 as cultivares mais eficientes e FT Abyara e Tucano as menos eficientes. O hábito diferencial de crescimento das cultivares ajuda a explicar esse comportamento. O modelo ajustado adequado para estimativa da CV foi: CV = 116589,976 + 0,422 . Tmed + 0,132 . PREC - 0,095 . UR + 0,000024 . Tmed², R² = 0,99 (P Vegetal cover of soil is decisive to reduce the erosive effects of direct impact of raindrops on the soil surface. Therefore, the objective of this study was to determine the vegetal cover (CC index and to develop models to estimate it for soybean cultivars, using climatic attributes in the period of intense rains in the South of the State of Minas Gerais in Brazil. CC was measured weekly in the experimental area of the Department of Soil Science, Federal University of Lavras, from November 1999 to May 2000, for 28 soybean cultivars with yield potential in this region. To evaluate the vegetal cover, the method described by

  4. Use of Different Vegetable Products to Increase Preschool-Aged Children's Preference for and Intake of a Target Vegetable

    NARCIS (Netherlands)

    Wild, de Victoire W.T.; Graaf, de Kees; Jager, Gerry

    2016-01-01

    Background: Children's low vegetable consumption requires effective strategies to enhance preference for and intake of vegetables. Objective: The study compared three preparation practices for a target vegetable (spinach) on their effectiveness in increasing preschool-aged children's preference f

  5. Comparative analysis of different retrieval methods for mapping grassland leaf area index using airborne imaging spectroscopy

    Science.gov (United States)

    Atzberger, Clement; Darvishzadeh, Roshanak; Immitzer, Markus; Schlerf, Martin; Skidmore, Andrew; le Maire, Guerric

    2015-12-01

    Fine scale maps of vegetation biophysical variables are useful status indicators for monitoring and managing national parks and endangered habitats. Here, we assess in a comparative way four different retrieval methods for estimating leaf area index (LAI) in grassland: two radiative transfer model (RTM) inversion methods (one based on look-up-tables (LUT) and one based on predictive equations) and two statistical modelling methods (one partly, the other entirely based on in situ data). For prediction, spectral data were used that had been acquired over Majella National Park in Italy by the airborne hyperspectral HyMap instrument. To assess the performance of the four investigated models, the normalized root mean squared error (nRMSE) and coefficient of determination (R2) between estimates and in situ LAI measurements are reported (n = 41). Using a jackknife approach, we also quantified the accuracy and robustness of empirical models as a function of the size of the available calibration data set. The results of the study demonstrate that the LUT-based RTM inversion yields higher accuracies for LAI estimation (R2 = 0.91, nRMSE = 0.18) as compared to RTM inversions based on predictive equations (R2 = 0.79, nRMSE = 0.38). The two statistical methods yield accuracies similar to the LUT method. However, as expected, the accuracy and robustness of the statistical models decrease when the size of the calibration database is reduced to fewer samples. The results of this study are of interest for the remote sensing community developing improved inversion schemes for spaceborne hyperspectral sensors applicable to different vegetation types. The examples provided in this paper may also serve as illustrations for the drawbacks and advantages of physical and empirical models.

  6. Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils.

    Science.gov (United States)

    Castro, T; Cabezas, A; De la Fuente, J; Isabel, B; Manso, T; Jimeno, V

    2016-03-01

    Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D' Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.

  7. 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)

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

    2014-01-01

    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.

  8. SPECIES COMPOSITION OF WEED VEGETATION IN DIFFERENT APPLE GROWING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Venera TASSEVA

    2005-08-01

    Full Text Available The investigation was carried out in the period 2001-2003 in an orchard of the Institute of Agriculture, Kyustendil, Bulgaria, created in the spring of 1996 on leached cinnamonic forest soil. The weed populations under four different farming technologies of growing of apple cultivar Florina were investigated. It was established, that the apple growing technologies influence the weed association composition. The highest weed diversity was found in the organic technology - 16 weed species were found. In the application of resource economical and integrated technologies, the development of 13-14 weed species was established. The smallest weed diversity was observed in the conventional technology - eight species, which was due to the twofold herbicide application.

  9. [Progress in retrieving vegetation water content under different vegetation coverage condition based on remote sensing spectral information].

    Science.gov (United States)

    Zhang, Jia-Hua; Li, Li; Yao, Feng-Mei

    2010-06-01

    The present paper reviews the progress in the methods of retrieving vegetation water content using remote sensing spectral information, including vegetation spectral reflectance information (VIR, SWIR, and NIR) to directly extract vegetation water content and establish vegetation water indices (WI), i. e. NDWI = (R860 - R1 240)/(R860 + R1 240) and PWI = R970/R900; and using radiation transfer (RT) model such as PROSPAIL to detect plant water content information. The authors analyze the method of retrieving vegetation water content under low crop coverage condition. The plant water can be estimated by using canopy physiological parameters firstly, and using vegetation indices and radiation transfer model secondly, which can eliminate soil background effect. The estimated agricultural drought and vegetation water content by using multi-angle polarized reflectance and bi-directional reflectance (BRDF) was discussed in this paper. In the end, the possible development trend of retrieval methods for plant water information under plant low coverage conditions was discussed.

  10. [Comparison of soil fertility among open-pit mine reclaimed lands in Antaibao regenerated with different vegetation types].

    Science.gov (United States)

    Wang, Xiang; Li, Jin-chuan; Yue, Jian-ying; Zhou, Xiao-mei; Guo, Chun-yan; Lu, Ning; Wang, Yu-hong; Yang, Sheng-quan

    2013-09-01

    Re-vegetation is mainly applied into regeneration in opencast mine to improve the soil quality. It is very important to choose feasible vegetation types for soil restoration. In this study, three typical forest restoration types were studied at Antaibao mine, namely, Medicago sativa, mixed forests Pinus taebelaefolius-Robinia pseudoacacia-Caragana korshinskii and Elaeagnus angustifolia-Robinia pseudoacacia-Caragana korshinskii-Hipophae rhamnoides, to determine the nutrient contents and enzyme activities in different soil layers. The results showed that re-vegetation markedly increased soil nutrient contents and the enzyme activities during the restoration process. The nutrient content of soil in the P. taebelaefolius-R. pseudoacacia-C. korshinskii mixed forest field was significantly higher than those in other plots. It was found that the soil of the P. taebelaefolius-R. pseudoacacia-C. korshinskii mixed forest had the highest integrated fertility index values. In conclusion, the restoration effects of the P. zaebelaefolius-R. pseudoacacia-C. Korshinskii mixed forest was better than that of E. angustifolia-R. pseudoacacia-C. korshinskii-H. rhamnoides, while M. sativa grassland had the least effect.

  11. Divergent responses of vegetation cover in Southwestern US ecosystems to dry and wet years at different elevations

    Science.gov (United States)

    Herrmann, Stefanie M.; Didan, Kamel; Barreto-Munoz, Armando; Crimmins, Michael A.

    2016-12-01

    In the semiarid Southwestern United States, prolonged drought conditions since the early 2000s have resulted in widespread declines of the vegetation productivity in this water-constrained ecosystem, as revealed by analyses of the Normalized Difference Vegetation Index (NDVI). However, the spatial pattern of the NDVI response to dry years is not uniform: a divergent response of NDVI to precipitation is observed between the low-lying desert and the high montane forests at elevations above 2,500 meter. We analyzed relationships between 15 years of Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI and gridded climate data (PRISM) along elevation gradients at scales from regional to local. Our elevation-explicit analysis captures the transition from water-limited to temperature-limited ecosystems, with a sign-reversal in the correlation coefficient between precipitation and NDVI observed at about 2,500-3,000m altitude. We suggest warmer temperatures and less snow cover associated with drier years as explanations for high elevation gains in vegetation productivity during dry years.

  12. Interannual Variations and Trends in Global Land Surface Phenology Derived from Enhanced Vegetation Index During 1982-2010

    Science.gov (United States)

    Zhang, Xiaoyang; Tan, Bin; Yu, Yunyue

    2014-01-01

    Land swiace phenology is widely retrieved from satellite observations at regional and global scales, and its long-term record has been demonstmted 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 srudy 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 OSL varied considerably during 1982-2010 across the globe. Generally, the interarmual 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 OSL 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

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

    Science.gov (United States)

    Zhang, Xiaoyang; Tan, Bin; Yu, Yunyue

    2014-05-01

    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

  14. Uls LiDAR Supported Analyses of Laser Beam Penetration from Different ALS Systems Into Vegetation

    Science.gov (United States)

    Wieser, M.; Hollaus, M.; Mandlburger, G.; Glira, P.; Pfeifer, N.

    2016-06-01

    This study analyses the underestimation of tree and shrub heights for different airborne laser scanner systems and point cloud distribution within the vegetation column. Reference data was produced by a novel UAV-borne laser scanning (ULS) with a high point density in the complete vegetation column. With its physical parameters (e.g. footprint) and its relative accuracy within the block as stated in Section 2.2 the reference data is supposed to be highly suitable to detect the highest point of the vegetation. An airborne topographic (ALS) and topo-bathymetric (ALB) system were investigated. All data was collected in a period of one month in leaf-off condition, while the dominant tree species in the study area are deciduous trees. By robustly estimating the highest 3d vegetation point of each laser system the underestimation of the vegetation height was examined in respect to the ULS reference data. This resulted in a higher under-estimation of the airborne topographic system with 0.60 m (trees) and 0.55 m (shrubs) than for the topo-bathymetric system 0.30 m (trees) and 0.40 m (shrubs). The degree of the underestimation depends on structural characteristics of the vegetation itself and physical specification of the laser system.

  15. Effectiveness of Vegetation Index Transformation for Land Use Identifying and Mapping in the Area of Oil palm Plantation based on SPOT-6 Imagery (Case Study: PT.Tunggal Perkasa Plantations, Air Molek, Indragiri Hulu)

    Science.gov (United States)

    Setyowati, H. A.; S, S. H. Murti B.; Sukentyas, E. S.

    2016-11-01

    The reflection of land surface, atmosphere and vegetation conditions affect the reflectance value of the object is recorded on remote sensing image so that it can affect the outcome of information extraction from remote sensing imagery one multispectral classification. This study aims to assess the ability of the transformation of generic vegetation index (Wide Dynamic Range Vegetation Index), the vegetation index transformation that is capable reducing the influence of the atmosphere (Atmospherically Resistant Vegetation Index), and the transformation of vegetation index that is capable of reducing the influence of the background soil (Second Modified Soil Adjusted Vegetation Index) for the identification and mapping of land use in the oil palm plantation area based on SPOT-6 archived on June 13, 2013 from LAPAN. The study area selected oil palm plantations PT. Tunggal Perkasa Plantations, Air Molek, Indragiri Hulu, Riau Province. The method is using the transformation of the vegetation index ARVI, MSAVI2, and WDRVI. Sample selection method used was stratified random sampling. The test method used mapping accuracy of the confusion matrix. The results showed that the best transformation of the vegetation index for the identification and mapping of land use in the plantation area is ARVI transformation with a total of accuracy is 96%. Accuracy of mapping land use settlements 100%, replanting 82.35%, 81.25% young oil palm, old oil palm 99.46%, 100% bush, body of water 100%, and 100% bare-soil.

  16. Performance of the Enhanced Vegetation Index to Detect Inner-annual Dry Season and Drought Impacts on Amazon Forest Canopies

    Science.gov (United States)

    Brede, B.; Verbesselt, J.; Dutrieux, L.; Herold, M.

    2015-04-01

    The Amazon rainforests represent the largest connected forested area in the tropics and play an integral role in the global carbon cycle. In the last years the discussion about their phenology and response to drought has intensified. A recent study argued that seasonality in greenness expressed as Enhanced Vegetation Index (EVI) is an artifact of variations in sun-sensor geometry throughout the year. We aimed to reproduce these results with the Moderate-Resolution Imaging Spectroradiometer (MODIS) MCD43 product suite, which allows modeling the Bidirectional Reflectance Distribution Function (BRDF) and keeping sun-sensor geometry constant. The derived BRDF-adjusted EVI was spatially aggregated over large areas of central Amazon forests. The resulting time series of EVI spanning the 2000-2013 period contained distinct seasonal patterns with peak values at the onset of the dry season, but also followed the same pattern of sun geometry expressed as Solar Zenith Angle (SZA). Additionally, we assessed EVI's sensitivity to precipitation anomalies. For that we compared BRDF-adjusted EVI dry season anomalies to two drought indices (Maximum Cumulative Water Deficit, Standardized Precipitation Index). This analysis covered the whole of Amazonia and data from the years 2000 to 2013. The results showed no meaningful connection between EVI anomalies and drought. This is in contrast to other studies that investigate the drought impact on EVI and forest photosynthetic capacity. The results from both sub-analyses question the predictive power of EVI for large scale assessments of forest ecosystem functioning in Amazonia. Based on the presented results, we recommend a careful evaluation of the EVI for applications in tropical forests, including rigorous validation supported by ground plots.

  17. [Comparison and analysis of hyperspectral remote sensing identifiable models for different vegetation under waterlogging stress].

    Science.gov (United States)

    Jiang, Jin-Bao; Steven, Michael D; He, Ru-Yan; Cai, Qing-Kong

    2013-11-01

    With the global climate warming, flooding disasters frequently occurred and its influence scope constantly increased in China. The objective of the present paper was to study the leaf spectral features of vegetation (maize and beetroot) under waterlogging stress and design a hyperspectral remote sensing model to monitor the flooding disasters through a field simulated experiment. The experiment was carried out in the Sutton Bonington Campus of University of Nottingham (52.8 degrees N, 1. 2 degrees W) from May to August in 2008, and samples were collected one time every week and spectra were measured in the laboratory. The result showed that the reflectance of the maize and beetroot decreased in the 550 and 800-1 300 nm region, and the reflectance slightly increased in the 680 nm region. This paper chose NDVI, SIPI, PRI, SRPI, GNDVI and R800 * R550/R680 to identify the vegetation under waterlogging stress, respectively. The result suggested that the SIPI and R800 * R550/R680 was sensitive for maize under waterlogging stress, and then SIPI and PRI and R800 * R550/R680 was sensitive for beetroot under waterlogging stress. In order to seek the best identifiable model, the normalized distances between means of control and stressed vegetation indices were calculated and analyzed, the result indicated that the distance of R800 * R550/R680 is more than that of indices' in the early stress stage, illustrated that the index identifiable ability for waterlogging stress is better than other indices, then the index has the strong sensitivity and stability. Therefore, the index R800 * R550/R680 could be used to quickly extract flooding disaster area by using hyperspectral remote sensing, and would provide information support for disaster relief decisions.

  18. Comparing the Normalized Difference Infrared Index (NDII) with root zone storage in a lumped conceptual model

    Science.gov (United States)

    Sriwongsitanon, Nutchanart; Gao, Hongkai; Savenije, Hubert H. G.; Maekan, Ekkarin; Saengsawang, Sirikanya; Thianpopirug, Sansarith

    2016-08-01

    With remote sensing we can readily observe the Earth's surface, but direct observation of the sub-surface remains a challenge. In hydrology, but also in related disciplines such as agricultural and atmospheric sciences, knowledge of the dynamics of soil moisture in the root zone of vegetation is essential, as this part of the vadose zone is the core component controlling the partitioning of water into evaporative fluxes, drainage, recharge, and runoff. In this paper, we compared the catchment-scale soil moisture content in the root zone of vegetation, computed by a lumped conceptual model, with the remotely sensed Normalized Difference Infrared Index (NDII) in the Upper Ping River basin (UPRB) in northern Thailand. The NDII is widely used to monitor the equivalent water thickness (EWT) of leaves and canopy. Satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used to determine the NDII over an 8-day period, covering the study area from 2001 to 2013. The results show that NDII values decrease sharply at the end of the wet season in October and reach lowest values near the end of the dry season in March. The values then increase abruptly after rains have started, but vary in an insignificant manner from the middle to the late rainy season. This paper investigates if the NDII can be used as a proxy for moisture deficit and hence for the amount of moisture stored in the root zone of vegetation, which is a crucial component of hydrological models. During periods of moisture stress, the 8-day average NDII values were found to correlate well with the 8-day average soil moisture content (Su) simulated by the lumped conceptual hydrological rainfall-runoff model FLEX for eight sub-catchments in the Upper Ping basin. Even the deseasonalized Su and NDII (after subtracting the dominant seasonal signal) showed good correlation during periods of moisture stress. The results illustrate the potential of the NDII as a proxy for catchment-scale root zone

  19. Modeling the effects of vegetation on methane oxidation and emissions through soil landfill final covers across different climates.

    Science.gov (United States)

    Abichou, Tarek; Kormi, Tarek; Yuan, Lei; Johnson, Terry; Francisco, Escobar

    2015-02-01

    Plant roots are reported to enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil as well as the supply of methane to bacteria. Therefore, methane oxidation can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This study consisted of using a numerical model that combines flow of water and heat with gas transport and oxidation in soils, to simulate methane emission and oxidation through simulated vegetated and non-vegetated landfill covers under different climatic conditions. Different simulations were performed using different methane loading flux (5-200 g m(-2) d(-1)) as the bottom boundary. The lowest modeled surface emissions were always obtained with vegetated soil covers for all simulated climates. The largest differences in simulated surface emissions between the vegetated and non-vegetated scenarios occur during the growing season. Higher average yearly percent oxidation was obtained in simulations with vegetated soil covers as compared to non-vegetated scenario. The modeled effects of vegetation on methane surface emissions and percent oxidation were attributed to two separate mechanisms: (1) increase in methane oxidation associated with the change of the physical properties of the upper vegetative layer and (2) increase in organic matter associated with vegetated soil layers. Finally, correlations between percent oxidation and methane loading into simulated vegetated and non-vegetated covers were proposed to allow decision makers to compare vegetated versus non-vegetated soil landfill covers. These results were obtained using a modeling study with several simplifying assumptions that do not capture the complexities of vegetated soils under field conditions.

  20. Assessing agricultural drought in summer over Oklahoma Mesonet sites using the water-related vegetation index from MODIS

    Science.gov (United States)

    Bajgain, Rajen; Xiao, Xiangming; Basara, Jeffrey; Wagle, Pradeep; Zhou, Yuting; Zhang, Yao; Mahan, Hayden

    2017-02-01

    Agricultural drought, a common phenomenon in most parts of the world, is one of the most challenging natural hazards to monitor effectively. Land surface water index (LSWI), calculated as a normalized ratio between near infrared (NIR) and short-wave infrared (SWIR), is sensitive to vegetation and soil water content. This study examined the potential of a LSWI-based, drought-monitoring algorithm to assess summer drought over 113 Oklahoma Mesonet stations comprising various land cover and soil types in Oklahoma. Drought duration in a year was determined by the number of days with LSWI 80 % (eastern Oklahoma) across regions. Our results illustrated that drought intensity thresholds can be established by counting DNLSWI (in days) and used as a simple complementary tool in several drought applications for semi-arid and semi-humid regions of Oklahoma. However, larger discrepancies between USDM and the LSWI-based algorithm in arid regions of western Oklahoma suggest the requirement of further adjustment in the algorithm for its application in arid regions.

  1. [Vegetable oil-induced acute respiratory distress syndrome (ARDS) in near drowning: evaluation based on extravascular lung water index].

    Science.gov (United States)

    Yoshida, Takeshi; Rinka, Hiroshi; Kaji, Arito

    2008-06-01

    Lipoid pneumonia usually presents after chronic recurrent ingestion of oily substances or accidental aspiration during "fire-eating" demonstrations. Massive exposure by near drowning extremely rare and potentially fatal. We present here a case of survival after total immersion in oil in her workplace. A 66-year-old woman who nearly drowned in a vat of vegetable oil was admitted as an emergency case with severe hypoxia after rescue. Chest computed tomography (CT) findings showed bilateral ground-glass opacity, consolidation, and the case fulfilled the criteria for acute respiratory distress syndrome (ARDS). Bronchoscopy and bronchoalveolar lavage performed on admission indicated oil droplets and marked neutrophilia (67%), which made us diagnose ARDS induced by lipoid pneumonia. We commenced treatment with pulsed steroids and strictly managed fluid balance under mechanical ventilation. Despite immediate improvement in oxygenation, the value of extravascular lung water index (EVLWI) measured by the PiCCO system consistently remained over 30 ml/Kg through her clinical course. We concluded that lipoid pneumonia is characterized by prolonged elevatation of pulmonary vascular permeability.

  2. Integrating vegetation index time series and meteorological data to understand the effect of the land use/land cover (LULC) in the climatic seasonality of the Brazilian Cerrado

    Science.gov (United States)

    Lins, D. B.; Zullo, J.; Friedel, M. J.

    2013-12-01

    The Cerrado (savanna ecosystem) of São Paulo state (Brazil) represent a complex mosaic of different typologies of uses, actors and biophysical and social restrictions. Originally, 14% of the state of São Paulo area was covered by the diversity of Cerrado phytophysiognomies. Currently, only 1% of this original composition remains fragmented into numerous relicts of biodiversity, mainly concentrated in the central-eastern of the state. A relevant part of the fragments are found in areas of intense coverage change by human activities, whereas the greatest pressure comes from sugar cane cultivation, either by direct replacement of Cerrado vegetation or occupying pasture areas in the fragments edges. As a result, new local level dynamics has been introduced, directly or indirectly, affecting the established of processes in climate systems. In this study, the main goal is analyzing the relationship between the Cerrado landscape changing and the climate dynamics in regional and local areas. The multi-temporal MODIS 250 m Vegetation Index (VI) datasets (period of 2000 to 2012) are integrated with precipitation data of the correspondent period (http://www.agritempo.gov.br/),one of the most important variable of the spatial phytophysiognomies distribution. The integration of meteorological data enable the development of an integrated approach to understand the relationship between climatic seasonality and the changes in the spatial patterns. A procedure to congregated diverse dynamics information is the Self Organizing Map (SOM, Kohonen, 2001), a technique that relies on unsupervised competitive learning (Kohonen and Somervuo 2002) to recognize patterns. In this approach, high-dimensional data are represented on two dimensions, making possible to obtain patterns that takes into account information from different natures. Observed advances will contribute to bring machine-learning techniques as a valid tool to provide improve in land use/land cover (LULC) analyzes at

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

    Directory of Open Access Journals (Sweden)

    Ying Cai

    2012-09-01

    Full Text Available 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

  4. 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)

    Chatterjee, Sumantra

    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

  5. Nutritional differences and leaf acclimation of climbing plants and the associated vegetation in different types of an Andean montane rainforest.

    Science.gov (United States)

    Salzer, J; Matezki, S; Kazda, M

    2006-03-01

    Climbing plants are known to play an important role in tropical forest systems, but key features for their distribution are only partly understood. Investigation was carried out to find if climbers differ from self-supporting vegetation in their adjustment of leaf parameters over a wide variety of light regimes in different forest types along an altitudinal gradient. Relative photon flux density (PFDrel) was assessed above 75 pairs of strictly linked climbers and supporting vegetation on seven plots between 2,020 and 2,700 m a.s.l. along a mountain range in South-Ecuador up to the Páramo vegetation. Leaf samples from both growth forms were analyzed for leaf area (LA), specific leaf mass (LMA), mass and area-based carbon and nitrogen concentration (C, Carea, N, and Narea) and concentrations of P, K, Ca, Mg, Mn and Al. Leaf size of climbers was independent of general light condition, whereas the leaf size of the self-supporting vegetation increased in shade. LMA increased as expected with altitude and irradiance for both growth forms, but climbers generally built smaller leaves with lower LMA. N, P, and K concentrations were higher in the leaves of climbers than in their supporters. Relationships of LMA and Narea to the light conditions were more pronounced within the climbers than within their supporters. Slope for the regression between climber's Narea and LMA was twice as steep as for the supporter leaves. Al accumulators were only found within the self-supporting vegetation. The investigated traits indicate improved adjustment towards light supply within climbers compared to self-supporting vegetation. Thus climbing plants seem to have a higher potential trade off in resource-use efficiency regarding irradiance and nutrients.

  6. Response of vegetable organisms to quasi-monochromatic light of different duration, intensity and wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Budagovsky, A V; Solovykh, N V [I.V.Michurin All-Russian Recearch Institute of Fruit Crops Genetics and Breeding (Russian Federation); Budagovskaya, O N [I.V.Michurin All-Russia Research and Development Institute of Gardening, Michurinsk, Tambov region (Russian Federation); Budagovsky, I A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-04-30

    By the example of vegetable organisms differing in structure and functional properties it is shown that their response to the action of quasi-monochromatic light from laser sources does not obey the Bunsen – Roscoe dose law. The dependence of biological effect on the irradiation time has the multimodal (multiextremal) form with alternating maxima and minima of the stimulating effect. Such a property manifests itself in the spectral ranges, corresponding to photoinduced conversion of chromoproteins of photocontrol systems and is probably related to the cyclic variations of metabolic activity in vegetable cells. (biophotonics)

  7. Predictors of College-Student Food Security and Fruit and Vegetable Intake Differ by Housing Type

    Science.gov (United States)

    Mirabitur, Erica; Peterson, Karen E.; Rathz, Colleen; Matlen, Stacey; Kasper, Nicole

    2016-01-01

    Objective: We assessed whether college-student characteristics associate with food security and fruit and vegetable (FV) intake and whether these associations differ in students in housing with and without food provision. Participants: 514 randomly-sampled students from a large, Midwestern, public university in 2012 and 2013 Methods: Ordered…

  8. Mitigation of heavy metals in different vegetables through biological washing techniques

    Directory of Open Access Journals (Sweden)

    Muhammad Umair Sattar

    2015-12-01

    Full Text Available Availability of nutritious and healthy food is the foremost challenging issue in all over the word. Vegetables are essential part in human diet and considered as natural reserves of nutrients gifted by Almighty Allah to human beings. Heavy metals are among the most toxic food pollutants and their intake through diet leads to several disorders. The sources of heavy metal contamination include waste water irrigation, industrial emissions, transportation and application of metal-based pesticides. In Pakistan this situation is more alarming as vegetables grown in peri-urban areas have shown high incidence of heavy metals accumulation. In this study effort was made to mitigate different heavy metals (Ar, Cd, Cr and Pb in cauliflower, spinach, okra and brinjal collected from peri-urban areas through washing with different biological solutions. Heavy metals contents were determined by using Atomic Absorption Spectrophotometry (AAS. Vegetable showed high load of heavy metals in unwashed form that reduced significantly by washing with different biological solutions. Among the different biological solutions, washing of vegetables with 8% ginger solution was found to be more effective.

  9. Drought footprint on European ecosystems between 1999 and 2010 assessed by remotely sensed vegetation phenology and productivity

    DEFF Research Database (Denmark)

    Ivits, Eva; Horion, Stéphanie Marie Anne F; Fensholt, Rasmus

    2014-01-01

    bioclimatic zones. The Standardized Precipitation and Evapotranspiration Index (SPEI) was used as drought indicator whereas changes in growing season length and vegetation productivity were assessed using remote sensing time-series of Normalized Difference Vegetation Index (NDVI). Drought spatio...

  10. The 2010 Russian Drought Impact on Satellite Measurements of Solar-Induced Chlorophyll Fluorescence: Insights from Modeling and Comparisons with the Normalized Differential Vegetation Index (NDVI)

    Science.gov (United States)

    Yoshida, Y.; Joiner, J.; Tucker, C.; Berry, J.; Lee, J. -E.; Walker, G.; Reichle, R.; Koster, R.; Lyapustin, A.; Wang, Y.

    2015-01-01

    We examine satellite-based measurements of chlorophyll solar-induced fluorescence (SIF) over the region impacted by the Russian drought and heat wave of 2010. Like the popular Normalized Difference Vegetation Index (NDVI) that has been used for decades to measure photosynthetic capacity, SIF measurements are sensitive to the fraction of absorbed photosynthetically-active radiation (fPAR). However, in addition, SIF is sensitive to the fluorescence yield that is related to the photosynthetic yield. Both SIF and NDVI from satellite data show drought-related declines early in the growing season in 2010 as compared to other years between 2007 and 2013 for areas dominated by crops and grasslands. This suggests an early manifestation of the dry conditions on fPAR. We also simulated SIF using a global land surface model driven by observation-based meteorological fields. The model provides a reasonable simulation of the drought and heat impacts on SIF in terms of the timing and spatial extents of anomalies, but there are some differences between modeled and observed SIF. The model may potentially be improved through data assimilation or parameter estimation using satellite observations of SIF (as well as NDVI). The model simulations also offer the opportunity to examine separately the different components of the SIF signal and relationships with Gross Primary Productivity (GPP).

  11. Effects of different vegetation restoration models on soil microbial biomass in eroded hilly Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    XUE Sha; LIU Guobin; DAI Quanhou; LAN Xue; YU Na

    2007-01-01

    Vegetation restoration is a key measure to improve the eco-environment in Loess Plateau,China.In order to find the effect of soil microbial biomass under different vegetation restoration models in this region,six trial sites located in Zhifanggou watershed were selected in this study.Results showed that soil microbial biomass,microbial respiration and physical and chemical properties increased apparently.After 30 years of vegetation restoration,soil microbial biomass C,N,P(SMBC,SMBN,SMBP)and microbial respiration,increased by 109.01%-144.22%,34.17%-117.09%,31.79%-79.94% and 26.78%-87.59% respectively,as compared with the farmland.However,metabolic quotient declined dramatically by 57.45%-77.49%.Effects of different models of vegetation restoration are different on improving the properties of soil.In general,mixed stands of Pinus tabulaeformisAmorpha fruticosa and Robinia pseudoacacia-A,fruticosa had the most remarkable effect,followed by R.pseudoacacia and Caragana korshinkii,fallow land and P.tabulaeformis was the lowest.Restoration of mixed forest had greater effective than pure forest in eroded Hilly Loess Plateau.The significant relationships were observed among SMBC,SMBP,microbial respiration,and physical and chemical properties of soil.It was concluded that microbial biomass can be used as indicators of soil quality.

  12. 基于光谱分析与角度斜率指数的植被含水量研究%The Research of Vegetation Water Content Based on Spectrum Analysis and Angle Slope Index

    Institute of Scientific and Technical Information of China (English)

    邓兵; 杨武年; 慕楠; 张超

    2016-01-01

    shows that the relativity between the spectral reflectance of different wavelengths and the vegetation water content varies consid-erably.The spectral reflectance of red band of visible light (620 ~ 700 nm)and the near-infrared band(800 ~ 1 350,1 600 ~1 950,2 200~2 400 nm)had a higher correlation with the vegetation water content.The slope angle indexes were used as pa-rameters for estimating the vegetation water content based on analyzing the relation between the slope angle indexes and vegeta-tion water content.An evaluation model of vegetation water content was set up by utilizing statistical linear regression model method.The band of 660,850,1 630,2 200 nm were selected as RED,NIR,SWIR1 and SWIR2 band value of the slope angle index based on the analysis of the correlation between spectral reflectance and vegetation water content.A large amount of vege-tation spectral information and vegetation water content were collected in the study area(the upstream of Minjiang River),and the linear regression model of the slope angle index (SANI,SASI,ANIR)and vegetation water content (FMC)was build.The linear regression model of ANIR and FMC has the highest of linear fitting and the linearity is up to 0.791.The near infrared an-gle index(ANIR)was improved on the basis of the analysis the linear regression results of angle slope vegetation index and water content.Near infrared angle normalized index (NANI)and near infrared angle slope index (NASI)were defined,and the linear regression model was established.Compared with the slope angle index (SANI,SASI,ANIR)which were proposed by Palacios-Orueta,NANI had more advantages in the vegetation water content inversion in the study area.The determination coefficient (R 2 )of the inversion model increased from 0.791 to 0.853,and root-mean-square error (RMSE)reduced from 0.047 to 0.039. Angle slope index had higher linear fitting and estimation accuracy by improving the angle of slope index.NANI and FMC linear regression model was

  13. Research of Heavy Metal Pollution in Different Vegetables in Xinchang County%新昌县不同蔬菜重金属污染研究

    Institute of Scientific and Technical Information of China (English)

    徐钦辉; 陈银根; 吕文君; 吴旭江; 梁丽伟

    2016-01-01

    通过对新昌县蔬菜生产基地6种蔬菜141个样品中的重金属元素As、Hg、Cd、Cr、Pb的含量进行调查分析,初步了解不同蔬菜重金属污染状况,并进行了蔬菜重金属污染安全评价。研究结果表明,不同品种蔬菜均不同程度地受到重金属污染,蔬菜中As、Hg、Cd、Cr、Pb的平均含量分别为0.0294、0.0074、0.0373、0.153、0.0986 mg/kg,均未超出国家蔬菜食品卫生标准;重金属综合污染程度顺序为青菜>萝卜>茄子>茭白>黄瓜>四季豆,Hg、Cr和Pb是新昌县蔬菜中的主要污染元素;各类蔬菜的综合污染指数均小于1,表明各蔬菜是安全的。%Based on the investigation and analysis of five heavy metals (As, Hg, Cd, Cr, Pb) contents in 141 samples of 6 kinds of vegetables from the vegetable production bases in Xinchang, the paper studied the pollution condition of heavy metals from different vegetables, and implemented a safe assessment on heavy metal pollution of vegetables. The results showed that different vegetables were polluted by heavy metals in different degree, and the average contents of As, Hg, Cd, Cr and Pb in vegetables were 0.029 4, 0.007 4, 0.037 3, 0.153 0 and 0.098 6 mg/kg, respectively, which were all below the national standards of food hygiene and vegetable. The heavy metal pollution levels were in order of green vegetable>radish>eggplant>Zizania aquatica>cucumber>kidney bean, and Hg, Cr and Pb were the major pollutant elements of vegetables in Xinchang. All the pollution indexes of the heavy metals in vegetables were less than 1, so it showed that all the tested vegetables were safe.

  14. Psychosocial work dimensions, personality, and body mass index: Sex differences

    Directory of Open Access Journals (Sweden)

    Angel Blanch

    2013-08-01

    Full Text Available Objectives: The association between psychosocial work dimensions (i.e. demand and control and obesity has been found to be inconclusive, indicating that individual differences factors might also contribute to explain the variability in BMI. Materials and Methods: The interaction between work dimensions and personality variables in a group of male and female workers (N = 506, and its associations with BMI were analyzed with a cross-sectional study with self-report data. Hierarhical regression analyses were used to predict the BMI levels from work and individual differences variables and their interactions for males and females. Results: The main effects of personality variables were not significant, physical workload interacted with neuroticism for males, whereas control interacted with activity for females. Conclusions: Psychosocial work dimensions and personality traits were related to BMI for men and women. These outcomes reinforce the notion that different models might account for the explanatory mechanisms of BMI in regard to sex.

  15. Estimates of evapotranspiration for riparian sites (Eucalyptus) in the Lower Murray -Darling Basin using ground validated sap flow and vegetation index scaling techniques

    Science.gov (United States)

    Doody, T.; Nagler, P. L.; Glenn, E. P.

    2014-12-01

    Water accounting is becoming critical globally, and balancing consumptive water demands with environmental water requirements is especially difficult in in arid and semi-arid regions. Within the Murray-Darling Basin (MDB) in Australia, riparian water use has not been assessed across broad scales. This study therefore aimed to apply and validate an existing U.S. riparian ecosystem evapotranspiration (ET) algorithm for the MDB river systems to assist water resource managers to quantify environmental water needs over wide ranges of niche conditions. Ground-based sap flow ET was correlated with remotely sensed predictions of ET, to provide a method to scale annual rates of water consumption by riparian vegetation over entire irrigation districts. Sap flux was measured at nine locations on the Murrumbidgee River between July 2011 and June 2012. Remotely sensed ET was calculated using a combination of local meteorological estimates of potential ET (ETo) and rainfall and MODIS Enhanced Vegetation Index (EVI) from selected 250 m resolution pixels. The sap flow data correlated well with MODIS EVI. Sap flow ranged from 0.81 mm/day to 3.60 mm/day and corresponded to a MODIS-based ET range of 1.43 mm/day to 2.42 mm/day. We found that mean ET across sites could be predicted by EVI-ETo methods with a standard error of about 20% across sites, but that ET at any given site could vary much more due to differences in aquifer and soil properties among sites. Water use was within range of that expected. We conclude that our algorithm developed for US arid land crops and riparian plants is applicable to this region of Australia. Future work includes the development of an adjusted algorithm using these sap flow validated results.

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

    Science.gov (United States)

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

    2007-05-25

    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.

  17. Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments

    OpenAIRE

    Pires Regina Célia de Matos; Folegatti Marcos Vinícius; Passos Francisco Antonio; Arruda Flávio Bussmeyer; Sakai Emílio

    2006-01-01

    The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene). Three water potential levels in the soil were used in order to defin...

  18. 植被指数-地面温度特征空间的生态学内涵及其应用%Ecological Connotation and Application of the Vegetation Index-Surface Temperature Feature Space

    Institute of Scientific and Technical Information of China (English)

    江东; 王乃斌; 杨小唤; 刘红辉

    2001-01-01

    植被指数与地面温度是描述土地覆盖特征的重要参数,对两种数据的综合分析,可以衍生出更丰富、更清晰的地表信息,有助于更加准确、有效地认知土地覆盖/土地利用的时空变化规律.本文探讨了植被指数与地面温度构成的二维向量空间的物理意义与生态学内涵,以基于NOAA AVHRR的时间序列数据为本底,分析了不同土地覆盖类型在该特征空间上的时序变化规律,并以黄淮海地区主要农作物冬小麦为例,研究了植被指数-地面温度指标与干旱、半干旱地区农作物产量之间的响应关系.%Studies on character and variation of land cover/land use become more and more important in geographical and ecological research. Vegetation index and surface temperature are important parameters to describe characters of land covers. More useful information will be created by integrated analyses of these two kinds of data together, which will help us to find out main principles of the temporal and spatial variation of land cover/land use. The paper focused on physical connotation and ecological meaning of the vegetation index-surface temperature feature space, analyzed temporal variation of different type of land covers in this feature space using NOAA AVHRR remote sensing data, and did much site work on relationship between water index and winter wheat yield in the Huang Huaihai campagna. Following views have been set forth and tested based on these data: (1) Large area and long time serials land surface parameters could be retrieved from remote sensed information; (2) Different types of land covers have different characters in the vegetation index-surface temperature feature space; (3) Water index, derived from vegetation index and surface temperature, is turned out to be a good indicate of growing situation of crops.

  19. Description of psychophysiological indexes of students of different sporting specializations

    Directory of Open Access Journals (Sweden)

    Barybina L.N.

    2010-08-01

    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.

  20. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan Sánchez

    2012-09-01

    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.

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

    Directory of Open Access Journals (Sweden)

    A. Martín

    2013-05-01

    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.

  2. The effects of different salt, biostimulant and temperature levels on seed germination of some vegetable species

    Directory of Open Access Journals (Sweden)

    Ertan Yildirim

    2013-12-01

    Full Text Available This research was conducted to determine the effects of two biostimulants (humic acid and biozyme or three different salt (NaCl concentrations at the temperature 10, 15, 20 and 25°C on parsley, leek, celery, tomato, onion, lettuce, basil, radish and garden cress seed germination. Two applications of both biostimulants increased seed germination of parsley, celery and leek at all temperature treatments. Germination rate decreased depending on high salt concentrations. At different salt and temperature levels garden cress was characterised by the highest germination percentage compared to other vegetable species.Interactions between NaCl concentrations and temperatures, as welI as biostimulants and temperatures were significant at p=0.001 in for all vegetable species except onion in NaCl concentrations and temperatures compared to that of the control.

  3. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan Sánchez

    2013-08-01

    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.

  4. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan SÁNCHEZ

    2013-05-01

    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.

  5. The Effectiveness of Web Search Engines to Index New Sites from Different Countries

    Science.gov (United States)

    Pirkola, Ari

    2009-01-01

    Introduction: Investigates how effectively Web search engines index new sites from different countries. The primary interest is whether new sites are indexed equally or whether search engines are biased towards certain countries. If major search engines show biased coverage it can be considered a significant economic and political problem because…

  6. The role of vegetated areas on fish assemblage of the Paraná River floodplain: effects of different hydrological conditions

    Directory of Open Access Journals (Sweden)

    Juan José Neiff

    Full Text Available In this paper, we analyze the changes in composition and abundance of fish assemblages in seven vegetated floodplain wetlands with different connectivity across different hydrologic conditions: after a prolonged connection of the floodplain with the main channel, during receding water, and after a prolonged isolation. We also investigated the size and abundance of large-sized migratory species found in these wetlands and the food resources exploited by the dominant fish. Fishes were captured by diurnal seining (8.0 m x 1.50 m, 5 mm mesh along macrophyte banks. Despite the high total number of species registered (100, sample species richness varied between 7 and 31, depending on the sampling site and the sampling date. Cluster analysis indicated low similarity between sites during both the isolation and the prolonged connection. Species turnover decreased from high water (β = 40.33 to low water (β = 33.83, with the minimum value of beta diversity index obtained during the isolation of the floodplain wetlands (β = 26.83. Our results indicated that different dominant populations of fish occur in different hydrological conditions, even though high water and isolation phases occur in the same season of different years. The ordination (NMDS indicated the importance of hydrologic conditions in structuring fish assemblages in the studied floodplain. Small-sized characids, typically associated with macrophytes, dominated the fish assemblages, whereas the younger stages of large sized migratory species were found in low abundance. The maximum standard length of the fish captured was 28 cm and for large migratory fish, standard length varied between 1.6 and 25.0 cm. The dominant fish used several food resources, but littoral macrophytes-associated organisms had a high frequency of occurrence in the three hydrologic conditions. The high species richness of fish in the small, vegetated lakes was related to the high spatial heterogeneity during different

  7. The Effects of Atmospheric Constituents on the Normalized Difference Vegetation Index in West Africa.

    Science.gov (United States)

    1992-01-01

    process of photosynthesis (from Tucker and Sellers, 1986) This reaction takes place in plant organelles called chloroplasts (Figure 1). Only 2-3% of...The harmattan and dust production will be discussed further in Chapter 3. Precipitation over the Sahelian region is largely controlled by the movement

  8. NOAA Climate Data Record Normalized Difference Vegetation Index: 1981-2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — National Oceanic and Atmospheric Administration (NOAA) Climate Data Records (CDR) provide historical climate information using data from weather satellites. This...

  9. Trends in vegetation change under different karst terrain conditions, southwest China

    Science.gov (United States)

    Tong, Xiaowei; Wang, Kelin; Yue, Yuemin; Liao, Chujie

    2013-10-01

    Trends in vegetation change and their relationships with terrain conditions are significant to understand and evaluate the efficiency of ecological engineering implemented in karst regions, Southwest China. This study aimed to identify vegetation change trends in Hechi, Guangxi, China using time-series of SPOT-VGT NDVI data (1999-2010) and DEM. Linear trend analysis was applied to examine NDVI change trends. The results indicated that most of NDVI values had increased during this time period. There were spatial variations in NDVI change trends, which could be partiallly explained by different karst terrain conditions. The areas of most obviously positive trends in NDVI change were found at the elevation of 500-1000m and the relief amplitude between 200 and 500 m. Negative trends in NDVI change were appeared on slopes of south (sunlit) and west (semi-sunlit) aspect and at the elevation of 200 - 500 m, where were mainly due to human activities.

  10. Refractometers for different refractive index range by surface plasmon resonance sensors in multimode optical fibers with different metals

    Science.gov (United States)

    Zuppella, P.; Corso, Alain J.; Pelizzo, Maria G.; Cennamo, N.; Zeni, L.

    2016-09-01

    We have realized a plasmonic sensor based on Au/Pd metal bilayer in a multimode plastic optical fiber. This metal bilayer, based on a metal with high imaginary part of the refractive index and gold, shows interesting properties in terms of sensitivity and performances, in different refractive index ranges. The development of highly sensitive platforms for high refractive index detection (higher than 1.38) is interesting for chemical applications based on molecularly imprinted polymer as receptors, while the aqueous medium is the refractive index range of biosensors based on bio-receptors. In this work we have presented an Au/Pd metal bilayer optimized for 1.38-1.42 refractive index range.

  11. Leaf Area Index (LAI) in different type of agroforestry systems based on hemispherical photographs in Cidanau Watershed

    Science.gov (United States)

    Nur Khairiah, Rahmi; Setiawan, Yudi; Budi Prasetyo, Lilik; Ayu Permatasari, Prita

    2017-01-01

    Ecological functions of agroforestry systems have perceived benefit to people around Cidanau Watershed, especially in the protection of water quality. The main causes of the problems encountered in the Cidanau Watershed are associated with the human factors, especially encroachment and conversion of forest into farmland. The encroachment has made most forest in Cidanau Watershed become bare land. To preserve the ecological function of agroforestry systems in Cidanau Watershed, monitoring of the condition of the vegetation canopy in agroforestry systems is really needed. High intensity thinning of crown density due to deforestation can change stand leaf area index dramatically. By knowing LAI, we can assess the condition of the vegetation canopy in agroforestry systems. LAI in this research was obtained from Hemispherical Photographs analysis using the threshold method in HemiView Canopy Analysis Software. Our research results indicate that there are six types of agroforestry in Cidanau Watershed i.e. Sengon Agroforestry, Clove Agroforestry, Melinjo Agroforestry, Chocolate Agroforestry, Coffee Agroforestry, and Complex Agroforestry. Several factors potentially contribute to variations in the value of LAI in different types of agroforestry. The simple assumptions about differences ranges of LAI values on six types of agroforestry is closely related to leaf area and plant population density.

  12. The Influencing Factors and Inter-Group Differences for Urban Residents’ Behavior of Consuming Edible Vegetable Oil

    Institute of Scientific and Technical Information of China (English)

    Qi WU; Wenjie MA

    2016-01-01

    To clarify the determinant factors and inter-group differences of Chinese urban residents’ edible vegetable oil consuming behavior is very important for us to understand their consumption features of edible vegetable oil,so as to guide their consuming behavior and improve China’s vegetable oil industry security.In this article,urban residents of China’s three traditional vegetable oil main production areas have been chosen as study objects,and multiple linear regression and one-way ANOVA have been used to do empirical analysis on the determinant factors and inter-group differences of their edible vegetable oil consuming behavior.The results indicate that the edible vegetable oil consuming behavior of urban residents from China’s three traditional vegetable oil main production areas show a trend of diversification;" publicity measures"," preference evaluation"," personal characteristics" and " family characteristics" remarkably affect urban residents’ edible vegetable oil consuming behavior and show obvious provincial characteristics.In addition,urban residents from different groups show differences in terms of " publicity measures" and " preference evaluation".

  13. Enrichment Difference of Different Types of Vegetables to Heavy Metals%不同种类蔬菜对土壤重金属的富集差异

    Institute of Scientific and Technical Information of China (English)

    韩峰; 高雪; 陈海燕

    2014-01-01

    To explore the feasibility of planting vegetaldes on the land with heavy metal content above the national standard,a field contrast experiment was conducted to analyze the contents of heavy metals (Cd,Hg,As,Pb)in 12 vegetable variety samples planted in soils with heavy metals exceed standard,and the pollution levels were evaluated in the paper.The results indicated that cucumber had the strongest enrichment capacity for Cd,celery had the strongest enrichment capacity for Hg,all vegetables had weak enrichment capability on As and Pb.Single factor pollution index Cd in cucumber,cabbage,lettuce, radish and kidney beans were 3.260,3.140,2.900,2.520,and 1.900,respectively,which were moderate and above pollution level.Hg reached severe and above polluted in celery,radish,carrot,eggplant, lettuce loofah,and cabbage.Whereas,both As and Pb had no significant effect on quality in different vegetable varieties,which reached clean level.Therefore,it was suggested that under the detection of heavy metal contents in the soil,and according to the differences of heavy metal absorption in different vegetables,selectively plant different vegetables types to avoid the exceed of heavy metal contents,and to expand the planting areas of vegetables in Guizhou.%为探索重金属含量超标的耕地种植蔬菜的可行性,通过田间种植对比试验,分析了 Cd、Hg、As、Pb 超标土壤上12个蔬菜品种中的重金属含量,并对污染程度进行了评价。结果表明:黄瓜、芹菜分别对 Hg、Cd 的富集能力最强,各类蔬菜均对 As 和 Pb 富集能力较弱。黄瓜、大白菜、生菜、萝卜和棒豆中 Cd的单因子污染指数分别为3.260、3.140、2.900、2.520和1.900,达中度及以上污染水平;Hg 达到重度污染水平以上的蔬菜品种有芹菜、萝卜、胡萝卜、茄子、生菜、丝瓜和大白菜;As 和 Pb 均达清洁水平,对不同蔬菜品种质量均无显著影响。在 As、Pb

  14. Characteristic of Soil Hydro-Physical Properties and Water Dynamics under Different Vegetation Restoration Types

    Institute of Scientific and Technical Information of China (English)

    MA Zelong; GONG Yuanbo; HU Tingxing

    2006-01-01

    By combining the observation of the soil profile at field and the chemical and physical analysis in laboratory, a study on the hydro-physical properties of soil in six different vegetation types and the dynamics of water content after rain was conducted in Wanchanggou, Guangyuan City to find out the vegetation types with effective water-conservation functions in order to serve the ecological restoration in the low hill heavy rain area upper the Jialing River. Results showed that:the hydro-physical properties of soil in the mixed Alnus cremastogyne and Cupressua Leyland forest (AcCl) were best. But in the depth of 0-20 cm. The properties of soil in the abandoned cropland (Fm) was better than that in the AcCl. The soil bulk densities varied significantly between the layers of 0-20 cm and 20-40 cm in all the six vegetation types except that in the Robinia pseudoacacia shrub forest (RpⅡ), and the changes of the maximum and the capillary moisture capacity between layers were significant only in the Fm and in the AcCl. Of these stands, the AcCl had the shortest water-absorbing period and the strongest moisture changes in the upper layer (0-15 cm). In the same stand, the deeper the soil layer, the slighter the soil moisture varied, and the longer the soil moisture accumulating process lasted.

  15. Effects of neighboring vascular plants on the abundance of bryophytes in different vegetation types

    Science.gov (United States)

    Jägerbrand, Annika K.; Kudo, Gaku; Alatalo, Juha M.; Molau, Ulf

    2012-07-01

    Due to the climate change, vegetation of tundra ecosystems is predicted to shift toward shrub and tree dominance, and this change may influence bryophytes. To estimate how changes in growing environment and the dominance of vascular plants influence bryophyte abundance, we compared the relationship of occurrence of bryophytes among other plant types in a five-year experiment of warming (T), fertilization (F) and T + F in two vegetation types, heath and meadow, in a subarctic-alpine ecosystem. We compared individual leaf area among shrub species to confirm that deciduous shrubs might cause severe shading effect. Effects of neighboring functional types on the performance of Hylocomium splendens was also analyzed. Results show that F and T + F treatments significantly influenced bryophyte abundance negatively. Under natural conditions, bryophytes in the heath site were negatively related to the abundance of shrubs and lichens and the relationship between lichens and bryophytes strengthened after the experimental period. After five years of experimental treatments in the meadow, a positive abundance relationship emerged between bryophytes and deciduous shrubs, evergreen shrubs and forbs. This relationship was not found in the heath site. Our study therefore shows that the abundance relationships between bryophytes and plants in two vegetation types within the same area can be different. Deciduous shrubs had larger leaf area than evergreen shrubs but did not show any shading effect on H. splendens.

  16. Effects of different vegetable oils on rumen fermentation and conjugated linoleic acid concentration in vitro

    Science.gov (United States)

    Roy, Amitava; Mandal, Guru Prasad; Patra, Amlan Kumar

    2017-01-01

    Aim: The objective of this study was to investigate the effect of different vegetable oils on rumen fermentation and concentrations of beneficial cis-9 trans-11 C18:2 conjugated linoleic acid (CLA) and trans-11 C18:1 fatty acid (FA) in the rumen fluid in an in vitro condition. Materials and Methods: Six vegetable oils including sunflower, soybean, sesame, rice bran, groundnut, and mustard oils were used at three dose levels (0%, 3% and 4% of substrate dry matter [DM] basis) in three replicates for each treatment in a completely randomized design using 6 × 3 factorial arrangement. Rumen fluid for microbial culture was collected from four goats fed on a diet of concentrate mixture and berseem hay at a ratio of 60:40 on DM basis. The in vitro fermentation was performed in 100 ml conical flakes containing 50 ml of culture media and 0.5 g of substrates containing 0%, 3% and 4% vegetable oils. Results: Oils supplementation did not affect (p>0.05) in vitro DM digestibility, and concentrations of total volatile FAs and ammonia-N. Sunflower oil and soybean oil decreased (p0.05) on protozoal numbers. Both trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations were increased (p0.05) increase the trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations as compared to the control. The concentrations of stearic, oleic, linoleic, and linolenic acids were not altered (p>0.05) due to the addition of any vegetable oils. Conclusion: Supplementation of sunflower and soybean oils enhanced beneficial trans-11 C18:1 FA and cis-9, trans-11 CLA concentrations in rumen fluid, while sesame, rice bran, groundnut, and mustard oils were ineffective in this study. PMID:28246442

  17. 植物细胞的分化与脱分化%Difference and de-difference of vegetable cell

    Institute of Scientific and Technical Information of China (English)

    黄坚钦

    2001-01-01

    细胞分化与脱分化是现代生物学的基本问题之一。综述了植物细胞分化、脱分化过程中的形态结构变化及其调控。结果表明:从形态结构水平很难找出标志细胞分化与脱分化的特征规律,激素被证明对细胞分化与脱分化的调控起作用,生长素与细胞分裂素的作用受到普遍的关注。参18%The difference and de-difference of cell is a fundamentalquestion in biology.The results of some studies show that the morphological and structural changes in vegetable cells cannot offer feasible feature.However,phyto-hormone makes function in regulation of difference and de-difference of vegetable cell,of which auxin and cytokinin are paid close attention to the effect.

  18. Estimating vegetation dryness to optimize fire risk assessment with spot vegetation satellite data in savanna ecosystems

    Science.gov (United States)

    Verbesselt, J.; Somers, B.; Lhermitte, S.; van Aardt, J.; Jonckheere, I.; Coppin, P.

    2005-10-01

    The lack of information on vegetation dryness prior to the use of fire as a management tool often leads to a significant deterioration of the savanna ecosystem. This paper therefore evaluated the capacity of SPOT VEGETATION time-series to monitor the vegetation dryness (i.e., vegetation moisture content per vegetation amount) in order to optimize fire risk assessment in the savanna ecosystem of Kruger National Park in South Africa. The integrated Relative Vegetation Index approach (iRVI) to quantify the amount of herbaceous biomass at the end of the rain season and the Accumulated Relative Normalized Difference vegetation index decrement (ARND) related to vegetation moisture content were selected. The iRVI and ARND related to vegetation amount and moisture content, respectively, were combined in order to monitor vegetation dryness and optimize fire risk assessment in the savanna ecosystems. In situ fire activity data was used to evaluate the significance of the iRVI and ARND to monitor vegetation dryness for fire risk assessment. Results from the binary logistic regression analysis confirmed that the assessment of fire risk was optimized by integration of both the vegetation quantity (iRVI) and vegetation moisture content (ARND) as statistically significant explanatory variables. Consequently, the integrated use of both iRVI and ARND to monitor vegetation dryness provides a more suitable tool for fire management and suppression compared to other traditional satellite-based fire risk assessment methods, only related to vegetation moisture content.

  19. Characterizing Spatial-Temporal Variations in Vegetation Phenology over the North-South Transect of Northeast Asia Based upon the MERIS Terrestrial Chlorophyll Index

    Directory of Open Access Journals (Sweden)

    Jiaxin Jin

    2012-01-01

    Full Text Available This study attempted to establish a broad regional phenological pattern for Northeast Asia using time-series data of the satellite measured index of terrestrial chlorophyll content (MERIS Terrestrial Chlorophyll Index from 2003 to 2007. A suite of phenological variables were extracted from 4 integral seasons of time-series Medium Resolution Imaging Spectrometer (MERIS Terrestrial Chlorophyll Index (MTCI of World Wildlife Fund (WWF ecoregions smoothed by an asymmetric Gaussian model. In this study, spatial variation with latitude was observed for the chlorophyll content and phenological variables for natural vegetation across north-south transect of northeast Asia (NSTNEA. The onset of greenness for most ecoregions followed a latitudinal pattern with an earlier onset of greenness at lower latitudes. In general, the length of growing season was higher at lower latitudes. For forests in NSTNEA, the average maximum MTCI value and range of MTCI value at lower latitudes were significantly larger than that at higher latitudes during the study period. In addition, the cumulative CV showed a declining trend with an increase in latitude overall. Our findings suggest that although precipitation plays a promoting role, temperature is still the dominant factor in vegetation phenological period at high latitudes.

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

    DEFF Research Database (Denmark)

    Sandholt, Inge; Rasmussen, Kjeld; Andersen, Jens Asger

    2002-01-01

    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...

  1. Enhanced Vegetation Index (EVI na análise da dinâmica da vegetação da reserva biológica de Sooretama, ES Use of Enhanced Vegetation Index (EVI in the analysis os vegetation dynamics of the Sooretama biological reservation, ES

    Directory of Open Access Journals (Sweden)

    André Quintão de Almeida

    2008-12-01

    Full Text Available Técnicas de análises de séries temporais são utilizadas para caracterizar o comportamento de fenômenos naturais no domínio do tempo. Neste artigo, segundo a metodologia proposta por Box et al. (1994, 125 observações do Enhanced Vegetation Index (EVI foram analisadas. Os valores modelados correspondem às variações temporais ocorridas no dossel florestal da reserva biológica de Sooretama, localizada ao Norte do Estado do Espírito Santo, no Município de Linhares. Os resultados indicaram que a metodologia foi adequada. Os resíduos do modelo ajustado são não correlacionados com distribuição normal, média zero e variância s². Com o menor valor do Critério de Informação de Akaike (AIC -570,51, o modelo ajustado foi o Sazonal Auto-Regressivo Integrado de Médias Móveis (1,0,1(1,0,112.Temporal series analysis techniques are used to characterize the behavior of natural phenomenon in time domain. In this paper, 125 Enhanced Vegetation Index (EVI observations were analyzed according to the methodology proposed by Box et al.(1994. The values modeled correspond to the temporal variations that occurred in the forest canopy of the Sooretama Biological Reserve, in northern Espírito Santo, in the district of Linhares. The results indicated that such methodology was adequate. The residues of the adjusted model are not correlated with normal distribution, zero average and s² variance. At the lowest value of the Akaike Information Criteria (AIC -570. 51, the model adjusted was the Mobile Average Integrated Self-Regressive Seasonal model (1, 0, 1 (1, 0, 1-12.

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

    Science.gov (United States)

    Meera, B. M.; Manjunath, M.

    2012-08-01

    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.

  3. Satellite monitoring of different vegetation types by differential optical absorption spectroscopy (DOAS in the red spectral range

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2007-01-01

    Full Text Available A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm reflectance structures (i.e. "fingerprint" structures of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS, which is usually applied for the analysis of atmospheric trace gas absorptions. Since the spectra of atmospheric absorption and vegetation reflectance are simultaneously included in the analysis, the effects of atmospheric absorptions are automatically corrected (in contrast to other algorithms. The inclusion of the vegetation spectra also significantly improves the results of the trace gas retrieval. The global maps of the results illustrate the seasonal cycles of different vegetation types. In addition to the vegetation distribution on land, they also show patterns of biological activity in the oceans. Our results indicate that improved sets of vegetation spectra might lead to more accurate and more specific identification of vegetation type in the future.

  4. Characterising Vegetation Structural and Functional Differences Across Australian Ecosystems From a Network of Terrestrial Laser Scanning Survey Sites and Airborne and Satellite Image Archives

    Science.gov (United States)

    Phinn, S. R.; Armston, J.; Scarth, P.; Johansen, K.; Schaefer, M.; Suarez, L.; Soto-Berelov, M.; Muir, J.; Woodgate, W.; Jones, S.; Held, A. A.

    2015-12-01

    Vegetation structural information is critical for environmental monitoring, management and compliance assessment. In this context we refer to vegetation structural properties as vertical, horizontal and volumetric dimensions, including: canopy height; amount and distribution of vegetation by height; foliage projective cover (FPC); leaf area index (LAI); and above ground biomass. Our aim was to determine if there were significant differences between vegetation structural properties across 11 ecosystem types in Australia as measured by terrestrial laser scanner (TLS) structure metrics. The ecosystems sampled included: mesophyll vineforest, wet-dry tropical savannah, mallee woodland, subtropical eucalypt forest, mulga woodland/grassland, wet eucalypt forest, dry eucalypt forest, tall and wet eucalypt forest, and desert grassland/shrublands. Canopy height, plant area-height profiles and LAI were calculated from consistently processed TLS data using Australia's Terrestrial Ecosystem Research Network's (TERN) Supersites by the TERN AusCover remote sensing field teams from 2012-2015. The Supersites were sampled using standardised field protocols within a core set of 1 ha plots as part of a 5 km x 5 km uniform area using a RIEGL-VZ400 waveform recording TLS. Four to seven scans were completed per plot, with one centre point and then at 25 m away from the centre point along transect lines at 0o, 60o and 240o. Individual foliage profiles were sensitive to spatial variation in the distribution of plant materials. Significant differences were visible between each of the vegetation communities assessed when aggregated to plot and ecosystem type scales. Several of the communities exhibited simple profiles with either grass and shrubs (e.g. desert grassland) or grass and trees (e.g. mallee woodland). Others had multiple vegetation forms at different heights, contributing to the profile (e.g. wet eucalypt forest). The TLS data provide significantly more detail about the relative

  5. The environmental vegetation index: A tool potentially useful for arid land management. [Texas and Mexico, plant growth stress due to water deficits

    Science.gov (United States)

    Gray, T. I., Jr.; Mccrary, D. G. (Principal Investigator)

    1981-01-01

    The NOAA-6 AVHRR data sets acquired over South Texas and Mexico during the spring of 1980 and after Hurricane Allen passed inland are analyzed. These data were processed to produce the Gray-McCrary Index (GMI's) for each pixel location over the selected area, which area contained rangeland and cropland, both irrigated and nonirrigated. The variations in the GMI's appear to reflect well the availability of water for vegetation. The GMI area maps are shown to delineate and to aid in defining the duration of drought; suggesting the possibility that time changes over a selected area could be useful for irrigation management.

  6. Exploration of Loggerhead Shrike Habitats in Grassland National Park of Canada Based on in Situ Measurements and Satellite-Derived Adjusted Transformed Soil-Adjusted Vegetation Index (ATSAVI

    Directory of Open Access Journals (Sweden)

    Li Shen

    2013-01-01

    Full Text Available The population of loggerhead shrike (Lanius ludovicianus excubutirudes in Grassland National Park of Canada (GNPC has undergone a severe decline due to habitat loss and limitation. Shrike habitat availability is highly impacted by the biophysical characteristics of grassland landscapes. This study was conducted in the west block of GNPC. The overall purpose was to extract important biophysical and topographical variables from both SPOT satellite imagery and in situ measurements. Statistical analysis including Analysis of Variance (ANOVA, measuring Coefficient Variation (CV, and regression analysis were applied to these variables obtained from both imagery and in situ measurement. Vegetation spatial variation and heterogeneity among active, inactive and control nesting sites at 20 m × 20 m, 60 m × 60 m and 100 m × 100 m scales were investigated. Results indicated that shrikes prefer to nest in open areas with scattered shrubs, particularly thick or thorny species of smaller size, to discourage mammalian predators. The most important topographical characteristic is that active sites are located far away from roads at higher elevation. Vegetation index was identified as a good indicator of vegetation characteristics for shrike habitats due to its significant relation to most relevant biophysical factors. Spatial variation analysis showed that at all spatial scales, active sites have the lowest vegetation abundance and the highest heterogeneity among the three types of nesting sites. For all shrike habitat types, vegetation abundance decreases with increasing spatial scales while habitat heterogeneity increases with increasing spatial scales. This research also indicated that suitable shrike habitat for GNPC can be mapped using a logistical model with ATSAVI and dead material in shrub canopy as the independent variables.

  7. Abundance and Dynamics of Soil Labile Carbon Pools Under Different Types of Forest Vegetation

    Institute of Scientific and Technical Information of China (English)

    JIANG Pei-Kun; XU Qiu-Fang

    2006-01-01

    Soil organic matter (SOM) in forest ecosystems is not only important to global carbon (C) storage but also to sustainable management of forestland with vegetation types, being a critical factor in controlling the quantity and dynamics of SOM. In this field experiment soil plots with three replicates were selected from three forest vegetation types: broadleaf,Masson pine (Pinus massoniana Lamb.), and Chinese fir (Cunninghamia lanceolata Hook.). Soil total organic C (TOC),two easily oxidizable C levels (EOC1 and EOC2, which were oxidized by 66.7 mmol L-1 K2Cr2O7 at 130-140 ℃ and333 mmol L-1 KMnO4 at 25 ℃, respectively), microbial biomass C (MBC), and water-soluble organic C (WSOC)were analyzed for soil samples. Soil under the broadleaf forest stored significantly higher TOC (P ≤ 0.05). Because of its significantly larger total soil C storage, the soil under the broadleaf forest usually had significantly higher levels (P ≤ 0.05)of the different labile organic carbons, EOC1, EOC2, MBC, and WSOC; but when calculated as a percentage of TOC each labile C fraction of the broadleaf forest was significantly lower (P ≤ 0.05) than one of the other two forests. Under all the three vegetation types temperature as well as quality and season of litter input generally affected the dynamics of different organic C fractions in soils, with EOC1, EOC2, and MBC increasing closely following increase in temperature,whereas WSOC showed an opposite trend.

  8. Differences between Used and Available Microhabitats and Vegetation Types for Giant Gartersnakes Associated with a Restored Marsh in California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data describe differences in percent cover of microhabitats and vegetation types at giant gartersnake locations and random points paired with giant gartersnake...

  9. Prediction of high spatio-temporal resolution land surface temperature under cloudy conditions using microwave vegetation index and ANN

    Science.gov (United States)

    Shwetha, H. R.; Kumar, D. Nagesh

    2016-07-01

    Land Surface Temperature (LST) with high spatio-temporal resolution is in demand for hydrology, climate change, ecology, urban climate and environmental studies, etc. Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the most commonly used sensors owing to its high spatial and temporal availability over the globe, but is incapable of providing LST data under cloudy conditions, resulting in gaps in the data. In contrast, microwave measurements have a capability to penetrate under clouds. The current study proposes a methodology by exploring this property to predict high spatio-temporal resolution LST under cloudy conditions during daytime and nighttime without employing in-situ LST measurements. To achieve this, Artificial Neural Networks (ANNs) based models are employed for different land cover classes, utilizing Microwave Polarization Difference Index (MPDI) at finer resolution with ancillary data. MPDI was derived using resampled (from 0.25° to 1 km) brightness temperatures (Tb) at 36.5 GHz channel of dual polarization from Advance Microwave Scanning Radiometer (AMSR)-Earth Observing System and AMSR2 sensors. The proposed methodology is tested over Cauvery basin in India and the performance of the model is quantitatively evaluated through performance measures such as correlation coefficient (r), Nash Sutcliffe Efficiency (NSE) and Root Mean Square Error (RMSE). Results revealed that during daytime, AMSR-E(AMSR2) derived LST under clear sky conditions corresponds well with MODIS LST resulting in values of r ranging from 0.76(0.78) to 0.90(0.96), RMSE from 1.76(1.86) K to 4.34(4.00) K and NSE from 0.58(0.61) to 0.81(0.90) for different land cover classes. During nighttime, r values ranged from 0.76(0.56) to 0.87(0.90), RMSE from 1.71(1.70) K to 2.43(2.12) K and NSE from 0.43(0.28) to 0.80(0.81) for different land cover classes. RMSE values found between predicted LST and MODIS LST during daytime under clear sky conditions were within acceptable

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

    Directory of Open Access Journals (Sweden)

    Algimantas Mečislovas Olšausaks

    2009-12-01

    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.

  11. VEGETATIVE SUPPORT OF CARDIAC ACTIVITY IN ATHLETES WITH DIFFERENT ANTHROPOMETRIC PROFILE

    Directory of Open Access Journals (Sweden)

    O. N. Kudrya

    2016-01-01

    Full Text Available The purpose of research – to study the features of the functioning of the cardiovascular system and regulatory mechanisms of the young athletes of different heights.Materials and methods. The study included athletes aged 15-16 (32 girls and 36 boys engaged in competitive sports. To study the autonomic regulation of the cardiovascular system using mathematical methods and spectral analysis of heart rate variability. To characterize the vegetative support the circulatory apparatus, all subjects performed an active orthostatic test.Results. The features of vegetative maintenance of heart activity in tall athletes: stress regulatory mechanisms observed resting in tall men and decrease the functionality of the sympathetic division of the autonomic nervous system during active orthostatic test in athletes of different sex. Athletes tall urgent adaptation of the cardiovascular system to changing external conditions associated with activation of suprasegmental divisions of the autonomic nervous system and the excessive activation of the sympathetic division, which is an inefficient way of adaptation.Conclusion. Thus, high growth is evident not only in the increase of total size of the body of athletes, but also in the peculiarities of morphofunctional state involved, indicating the need of individual rationing of loads for tall players. The revealed morphofunctional characteristics of the organism tall athletes allow us to recommend an increase in the proportion of aerobic exercise to enhance the adaptive capacities of the organism. 

  12. Acidity and origin of dissolved organic carbon in different vegetation zones

    Science.gov (United States)

    Hruška, Jakub; Oulehle, Filip; Myška, Oldřích; Chuman, Tomáš

    2016-04-01

    The acid/base character of aquatic dissolved organic carbon (DOC) has been studied intensively during recent decades with regard to the role of DOC in stream water acidity and the balance between natural acidity and anthropogenic acidification. Recently, DOC has been shown to play an important role in preindustrial surface waters. Studies focused on the acid/base properties of DOC have been carried out in mainly in Europe and North America and paint a conflicting picture. Some studies reported large differences in acid base properties, sometimes between quite similar and nearby localities, or between seasons at the same site. Other studies, however, found similar acid/base properties in waters from a variety of sites, sometimes far from each other as well as stable acid/base properties at the same site through different seasons or runoff events. Site density of DOC (amount of carboxylic groups per milligram of DOC) and SUVA was measured for streams (or small tundra ponds respectively) from the tundra in northern Alaska, boreal zone of Sweden, western Czech Republic (temperate region), and tropical Congo rain forest in central Africa. At least 10 samples from each region were taken from surface waters during the growing season. Titration of carboxylic groups after proton saturation on cation-exchange resin was used for site density determination. Despite very different climatic and vegetation properties and internal variation within a region, there was no statistically significant difference among regions for site density (it varied between 10.2-10.5 ueq/mg DOC) as well as for SUVA (tested by ANOVA). Results suggest that different vegetation and climate produced generally the same DOC in respect of acid/base character and SUVA. It also suggests that use of the one analytical technique was more important than differences between climatic zones itself.

  13. Yield and vegetative growth of cactus pear at different spacings and under chemical fertilizations

    Directory of Open Access Journals (Sweden)

    João A. da Silva

    2016-06-01

    Full Text Available ABSTRACT The objective was to evaluate the effect of different spacings and mineral fertilizations on cactus pear growth and production in a randomized block design, with three replicates, in a 3 x 4 factorial scheme: three spacings, 1.00 x 0.50 m, 2.00 x 0.25 m and 3.00 x 1.00 x 0.25 m, and four fertilizations, 000-000-000, 000-150-000, 200-150-000 and 200-150-100 kg ha-1 of N, P2O5 and K2O, respectively. Plant growth was evaluated between 90 and 390 days and production and growth were evaluated at 620 days after planting. There were significant interactions between spacing and fertilization for plant height, number of cladodes and cladode area index from 90 to 390 days and for production of fresh and dry matter at 620 days after planting. Spacing influenced cladode area index, while fertilization influenced plant height, number of cladodes and cladode area index at 620 days after planting. Plant height showed cubic effect for the days after planting. Number of cladodes and cladode area index were dependent on spacing, fertilization and plant age, and fitted to cubic models. The best results of growth and production of fresh and dry matter are associated with NPK and NP fertilizations and the spacing of 1.00 x 0.50 m.

  14. Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age

    DEFF Research Database (Denmark)

    Jelenkovic, Aline; Yokoyama, Yoshie; Sund, Reijo

    2015-01-01

    A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins...

  15. Ethnic Differences in Eating Disorder Symptoms among College Students: The Confounding Role of Body Mass Index.

    Science.gov (United States)

    Arriaza, Cecilia A.; Mann, Traci

    2001-01-01

    Explored the role of body mass index (BMI) in eating disorders among Hispanic, Asian American, and non-Hispanic white female college students. Data from student surveys indicated that after controlling for BMI, ethnic differences in eating disorder symptoms of concern about weight and shape disappeared, but differences in restrained eating…

  16. Low perfusion index affects the difference in glucose level between capillary and venous blood

    Directory of Open Access Journals (Sweden)

    Acar N

    2014-11-01

    Full Text Available Nurdan Acar,1 Hamit Ozcelik,1 Arif Alper Cevik,1 Engin Ozakin,1 Goknur Yorulmaz,2 Nur Kebapci,2 Ugur Bilge,3 Muzaffer Bilgin4 1Emergency Department, 2Endocrinology Department, 3Family Medicine Department, 4Biostatistics Department, Medical School, Eskisehir Osmangazi University, Eskisehir, Turkey Aim: In emergency cases, finger stick testing is primarily used to check the blood glucose value of patients since it takes longer to obtain the venous value. In critical patients, under conditions that cause an increase in metabolic state and level of stress, there occurs considerable difference in glucose levels between capillary and venous measurements. This study aimed to investigate the comparability of capillary and venous glucose values, according to the perfusion index level obtained with the Masimo Radical-7® device, in critical patients aged 18 years and over.Method: We conducted this prospective and observational study in the emergency department of the Eskisehir Osmangazi University hospital between November 3, 2008 and February 2, 2009.Results: The blood glucose of 300 critical patients was checked by finger stick in the emergency unit. The participants with normal vital signs had perfusion index between 0 and 5; the results obtained by the two methods were more consistent for perfusion index values of 6 and over. The results were most consistent in aged participants with normal vital sign findings and low perfusion index and in young patients with high perfusion index. In the cases where at least one of the vital signs was abnormal, the glucose values obtained by the two methods were more consistent when the perfusion index was 6 or over. In this group, independently from the perfusion index value, the consistency was higher in younger patients compared with aged patients.Conclusion: In the emergency department, perfusion index value measured by Masimo Radical-7 and capillary blood glucose levels can serve in blood sugar management in

  17. Sixteen years of agricultural drought assessment of the BioBío region in Chile using a 250 m resolution Vegetation Condition Index (VCI)

    Science.gov (United States)

    Zambrano, Francisco; Lillo-Saavedra, Mario; Verbist, Koen; Lagos, Octavio

    2016-10-01

    Drought is one of the most complex natural hazards because of its slow onset and long-term impact; it has the potential to negatively affect many people. There are several advantages to using remote sensing to monitor drought, especially in developing countries with limited historical meteorological records and a low weather station density. In the present study, we assessed agricultural drought in the croplands of the BioBio Region in Chile. The vegetation condition index (VCI) allows identifying the temporal and spatial variations of vegetation conditions associated with stress because of rainfall deficit. The VCI was derived at a 250m spatial resolution for the 2000-2015 period with the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD13Q1 product. We evaluated VCI for cropland areas using the land cover MCD12Q1 version 5.1 product and compared it to the in situ Standardized Precipitation Index (SPI) for six-time scales (1-6 months) from 26 weather stations. Results showed that the 3-month SPI (SPI-3), calculated for the modified growing season (Nov-Apr) instead of the regular growing season (Sept-Apr), has the best Pearson correlation with VCI values with an overall correlation of 0.63 and between 0.40 and 0.78 for the administrative units. These results show a very short-term vegetation response to rainfall deficit in September, which is reflected in the vegetation in November, and also explains to a large degree the variation in vegetation stress. It is shown that for the last 16 years in the BioBio Region we could identify the 2007/2008, 2008/2009, and 2014/2015 seasons as the three most important drought events; this is reflected in both the overall regional and administrative unit analyses. These results concur with drought emergencies declared by the regional government. Future studies are needed to associate the remote sensing values observed at high resolution (250m) with the measured crop yield to identify more detailed individual crop

  18. Sixteen Years of Agricultural Drought Assessment of the BioBío Region in Chile Using a 250 m Resolution Vegetation Condition Index (VCI

    Directory of Open Access Journals (Sweden)

    Francisco Zambrano

    2016-06-01

    Full Text Available Drought is one of the most complex natural hazards because of its slow onset and long-term impact; it has the potential to negatively affect many people. There are several advantages to using remote sensing to monitor drought, especially in developing countries with limited historical meteorological records and a low weather station density. In the present study, we assessed agricultural drought in the croplands of the BioBío Region in Chile. The vegetation condition index (VCI allows identifying the temporal and spatial variations of vegetation conditions associated with stress because of rainfall deficit. The VCI was derived at a 250 m spatial resolution for the 2000–2015 period with the Moderate Resolution Imaging Spectroradiometer (MODIS MOD13Q1 product. We evaluated VCI for cropland areas using the land cover MCD12Q1 version 5.1 product and compared it to the in situ Standardized Precipitation Index (SPI for six-time scales (1–6 months from 26 weather stations. Results showed that the 3-month SPI (SPI-3, calculated for the modified growing season (November–April instead of the regular growing season (September–April, has the best Pearson correlation with VCI values with an overall correlation of 0.63 and between 0.40 and 0.78 for the administrative units. These results show a very short-term vegetation response to rainfall deficit in September, which is reflected in the vegetation in November, and also explains to a large degree the variation in vegetation stress. It is shown that for the last 16 years in the BioBío Region we could identify the 2007/2008, 2008/2009, and 2014/2015 seasons as the three most important drought events; this is reflected in both the overall regional and administrative unit analyses. These results concur with drought emergencies declared by the regional government. Future studies are needed to associate the remote sensing values observed at high resolution (250 m with the measured crop yield to identify

  19. Growth and photosynthetic capacity in two woody species of cerrado vegetation under different radiation availability

    Directory of Open Access Journals (Sweden)

    Ronquim Carlos Cesar

    2003-01-01

    Full Text Available Seedlings of two woody species of cerrado vegetation, Copaifera langsdorffii and Eriotheca gracilipes, were studied under three different radiation availability (100, 80 and 30% transmittance. Full solar radiation brought about more biomass, higher total leaf area, higher maximal photosynthesis per crown on area or on mass bases and higher photosynthetic capacity on area bases. Only the photosynthetic capacity values on leaf mass bases were higher in both species under low radiation availability (80 and 30% transmittance. The differences of accumulated biomass appeared more clearly after 4 months of sowing but the root/shoot dry biomass ratio and height were maintained constant for both species independently of the available radiation. Cultivated under full solar radiation both species will be able to cover more suitable the two processes during seedling's phase: growth and defense.

  20. Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

    Science.gov (United States)

    Fang, Xuening; Zhao, Wenwu; Wang, Lixin; Feng, Qiang; Ding, Jingyi; Liu, Yuanxin; Zhang, Xiao

    2016-08-01

    Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80-500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120-140 and 480-500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80-220 cm); (ii) a transition layer (220-400 cm); and (iii) a stable layer (400-500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially

  1. Effect of Different Vegetation Systems on Soil Erosion and Soil Nutrients in Red Soil Region of Southeastern China

    Institute of Scientific and Technical Information of China (English)

    TIAN GUANGMING; WANG FEIER; CHEN YINGXU; HE YUNFENG; FU QINGLIN; S.KUMAR; LIN QI

    2003-01-01

    The effect of different vegetation systems including bamboo plantation (BP), forest ecosystem (CF),citrus orchard (Ctr) and farmland (FL) on erosion and nutrients of red soil were investigated in hilly region of southeastern China to find effective control measures for soil erosion. The results showed that all the vegetation systems could significantly reduce soil erosion and nutrient losses compared to bare land (Br).The ability of different vegetation systems to conserve soil and water was in the order of Ctr > BP > CF > FL > Br. Vegetation could also improve soil fertility. The soil organic matter, total N and total P contents were much higher in all the vegetation systems than in bare land, especially for the top soils. Vegetation systems improved soil physical properties remarkably. Compared to the bare land, soil organic matter, TP,TK and available K, especially soil microbial biomass C, N and P, increased under all the vegetation covers.However, they were still much lower than expected, thus these biological measurements are still needed to be carried out continuously.

  2. 我国温度植被旱情指数TVDI的应用现状及问题简述%Introduction of Application of Temperature Vegetation Dryness Index in China

    Institute of Scientific and Technical Information of China (English)

    沙莎; 郭铌; 李耀辉; 韩涛; 赵艳霞

    2014-01-01

    Reducing of vegetation index and rising of surface temperature are two kinds of important physiological performance of plants when they are under severe drought stress,so remote -drought indices based on vegetation index(VI)and land surface temperature (LST)are commonly used in drought monitoring.Indices based on vegetation index are difficult to exclude the influence of irrigation, pest and the flood disasters,and due to their larger lag time,they are difficult to monitor drought events which occurred suddenly.The land surface temperature is rising rapidly under the condition of water deficiency,so the indices based on land surface temperature (LST)can detect drought events,but it can’t distinguish water stress conditions under different vegetation cover and it’s easy to be influenced by the surface heat exchange and soil background temperature.The temperature vegetation drought index(TVDI)based on spectral feature space combined the vegetation index and land surface temperature,its physical meaning is more definite and it is well defined.TVDI could overcoming the deficiency of using VI and LST only,there for it is widely used to estimate evapotranspiration and soil moisture.For well understanding the application situation of TVDI in our country and the method to calculate and improve it,this paper expounded the principle of TVDI firstly,and then gave a detail introduce about the calculation and improving methods as well as the way of monitoring drought based on TVDI,etc.The aim is to offer some reference for the calculation and application of TVDI.%植被指数和地表温度是2类常见的遥感干旱监测方法,它们分别利用植被受旱时植被指数降低和植被冠层温度升高这2种重要的生理表现来监测干旱。但植被指数对干旱指示具有一定滞后性,地表温度监测干旱时易受土地背景等影响。基于特征空间的温度植被旱情指数(TVDI )综合了植被指数和地表温度监测干旱的特

  3. Ambient flux-based critical values of ozone for protecting vegetation: differing spatial scales and uncertainties in risk assessment

    Science.gov (United States)

    Grünhage, L.; Krupa, S. V.; Legge, A. H.; Jäger, H.-J.

    The current European critical levels for ozone (O 3) to protect crops, natural and semi-natural vegetation and forest trees (Level I) are based on the accumulated exposure over a threshold of 40 ppb exposure index. For the revision of the 1999 UN-ECE protocol (Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution to Abate Acidification, Eutrophication and Ground-Level Ozone. Gothenburg, 30 November), critical levels are partly replaced by critical cumulative stomatal uptake (critical absorbed dose or CAD). Here, we discuss possible improvements in deriving CAD. At present, the main problems with the flux approach can be attributed to uncertainties in the parameterisation of, (1) stomatal conductance, (2) non-stomatal deposition, and (3) the representativeness of species used in flux-effect studies. Although in general, the flux approach is well accepted by plant effects scientists in North America, concerted research efforts have not taken place in that direction. Furthermore, because of the differences in the approach to setting ambient air quality standards, it appears very doubtful that policy makers and air quality regulators in the US and Canada will readily accept the overall philosophy.

  4. Study and application of Northwest Guangxi drought remote sensing monitoring based on vegetation supply water index%基于植被供水指数的桂西北旱情遥感监测研究与应用

    Institute of Scientific and Technical Information of China (English)

    黄建波; 吴立愿; 张文明

    2014-01-01

    In view of frequent extreme weather,drought increasing and being more and more serious,Northwest Guangxi was studied. Remote sensing images of different periods were collected. Based on analysis of image indexes such as vegetation and temperature,grading rules of vegetation supply water index was determined according to his⁃torical drought information. In accordance with the rules,real-time and dynamic drought information monitoring is possible. The achievements of study may strengthen drought alarm capability and provide technical basis for drought prevention and protection.%针对极端天气频繁出现,干旱增多、严重等问题,以桂西北为研究区域,获取不同时期遥感影像数据,通过分析植被及温度等影像指数,依据历史旱情发生情况,建立植被供水指数分级规则,并依此规则,可实时、动态地监测旱情信息。其成果可增强旱情的预警能力,为防旱、抗旱决策提供了技术参考依据。

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

    Directory of Open Access Journals (Sweden)

    SUNITA UGALE

    2010-09-01

    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.

  6. Effects of different vegetation types on the shear strength of root-permeated soils

    Science.gov (United States)

    Yildiz, Anil; Graf, Frank; Rickli, Christian; Springman, Sarah M.

    2016-04-01

    The effects of vegetation and, in particular, of forests on the stability of slopes are well recognized and have been widely studied in recent decades. However, there is still a lack of understanding of the underlying processes that occur prior to triggering superficial failures in root-permeated soil. Thus, appropriate quantification of the vegetation effects on the shear strength of soil is crucial in order to be able to evaluate the stability of a vegetated slope. Direct shear testing is widely employed to determine the shearing response of root-permeated soil. However, mechanical aspects of direct shear apparatuses may affect the shear strength parameters derived, which often remains unnoticed and hampers direct comparison between different studies. A robust Inclinable Large-scale Direct Shear Apparatus (ILDSA), with dimensions of 500x500x400 mm, was built in order to shear root-permeated soil specimens and to analyse the influence of the machine setup on the results, too. Two different sets of planted specimens were prepared using moraine (SP-SM) from a recent landslide area in Central Switzerland: a first set consisting of Alnus incana, Trifolium pratense, Poa pratensis and a second set, consisting of these three species complemented with Salix appendiculata, Achillea millefolium, Anthyllis vulneraria. Direct shear tests were conducted on specimens planted with the different vegetation types, at a constant rate of horizontal displacement of 1 mm/min up to a maximum horizontal displacement of 190 mm, and under three different applied normal stresses: 6 kPa, 11 kPa and 16 kPa. Artificial rainfall was applied at a constant intensity (100 mm/h) prior to shearing. Tensiometers had been installed close to the shear surface and were monitored continuously to obtain the matric suction during the saturation process. Suctions were reduced as close to 0 kPa as possible, in order to simulate the loss of strength after a heavy period of rainfall. The analyses of the above

  7. Calibration of the physiological equivalent temperature index for three different climatic regions

    Science.gov (United States)

    Krüger, E.; Rossi, F.; Drach, P.

    2017-02-01

    In human biometeorology, the integration of several microclimatic variables as a combined index facilitates the understanding of how users perceive thermal environments. Indices, such as the physiological equivalent temperature (PET) index, translate the combined effects of meteorological variables on humans in terms of thermal stress or comfort and serve as important aids to climate-responsive urban and regional planning as well as heat stress and thermal comfort analyses. However, there is a need for adjusting proposed comfort/stress ranges of a given index when using it in different climatic contexts. The purpose of this study is to present a preliminary calibration procedure for the PET index for three different climatic regions: Curitiba, Brazil, a subtropical location; Rio de Janeiro, Brazil, a tropical city; and Glasgow, UK, a high-latitude location. Field studies have been carried out by the authors according to a similar protocol and using similar equipment, yielding actual thermal sensation votes and microclimate data, post-processed as PET data. The calibration procedure uses exclusively thermal sensation data as reported by pedestrians during outdoor comfort campaigns and concurrent microclimatic data recorded during the interviews. PET comfort/stress classes differ among the three locations and, in general, are less restrictive as in the original ranges proposed by the index developers.

  8. Relationships between different burn, vegetation and soil ratios with Landsat spectral reflectance values in fire affected areas

    Science.gov (United States)

    Krina, Anastasia; Koutsias, Nikos

    2016-04-01

    The proportion of unburned vegetation within a fire affected area can be regarded as a proxy measure of fire severity that can be estimated by means of remote sensing techniques. Yet, in order to obtain sound results, it is essential to improve our current knowledge regarding the spectral discrimination of areas that have been completely burnt from adjacent areas within a fire perimeter that still have patches of vegetation, or unburned proportion of vegetation on them. The aim of our research is to reveal the role of the vegetation or the small vegetation gaps in spectral characteristics of pixels with mixed land cover synthesis (burned, vegetation and soil) to achieve a better assessment of fire mapping and the impact of fire in the burned area. Three land cover types were identified, namely vegetation, bare land and burned area by applying pixel based classification using the maximum likelihood algorithm in high-resolution aerial photographs (1m). Moreover, multispectral satellite Landsat data that were acquired close to capture date of the aerial photos and were converted to TOC reflectance from USGS, were used to measure the association between land cover portions and satellite-derived VIs and spectral signatures. A grid of 30x30m was created to extract the ratio of the land cover categories corresponding to each selected pixel of the satellite image LANDSAT TM. Samples of different land cover ratios and of different types of substrate (e.g. rocks, light- or dark-colored soil) were delineated and their reflectance values at each spectral channel were extracted and used to calculate statistics in order to characterize the spectral properties. Finally, various vegetation indices were computed to investigate the role of the proportion of land cover and substrate in the variation of VIs. The results of our study reveal the spectral characteristics of burnt area at the pixel level and suggest the efficiency of certain spectral channels for the estimation of the

  9. Evaluation Of Genetoxic Effect Of Radiation Over Vegetal Embryos In Species With Different Radiosensibilities

    Science.gov (United States)

    Vrîncianu, Diana; Ionită, Cristina; Băra, Iulia; Creangă, Dorina

    2012-12-01

    This study presents the effects induced by X-rays, medium doses (20-70 Gy), over the meristematic tissues of three cereal species: one of barley and two of wheat. The cytogenetic investigation was based on the response of young seedlings during their very early ontogenetic stages to the ionizing radiation exposure. The study was focused on the identification and counting of the chromosomal aberrations for various doses compared to the control samples. Qualitative evaluation revealed: interchromatidian bridges, expulsed chromosomes or chromosome fragments, and complex aberrations (combination of the already mentioned ones). The different behavior of these three species was discussed over the mitotic index, the number of abnormal ana-telophases and over the percentages of the mitosis phases. In each case, the mitotic index was increased in comparison with the control, and also the number of aberrations was found increased; however no evident mathematical correlations with applied doses could be established.

  10. Ultrasensitive optical microfiber coupler based sensors operating near the turning point of effective group index difference

    Science.gov (United States)

    Li, Kaiwei; Zhang, Ting; Liu, Guigen; Zhang, Nan; Zhang, Mengying; Wei, Lei

    2016-09-01

    We propose and study an optical microfiber coupler (OMC) sensor working near the turning point of effective group index difference between the even supermode and odd supermode to achieve high refractive index (RI) sensitivity. Theoretical calculations reveal that infinite sensitivity can be obtained when the measured RI is close to the turning point value. This diameter-dependent turning point corresponds to the condition that the effective group index difference equals zero. To validate our proposed sensing mechanism, we experimentally demonstrate an ultrahigh sensitivity of 39541.7 nm/RIU at a low ambient RI of 1.3334 based on an OMC with the diameter of 1.4 μm. An even higher sensitivity can be achieved by carrying out the measurements at RI closer to the turning point. The resulting ultrasensitive RI sensing platform offers a substantial impact on a variety of applications from high performance trace analyte detection to small molecule sensing.

  11. Race and sex differences in associations of vegetables, fruits, and carotenoids with lung cancer risk in New Jersey (United States).

    Science.gov (United States)

    Dorgan, J F; Ziegler, R G; Schoenberg, J B; Hartge, P; McAdams, M J; Falk, R T; Wilcox, H B; Shaw, G L

    1993-05-01

    We used data from a case-control study conducted in New Jersey between 1980 and 1983 to evaluate race and sex differences in associations of vegetable, fruit, and carotenoid consumption with lung cancer. Cases included 736 White males, 860 White females, 269 Black males, and 86 Black females with incident, histologically confirmed, primary cancer of the trachea, bronchus, or lung. Controls were identified through drivers' license and Health Care Financing Administration files and included 548 White males, 473 White females, 170 Black males, and 47 Black females. Usual intakes of vegetables (predominantly yellow/green) and fruit (predominantly yellow/orange) as well as other food sources of carotenoids were ascertained by a food frequency questionnaire. White females showed significant inverse associations of lung cancer with vegetables, fruit, and carotenoids. White males showed nonsignificant inverse associations with vegetables and carotenoids, and Black females just with vegetables. No inverse associations were found for Black males. Vegetable consumption was associated with risk of all histologic types of lung cancer, but the pattern of increasing risk with decreasing intake was limited to smokers. We infer that consumption of yellow/green vegetables and carotenoids may confer protection from lung cancer to White male and White female smokers. Further studies are needed to clarify the effect in Blacks.

  12. High resolution mapping of Normalized Difference Vegetation Indices (NDVI) of biological soil crusts

    Science.gov (United States)

    Fischer, T.; Veste, M.; Eisele, A.; Bens, O.; Spyra, W.; Hüttl, R. F.

    2012-04-01

    Normalized Difference Vegetation Indices (NDVI) are typically determined using satellite or airborne remote sensing, or field portable spectrometers, which give an averaged signal on centimetre to meter scale plots. Biological soil crust (BSC) patches may have smaller sizes, and ecophysiological, hydrological as well as pedological processes may be heterogeneously distributed within this level of resolution. A ground-based NDVI imaging procedure using low-cost equipment (Olympus Camedia 5000z digital camera equipped with a Hoya R72 infrared filter) was developed in this study to fill this gap at the level of field research, where carrying costly and bulky equipment to remote locations is often the limiting factor for data collection. A commercially available colour rendition chart (GretagMacbeth ColorChecker®) with known red (600-700 nm) and NIR (800-900 nm) reflectances was placed into each scene and used for calibration purposes on a per-image basis. Generation of NDVI images involved (i) determination of red and NIR reflectances from the pixel values of the red and NIR channels, respectively, and (ii) calculation and imaging of the NDVI, where NDVI values of -1 to +1 were mapped to grey values of 0 to 255. The correlation between NDVI values retrieved from these images and NDVI values determined using conventional field spectrometry (ASD FieldSpec 3 portable spectroradiometer) was close (r2 =0.91), the 95% confidence interval amounted to 0.10 NDVI units. The pixel resolution was 0.8 mm in the field and 0.2 mm in the laboratory, but can still be improved significantly with closer distance to the crust or with higher camera resolution. Geostatistical analysis revealed that both spatial variability as well as size of individual objects characterized by the NDVI increased with crust development. The latter never exceeded 4 mm in the investigated crusts, which points to the necessity of high resolution imaging for linking remote sensing with ecophysiology

  13. Multi-Temporal Crop Surface Models Combined with the RGB Vegetation Index from Uav-Based Images for Forage Monitoring in Grassland

    Science.gov (United States)

    Possoch, M.; Bieker, S.; Hoffmeister, D.; Bolten, A.; Schellberg, J.; Bareth, G.

    2016-06-01

    Remote sensing of crop biomass is important in regard to precision agriculture, which aims to improve nutrient use efficiency and to develop better stress and disease management. In this study, multi-temporal crop surface models (CSMs) were generated from UAV-based dense imaging in order to derive plant height distribution and to determine forage mass. The low-cost UAV-based RGB imaging was carried out in a grassland experiment at the University of Bonn, Germany, in summer 2015. The test site comprised three consecutive growths including six different nitrogen fertilizer levels and three replicates, in sum 324 plots with a size of 1.5×1.5 m. Each growth consisted of six harvesting dates. RGB-images and biomass samples were taken at twelve dates nearly biweekly within two growths between June and September 2015. Images were taken with a DJI Phantom 2 in combination of a 2D Zenmuse gimbal and a GoPro Hero 3 (black edition). Overlapping images were captured in 13 to 16 m and overview images in approximately 60 m height at 2 frames per second. The RGB vegetation index (RGBVI) was calculated as the normalized difference of the squared green reflectance and the product of blue and red reflectance from the non-calibrated images. The post processing was done with Agisoft PhotoScan Professional (SfM-based) and Esri ArcGIS. 14 ground control points (GCPs) were located in the field, distinguished by 30 cm × 30 cm markers and measured with a RTK-GPS (HiPer Pro Topcon) with 0.01 m horizontal and vertical precision. The errors of the spatial resolution in x-, y-, z-direction were in a scale of 3-4 cm. From each survey, also one distortion corrected image was georeferenced by the same GCPs and used for the RGBVI calculation. The results have been used to analyse and evaluate the relationship between estimated plant height derived with this low-cost UAV-system and forage mass. Results indicate that the plant height seems to be a suitable indicator for forage mass. There is a

  14. MULTI-TEMPORAL CROP SURFACE MODELS COMBINED WITH THE RGB VEGETATION INDEX FROM UAV-BASED IMAGES FOR FORAGE MONITORING IN GRASSLAND

    Directory of Open Access Journals (Sweden)

    M. Possoch

    2016-06-01

    Full Text Available Remote sensing of crop biomass is important in regard to precision agriculture, which aims to improve nutrient use efficiency and to develop better stress and disease management. In this study, multi-temporal crop surface models (CSMs were generated from UAV-based dense imaging in order to derive plant height distribution and to determine forage mass. The low-cost UAV-based RGB imaging was carried out in a grassland experiment at the University of Bonn, Germany, in summer 2015. The test site comprised three consecutive growths including six different nitrogen fertilizer levels and three replicates, in sum 324 plots with a size of 1.5×1.5 m. Each growth consisted of six harvesting dates. RGB-images and biomass samples were taken at twelve dates nearly biweekly within two growths between June and September 2015. Images were taken with a DJI Phantom 2 in combination of a 2D Zenmuse gimbal and a GoPro Hero 3 (black edition. Overlapping images were captured in 13 to 16 m and overview images in approximately 60 m height at 2 frames per second. The RGB vegetation index (RGBVI was calculated as the normalized difference of the squared green reflectance and the product of blue and red reflectance from the non-calibrated images. The post processing was done with Agisoft PhotoScan Professional (SfM-based and Esri ArcGIS. 14 ground control points (GCPs were located in the field, distinguished by 30 cm × 30 cm markers and measured with a RTK-GPS (HiPer Pro Topcon with 0.01 m horizontal and vertical precision. The errors of the spatial resolution in x-, y-, z-direction were in a scale of 3-4 cm. From each survey, also one distortion corrected image was georeferenced by the same GCPs and used for the RGBVI calculation. The results have been used to analyse and evaluate the relationship between estimated plant height derived with this low-cost UAV-system and forage mass. Results indicate that the plant height seems to be a suitable indicator for forage mass

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

    Science.gov (United States)

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

    2014-05-01

    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

  16. Vegetation Community Convergence of Pastoralists’ Pasture at Different Economic Levels in Desert Steppe

    Institute of Scientific and Technical Information of China (English)

    YIN Yan-ting; REN Ji-zhou; HOU Xiang-yang

    2014-01-01

    Vegetation characteristics of pastoralist households’ pastures at different economic levels were quantiifed to compare the grassland conditions in Sunite Right Banner, Inner Mongolia, China in 2011 and 2012. The results showed that the heights of Stipa klemenzis and Cleistogenes songorica were similar among economic treatments. And the height of Allium polyrhizm had no signiifcant differences between high-economic-level (HEL) and low-economic-level (LEL) treatments. There were no signiifcant difference among treatments in the canopy cover of C. songorica. The densities of dominant species (S. klemenzis, C. songorica and A. polyrhizm) were signiifcantly similar among treatments. Aboveground community biomass in reference area (CK) was higher than that in other three treatments in 2011, but their biomass showed no signiifcant difference among three economic treatments;for 2012, biomass in HEL was higher than low-economic-level treatment (LEL), while the biomass in middle-economic-level treatment (MEL) and CK was similar to that in HEL and LEL, respectively. Aboveground biomass of S. klemenzis and C. songorica was similar among treatments in both 2011 and 2012. Biomass of A. polyrhizum had no signiifcant difference between HEL and MEL. Households of LEL had rented out excess lands and those of HEL had leased their available lands thus resulting uniform utilization and convergence of pastoralist households’ pastures across all economic levels.

  17. A Fractal Method of Estimating Soil Structure Changes Under Different Vegetations on Ziwuling Mountains of the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shi-wei; SU Jing; YANG Yong-hui; LIU Na-na; WU Jin-shui; SHANGGUAN Zhou-ping

    2006-01-01

    Fractal method is a new method to estimate soil structure. It has been shown to be a useful tool in studies related to physical properties of soil as well as erosion and other hydrological processes. Fractal dimension was used to study the soil structure in soil at different stages of vegetative succession on the Ziwuling Mountains. The land use and vegetation types included cultivated land, abandoned land, grassland, two types of shrub land, and three types of forests. The grassland, shrub land, and forested areas represented a continuum in vegetative succession that had occurred naturally,as the land was abandoned in 1862. Disturbed and undisturbed soil samples were collected from ten vegetation types from depths of 0-10, 10-20, and 20-30 cm on the Ziwuling Mountains, at a site with an elevation of about 1 500 m. Particle size distribution was determined by the pipette method and aggregate size distribution was determined by wet sieving. The results were used to calculate the particle and aggregate fractal dimension. The results showed that particle and aggregate fractal dimensions varied between vegetation types. There was a positive correlation between the particle fractal dimension and the weight of particles with diameter < 0.001 mm, but no relationship between particle fractal dimension and the other particle size classes. Particle fractal dimension was lower in vegetated soils compared to cropland and there was no consistent relationship between fractal dimension and vegetation type. Aggregate fractal dimension was positively correlated with the weight of > 0.25 mm aggregates. Aggregate fractal dimension was lower in vegetated soils compared with cropland. In contrast to particle fractal dimension, aggregate fractal dimension described changes in soil structure associated with vegetative succession. The results of this study indicate that aggregate fractal dimension is more effective in describing soil structure and function compared with particle

  18. Performance comparison of different graylevel image fusion schemes through a universal image quality index

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2003-01-01

    We applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the refere

  19. Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age

    DEFF Research Database (Denmark)

    Yokoyama, Yoshie; Jelenkovic, Aline; Sund, Reijo

    2016-01-01

    We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years ...

  20. A Different Approach to Preparing Novakian Concept Maps: The Indexing Method

    Science.gov (United States)

    Turan Oluk, Nurcan; Ekmekci, Güler

    2016-01-01

    People who claim that applying Novakian concept maps in Turkish is problematic base their arguments largely upon the structural differences between the English and Turkish languages. This study aims to introduce the indexing method to eliminate problems encountered in Turkish applications of Novakian maps and to share the preliminary results of…

  1. Research of Aquatic Vegetation Classification based on NDVI Index in Luoma Lake%基于NDVI指数的骆马湖水生植被分级研究

    Institute of Scientific and Technical Information of China (English)

    曹毅; 王辉

    2014-01-01

    基于典型时段骆马湖 Landsat TM遥感影像,利用归一化植被指数(NDVI)法对骆马湖水生植被进行分级研究。采用标准差分级方法,将骆马湖水生植被分为5个等级。研究结果表明,利用这种分级方法处理的图像能够较准确地反映骆马湖水生植被区域分布和等级分区,能够更准确地给出采砂区和生态保护区域的位置,增强湖区水生态环境保护工作的有效性和针对性。%Based on a typical period of Luoma Lake Landsat images,and using normalized difference vege-tation index (NDVI),the aquatic vegetation classification research on Luoma Lake was carried out.Using the standard deviation and classification method,the Luoma Lake aquatic vegetation was divided into 5 grades.The results showed that,the images processed by this classification method could more accurately reflect the level of regional distribution and aquatic vegetation in Luoma Lake,more accurately position mining district and ecologi-cal protection areas,and improve ecological and environmental conservation work.

  2. Vegetation index-based crop coefficients to estimate evapotranspiration by remote sensing in agricultural and natural ecosystems

    Science.gov (United States)

    Glenn, E.P.; Neale, C. M. U.; Hunsaker, D.J.; Nagler, P.L.

    2011-01-01

    Crop coefficients were developed to determine crop water needs based on the evapotranspiration (ET) of a reference crop under a given set of meteorological conditions. Starting in the 1980s, crop coefficients developed through lysimeter studies or set by expert opinion began to be supplemented by remotely sensed vegetation indices (VI) that measured the actual status of the crop on a field-by-field basis. VIs measure the density of green foliage based on the reflectance of visible and near infrared (NIR) light from the canopy, and are highly correlated with plant physiological processes that depend on light absorption by a canopy such as ET and photosynthesis. Reflectance-based crop coefficients have now been developed for numerous individual crops, including corn, wheat, alfalfa, cotton, potato, sugar beet, vegetables, grapes and orchard crops. Other research has shown that VIs can be used to predict ET over fields of mixed crops, allowing them to be used to monitor ET over entire irrigation districts. VI-based crop coefficients can help reduce agricultural water use by matching irrigation rates to the actual water needs of a crop as it grows instead of to a modeled crop growing under optimal conditions. Recently, the concept has been applied to natural ecosystems at the local, regional and continental scales of measurement, using time-series satellite data from the MODIS sensors on the Terra satellite. VIs or other visible-NIR band algorithms are combined with meteorological data to predict ET in numerous biome types, from deserts, to arctic tundra, to tropical rainforests. These methods often closely match ET measured on the ground at the global FluxNet array of eddy covariance moisture and carbon flux towers. The primary advantage of VI methods for estimating ET is that transpiration is closely related to radiation absorbed by the plant canopy, which is closely related to VIs. The primary disadvantage is that they cannot capture stress effects or soil

  3. Large Differences in Terrestrial Vegetation Production Derived from Satellite-Based Light Use Efficiency Models

    Directory of Open Access Journals (Sweden)

    Wenwen Cai

    2014-09-01

    Full Text Available Terrestrial gross primary production (GPP is the largest global CO2 flux and determines other ecosystem carbon cycle variables. Light use efficiency (LUE models may have the most potential to adequately address the spatial and temporal dynamics of GPP, but recent studies have shown large model differences in GPP simulations. In this study, we investigated the GPP differences in the spatial and temporal patterns derived from seven widely used LUE models at the global scale. The result shows that the global annual GPP estimates over the period 2000–2010 varied from 95.10 to 139.71 Pg C∙yr−1 among models. The spatial and temporal variation of global GPP differs substantially between models, due to different model structures and dominant environmental drivers. In almost all models, water availability dominates the interannual variability of GPP over large vegetated areas. Solar radiation and air temperature are not the primary controlling factors for interannual variability of global GPP estimates for most models. The disagreement among the current LUE models highlights the need for further model improvement to quantify the global carbon cycle.

  4. 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)

    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

    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

  5. Caseinomacropeptide index in UHT whole milk stored under different conditions of temperature and time

    Directory of Open Access Journals (Sweden)

    C.N.B.C. Villanoeva

    2014-02-01

    Full Text Available Caseinomacropeptide (CMP index is a method used to detect adulteration of milk by addition of cheese whey, since CMP is a glycopeptide characteristic produced during cheesemaking, and soluble in the whey phase. The objective of this work was to evaluate the caseinomacropeptide index of UHT milk stored under different temperatures. Six batches of recently processed UHT milk were collected and stored under three temperatures (21ºC, 6ºC, and -12ºC and analyzed by HPLC in the day of the milk collection (day 0 and at 30, 60, 90, and 120 days of storage. The experiment was run as a randomized block design with a 3x5 factorial arrangement, and the Student-Newman-Keuls (SNK method was used as the post-hoc test (p = 0.05. There was a progressive increase of the CMP index during the storage period of 120 days, and this indicates the possibility of false positive results if the CMP index is used as an adulteration test for long term stored UHT milk. The validity of the CMP index as an adulteration indicator is only possible soon after packaging, and sample freezing is the only alternative when immediate analysis is not possible. The method was found to be precise, with robust CV of 1.9% even with high CMP levels.

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

    Directory of Open Access Journals (Sweden)

    Poornima Janipati

    2014-10-01

    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.

  7. Different Disinfectants Efficiency of Fruits and Vegetables Available in Market of

    Directory of Open Access Journals (Sweden)

    Abdollah Dargahi

    2013-11-01

    Full Text Available The fruits and vegetables are carrier microbial flora and in every stage of production, transportation, packaging, storage and sale to consumers are exposed to microbial contamination. Raw fruits and vegetables are suitable place for growing a variety of parasites and bacteria such as Shigella, Pseudomonas aeruginosa and Campylobacter that many of theirs can cause epidemic if the conditions have provide.

  8. Different Disinfectants Efficiency of Fruits and Vegetables Available in Market of

    OpenAIRE

    Abdollah Dargahi; Ali Almasi; Ehsan Sadeghi; Nasrin Safaipour

    2013-01-01

    The fruits and vegetables are carrier microbial flora and in every stage of production, transportation, packaging, storage and sale to consumers are exposed to microbial contamination. Raw fruits and vegetables are suitable place for growing a variety of parasites and bacteria such as Shigella, Pseudomonas aeruginosa and Campylobacter that many of theirs can cause epidemic if the conditions have provide.

  9. Evaluation of the nitrate content in leaf vegetables produced through different agricultural systems.

    Science.gov (United States)

    Guadagnin, S G; Rath, S; Reyes, F G R

    2005-12-01

    The nitrate content of leafy vegetables (watercress, lettuce and arugula) produced by different agricultural systems (conventional, organic and hydroponic) was determined. The daily nitrate intake from the consumption of these crop species by the average Brazilian consumer was also estimated. Sampling was carried out between June 2001 to February 2003 in Campinas, São Paulo State, Brazil. Nitrate was extracted from the samples using the procedure recommended by the AOAC. Flow injection analysis with spectrophotometric detection at 460 nm was used for nitrate determination through the ternary complex FeSCNNO+. For lettuce and arugula, the average nitrate content varied (p < 0.05) between the three agricultural systems with the nitrate level in the crops produced by the organic system being lower than in the conventional system that, in turn, was lower than in the hydroponic system. For watercress, no difference (p < 0.05) was found between the organic and hydroponic samples, both having higher nitrate contents (p < 0.05) than conventionally cultivated samples. The nitrate content for each crop species varied among producers, between different parts of the plant and in relation to the season. The estimated daily nitrate intake, calculated from the consumption of the crops produced by the hydroponic system, represented 29% of the acceptable daily intake established for this ion.

  10. A Satellite-Based Estimation of Evapotranspiration Using Vegetation Index-Temperature Trapezoid Concept: A Case Study in Southern Florida, U.S.A.

    Science.gov (United States)

    Yagci, A. L.; Santanello, J. A., Jr.; Jones, J. W.

    2015-12-01

    One of the key surface variables for hydrological applications, monitoring of natural and anthropogenic water consumption, closing energy balance and water budgets and drought identification is evapotranspiration (ET). There is currently a strong need for high temporal and spatial resolution ET products for climate and hydrological modelers. A satellite-based retrieval method based on vegetation index-temperature trapezoid (VITT) concept has been developed. This model has the ability to generate accurate ET estimates at high temporal and spatial resolutions by taking advantage of key remotely sensed parameters such as vegetation indices (VIs) and land surface temperature (LST) acquired by satellites as well as routinely-measured meteorological variables such as air temperature (Ta) and net radiation. For local-scale applications, the model has been successfully implemented in Python programming language and tested using Landsat satellite products at an eddy covariance flux tower in Florida. It is fully functional and automated such that there is no need of user intervention to run the model. The model development for continental-scale applications using VI and LST products from NASA satellites such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS) is currently in progress. The results for local-scale application and early results for continental-scale (US) will be presented and discussed.

  11. An angular vegetation index for imaging spectroscopy data—Preliminary results on forest damage detection in the Bavarian National Park, Germany

    Science.gov (United States)

    Fassnacht, Fabian Ewald; Latifi, Hooman; Koch, Barbara

    2012-10-01

    A vegetation index (VI) is presented which is calculated as the inner angles of a triangle. The triangle is spanned between three distinct points (on a spectral curve of imaging spectroscopy data) which are defined for each individual pixel by the wavelength (x-axis) and the reflection value (y-axis). The ideal wavelengths of the three points are dependent on the response variable investigated. The case-study within this paper in which this angular VI is applied, aims at the development of an index to automatically detect spruce bark beetle infections in the Bavarian National Park, Germany. In order to determine the optimum wavelengths to separate damaged from non-damaged trees the three-angle-indices (TAIs) for all possible combinations of available wavelengths of HyMap imaging spectroscopy data in the vis-NIR-region (0.455-0.986 μm) were calculated. The resulting 27,417 images served as input predictor variables to a genetic algorithm (GA) which used nearest centroid classifier as fitness functions to detect the most stable predictors and separate the six classes (three damage classes) defined within the study area. The fitness functions integrated in the GA reached classification accuracies of up to 94.8% when using forward selection models of the most stable genes featuring maximum 50 predictors. Based on those results, three from the original 27,417 predictors were extracted to map forest damages over the full image extent based on a support vector machines (SVMs) classification. We conducted the same experiment with 82 vegetation indices described in literature and achieved slightly lower GA overall accuracies of 86.8% using the nearest centroid classifier. The SVM maps produced with the three best VI predictors were comparable to the TAI results.

  12. Effect of different doses of dezocine on degree of emergence agitation under bispectral index monitoring

    Institute of Scientific and Technical Information of China (English)

    Xing-Bao Liang; Zong-Rong Guo

    2016-01-01

    Objective:To analyze the effect of different doses of dezocine on degree of emergence agitation under bispectral index monitoring. Methods:A total of 196 cases who received general anesthesia in our hospital from September 2012 to December 2014 were selected as research subjects, bispectral index (BIS) monitoring was continuously conducted during anesthesia induction and extubation anesthesia recovery, and according to different methods of dezocine intervention, they were randomly divided into control group, D1 group, D2 group and D3 group, each group with 49 cases. Differences in levels of recovery time-related indexes, BIS values before dezocine administration (T0), sputum suction before extubation (T1), extubation time (T2) and 10 min after extubation (T3), hemodynamic indexes and stress indexes of all groups were compared. Results:Recovery time and extubation time of D2 group were shorter than those of control group, D1 group and D3 group, restlessness scale after extubation and VAS were lower than those of control group and D1 group, and Ramsay sedation scale was higher than that of control group and D1 group (P0.05);cortisol and blood glucose levels at T1, T2 and T3 points in time of D2 and D3 group were lower than those of other two groups (P0.05). Conclusions:0.1 mg/kg dezocine administration before end of operation can reduce emergence agitation without causing excessive sedation or prolonged extubation time, and it has active significance in stabilizing patients’ hemodynamic and stress levels in extubation period.

  13. The trend of indexed papers in PubMed covering different aspects of self-immolation.

    Science.gov (United States)

    Rezaeian, Mohsen

    2014-01-01

    Self-immolation is a fatal and devastating method of committing suicide used around the world. The chief aim of the present article is to look at the trend of indexed papers in PubMed covering different aspects of self-immolation. PubMed search engine (http://www.ncbi.nlm.nih.gov) was searched by using six keywords i.e. "self-immolation", "self-inflicted burn", "self-burning", "self-incineration", "suicidal burns" and "suicide by burning". These keywords should appear either in the title or the abstract of the articles. The time frame was set as to retrieve papers expanding from early indexing time up to end of the year 2011. Based on the search strategy 132 papers were retrieved from these total numbers; 12 (9%) were categorized as review papers; 24 (18%) as case reports and the rest 96 (73%) were original studies. It seems that the number of papers increased during the years of investigations and the highest indexed papers i.e. 14 (10.6%) belonged to the year 2011. While most journals, published only one article the highest indexed papers i.e. 35 (26.5%) belonged to Burns. There was an increasing trend in the number of self-immolation articles indexed in PubMed since 1965. Three journals i.e. Burns, Journal of Burn Care and Rehabilitation and Journal of Forensic Sciences hosted for more than 37% of all those indexed articles. However, given the increasing trend of self-immolation still more studies are needed to shed light on the diverse aspects of this appalling human behavior.

  14. Essential and non-essential elements in natural vegetation in southern Norway: Contribution from different sources

    Energy Technology Data Exchange (ETDEWEB)

    Nordløkken, Marit, E-mail: marit.nordlokken@ntnu.no; Berg, Torunn; Flaten, Trond Peder; Steinnes, Eiliv

    2015-01-01

    Concentrations of essential and non-essential elements in five widespread species of natural boreal vegetation were studied with respect to seasonal variation and contribution from different sources. The plant species included in the study were Betula pubescens, Sorbus aucuparia, Vaccinium myrtillus, Vaccinium uliginosum, Calluna vulgaris and Deschampsia flexuosa. Concentrations of elements essential to plants remained essentially constant or decreased slightly throughout the growing season. Concentrations of most non-essential elements increased or tended to increase on a dry mass basis from June to July as well as from July to September. The increasing trend for these elements was observed for all species except C. vulgaris. Principal component analysis (PCA) of the material indicated a common source for many of the non-essential elements; Sc, Ti, V, Ga, As, Y, Sb, lanthanides, Pb, Bi, and U, i.e. both elements presumably of geogenic origin and elements associated with trans-boundary air pollution. Uptake by plant roots appeared to be the main source of nutrient elements as well as some non-essential elements. - Highlights: • Concentrations of elements in different plant species were studied. • Changes in concentrations during a growing season were identified. • PCA indicated a common source for many of the non-essential elements. • Uptake by roots appeared to be the plant’s main source of nutrient elements.

  15. Food safety controls in different governance structures in China’s vegetable and fruit industry

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie-hong; LI Kai; LIANG Qiao

    2015-01-01

    Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by ifrms with different governance structures in China. Food safety control is expressed by the folowing aspects, i.e., polution-free, green, organic, and/or geographical indication prod-ucts certiifcation, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most ifrms, folowed by products certiifcation, and production records are adopted by the fewest ifrms, and (2) agricul-tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    Directory of Open Access Journals (Sweden)

    Z. Yin

    2014-05-01

    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.

  18. Haze detection by using modified normalized difference haze index in Beijing, Tianjin, and Hebei province

    Science.gov (United States)

    Han, Xinlei; Yao, Fengmei; Zhang, Jiahua; Waqar, Mirza Muhammad; Zha, Yong; He, Junliang

    2016-04-01

    This paper presents the development of index to detect haze from moderate resolution imaging spectroradiometer remote sensing data. Detection of haze over a large area has always been a problem. This study focuses on Beijing, Tianjin, and Shijiazhuang cities in China. These cities have suffered the worst hazy weather in recent years. The spectral influence of haze on surface features was determined through analysis of the spectral variations of surface covers between hazy and haze-free days. A spectral index known as modified normalized difference haze index (m-NDHI) is developed that can be used to monitor haze distribution and intensity. Correlation analysis of the derived m-NDHI and previously developed NDHI with in situ PM2.5 (particulate matter with diameter <2.5 μm) data reveals that m-NDHI over water bodies has a coefficient of 0.7096, 0.5864, and 0.4857 and NDHI has coefficient of 0.5625, 0.5321, and 0.4618 with PM2.5 for Beijing, Tianjin, and Shijiazhuang, respectively, in winter. Moreover, the correlation of m-NDHI with PM2.5 is 0.4097, 0.8092, and 0.5546 during the spring, summer, and autumn, respectively, in Beijing. This developed index can be a much easier and more effective method to detect haze in large scales from remotely sensing data and characterize the situation of urban atmospheric pollution.

  19. Simulation Models of Leaf Area Index and Yield for Cotton Grown with Different Soil Conditioners.

    Directory of Open Access Journals (Sweden)

    Lijun Su

    Full Text Available Simulation models of leaf area index (LAI and yield for cotton can provide a theoretical foundation for predicting future variations in yield. This paper analyses the increase in LAI and the relationships between LAI, dry matter, and yield for cotton under three soil conditioners near Korla, Xinjiang, China. Dynamic changes in cotton LAI were evaluated using modified logistic, Gaussian, modified Gaussian, log normal, and cubic polynomial models. Universal models for simulating the relative leaf area index (RLAI were established in which the application rate of soil conditioner was used to estimate the maximum LAI (LAIm. In addition, the relationships between LAIm and dry matter mass, yield, and the harvest index were investigated, and a simulation model for yield is proposed. A feasibility analysis of the models indicated that the cubic polynomial and Gaussian models were less accurate than the other three models for simulating increases in RLAI. Despite significant differences in LAIs under the type and amount of soil conditioner applied, LAIm could be described by aboveground dry matter using Michaelis-Menten kinetics. Moreover, the simulation model for cotton yield based on LAIm and the harvest index presented in this work provided important theoretical insights for improving water use efficiency in cotton cultivation and for identifying optimal application rates of soil conditioners.

  20. COMPARISON OF BIODIESEL PRODUCTIVITIES OF DIFFERENT VEGETABLE OILS BY ACIDIC CATALYSIS

    Directory of Open Access Journals (Sweden)

    AYTEN SAGIROGLU

    2011-03-01

    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.

  1. Effects of Different Addition Amounts of Superphosphate on Vegetable Waste Compost

    Directory of Open Access Journals (Sweden)

    YANG Yan

    2017-01-01

    Full Text Available The effects of different addition amounts of superphosphate on vegetable waste compost were studied. Results showed that, addition of superphosphate improved the temperature during the compost. It had the highest temperature of 64.33℃, when the addition quantity of superphosphate was 10.26% of dry matter weight. At the end of the composting, adding superphosphate had no significant effect on C/N, however, it decreased pH and improved the EC of the compost. The EC values were significantly higher than CK, when the addition amount was be tween 4.10%and 10.26%of dry matter weight. When the addition below 10.26%, the GI values were significantly higher than CK(P<0.01, and the highest value was 105.61%, when the addition was 2.05%(S5. Adding superphosphate significantly reduced the nitrogen loss rate of composting(P<0.05, and the lowest was 23.94%,when the addition was 2.05%, meanwhile, the input-output ratio was 3.93, which was the highest value. Under this experimental condition, adding superphosphate promoted the compost maturity significantly, reduced the nitrogen loss rate, and the optimal addition of superphosphate was 2.05%of dry matter weight.

  2. Effects of different media on vegetative growth of two Lilium cultivars in soilless culture

    Directory of Open Access Journals (Sweden)

    A. Khaligy

    2011-07-01

    Full Text Available Strong, tall and healthy stems, as well as green background by means of leaves, are very important characters in marketing of cut flowers including Lily (Lilium. Also, in order to reuse the bulbs for next crop production, they should have enough stored materials and perimeter. This investigation was conducted to evaluate the effects of different media on some vegetative characters of two Lillium cultivars in greenhouse conditions and determine the most suitable medium. The experiment was based on randomized complete design with two cultivars namely Bernini (Oriental and Cebdazzle (Asiatic and 4 replicates. Ten treatments of the experiment were organic and mineral media including cocopeat, sand, vermiculite, perlite and mixture of each two media at equal volumes (50: 50. All the pots were fertigated daily by 250 ml of Hoagland half strength solution. Means were compared by Duncan multiple range test at 5% probability level. The results showed superiority of cocopeat over other media in terms of plant chlorophyll content, fresh and dry weight of leaves and stem, leaf area, height, stem diameter, number of leaves, and bulb perimeter in both cultivars. Root length of both cultivars reached the highest using the mixture of perlite and cocopeat. The performance of Cebdazzle cv. against Bernini cv. regarding fresh and dry weight of leaves, leaf area, stem diameter, number of leaves, stem dry weight and root length were better in all the media. While, mean chlorophyll content and fresh weight of stems in Bernini was significantly higher than Cebdazzle.

  3. Evaluating the effect of different vegetative filter strip designs on sediment movement in an agricultural watershed using LISEM, Iowa, USA

    Science.gov (United States)

    Luquin Oroz, Eduardo; Cruse, Rick; Baartman, Jantiene; Keesstra, Saskia

    2016-04-01

    Although restoration of native vegetation in vulnerable areas would decrease soil loss, this approach is not feasible in communities that base their income on agriculture. However, an alternative exists: strategically placing a small percentage of vegetative filter strips (VFS) within agriculture fields for erosion control. Factors influencing their effectiveness are shallow conditions, vegetation type, filter strip width, slope, soil type, and rainfall characteristics. Generally, the first few meters of the strip are where most sediments deposit. For slopes higher than 10%, effectiveness decreases with increasing slope gradient. Usually, high rainfall intensity and sediment load in overland flow decrease vegetative filter strips' effectiveness. Nowadays, Iowa (USA), experiences increasingly stronger rainstorms; climate change is expected to increase rainfall erosive forces between 16 to 58%. Thus, there is a need to obtain new insights about strip design and its influence on sediment dynamics. Therefore, the objective of this study is to analyze strip design (width) impact on soil and water movement. To do so, different strip widths (no strips, 1.5, 3, 5, 7.5 and 10 meters wide) were analyzed under four rainfall intensities (increments of 10, 25, 50 and 75%) The event-based, hydrological and soil erosion model LISEM was used to simulate different scenarios. The model has been calibrated with data from 3-ha 'Interim 1' watershed, which is part of Walnut Creek (Iowa, USA). During a single event with sediment load, on July 18th 2010, intensities reached up to 80 mm/h. Two different land covers exist: (i) perennial vegetation, which has prairie vegetation covering patches and strips; and (ii) row crop agriculture where corn and soybeans are the main two crops in the area. Based on the different combination of widths and intensities, 24 scenarios were generated. At the moment, the model is on the final part of the calibration; scenario results will be presented on the

  4. Physiological and Biochemical Indexes of Tibetan Sheep at Different Months of Age

    Institute of Scientific and Technical Information of China (English)

    Zhou Mingliang; Jiang Shihai; Chen Minghua; Yang Pinggui; Wu Weisheng; Xie Rongqing

    2015-01-01

    To study the changes in physiological and biochemical indexes of Tibetan sheep from the plateau area at different months of age,we measured the physiological and biochemical indexes of Tibetan sheep reared in Hongyuan County of Sichuan Province according to their growth stages. The results showed that the respiration,body temperature and heart rate of Tibetan sheep at 3- 24 months of age were( 24. 60 ± 6. 33)-( 50. 30 ± 21. 18) times / min,( 39. 14 ± 0. 28) ℃-( 39. 64 ± 0. 17) ℃ and( 91. 00 ± 13. 27)-( 112. 00 ± 8. 69) times/min,respectively. The blood physiological indexes of Tibetan sheep including white blood cell count( WBC),hematocrit( HCT) and red blood cell distribution width coefficient of variation( RDW- CV) at 3,6,15 and 18 months of age were relatively lower than those at 9,12,21 and 24 months of age. The blood physiological indexes including red blood cell count( RBC),mean corpuscular capacity( MCV),mean corpuscular hemoglobin concentration( MCHC) and mean corpuscular hemoglobin( MCH) at 3,6,15 and 18 months of age were relatively higher than those at 9,12,21 and 24 months of age,while hemoglobin( HGB) and platelet count( PLT) did not vary with months of age. For blood biochemical indexes,alanine aminotransferase( ALT),albumin( ALB),globulin( GLO) and total cholesterol( CHOL) reached the maximum values at 21 months of age; alkaline phosphatase( ALKP),lactate dehydrogenase( LDH),blood glucose( GLU) and pseudocholinesterase( PCHE) reached the maximum values at 3 months of age;and total calcium( CA),total protein( TP),aspartate aminotransferase( AST) reached the maximum values at 9,18 and 24 months of age,respectively.

  5. Monitoring of vegetation dynamics and assessing vegetation response to drought in the Iberian Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Haro, F. J.; Moreno, A.; Perez-Hoyos, A.; Gilabert, M. A.; Melia, J.; Belda, F.; Poquet, D.; Martinez, B.; Verger, A.

    2009-07-01

    Monitoring the vegetation activity over long time-scales is necessary to discern ecosystem response to climate variability. Spatial and temporally consistent estimates of the biophysical variables such as fractional vegetation cover (FVC) and leaf area index (LAI) have been obtained in the context of DULCINEA Project. We used long-term monthly climate statistics to build simple climatic indices (SPI, moisture index) at different time scales. From these indices, we estimated that the climatic disturbances affected both the growing season and the total amount of vegetation. This implies that the anomaly of vegetation cover is a good indicator of moisture condition and can be an important data source when used for detecting an monitoring drought in the Iberian Peninsula. The impact of climate variability on the vegetation dynamics has shown not to be the same for every region. We concluded that the relationships between vegetation anomaly and moisture availability are significant for the arid and semiarid areas. (Author) 6 refs.

  6. Effect of novel ultrasound based processing on the nutrition quality of different fruit and vegetable juices.

    Science.gov (United States)

    Khandpur, Paramjeet; Gogate, Parag R

    2015-11-01

    Increasing consumer awareness regarding the health benefits of different nutrients in food have led to the requirement of assessing the effect of food processing approaches on the quality attributes. The present work focuses on understanding the effects of novel approaches based on the use of ultrasound and ultraviolet irradiations on the nutritional quality of different fruit and vegetable juices (orange, sweet lime, carrot and spinach juices) and its comparison with the conventional thermal pasteurization operated at 80°C for 10 min. The ultrasound sterilization parameters were maintained at ultrasound frequency of 20 kHz and power of 100 W with treatment time as 15 min. For the case of ultraviolet irradiations, 2 UVC lamps (254 nm) of 8 W were placed in parallel on either sides of the reactor. The treated juices were analyzed for total phenol content, antioxidant activity, vitamin C, carbohydrates etc. It has been established that ultrasound processed juice retained most of the nutrient components to higher extent in comparison to all the other techniques used in the work. Combination of ultrasound and ultraviolet irradiations used to achieve an effective decontamination of juices (recommended 5 log reduction of microorganisms) also retained nutrients to a higher level in comparison to the thermal method; however some losses were observed as compared to the use of only ultrasound which could be attributed to inefficient heat exchange in the combined approach. A scale up attempt was also made for treatment of spinach juice using ultrasonic reactors and analysis for quality attributes confirmed that the juice satisfied the criteria of required nutrient contents for 18 days shelf life trial in refrigerated storage conditions. The present work has clearly established the usefulness of ultrasound based treatment in maintaining the nutritional quality of beverages while giving enhanced shelf life as compared to the conventional approaches.

  7. Effects of adding bentonite to different substrates on vegetative growth and yield of snap beans (Phaseulus vulgaris L.

    Directory of Open Access Journals (Sweden)

    P. Aghdak

    2010-12-01

    Full Text Available To study the effects of adding a superabsorbent (bentonite to different substrates on the vegetative growth and yield of snap beans, two randomized complete block design experiments with 4 replications were conducted at Greenhouse of Isfahan University of Technology. In the first experiment, 9 treatments including rice hull, saw dust, sand and their combinations, with 10 and 20% superabsorbent (v/v were used. The results showed that the highest stem length, number of nodes and leaves, shoot fresh weight and pod number were observed using rice hull (90%+superabsorbent (10%. The lowest vegetative growth was related to treatments containing sand and superabsorbent. Increasing superabsorbent from 10 to 20% reduced vegetative growth parameters in most cases. Based on the results of the first experiment, sand treatment was deleted and in the second experiment rice hull, saw dust, perlite and their combinations with 5 and 10% superabsorbent were used. The results showed that the highest plant height, number of nodes and leaves, plant dry weight, branch number and yield were obtained in perlite (95%+superabsorbent (5% and pure perlite. Adding 5 and 10% superabsorbent to rice hull and saw dust caused a significant increase in the vegetative growth. This increase was higher for 10% superabsorbent compared to 5% superabsorbent. Finally, the results showed that adding 10% superabsorbent to rice hull and saw dust increased vegetative growth and yield, while it decreased the loss of nutrient solution.

  8. Adapting Extension Food Safety Programming for Vegetable Growers to Accommodate Differences in Ethnicity, Farming Scale, and Other Individual Factors

    Science.gov (United States)

    Kline, Terence R.; Kneen, Harold; Barrett, Eric; Kleinschmidt, Andy; Doohan, Doug

    2012-01-01

    Differences in vegetable production methods utilized by American growers create distinct challenges for Extension personnel providing food safety training to producer groups. A program employing computers and projectors will not be accepted by an Amish group that does not accept modern technology. We have developed an outreach program that covers…

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

    Directory of Open Access Journals (Sweden)

    Z. Yin

    2013-09-01

    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 a new carbon-water-energy coupled model 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 maximizes 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, an important negative feedback mechanism 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.

  10. Timely monitoring of Asian Migratory locust habitats in the Amudarya delta, Uzbekistan using time series of satellite remote sensing vegetation index.

    Science.gov (United States)

    Löw, Fabian; Waldner, François; Latchininsky, Alexandre; Biradar, Chandrashekhar; Bolkart, Maximilian; Colditz, René R

    2016-12-01

    The Asian Migratory locust (Locusta migratoria migratoria L.) is a pest that continuously threatens crops in the Amudarya River delta near the Aral Sea in Uzbekistan, Central Asia. Its development coincides with the growing period of its main food plant, a tall reed grass (Phragmites australis), which represents the predominant vegetation in the delta and which cover vast areas of the former Aral Sea, which is desiccating since the 1960s. Current locust survey methods and control practices would tremendously benefit from accurate and timely spatially explicit information on the potential locust habitat distribution. To that aim, satellite observation from the MODIS Terra/Aqua satellites and in-situ observations were combined to monitor potential locust habitats according to their corresponding risk of infestations along the growing season. A Random Forest (RF) algorithm was applied for classifying time series of MODIS enhanced vegetation index (EVI) from 2003 to 2014 at an 8-day interval. Based on an independent ground truth data set, classification accuracies of reeds posing a medium or high risk of locust infestation exceeded 89% on average. For the 12-year period covered in this study, an average of 7504 km(2) (28% of the observed area) was flagged as potential locust habitat and 5% represents a permanent high risk of locust infestation. Results are instrumental for predicting potential locust outbreaks and developing well-targeted management plans. The method offers positive perspectives for locust management and treatment of infested sites because it is able to deliver risk maps in near real time, with an accuracy of 80% in April-May which coincides with both locust hatching and the first control surveys. Such maps could help in rapid decision-making regarding control interventions against the initial locust congregations, and thus the efficiency of survey teams and the chemical treatments could be increased, thus potentially reducing environmental pollution

  11. The effect of cutting regime on yield of sorghum in different climatic (vegetation seasons

    Directory of Open Access Journals (Sweden)

    Darko Uher

    2005-01-01

    Full Text Available Forage could be produced on natural grasslands, leys or arable land, but in lowland and in dry areas short season forage crops should be interpolated due to instability of yields from grasslands. Using that pattern, it is possible to better utilize the potential of arable land and the energy of the sun instead of leaving the fields empty (3-8 months, and to produce high yield of quality forage. Sorghum hybrids fit well in that system of forage production on family farms. It could be sown after harvesting of winter and early sown spring crops, and utilized in few cuts during a second part of summer, until the beginning of autumn and appearance of the first frost. Furthermore, it could ensure good yields of quality green forage and the rest quantity could be ensilaged. In that way higher yields of quality forage per hectare could be provided during vegetation season. The experiment was conducted at Maksimir experimental field, Faculty of Agriculture University of Zagreb. The aim of this research was to determine green mass yield (GMY and dry matter yield (DMY of sorghum (cv. Grazer N, at different cutting regime in two various seasons (dry and wet summer. The highest GMY and DMY were obtained when sorghum was cut 2 times at 200 cm height in 2002 and 2003 experimental years. Climatic conditions were better in the year 2002, so in that year GMY varied from 85.2 to 100.7 t/ha, while DMY varied from 18.7 to 31.0 t/ha. In the experimental year 2003 GMY varied from 58.6 to 86.6 t/ha, while DMY varied from 14.6 to 26.6 t/ha. Even in such unfavorable year, as 2003 was, sorghum (cv. Grazer N expressed its great potential for continuing utilization in summer and early autumn.

  12. Parallel Computing of Vegetation Index Products Based on MPI and OpenCV%基于MPI和OpenCV遥感植被指数产品的并行计算

    Institute of Scientific and Technical Information of China (English)

    崔丹丹; 张耀南; 赵国辉

    2013-01-01

    遥感传感器和计算机技术的发展,每天都会汇集大量新的地理空间数据。地球科学许多应用要求数据实时或接近实时地处理,发展高性能计算是进行海量数据处理的必然趋势。本文以 TM 影像制备黑河流域归一化指数产品为例,基于高性能集群,实现了植被指数快速提取的并行计算方法,并采用对等并行编程模式,通过 C 语言调用 MPI (Message Passing Interface,消息传递接口)和OpenCV (Open Source Computer Vision Library,开源计算机视觉库)函数库,实现了NDVI (Normalized Difference Vegetation Index,归一化植被指数)的并行计算,获得了黑河流域的NDVI。性能测试表明,并行计算可以显著提高遥感图像处理的速度。文章最后讨论了从原始影像提取植被指数产品的流程。%With the advances of sensors and computer technology, a large number of new geospatial data is collected every day. In particular, many current and future applications of remote sensing in earth science require real or near real-time processing capabilities. Employing high performance computing (HPC) for remote sensing missions is an inevitable trend. As an example, we have made products of normalized difference vegetation index in Heihe watershed, and this paper presents how to implement parallel processing of remote sensing image based on high performance cluster. We use C language combined with MPI and OpenCV library and apply peer-to-peer parallel programming model to realize the parallel computation of NDVI. The performance test shows that this parallel method can signiifcantly improve the speed of remote sensing image processing. At the end, the procedure of making vegetation index products from the original image is discussed.

  13. [Heidaigou Opencast Coal Mine: Soil Enzyme Activities and Soil Physical and Chemical Properties Under Different Vegetation Restoration].

    Science.gov (United States)

    Fang, Ying; Ma, Ren-tian; An, Shao-shan; Zhao, Jun-feng; Xiao, Li

    2016-03-15

    Choosing the soils under different vegetation recovery of Heidaigou dump as the research objects, we mainly analyzed their basic physical and chemical properties and enzyme activities with the method of Analysis of Variance as well as their relations using Pearson correlation analysis and path analysis hoping to uncover the driving factors of the differences between soil enzyme activities under different vegetation restoration, and provide scientific suggestions for the plant selection as well as make a better evaluation to the reclamation effect. The results showed that: (1) Although the artificial vegetation restoration improved the basic physical and chemical properties of the soils while increasing their enzyme activities to a certain extent, the soil conditions still did not reach the level of the natural grassland; (2) Contents of soil organic carbon (SOC) and soil total nitrogen (TN) of the seabuckthorns were the nearest to those of the grassland, which reached 54. 22% and 70. 00% of those of the grassland. In addition, the soil bulk density of the seabuckthorns stand was 17. 09% lower than the maximum value of the amorpha fruitcosa land. The SOC and TN contents as well as the bulk density showed that seabuckthorns had advantages as the species for land reclamation of this dump; Compared with the seabuckthorn, the pure poplar forest had lower contents of SOC and TN respectively by 35.64% and 32.14% and displayed a 16.79% higher value of soil bulk density; (3) The activities of alkaline phosphotase under different types of vegetation rehabilitation had little variation. But soil urease activities was more sensitive to reflect the effects of vegetation restoration on soil properties; (4) Elevation of the SOC and TN turned out to be the main cause for soil fertility restoration and increased biological activities of the dump.

  14. Feed intake and activity level of two broiler genotypes foraging different types of vegetation in the finishing period

    DEFF Research Database (Denmark)

    Almeida, Gustavo Fonseca; Hinrichsen, Lena Karina; Horsted, Klaus;

    2012-01-01

    were included in a 2 × 2 factorial design with groups of 25 birds replicated 3 times. The use of outdoor areas, performance, and forage intake were investigated. To identify possible differences in foraging activity, the use of the range was monitored one day per week at 4 different times of the day......A study was performed with 2 broiler genotypes (slow and medium growth) restricted in supplementary feed and foraging 2 different mixed vegetations (grass/clover or chicory) to identify possible benefits of herbage on nutrition during the finishing period (80 to 113 d of age). Three hundred birds....... Feed intake from foraging was estimated by killing 4 birds per plot (2 males and 2 females) in the morning and in the evening on 3 d during the experiment and measuring crop content. Vegetation type did not influence broiler use of the free-range area, feed intake, or performance. Differences...

  15. In vitro analysis of shear bond strength and adhesive remnant index of different metal brackets

    Directory of Open Access Journals (Sweden)

    Fernanda de Souza Henkin

    Full Text Available ABSTRACT Introduction: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. Objectives: To evaluate the bond strength and the adhesive remnant index (ARI of different brands of metal brackets. Material and Methods: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM. Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. Results: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM to 9.871 ± 5.106 MPa (TecnidentTM. The majority of the ARI index scores was 0 and 1. Conclusion: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface.

  16. In vitro analysis of shear bond strength and adhesive remnant index of different metal brackets

    Science.gov (United States)

    Henkin, Fernanda de Souza; de Macêdo, Érika de Oliveira Dias; Santos, Karoline da Silva; Schwarzbach, Marília; Samuel, Susana Maria Werner; Mundstock, Karina Santos

    2016-01-01

    ABSTRACT Introduction: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. Objectives: To evaluate the bond strength and the adhesive remnant index (ARI) of different brands of metal brackets. Material and Methods: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM). Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. Results: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM) to 9.871 ± 5.106 MPa (TecnidentTM). The majority of the ARI index scores was 0 and 1. Conclusion: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface. PMID:28125142

  17. Energy partitioning and environmental influence factors in different vegetation types in the GEWEX Asian Monsoon Experiment

    Science.gov (United States)

    Liu, Fengshan; Tao, Fulu; Li, Shenggong; Zhang, Shuai; Xiao, Dengpan; Wang, Meng

    2014-12-01

    Environmental influences upon energy balance in areas of different vegetation types (i.e., forest at Kog-Ma in Thailand and at Yakutsk in Russia, grassland at Amdo in Chinese Tibet and at Arvaikheer in Mongolia, and mixed farmland at Tak in Thailand) in the GEWEX Asian Monsoon Experiment were investigated. The sites we investigated are geographically and climatologically different; and consequently had quite large variations in temperature ( T), water vapor pressure deficit (VPD), soil moisture (SM), and precipitation (PPT). During May-October, the net radiation flux ( R n) (in W·m-2) was 406.21 at Tak, 365.57 at Kog-Ma, 390.97 at Amdo, 316.65 at Arvaikheer, and 287.10 at Yakutsk. During the growing period, the R n partitioned into latent heat flux ( λE/ R n) was greater than that partitioned into sensible heat flux ( H/ R n) at Tak and at Kog-Ma. In contrast, λE/ R n was lower than H/ R n at Arvaikheer, H/ R n was less than λE/ R n between DOY 149 and DOY 270 at Amdo, and between DOY 165 and DOY 235 at Yakutsk. The R n partitioned into ground heat flux was generally less than 0.15. The short-wave albedo was 0.12, 0.18, and 0.20 at the forest, mixed land, and grass sites, respectively. At an hourly scale, energy partitions had no correlation with environmental factors, based on average summer halfhourly values. At a seasonal scale energy partitions were linearly correlated (usually p<0.05) with T, VPD, and SM. The λE/ R n increased with increases in SM, T, and VPD at forest areas. At mixed farmlands, λE/ R n generally had positive correlations with SM, T, and VPD, but was restrained at extremely high values of VPD and T. At grasslands, λE/ R n was enhanced with increases of SM and T, but was decreased with VPD.

  18. Heavy Metals Levels in Soil and Vegetables in Different Growing Systems

    Directory of Open Access Journals (Sweden)

    Hura C.

    2013-04-01

    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

  19. Different body mass index grade on the risk of developing glioma: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Zifeng Dai; Qilin Huang; Haipeng Liu

    2015-01-01

    Background: Previous studies reported conflicting results about the risk of developing glioma and different body mass index.So we decided to execute a meta-analysis to solve the dispute.Methods: Comprehensive literature retrieval was carried in PubMed, MEDLINE, and EMBASE up to September 15, 2014.Hand literature information retrieval was not carried.Six studies were fit for this meta-analysis.Pooled hazard ratio (HR) and 95 % confidence interval (CI) of different body mass index grade were performed by fixed/random-effects models, except for normal weight which was referent.Results: Data of 3726 cases were included.Compared with normal weight (20 kg.m-2 < body mass index (BMI) ≤ 24.9 kg.m-2), the underweight (BMI ≤ 20 kg.m-2) might have lower incidence on the risk of developing glioma (HR =1.08, 95 % CI ranged 0.74 to 1.58, P =0.678).While the overweight (25 kg.m-2 < BMI ≤ 29.9 kg.m-2)and obesity (BMI ≥ 30 kg.m-2) were performed as a risk factor of developing glioma.The pooled HR of overweight group was 1.12 (95 % CI ranged 1.02 to 1.22, P=0.013);the pooled HR of obesity was 1.14 (95 % CI ranged 1.02 to 1.27, P =0.017).Sensitivity analysis approved that our results were stable.There was no publication bias of these studies.Conclusions: Underweight could decrease the risk of developing glioma.Excess BMI was considered as a risk factor to develop glioma.

  20. Crop Species Recognition and Discrimination Paddy-Rice from Reaped-Fields by the Radar Vegetation Index (rvi) of ALOS-2/PALSAR2

    Science.gov (United States)

    Yamada, Y.

    2016-06-01

    The Japanese ALOS-2 satellite was launched on May 24th, 2014. It has the L-band SAR, PALSAR-2. Kim,Y. and van Zyl, J.J. proposed a kind of Radar Vegetation Index (RVI) as RVI = 8 * σ0hv / (σ0hh + σ0vv + 2* σ0hv) by L-band full-polarimetric radar data. Kim, Y. and Jackson, T.J., et al. applied the equation into rice and soybean by multi-frequency polarimetric scatterometer above 4.16 meters from the ground. Their report showed the L-band was the most promising wave length for estimating LAI and NDVI from RVI. The author tried to apply the analysis to the actual paddy field areas, both Inashiki region and Miyagi region in the eastern main island, "Honshu", areas of Japan by ALOS-2/PALSAR-2 full-polarimetry data in the summer season, the main crop growing time, of 2015. Judging from conventional methods, it will be possible to discriminate paddy rice growing fields from reaped fields or the other crops growing fields by the PALSAR-2 data. But the RVI value is vaguely related to such land use or biomass at the present preliminary experiment. The continuous research by the additional PALSAR-2 full-polarimetry data should be desired.

  1. Effect of harvest at different times of day on the physical and chemical characteristics of vegetable-type soybean

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Santana

    2012-06-01

    Full Text Available The objective of this study was to evaluate the effect of harvest at different times of day on the chemical and physical characteristics of vegetable-type soybean BRS 267 cultivar, harvested at the R6 stage (seed development and to compare it with that on the grains harvested at the R8 stage (maturation. The pods of the BRS 267 cultivar were harvested at the R6 stage (at 8:00 AM, 12:00 AM, and 6:00 PM, the color parameters were evaluated, and the grains were analyzed for chemical composition, activity inhibitor trypsin, phytic acid content, starch, sugars, fatty acids, and isoflavones. No differences were observed among the different harvest times in terms of the chemical constituents of vegetable-type soybean BRS 267 cultivar harvested at the R6 stage. Isoflavones content did not change with different harvest times, and the aglycone forms (daidzein, glycitein, and genistein were found in smaller quantities at the R6 stage compared to the R8 stage. The color of the pods of soybean BRS 267 cultivar, harvested at the R6 stage did not change with different harvest times. The grains harvested at the R6 stage had lower protein content, phytic acid, and sucrose and higher levels of lipids, carbohydrates, starch, glucose, fructose, stachyose, and linolenic acids than those collected at the R8 stage. The different times of harvest did not affect the quality of the vegetable-type soybean BRS 267 cultivar harvested at stage R6. Nevertheless, it is recommended to harvest in the morning, when the temperature is milder, like other vegetables, to facilitate and optimize its marketing and in natura consumption.

  2. On the calculation of the topographic wetness index: evaluation of different methods based on field observations

    Directory of Open Access Journals (Sweden)

    R. Sørensen

    2006-01-01

    Full Text Available The topographic wetness index (TWI, ln(a/tanβ, which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwater level, soil moisture, and a constructed wetness degree. The TWI was calculated by varying six parameters affecting the distribution of accumulated area among downslope cells and by varying the way the slope was calculated. All possible combinations of these parameters were calculated for two separate boreal forest sites in northern Sweden. We did not find a calculation method that performed best for all measured variables; rather the best methods seemed to be variable and site specific. However, we were able to identify some general characteristics of the best methods for different groups of measured variables. The results provide guiding principles for choosing the best method for estimating species richness, soil pH, groundwater level, and soil moisture by the TWI derived from digital elevation models.

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

    Science.gov (United States)

    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

    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 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 vegetable-fresh bovine blood-ensiled rumen digesta (P3) up to 6% level of inclusion.

  4. Guided propagation in a step-index, multi-mode fiber: effect of index difference variation on allowable TM propagation constants

    Science.gov (United States)

    Downey, Todd R.; Meriaudeau, Fabrice; Passian, Ali; Wig, Andrew; Ferrell, Thomas L.

    1999-11-01

    The effect of variation of core and cladding index difference, Δ n= ncore- ncladding, on allowable values for the guided mode transverse magnetic propagation constants within a step-index, multi-mode optical fiber is investigated. We use a iterative computational technique to calculate the propagation constants for modes inside and outside the core that satisfy the boundary conditions contained within the characteristic eigen-equation for the TM field components. Evidence of a strong dependence of the allowable propagation constants on changes of Δ n is shown.

  5. EMG parameters and EEG α Index change at fatigue period during different types of muscle contraction

    Science.gov (United States)

    Zhang, Li; Zhou, Bin; Song, Gaoqing

    2011-03-01

    The purpose of this study is to measure and analyze the characteristics in change of EMG and EEG parameters at muscle fatigue period in participants with different exercise capacity. Twenty participants took part in the tests. They were divided into two groups, Group A (constant exerciser) and Group B (seldom-exerciser). MVC dynamic and 1/3 isometric exercises were performed; EMG and EEG signals were recorded synchronously during different type of muscle contraction. Results indicated that values of MVC, RMS and IEMG in Group A were greater than Group B, but isometric exercise time was shorter than the time of dynamic exercise although its intensity was light. Turning point of IEMG and α Index occurred synchronously during constant muscle contraction of isometric or dynamic exercise. It is concluded that IEMG turning point may be an indication to justify muscle fatigue. Synchronization of EEG and EMG reflects its common characteristics on its bio-electric change.

  6. A quasi-vector finite difference mode solver for optical waveguides with step-index profiles

    Institute of Scientific and Technical Information of China (English)

    Jinbiao Xiao; Mingde Zhang; Xiaohan Sun

    2006-01-01

    @@ A finite difference scheme based on the polynomial interpolation is constructed to solve the quasi-vector equations for optical waveguides with step-index profiles. The discontinuities of the normal components of the electric field across abrupt dielectric interfaces are taken into account. The numerical results include the polarization effects, but the memory requirement is the same as in solving the scalar wave equation. Moreover, the proposed finite difference scheme can be applied to both uniform and non-uniform mesh grids. The modal propagation constants and field distributions for a buried rectangular waveguide and a rib waveguide are presented. Solutions are compared favorably with those obtained by the numerical approaches published earlier.

  7. An integrated probabilistic assessment to analyse stochasticity of soil erosion in different restoration vegetation types

    Science.gov (United States)

    Zhou, Ji; Fu, Bojie; Gao, Guangyao; Lü, Yihe; Wang, Shuai

    2017-03-01

    The stochasticity of soil erosion reflects the variability of soil hydrological response to precipitation in a complex environment. Assessing this stochasticity is important for the conservation of soil and water resources; however, the stochasticity of erosion event in restoration vegetation types in water-limited environment has been little investigated. In this study, we constructed an event-driven framework to quantify the stochasticity of runoff and sediment generation in three typical restoration vegetation types (Armeniaca sibirica (T1), Spiraea pubescens (T2) and Artemisia copria (T3)) in closed runoff plots over five rainy seasons in the Loess Plateau of China. The results indicate that, under the same rainfall condition, the average probabilities of runoff and sediment in T1 (3.8 and 1.6 %) and T3 (5.6 and 4.4 %) were lowest and highest, respectively. The binomial and Poisson probabilistic model are two effective ways to simulate the frequency distributions of times of erosion events occurring in all restoration vegetation types. The Bayes model indicated that relatively longer-duration and stronger-intensity rainfall events respectively become the main probabilistic contributors to the stochasticity of an erosion event occurring in T1 and T3. Logistic regression modelling highlighted that the higher-grade rainfall intensity and canopy structure were the two most important factors to respectively improve and restrain the probability of stochastic erosion generation in all restoration vegetation types. The Bayes, binomial, Poisson and logistic regression models constituted an integrated probabilistic assessment to systematically simulate and evaluate soil erosion stochasticity. This should prove to be an innovative and important complement in understanding soil erosion from the stochasticity viewpoint, and also provide an alternative to assess the efficacy of ecological restoration in conserving soil and water resources in a semi-arid environment.

  8. Soil carbon fractions and enzyme activities under different vegetation types on the Loess Plateau of China

    OpenAIRE

    Zhang, Haixin; Zeng, Quanchao; An, Shaoshan; Dong, Yanghong; Darboux, Frédéric

    2016-01-01

    Vegetation restoration was effective way of protecting soil erosion and water conservation on the Loess Plateau. Carbon fractions and enzyme activities were sensitive parameters for assessment of soil remediation through revegetation. Forest, forest steppe and grassland soils were collected at 0–5 cm and 5–20 cm soil layers in Yanhe watershed, Shaanxi Province. Urease, sucrase, alkaline phosphatase, soil organic carbon (SOC), microbial biomass carbon (MBC), easily ox...

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

    Science.gov (United States)

    Pleniou, M.; Koutsias, N.

    2013-08-01

    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.

  10. Effects of Different Vegetation Zones on CH4 and N2O Emissions in Coastal Wetlands: A Model Case Study

    Directory of Open Access Journals (Sweden)

    Yuhong Liu

    2014-01-01

    Full Text Available The coastal wetland ecosystems are important in the global carbon and nitrogen cycle and global climate change. For higher fragility of coastal wetlands induced by human activities, the roles of coastal wetland ecosystems in CH4 and N2O emissions are becoming more important. This study used a DNDC model to simulate current and future CH4 and N2O emissions of coastal wetlands in four sites along the latitude in China. The simulation results showed that different vegetation zones, including bare beach, Spartina beach, and Phragmites beach, produced different emissions of CH4 and N2O in the same latitude region. Correlation analysis indicated that vegetation types, water level, temperature, and soil organic carbon content are the main factors affecting emissions of CH4 and N2O in coastal wetlands.

  11. Urban vegetation and thermal patterns following city growth in different socio-economic contexts

    Science.gov (United States)

    Dronova, I.; Clinton, N.; Yang, J.; Radke, J.; Marx, S. S.; Gong, P.

    2015-12-01

    Urban expansion accompanied by losses of vegetated spaces and their ecological services raises significant concerns about the future of humans in metropolitan "habitats". Despite recent growth of urban studies globally, it is still not well understood how environmental effects of urbanization vary with the rate and socioeconomic context of development. Our study hypothesized that with urban development, spatial patterns of surface thermal properties and green plant cover would shift towards higher occurrence of relatively warmer and less vegetated spaces such as built-up areas, followed by losses of greener and cooler areas such as urban forests, and that these shifts would be more pronounced with higher rate of economic and/or population growth. To test these ideas, we compared 1992-2011 changes in remotely sensed patterns of green vegetation and surface temperature in three example cities that experienced peripheral growth under contrasting socio-economic context - Dallas, TX, USA, Beijing, China and Kyiv, Ukraine. To assess their transformation, we proposed a metric of thermal-vegetation angle (TVA) estimated from per-pixel proxies of vegetation greenness and surface temperature from Landsat satellite data and examined changes in TVA distributions within each city's core and two decadal zones of peripheral sprawl delineated from nighttime satellite data. We found that higher economic and population growth were coupled with more pronounced changes in TVA distributions, and more urbanized zones often exhibited higher frequencies of warmer, less green than average TVA values with novel patterns such as "cooler" clusters of building shadows. Although greener and cooler spaces generally diminished with development, they remained relatively prevalent in low-density residential areas of Dallas and peripheral zones of Kyiv with exurban subsistence farming. Overall, results indicate that the effects of modified green space and thermal patterns within growing cities

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

    Directory of Open Access Journals (Sweden)

    Abdelghani Chehbouni

    2011-11-01

    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.

  13. Variation in spread of Heterobasidion annosum in clones of Picea abies grown at different vegetation phases under greenhouse conditions

    Energy Technology Data Exchange (ETDEWEB)

    Svedjemark, G.; Stenlid, J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1996-06-01

    Forty-nine Picea abies (L.) Karst clones were inoculated under greenhouse conditions with a Heterobasidion annosum (Fr.) Bref. isolate of the S intersterility group. The cuttings were inoculated at the following vegetation stages; bud-flushing stage, vegetative stage and after bud-set. Fungal growth in sapwood and leison length in the inner bark were measured after 34 days. The susceptibility of the various clones to H. annosum was strongly correlated among the three vegetation stages, both in terms of mean growth and mean growth ranking. Partitioning of variance components showed that variation in growth was explained by physiological stages and clone to 4% and 24%, respectively, and for interaction between clone and physiological stage to 9%. Corresponding values for leison length in the inner bark were 3%, 14% and 5%, respectively. Fungal growth in wood and leison length in the inner bark were strongly correlated (r{sup 2} ranging between 0.23 and 0.36). When cuttings were inoculated during bud-flushing, leison length and fungal growth in wood were both strongly correlated with bud-flushing index of the cuttings (r{sup 2} = 0.03 and 0.04 respectively) but that was not the case for the other stages. The number of active fine-roots and the degree of wilting of the cuttings were negatively correlated with leison length and fungal growth (r{sup 2} ranging between 0.01 and 0.13). Height and diameter varied greatly between the clones and both were negatively correlated with fungal extension (r{sup 2} ranging between 0.01 and 0.09). 33 refs, 2 figs, 3 tabs

  14. 遥感数字影像中提取植被指数并行算法的研究与实现%Research and Implementation of Parallel Algorithm for Extracting Vegetation Index in Remote Sensing Digital Image

    Institute of Scientific and Technical Information of China (English)

    于延; 王建华; 段喜萍

    2013-01-01

    In remote sensing processing, extracting vegetation index could be used to evaluate the coverage of vegetation or growth vitality quantitatively.Because of the increase of the projects for satellite observation and the increase of space time resolution induced by electronic technology, the materials of satellite remote sensing are growing exponentially.Traditional serial extracting vegetation index algorithms could not deal with huge amount of image materials efficiently.In this paper, we propose a parallel extracting vegetation index algorithm based on CUDA, this parallel algorithm could compute vegetation index efficiently and fast.The experimental results show that the algorithm proposed by this paper has a good speed-up comparing to the traditional algorithms, and has a low error.%在遥感影像处理中,植被指数的提取可以用来定性和定量评价植被覆盖及生长活力.由于现有的卫星观测项目的增多以及电子技术的进步引起的数据时空分辨率增加,获取的卫星遥感资料成指数级地增加.传统已有的串行的植被指数提取算法已经不能有效地处理大量的影像资料.本文提出了基于CUDA的并行植被指数提取算法.该并行算法可以快速、高效地计算植被指数.实验结果表明,本文提出的算法与传统的算法在时间上取得了很好的加速比,并且有很低的误差.

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

    Directory of Open Access Journals (Sweden)

    Monty Kujur

    2014-03-01

    Full Text Available 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 < 0.01 and OC (r = 0.880; p < 0.01. Principal component analysis was able to discriminate seven different soil samples into seven independent clusters based on their enzyme activities and kinetic parameters. Indeed, the study revealed the importance of kinetics study of soil enzymes, which can be considered valid parameters to monitor the evolution of microbiological activity in soil, and hence an index of soil quality.

  16. Human health risk assessment of heavy metals via consumption of contaminated vegetables collected from different irrigation sources in Lahore, Pakistan

    Directory of Open Access Journals (Sweden)

    Adeel Mahmood

    2014-01-01

    Full Text Available Soil pollution with heavy metals due to discharge of untreated urban and industrial wastewater is a major threat to ecological integrity and human well-being. The presenting study aimed to determine human health risks associated via food chain contamination of heavy metals routing from irrigation of urban and industrial wastewater. Irrigated water, soil and vegetables were analyzed for Cr2+, Co2+, Ni2+, Cu2+, Pb2+, Cd2+, Mn2+ and Zn2+; transfer factor (TF, daily intake of metals (DIM and health risk index (HRI were also calculated. Cr2+, Pb2+ and Cd2+ in vegetables cultivated by wastewater exceeded the permissible limits (European Union, 2002 while TF was lower for all metals except Co2+ and HRI was found to be maximum for Spinacia oleracea (2.42 mg/kg and Brassica campestris (2.22 mg/kg cultivated by wastewater. S. oleracea, B. campestris, Coriandrum sativum posed a severe health risk with respect to Cd and Mn.

  17. Comparison of body mass index in children of two different regions of welfare.

    Directory of Open Access Journals (Sweden)

    Abbas Shapouri Moghadam

    2015-02-01

    Full Text Available Socioeconomic basis of children obesity is of high importance for preventive policies. This study aimed to compare the prevalence of obesity among children living in two different levels of welfare regions in Mashhad northeast of Iran. A total of 625 primary school girls and boys aged 78-127 months were randomly selected, and values of their body mass index (BMI were measured. The prevalence of both overweight and obesity were higher among students of enriched area in comparison with that of resource restricted (P<0.05.The prevalence of overweight concerns in urban and rural areas. These results highlight the relation between socio-economic status and prevalence of obesity among children.

  18. Can gender differences during exercise-heat stress be assessed by the physiological strain index?

    Science.gov (United States)

    Moran, D S; Shapiro, Y; Laor, A; Izraeli, S; Pandolf, K B

    1999-06-01

    A physiological strain index (PSI) based on rectal temperature (Tre) and heart rate (HR) was recently suggested to evaluate exercise-heat stress. The purpose of this study was to evaluate PSI for gender differences under various combinations of exercise intensity and climate. Two groups of eight men each were formed according to maximal rate of O2 consumption (VO2 max). The first group of men (M) was matched to a group of nine women (W) with similar (P > 0.001) VO2 max (46.1 +/- 2.0 and 43.6 +/- 2.9 ml. kg-1. min-1, respectively). The second group of men (MF) was significantly (P 0.05) were found between matched genders (M and W) at the same exposure for sweat rate, relative VO2 max (%VO2 max), and PSI. However, MF had significantly (P acceptance and application.

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

    Science.gov (United States)

    Bonifaz, R.

    2005-12-01

    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.

  20. Simple and robust methods for remote sensing of canopy chlorophyll content: a comparative analysis of hyperspectral data for different types of vegetation.

    Science.gov (United States)

    Inoue, Yoshio; Guérif, Martine; Baret, Frédéric; Skidmore, Andrew; Gitelson, Anatoly; Schlerf, Martin; Darvishzadeh, Roshanak; Olioso, Albert

    2016-12-01

    Canopy chlorophyll content (CCC) is an essential ecophysiological variable for photosynthetic functioning. Remote sensing of CCC is vital for a wide range of ecological and agricultural applications. The objectives of this study were to explore simple and robust algorithms for spectral assessment of CCC. Hyperspectral datasets for six vegetation types (rice, wheat, corn, soybean, sugar beet and natural grass) acquired in four locations (Japan, France, Italy and USA) were analysed. To explore the best predictive model, spectral index approaches using the entire wavebands and multivariable regression approaches were employed. The comprehensive analysis elucidated the accuracy, linearity, sensitivity and applicability of various spectral models. Multivariable regression models using many wavebands proved inferior in applicability to different datasets. A simple model using the ratio spectral index (RSI; R815, R704) with the reflectance at 815 and 704 nm showed the highest accuracy and applicability. Simulation analysis using a physically based reflectance model suggested the biophysical soundness of the results. The model would work as a robust algorithm for canopy-chlorophyll-metre and/or remote sensing of CCC in ecosystem and regional scales. The predictive-ability maps using hyperspectral data allow not only evaluation of the relative significance of wavebands in various sensors but also selection of the optimal wavelengths and effective bandwidths.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

    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

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

    Science.gov (United States)

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

    2009-01-01

    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.

  3. Soil quality index as affected by different cropping systems in northwestern Himalayas.

    Science.gov (United States)

    Sofi, J A; Bhat, A G; Kirmai, N A; Wani, J A; Lone, Aabid H; Ganie, Mumtaz A; Dar, G I H

    2016-03-01

    Soil quality assessment provides a tool for evaluating the sustainability of soils under different crop cafeterias. Our objective was to develop the soil quality index for evaluating the soil quality indicators under different cropping systems in northwest Himalaya-India. Composite soil samples were taken from the study area from different cropping systems which include T1 (forest soil control), T2 (rice-oilseed, lower belts), T3 (rice-oilseed, higher belts), T4 (rice-oats), T5 (rice-fallow), T6 (maize-oats), T7 (maize-peas), T8 (apple), T9 (apple-beans), and T10 (apple-maize). Physical, chemical, and biological soil indicators were determined, and it was found that soil enzyme activities involved in nutrient cycling were significantly higher in forest soils, which were reflected in higher levels of available pool of nutrients. Carbon stocks were found significantly higher in forest soil which was translated in improved soil physical condition. Principal component analysis (PCA) was performed to reduce multidimensionality of data followed by scoring by homothetic transformation of the selected indicators. Pearson's interclass correlation was performed to avoid redundancy, and highly correlated variables were not retained. Inclusion of legumes in the apple orchard floor recorded highest soil quality rating across the treatments. Cereal-based cropping systems were found in lower soil quality rating; however, the incorporation of peas in the system improved soil health.

  4. Forest vegetation dynamics and its response to climate changes

    Science.gov (United States)

    Zoran, Maria A.; Zoran, Liviu Florin V.; Dida, Adrian I.

    2016-10-01

    Forest areas are experiencing rapid land cover change caused by human-induced land degradation and extreme climatic events. Satellite remote sensing provides a useful tool to capture the temporal dynamics of forest vegetation change in response to climate shifts, at spatial resolutions fine enough to capture the spatial heterogeneity. Frequent satellite data products, for example, can provide the basis for studying time-series of biophysical parameters related to vegetation dynamics. Vegetation index time series provide a useful way to monitor forest vegetation phenological variations. In this study, we used MODIS Terra/Aqua time-series data, along with yearly and monthly net radiation, air temperature, and precipitation data to examine the feedback mechanisms between climate and forest vegetation. Have been quantitatively described Normalized Difference Vegetation Index(NDVI) /Enhanced Vegetation Index (EVI), Leaf Area Index (LAI), Evapotranspiration (ET) and Gross Primary Production (GPP) temporal changes for Cernica- Branesti forest area, a periurban zone of Bucharest city in Romania, from the perspective of vegetation phenology and its relation with climate changes and extreme climate events (summer heat waves). A time series from 2000 to 2016 of the MODIS Terra was analyzed to extract forest biophysical parameters anomalies. Forest vegetation phenology analyses were developed for diverse forest land-covers providing a useful way to analyze and understand the phenology associated to those landcovers. Correlations between NDVI/EVI , LAI, ET and GPP time series and climatic variables have been computed.

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

    Directory of Open Access Journals (Sweden)

    Frank Canters

    2008-06-01

    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.

  6. Fourier transform infrared spectroscopy (FTIR) and multivariate analysis for identification of different vegetable oils used in biodiesel production.

    Science.gov (United States)

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

    2013-03-28

    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 component analysis (PCA), hierarchical cluster analysis (HCA), interval principal component analysis (iPCA) and soft independent modeling of class analogy (SIMCA) were used. The results indicate that is possible to develop a methodology to identify vegetable oils used as raw material in the production of biodiesel by FTIR-UATR applying multivariate analysis. It was also observed that the iPCA found the best spectral range for separation of biodiesel batches using FTIR-UATR data, and with this result, the SIMCA method classified 100% of the soybean biodiesel samples.

  7. Response of rhizosphere soil microbial to Deyeuxia angustifolia encroaching in two different vegetation communities in alpine tundra

    Science.gov (United States)

    Li, Lin; Xing, Ming; Lv, Jiangwei; Wang, Xiaolong; Chen, Xia

    2017-02-01

    Deyeuxia angustifolia (Komarov) Y. L Chang is an herb species originating from the birch forests in the Changbai Mountain. Recently, this species has been found encroaching into large areas in the western slopes of the alpine tundra in the Changbai Mountain, threatening the tundra ecosystem. In this study, we systematically assessed the response of the rhizosphere soil microbial to D. angustifolia encroaching in alpine tundra by conducting experiments for two vegetation types (shrubs and herbs) by real-time PCR and Illumina Miseq sequencing methods. The treatments consisted of D. angustifolia sites (DA), native sites (NS, NH) and encroaching sites (ES, EH). Our results show that (1) Rhizosphere soil properties of the alpine tundra were significantly impacted by D. angustifolia encroaching; microbial nutrient cycling and soil bacterial communities were shaped to be suitable for D. angustifolia growth; (2) The two vegetation community rhizosphere soils responded differently to D. angustifolia encroaching; (3) By encroaching into both vegetation communities, D. angustifolia could effectively replace the native species by establishing positive plant-soil feedback. The strong adaptation and assimilative capacity contributed to D. angustifolia encroaching in the alpine tundra. Our research indicates that D. angustifolia significantly impacts the rhizosphere soil microbial of the alpine tundra.

  8. Durability Index Performance of High Strength Concretes Made Based on Different Standard Portland Cements

    Directory of Open Access Journals (Sweden)

    Stephen O. Ekolu

    2012-01-01

    Full Text Available A consortium of three durability index test methods consisting of oxygen permeability, sorptivity and chloride conductivity were used to evaluate the potential influence of four (4 common SANS 10197 cements on strength and durability of concrete. Twenty four (24 concrete mixtures of water-cement ratios (w/c's = 0.4, 0.5, 0.65 were cast using the cement types CEM I 42.5N, CEM II/A-M (V-L 42.5N, CEM IV/B 32.5R and CEM II/A-V 52.5N. The concretes investigated fall in the range of normal strength, medium strength and high strength concretes. It was found that the marked differences in oxygen permeability and sorptivity results observed at normal and medium strengths tended to vanish at high concrete strengths. Also, the durability effects attributed to use of different cement types appear to diminish at high strengths. Cements of low strength and/or that contained no extenders (CEM 32.5R, CEM I 42.5N showed greater sensitivity to sorptivity, relative to other cement types. Results also show that while concrete resistance to chlorides generally improves with increase in strength, adequately high chloride resistance may not be achieved based on high strength alone, and appropriate incorporation of extenders may be necessary.

  9. The effect of food with different glycaemic index on the blood glucose level

    Directory of Open Access Journals (Sweden)

    Lenka Kouřimská

    2015-08-01

    Full Text Available Blood glucose levels are affected by many factors including the type of foods consumed, processing technology and cooking method. Hormone insulin lowers blood glucose to its constant level, while glucagon, growth hormone, adrenalin and glucocorticoids have the opposite effect. High steepness of the blood glucose level rise after meals may be unfavourable for the organism. Sugars are transferred into the blood at different speeds according to the type of food. Therefore the aim of this study was to confirm experimentally the effect of food on blood glucose levels in men and women of different ages. Two types of low, medium and high-glycaemic index (GI foods were given to 4 men and 4 women of different age (from 35 to 65 years. All volunteers were healthy, slightly overweight, and without any regular sporting activity. None of them had any idea about their daily carbohydrates consumption and what the term glycaemic index meant. The volunteers came to the GI determination fasted in the morning. Their rise in blood glucose level was monitored by glucometer before the meal and after 1 and 2 hours of the consumption of baked potatoes (GI 85, white bread bun (GI 70, boiled potatoes (GI 64, rye bread (GI 62, potato dumplings (GI 52 and white cooked spaghetti (GI 41. Fasting blood sugar levels of volunteers highly depended on their age (p <0.0001 and gender (p <0.0001. The blood glucose values increased with age and were higher in men than in women. Significant influence of food GI on blood glucose levels in both men and women in all the age categories was observed (p <0.0001. An interaction between age and gender was also statistically highly significant (p <0.0001. One hour after consuming food the blood glucose values were significantly different from the values of fasting (p = 0.0035. The differences of these values did not depend on the age (p = 0.0574 and sex (p = 0.8256 of volunteers, but there was a significant difference on the GI value of food

  10. Retrieving LAI of Winter Wheat Based on Sensitive Vegetation Index by the Segmentation Method%基于分段方式选择敏感植被指数的冬小麦叶面积指数遥感反演

    Institute of Scientific and Technical Information of China (English)

    李鑫川; 徐新刚; 鲍艳松; 黄文江; 罗菊花; 董莹莹; 宋晓宇; 王纪华

    2012-01-01

    [目的]考虑到利用单一植被指数(Ⅵ)反演叶面积指数(LAI)时,存在着不同程度的饱和性和易受土壤背景影响的问题,提出通过分段的方式选择敏感植被指数形成最佳Ⅵ组合以提高LAI反演的精度.[方法]通过ACRM辐射传输模型模拟数据,结合地面实测光谱数据,选择常用的植被指数进行土壤敏感性分析以及饱和性分析确定LAI的分段点,并在此基础上分段选择最佳植被指数形成组合Ⅵ来实现LAI的最终反演,并利Landsat5 TM开展区域条件下冬小麦LAI反演应用.[结果]以LAI=3是较为适宜的分段点,利用植被指数最佳分段组合OSAVI(LAI≤3)+TGDVI(LAI>3)可在一定程度上有效克服土壤影响因素以及饱和性问题,联合反演的结果明确优于单一植被指数反演精度.[结论]通过分段选择最佳植被指数形成联合Ⅵ可以有效提高LAI反演精度.%[ Objective ] The method of inversion leaf area index (LAI) using a single vegetation index (VI) is influenced by different degrees of saturability and soil background. This paper proposed a method choosing sensitive vegetation index by the segmentation method to form optimal VI combination, and to improve the accuracy of LAI inversion. [Method] In this study the ACRM radiation transmission model was used to simulate data, and the ground measured spectrum data were obtained. The study analyzed soil sensitivity and saturability about the common vegetation index to determine the segment point of LAI, and chose the best vegetation index based on segment point of LAI to form a combination VI for achieving the final inversion of the LAI. This method was also used in the regional winter wheat LAI inversion application with the Landsat5 TM data. [Result] The analysis showed that, LAI = 3 was the more appropriate segment point, and the use of vegetation index segment combination OSAVI (LAI ≤3) + TGDVI (LAI>3) partly overcame soil factors and the saturation problems. The

  11. Description of the difference in plaque index between normal and autistic children age 6-12 years

    Directory of Open Access Journals (Sweden)

    Arinda M Nadya

    2013-07-01

    Full Text Available Background: Oral hygiene status can be seen from the plaque index contained in the mouth. Children aged 6-12 years are school age, they can be taught about oral health care independently. The research objective was to obtain data about description of the differences in plaque index between normal and autistic children aged 6-12 years in Yayasan Autisme Ourdream, Lembaga Pendidikan Autisme Prananda, and SDN Banjarsari in the Bandung city. Materials and Methods: This study was a descriptive analytic. The population was all the students at SDN Banjarsari and autistic children aged 6-12 years in both the foundation. Samplings were collected by simple random sampling, the number of samples obtained normal and autistic children each were 21 persons. Clinical examinations for plaque index using Patient Hygiene Performance (PHP index of Podshadley and Halley. The data were analyzed with independent t-test. Results: The results showed an average of plaque index normal and autistic children aged 6-12 years was 2.06 with a standard deviation of 0.573 and 3.23 with a standard deviation of 0.473. C onclusion: The conclusions showed that there were significant differences in plaque index between normal and autistic children, these values are equally moderate category by Patient Hygiene Performance (PHP index of Podshadley and Halley.

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

    DEFF Research Database (Denmark)

    Irala-Estevez, J. De; Groth, Margit Velsing; Johansson, L.;

    2000-01-01

    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....

  13. Effect of different extracting solvents on antioxidant activity and phenolic compounds of a fruit and vegetable residue flour

    Directory of Open Access Journals (Sweden)

    Mônica C. P. Santos

    2016-01-01

    Full Text Available In order to quantify antioxidant capacity in food products, several methods have been proposed over the years. Among them, DPPH radical is widely used to determine the antioxidant capacity of different substrates. However, it is known that different types of extractants, providing different responses, can extract a variety of bioactive compounds. Besides, storage time seems to interfere in the stability of these substances. Integral use of fruits and vegetables has been proposed along the years as a means of reducing environmental pollution and give a better destination to by-products from food industries. Thus, this study aimed to evaluate the antioxidant potential of a fruit and vegetables residue flour (FVR with sequential and non-sequential extraction, in order to evaluate its antioxidant activity and phenolic compounds. And these compounds stability during storage of 180 days. It was observed that in non-sequential extraction, water was able to reduce by 74% the radical; however, at sequential extraction process, using six different extractors, each one was able to reduce at least 40% of DPPH. The total soluble phenolic contents in sequential extraction were 22.49 ± 1.59 mg GAE/g FVR on the first day and 5.35 ± 0.32 mg GAE/g FVR after 180 days.

  14. Metabolic response to different glycemic indexes of pre-exercise meal

    Directory of Open Access Journals (Sweden)

    Valéria Cristina de Faria

    2015-08-01

    Full Text Available INTRODUCTION: To ensure performance and health, the type of food and the time of pre-exercise ingestion should be considered by practitioners of morning physical activity. Objective: This study assessed the metabolic response after pre-exercise meals with different glycemic indexes (GI and in the fasting state adopting different types of hydration.METHODS: Twelve men performed four experimental tests; two with pre-exercise meals of high GI (HGI and low GI (LGI, and two were performed in the fasting state with hydration: water (H2O and carbohydrate drink (CHO. Each test consisted of a pre-exercise rest period of 30 minutes followed by 60 minutes of cycle ergometer with continuous load equivalent to 60% of the extrapolated maximal oxygen consumption (VO2MaxExt. During the exercise, participants were hydrated every 15 minutes with 3mL per kg body weight. During each experimental test, venous blood samples were obtained for fasting and at 15-minute intervals during rest, and every 20 minutes during exercise. The gas analysis was carried out in periods of 5 minutes every 20 minutes of exercise.RESULTS: There was no difference in substrate oxidation. After 20 minutes of exercise, pre-exercise food intake procedures showed similar behavior, having only reduced blood glucose levels compared to fasting procedures (p<0.01. There was maintenance of blood glucose at stable and higher levels during exercise in relation to the other tests in the fast procedure with CHO.CONCLUSION: The data suggest that despite the similar metabolic behavior between LGI and HGI meals, the adoption of a LGI meal before the morning exercise seems to be a more suitable feeding practice due to higher tendency of rebound hypoglycemia after HGI meal and when morning exercise is performed on fasting, hydration with CHO seems to minimize the hypoglycemic risk arising from that state.

  15. Organic Matter Fractions and Quality of the Surface Layer of a Constructed and Vegetated Soil After Coal Mining. II - Physical Compartments and Carbon Management Index

    Directory of Open Access Journals (Sweden)

    Otávio dos Anjos Leal

    2015-06-01

    Full Text Available Soils constructed after mining often have low carbon (C stocks and low quality of organic matter (OM. Cover crops are decisive for the recovery process of these stocks, improving the quality of constructed soils. Therefore, the goal of this study was to evaluate the effect of cover crops on total organic C (TOC stocks, C distribution in physical fractions of OM and the C management index (CMI of a soil constructed after coal mining. The experiment was initiated in 2003 with six treatments: Hemarthria altissima (T1, Paspalum notatum (T2, Cynodon dactylon (T3, Urochloa brizantha (T4, bare constructed soil (T5, and natural soil (T6. Soil samples were collected in 2009 from the 0.00-0.03 m layer, and the TOC and C stocks in the physical particle size fractions (carbon in the coarse fraction - CCF, and mineral-associated carbon - MAC and density fractions (free light fraction - FLF; occluded light fraction - OLF, and heavy fraction - HF of OM were determined. The CMI components: carbon pool index (CPI, lability (L and lability index (LI were estimated by both fractionation methods. No differences were observed between TOC, CCF and MAC stocks. The lowest C stocks in FLF and OLF fractions were presented by T2, 0.86 and 0.61 Mg ha-1, respectively. The values of TOC stock, C stock in physical fractions and CMI were intermediate, greater than T5 and lower than T6 in all treatments, indicating the partial recovery of soil quality. As a result of the better adaptation of the species Hemarthria and Brizantha, resulting in greater accumulation of labile organic material, the CPI, L, LI and CMI values were higher in these treatments, suggesting a greater potential of these species for recovery of constructed soils.

  16. Comparison of Different Methods for the Calculation of the Microvascular Flow Index

    Directory of Open Access Journals (Sweden)

    Mario O. Pozo

    2012-01-01

    Full Text Available The microvascular flow index (MFI is commonly used to semiquantitatively characterize the velocity of microcirculatory perfusion as absent (0, intermittent (1, sluggish (2, or normal (3. There are three approaches to compute MFI: (1 the average of the predominant flow in each of the four quadrants (MFIby quadrants, (2 the direct assessment during the bedside video acquisition (MFIpoint of care, and (3 the mean value of the MFIs determined in each individual vessel (MFIvessel by vessel. We hypothesized that the agreement between the MFIs is poor and that the MFIvessel by vessel better reflects the microvascular perfusion. For this purpose, we analyzed 100 videos from septic patients. In 25 of them, red blood cell (RBC velocity was also measured. There were wide 95% limits of agreement between MFIby quadrants and MFIpoint of care (1.46, between MFIby quadrants and MFIvessel by vessel (2.85, and between MFIby point of care and MFIvessel by vessel (2.56. The MFIs significantly correlated with the RBC velocity and with the fraction of perfused small vessels, but MFIvessel by vessel showed the best R2. Although the different methods for the calculation of MFI reflect microvascular perfusion, they are not interchangeable and MFIvessel by vessel might be better.

  17. Agreement and association between different indicators of body image and body mass index in adolescents.

    Science.gov (United States)

    Santos, Carla Fernandez Dos; Castro, Inês Rugani Ribeiro de; Cardoso, Letícia de Oliveira; Tavares, Letícia Ferreira

    2014-01-01

    The aim of the study was to examine the correlation among different indicators of body image; between each one of these and nutritional status; and the association of these indicators with the Body Mass Index (BMI) of adolescents. A random sample of 152 students from public and private schools in the city of Rio de Janeiro, Brazil, was studied. On four occasions, two silhouette scales and two questions regarding the opinion of the student about his/her body and weight were applied and weight and height were measured. The BMI was examined both as a continuous and as a categorical variable. The agreement between the variables was analyzed using the quadratic weighted Kappa statistics. The association between body image variables and BMI was examined by the comparison among median, mean, standard deviation and 95% confidence interval of BMI for each category of the body image variables. In general, the correlation among the body image variables ranged from reasonable to good; between these and the variable nutritional status, correlation ranged from regular to reasonable. Best results were observed among boys and students from private schools. All body image variables showed good discriminatory power for BMI, when it was analyzed as a continuous variable, even when controlling for potential confounders. The question about body seems to be better than that about weight to compose the questionnaire of a surveillance system for risk and protective factors for adolescent health.

  18. Respirometric Index and Biogas Potential of Different Foods and Agricultural Discarded Biomass

    Directory of Open Access Journals (Sweden)

    Simona Ciuta

    2016-12-01

    Full Text Available The biological stability of biomass is an important parameter for treatment plant design, process control or compost use. Measuring the biological reactivity of waste with the help of indicators such as respirometric indexes (RI becomes an important tool to prevent the significant environmental impact of biodegradable wastes in accordance with European legislation. The aim of this paper is to show the importance of the RI technique as a tool to establish further uses of biomass such as fertilizer or biogas. The respirometric process length for different types of biomass (grape marc, apple pomace and olive pomace was quantified. Higher moisture content seemed to favor the biological activity during the respirometric experiments and shorten the length of the process. The duration of olive pomace respirometry did not exceed 3 days, while the respirometric activity of apple scraps the lasted approximately 2 days. The highest RI values were encountered for the apple pomace, 4888 mgO2·kgVS−1·h−1. The majority of the discarded biomasses are categorized in the third class of stability materials in the course of degradation. This technique is important to detect the biodegradability of substrates, as well as to gain insight into the quantity and generation rate of biogas produced, information that is important from an engineering management perspective.

  19. Physical Explanation on Designing Three Axes as Different Resolution Indexes from GRACE Satellite-Borne Accelerometer

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wei; XU Hou-Ze; ZHONG Min; YUN Mei-Juan

    2008-01-01

    @@ The GRACE Earth's gravitational field complete up to degree and order 120 is recovered based on the same and different three-axis resolution indexes from satellite-borne accelerometer using the improved energy conservation principle. The results show that designing XA1(2) as low-sensitivity axis (3 × 10-9 m/s2) of accelerometer and designing YA1(2) and ZA1(2) as high-sensitivity axes (3 × 10-10m/s2) are reasonable. The physical reason why the resolution of XA1(2) is one order of magnitude lower than YA1(2) and ZA1(2) is that non-conservative forces acting on GRACE satellites axe mainly decomposed into YA1(2) and ZA1(2) in the orbital plane.Since X A1(2) is not orthogonal accurately to orbital plane during the development of accelerometer, the measurement of X A1(2) can not be thrown off entirely, but be reduced properly.

  20. Optimising view angles for the estimation of leaf area index via entropy-difference analysis

    Indian Academy of Sciences (India)

    Yanjuan Yao; Qiang Liu; Qinhuo Liu; Yanhua Gao

    2012-06-01

    It is important to evaluate the information content of remote sensing data in order to synthetically use multi-source remote sensing data to improve the accuracy and consistency of land surface parameter retrieval. This paper presents a technique for information content evaluation of multi-spectral/angular remote sensing data for the leaf area index (LAI) inversion, the method of entropy-difference analysis.The proposed method is based on a numerical evaluation of the entropy of the observed dataset to learn how much variation in observation is caused by the variation in LAI. The relationship between remote sensing information and the LAI inversion accuracy is validated based on the model-simulated canopy reflectance data and the experiment data. We make the following observation: the larger the entropydifference for canopy reflectance data, the higher the LAI inversion accuracy. That is, choosing a good combination of observation angles is sometimes more important than simply increasing the number of observations. The presented technique may be useful in designing and evaluating quantitative remote sensing algorithms and products.

  1. Vegetative and adaptive traits predict different outcomes for restoration using hybrids

    Directory of Open Access Journals (Sweden)

    Philip Crystal

    2016-11-01

    Full Text Available Abstract – Hybridization has been implicated as a driver of speciation, extinction, and invasiveness, but can also provide resistant breeding stock following epidemics. However, evaluating the appropriateness of hybrids for use in restoration programs is difficult. Past the F1 generation, the proportion of a progenitor’s genome can vary widely, as can the combinations of parental genomes. Detailed genetic analysis can reveal this information, but cannot expose phenotypic alterations due to heterosis, transgressive traits, or changes in metabolism or development. In addition, because evolution is often driven by extreme individuals, decisions based on phenotypic averages of hybrid classes may have unintended results. We demonstrate a strategy to evaluate hybrids for use in restoration by visualizing hybrid phenotypes across selected groups of traits relative to both progenitor species. Specifically, we used discriminant analysis to differentiate among butternut (Juglans cinerea L., black walnut (J. nigra L., and Japanese walnut (J. ailantifolia Carr. var. cordiformis using vegetative characters and then with functional adaptive traits associated with seedling performance. When projected onto the progenitor trait space, naturally occurring hybrids (J. ×bixbyi Rehd. between butternut and Japanese walnut showed introgression towards Japanese walnut at vegetative characters but exhibited a hybrid swarm at functional traits. Both results indicate that hybrids have morphological and ecological phenotypes that distinguish them from butternut, demonstrating a lack of ecological equivalency that should not be carried into restoration breeding efforts. Despite these discrepancies, some hybrids were projected into the space occupied by butternut seedlings’ 95% confidence ellipse, signifying that some hybrids were similar at the measured traits. Determining how to consistently identify these individuals is imperative for future breeding and species

  2. Drought Monitoring by Remote Sensing over India and Pakistan Based on Temperature Vegetation Dryness Index%基于温度植被干旱指数的印度和巴基斯坦干旱监测

    Institute of Scientific and Technical Information of China (English)

    高华; 张佳华; 夏学齐

    2016-01-01

    Drought has frequently been witnessed in the country due to various environmental changes such as rise in atmospheric pollution and climatic changes.Based on MOD13A3 and MOD11A2 data,the temperature vegetation dryness index (TVDI)model was constructed and verified.This study used MODIS data for many years during the same period over India and Pakistan to build the feature space of normalized difference vegetation index (NDVI)and land surface temperature (Ts),and fit dry and wet edge equations in the feature space.The TVDI was calculated over India and Pakistan of hot season (from March to May)from 2009 to 2014.In addition,the TVDI drought level standard is graded to analyze its temporal and spatial variation characteristics with using land use type and terrain data.TVDI is verified using the precipitation data from meteorological sites, and TVDI is contrasted with the standard precipitation index (SPI).The results show that:1)from the drought area statistics, the study region is mainly moderate drought,the area proportion of other grades is smaller;2)from the land use type,the land cover of entire district is good,the TVDI has certain rationality as drought evaluation index for study area;3 ) from meteorological sites,the inversion of TVDI from NDVI-Ts feature space and the total precipitation of the prophase and same period are closely related.%针对印度和巴基斯坦近年干旱频发的问题,该文使用温度植被干旱指数对印巴地区2009~2014年干季(3~5月)实现遥感干旱监测,利用多年同期 MODIS 卫星数据构建印巴地区归一化植被指数-陆地表面温度的特征空间,拟合特征空间中的干、湿边方程,进一步反演温度植被干旱指数,对该区土地利用和地形作了统计与分析,对温度植被干旱指数划分等级,并利用印巴气象站点的实测降水量以及标准降水指数进行验证。结果表明:1)从干旱等级面积统计来看,印巴地区干季主要

  3. Application Of Normalized Difference Vegetation Index In Monitoring Of The Mangrove: The Southern Coast Of Pernambuco-Brazil

    Directory of Open Access Journals (Sweden)

    Fátima Verônica Pereira Vila Nova

    2013-12-01

    Full Text Available El objetivo de este estudio fue analizar la eficacia del Índice de Vegetación de Diferencia Normalizada como una herramienta para el seguimiento de los manglares en la costa sur de Pernambuco, Brasil. Las transformaciones son la respuesta espacial a los cambios económicos que tienen lugar en la región y han puesto en peligro el equilibrio del medio ambiente local. El uso de NDVI demostrado su eficacia al permitir el seguimiento de los cambios estructurales en las áreas estudiadas, que revelan aspectos importantes de las condiciones ambientales, tales como el aumento de la zona urbana, la fragmentación del resto de la forma en que se presenta la información útil que se puede informar estrategias de conservación. El uso de NDVI fue eficaz en el seguimiento de los cambios estructurales evidenciadas en las áreas estudiadas, tales como la fragmentación de la vegetación de manglar y la remodelación de sus restos a expensas de la expansión de área urbana y / o suelo expuesto, información que puede subvencionar estrategias de conservación.

  4. Influence of animal fat substitution by vegetal fat on Mortadella-type products formulated with different hydrocolloids

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2015-12-01

    Full Text Available Meat has played a crucial role in human evolution and is an important component of a healthy and well-balanced diet on account of its nutritional properties, its high biological value as a source of protein, and the vitamins and minerals it supplies. We studied the effects of animal fat reduction and substitution by hydrogenated vegetal fat, sodium alginate and guar gum. Fatty acid composition, lipid oxidation, color and instrumental texture as well as the sensorial difference between low, substituted-fat and the traditional formulations for mortadella-type products were analyzed. Both substitution and reduction of animal fat decreased the saturated fatty acids percentage from 40% down to 31%. A texture profile analysis showed differences between the formulations. Furthermore, lipid oxidation values were not significant for treatments as regards the type and quantity of fat used while the use of sodium alginate and guar gum reduced the amounts of liquid released after cooking. Animal fat substitution does cause, however, a difference in overall sensorial perception compared with non-substituted products. The results confirm the viability of substituting vegetal fat for animal fat.

  5. Microbial Community and Greenhouse Gas Fluxes from Abandoned Rice Paddies with Different Vegetation.

    Science.gov (United States)

    Kim, Sunghyun; Lee, Seunghoon; McCormick, Melissa; Kim, Jae Geun; Kang, Hojeong

    2016-10-01

    The area of rice paddy fields has declined continuously in East Asian countries due to abandonment of agriculture and concurrent socioeconomic changes. When they are abandoned, rice paddy fields generally transform into wetlands by natural succession. While previous studies have mainly focused on vegetation shifts in abandoned rice paddies, little information is available about how these changes may affect their contribution to wetland functions. As newly abandoned fields proceed through succession, their hydrology and plant communities often change. Moreover, the relationships between these changes, soil microbial characteristics, and emissions of greenhouse gasses are poorly understood. In this study, we examined changes over the course of secondary succession of abandoned rice paddies to wetlands and investigated their ecological functions through changes in greenhouse gas fluxes and microbial characteristics. We collected gas and soil samples in summer and winter from areas dominated by Cyperaceae, Phragmites, and Sphagnum in each site. We found that CO2 emissions in summer were significantly higher than those in winter, but CH4 and N2O emission fluxes were consistently at very low levels and were similar among seasons and locations, due to their low nutrient conditions. These results suggest that microbial activity and abundance increased in summer. Greenhouse gas flux, soil properties, and microbial abundance were not affected by plant species, although the microbial community composition was changed by plant species. This information adds to our basic understanding of the contribution of wetlands that are transformed from abandoned rice paddy systems.

  6. Study on comparison of different methods to calculating sensitivity index of Jensen model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Real coded Accelerating Genetic Algorithm (RAGA), Chaos Algorithm (CA) were used to solve the sensitivity index of Jensen model which is one of models of crop water production function. After comparing with the outcome of Least Square Regression (LSR), the result showed that RAGA not only had high accuracy and more effective, but also saved calculating time. The authors provides new effective methods for calculating index of crop water production function.

  7. Acidity Regimes of Soils Under Different Vegetations in the Changbai Mountains Region

    Institute of Scientific and Technical Information of China (English)

    YUTIANREN; GAOZIQIN; 等

    1997-01-01

    The acidity regimes of representative soils on the north slope of the Changbai Mountains were examined through determinations of pH and pCa of the soil paste as well as in-situ determinations,For soils under broad-leaf forest or broad-leaf-Korean pine forest,the pH decreased from the litte to lower layers gradually until it did not change or decreased further slightly .For soils under coniferous of Erans birch forest,ther was a minimum in pH at a depth of 3-6 cm where the content of humus was high,The pCa increased gradually from the soil surface downward to a constant value.The lime potential(pH-0.5pCa) showed a similar trend as the pH in its distribution.For a given soil,the measured pH value of the thick paste,ranging from 4.5 to 5.5,was lower by about 0.5 units than the value determined by the conventional method with a water to soil ratio of 5:1 ,The pH determined in situ was even lower.It was found that there was a firly close relationship between soil acidity and the type of vegetation.The pH showed a trend of decreasing from soils under broda-leaf forest through broad-leaf-conifer mixed rorest and coniferos forest to Ermans birch forest,and the pCa showed an opposite trend in variation.

  8. Retention based bio accessibility of carotenoids in green leafy vegetables: effect of different Indian culinary practices

    Directory of Open Access Journals (Sweden)

    Sreeenivasa J Rao

    2014-12-01

    Full Text Available Back ground: Green Leafy Vegetables (GLV is pigment-rich and nutritionally relevant functional food sources with unique phytochemical constituents that include carotenoids which are precursors for vitamin A and protect cells from oxidation and cellular damage. Cooking processes and other factors such as temperature, light and alteration in moisture content generally promote either isomerization (trans to cis form or oxidative degradation of carotenoids to epoxides. Rationale: Studies pertaining to the effect of cooking methods on dietary carotenoids bio accessibility and their retention percent are scarce, particularly in an Indian Diasporas. Objective: Present study was to determine the carotenoids retention based bio accessibility in GLV such as amaranth (Amaranthus gangeticus, spinach (Spinacia oleracea and curry leaves (Murraya koenigii, when subjected to domestic cooking methods of microwave cooking, sautéing, pressure cooking, steaming and deep frying in oil, for a time duration of 8 and 12 minutes, either with lid closed or open. Method: The retention based bio accessibility of carotenoids were quantified by rapid separation liquid chromatography (RSLC using RP-C-18 column (150mm×4.6µ with 70% acetonitrile, 20% dichlomethane and 10% methanol for 20 minutes at flow rate of 0.5 ml/min. Results: The maximum retention based bio accessibility of total carotenoids and β-carotene were observed with micro wave cooking, steaming and sautéing methods. (Spinach: 57.88% and 55.92%, Amaranth: 56.15% and 57.49%, Curry leaves: 50.55% and 52.66% respectively. Conclusion: The reduction in the contents of carotenes in GLVs in correlation to various cooking methods are discussed which would be valuable for food researchers, nutritionists as well as health practitioners and dietitians, in developing and promoting nutritionally balanced diets and minimize vitamin A deficiency in Indian context.

  9. Absolute Viscosities of Vegetable Oils at Different Temperatures and Shear Rate Range of 64.5 to 4835 s−1

    Directory of Open Access Journals (Sweden)

    Lemuel M. Diamante

    2014-01-01

    Full Text Available A study was carried out to determine the effect of higher shear rates (64.5 to 4835 s−1 on the absolute viscosities of different vegetable oils at different temperatures (26 to 90°C. The absolute viscosities of the different vegetable oils were determined using a Lamy Viscometer RM100, a rotating viscometer with coaxial cylinder. The torque of each sample at different temperatures was recorded at different shear rates. Based on the rheograms (plot of mean shear stress against shear rate, all of the vegetable oils studied were found to be Newtonian fluids. Rice bran oil was the most viscous (0.0398 Pa·s at 38°C while walnut oil was the least viscous (0.0296 Pa·s at 38°C among the oils studied. The higher shear range used did not significantly affect the absolute viscosities of the vegetable oils at the different temperatures. The absolute viscosities of the vegetable oils decreased with increasing temperature and can be fitted with an Arrhenius type relationship. The activation energies for the different vegetable oils ranged from 21 to 30 kJ/mole. The peanut and safflower oils had the highest and lowest activation energies, respectively. This means that greater energy was needed to effect a viscosity change in the peanut oil.

  10. Design and Development of a Spectral Library for Different Vegetation and Landcover Types for Arctic, Antarctic and Chihuahua Desert Ecosystem

    Science.gov (United States)

    Matharasi, K.; Goswami, S.; Gamon, J.; Vargas, S.; Marin, R.; Lin, D.; Tweedie, C. E.

    2008-12-01

    All objects on the Earth's surface absorb and reflect portions of the electromagnetic spectrum. Depending on the composition of the material, every material has its characteristic spectral profile. The characteristic spectral profile for vegetation is often used to study how vegetation patterns at large spatial scales affect ecosystem structure and function. Analysis of spectroscopic data from the laboratory, and from various other platforms like aircraft or spacecraft, requires a knowledge base that consists of different characteristic spectral profiles for known different materials. This study reports on establishment of an online and searchable spectral library for a range of plant species and landcover types in the Arctic, Anatarctic and Chihuahuan desert ecosystems. Field data were collected from Arctic Alaska, the Antarctic Peninsula and the Chihuahuan desert in the visible to near infrared (IR) range using a handheld portable spectrometer. The data have been archived in a database created using postgre sql with have been made publicly available on a plone web-interface. This poster describes the data collected in more detail and offers instruction to users who wish to make use of this free online resource.

  11. Automatic Assessment of Global Craniofacial Differences between Crouzon mice and Wild-type mice in terms of the Cephalic Index

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Oubel, Estanislao; Frangi, Alejandro F.;

    2006-01-01

    This paper presents the automatic assessment of differences between Wild-Type mice and Crouzon mice based on high-resolution 3D Micro CT data. One factor used for the diagnosis of Crouzon syndrome in humans is the cephalic index, which is the skull width/length ratio. This index has traditionally...... been computed by time-consuming manual measurements that prevent large-scale populational studies. In this study, an automatic method to estimate cephalic index for this mouse model of Crouzon syndrome is presented. The method is based on constructing a craniofacial atlas of Wild-type mice...... and then registering each mouse to the atlas using affine transformations. The skull length and width are then measured on the atlas and propagated to all subjects to obtain automatic measurements of the cephalic index. The registration accuracy was estimated by RMS landmark errors. Even though the accuracy...

  12. 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)

    Michelle Cristina Araujo Picoli

    2009-09-01

    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

  13. Effect of Different Vegetation Types on the Rhizosphere Soil Microbial Community Structure in the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chao; LIU Guo-bin; XUE Sha; and XIAO Lie

    2013-01-01

    The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows:two natural grassland (Artemisia capillaries and Heteropappus altaicus), two artificial grassland (Astragalus adsurgens and Panicum virgatum), and two artificial shrubland (Caragana korshinskii and Hippophae rhamnoides) species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids (PLFAs) and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative (G-) bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive (G+) bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal:bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.

  14. Comprehensive Research on Essential Oil and Phenolic Variation in Different Foeniculum vulgare Populations During Transition from Vegetative to Reproductive Stage.

    Science.gov (United States)

    Salami, Maryam; Rahimmalek, Mehdi; Ehtemam, Mohammad Hossein

    2017-02-01

    Chemical composition and antioxidant activity of four fennel populations (England, Spain, Poland and Iran) were investigated during six developmental stages including two vegetative and four reproductive phases. In reproductive phase, the essential oil content of fruits decreased and the maximum content (5.9%) was obtained in immediate fruits. The essential oils were analyzed using GC/MS. trans-Anethole was the main component of the leaves and the fruits oil. In leaves, it ranged from 41.28% in England at late vegetative stage to 56.6% in Poland population at early vegetative stage. Other major compounds of leaves were limonene, α-pinene and (Z)-β-ocimene. In reproductive phases the trans-anethole increased dramatically. It varied from 85.25% in immature fruits from Poland to 90.7% in pre-mature stage from Spain. The highest phenolic content in the extracts at different growth stages obtained 189 mg TAE/g DW at full mature stage of seed in Iran population. The flavonoid of leaves extract ranged from 3 to 7.5 mg QUE/g DW, while in fruits extract varied from 3 to 10.3 mg QUE/g DW. Antioxidant activity of the extracts was evaluated using 1,1-diphenyl-2-picrylhydrazy (DPPH) and β-carotene model systems. Immature and full mature growth stages of fennel population from Spain indicated the highest activity in quenching of DPPH radical (74.2% and 74.5, respectively). Antioxidant activities of the extracts had high positive correlation with their phenolic contents in all fruit maturity stages. Finally, it might probably be suggested that in fennel the hot and humid condition can lead to increase trans-anethole, while the hot and dry one can produce higher amount of phenolics and flavonoids.

  15. Vegetation and soil properties under different vegetation patterns along the slope in the hilly area of the Loess Plateau%黄土丘陵区坡面尺度上不同植被格局下植物群落和土壤性质研究

    Institute of Scientific and Technical Information of China (English)

    胡婵娟; 刘国华; 陈利顶; 吴雅琼

    2012-01-01

    通过对黄土丘陵沟壑区陕西延安羊圈沟小流域坡面上退耕还林还草后形成的林地(单一种植刺槐人工林)、草地(单一的撂荒草地)、草地-林地-草地(上坡位和下坡位撂荒草地,中坡位种植刺槐人工林)及林地-草地-林地(上坡位和下坡位种植刺槐人工林,中坡位为撂荒草地)四种不同的植被格局下植物物种多样性及土壤理化性质变化的研究,旨在揭示植被恢复过程中,坡面上植被不同的空间配置模式对植物物种的组成及土壤环境变化的影响.研究发现,4种植被格局下植物物种的多样性以单一的撂荒草地坡面最高,人工林的种植一定程度上影响了林下植物物种多样性的恢复,但整个灌木和草本的群落结构4种植被格局之间均未达到极不相似水平.土壤有机碳及总氮含量均以坡面上草地-林地-草地的空间配置格局最高且有机碳存在显著差异,而撂荒草地则在土壤水分的保持及改善土壤pH值上优于其他3种植被格局.%Variation of plant community and soil property are a key index for vegetation restoration assessment. However, in the hilly area of the Loess Plateau, studies about variation of plant community and soil properties on slope scale under different vegetation patterns are limited. Therefore, in order to understand the effects of different vegetation patterns on plant community and soil properties during vegetation restoration, a case study was conducted in the hilly area of the Loess Plateau, located at the Yangjuangou catchment, Yan 'an City, Shaanxi Province. In 2007 , variation of plant community and soil physicochemical properties were measured under four types of slopes, each with different vegetation pattern, including Forest ( forest planted by human) , Grass, Grass - Forest - Grass ( grass on the upper and lower slopes and forest on the middle slope) , and Forest - Grass - Forest (forest on the upper and lower slopes and grass on the

  16. CROP YIELD OF CONILON COFFEE PLANTS OF DIFFERENT LEVELS OF VEGETATIVE VIGOR AND RUST SEVERITY

    Directory of Open Access Journals (Sweden)

    Wagner Nunes Rodrigues

    2012-12-01

    adjusted to a response surface model. The combinations between the levels of vigor and rust severity influenced the crop yield of conilon coffee in the evaluated conditions. The vegetative vigor factor was the more limiting than the rust severity in determining the coffee plants yield.

  17. Promoting fruit and vegetable consumption in different lifestyle groups: recommendations for program development based on behavioral research and consumer media data.

    Science.gov (United States)

    Della, Lindsay J; DeJoy, David M; Lance, Charles E

    2008-01-01

    Fruit and vegetable consumption affects the etiology of cardiovascular disease as well as many different types of cancers. Still, Americans' consumption of fruit and vegetables is low. This article builds on initial research that assessed the validity of using a consumer-based psychographic audience segmentation in tandem with the theory of planned behavior to explain differences among individuals' consumption of fruit and vegetables. In this article, we integrate the findings from our initial analyses with media and purchase data from each audience segment. We then propose distinct, tailored program suggestions for reinventing social marketing programs focused on increasing fruit and vegetable consumption in each segment. Finally, we discuss the implications of utilizing a consumer-based psychographic audience segmentation versus a more traditional readiness-to-change social marketing segmentation. Differences between these two segmentation strategies, such as the ability to access media usage and purchase data, are highlighted and discussed.

  18. Promoting fruit and vegetable consumption in different lifestyle groups: Recommendations for program development based on behavioral research and consumer media data

    Science.gov (United States)

    DeJoy, David M.; Lance, Charles E.

    2014-01-01

    Fruit and vegetable consumption impacts the etiology of cardiovascular disease as well as many different types of cancers. Still, Americans' consumption of fruit and vegetables is low. This article builds on initial research that assessed the validity of using a consumer-based psychographic audience segmentation in tandem with the theory of planned behavior to explain differences among individuals' consumption of fruit and vegetables. In this article, we integrate the findings from our initial analyses with media and purchase data from each audience segment. We then propose distinct, tailored program suggestions for reinventing social marketing programs focused on increasing fruit and vegetable consumption in each segment. Finally, we discuss the implications of utilizing a consumer-based psychographic audience segmentation versus more traditional readiness-to-change social marketing segmentation. Differences between these two segmentation strategies, such as the ability to access media usage and purchase data, are highlighted and discussed. PMID:18935880

  19. Animal performance and fatty acid composition of lambs fed with different vegetable oils.

    Science.gov (United States)

    Manso, T; Bodas, R; Castro, T; Jimeno, V; Mantecon, A R

    2009-11-01

    Twenty-seven lambs were used to investigate the effects of the inclusion of 4% hydrogenated palm oil (HPO) or sunflower oil (SFO) in the concentrate on animal performance, carcass and meat quality and fat characteristics and fatty acid composition. Animals (16.2±0.27kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25kg. SFO lambs tended to eat less concentrate than HPO animals (Pcharacteristics studied, meat pH and meat and fat colour (P>0.05). SFO decreased proportions of C16:0, C18:1 cis-11 and C18:3 (P<0.05) and increased C18:1 trans (P<0.001) and C18:2/C18:3 ratio (P<0.05). Atherogenicity index was lower (P<0.05) when SFO was included in the concentrate. HPO did not affected and SFO improved fatty acid composition of fattening lambs without affecting animal performance.

  20. Sensitivity of fire weather index to different reanalysis products in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    J. Bedia

    2012-03-01

    Full Text Available Wildfires are a major concern on the Iberian Peninsula, and the establishment of effective prevention and early warning systems are crucial to reduce impacts and losses. Fire weather indices are daily indicators of fire danger based upon meteorological information. However, their application in many studies is conditioned to the availability of sufficiently large climatological time series over extensive geographical areas and of sufficient quality. Furthermore, wind and relative humidity, important for the calculation of fire spread and fuel flammability parameters, are relatively scarce data. For these reasons, different reanalysis products are often used for the calculation of surrogate fire danger indices, although the agreement with those derived from observations remains as an open question to be addressed.

    In this study, we analyze this problem focusing on the Canadian Fire Weather Index (FWI – and the associated Seasonal Severity Rating (SSR – and considering three different reanalysis products of varying resolutions on the Iberian Peninsula: NCEP, ERA-40 and ERA-Interim. Besides the inter-comparison of the resulting FWI/SSR values, we also study their correspondence with observational data from 7 weather stations in Spain and their sensitivity to the input parameters (precipitation, temperature, relative humidity and wind velocity.

    As a general result, ERA-Interim reproduces the observed FWI magnitudes with better accuracy than NCEP, with lower/higher correlations in the coast/inland locations. For instance, ERA-Interim summer correlations are above 0.5 in inland locations – where higher FWI magnitudes are attained – whereas the corresponding values for NCEP are below this threshold. Nevertheless, departures from the observed distributions are generally found in all reanalysis, with a general tendency to underestimation, more pronounced in the case of NCEP. In spite of these limitations, ERA-Interim may still

  1. 基于主成分分析法的蔬菜供应链风险指标筛选研究%Research on Index Selection in Vegetable Supply Chain Risk on Base of Principle Component Analysis

    Institute of Scientific and Technical Information of China (English)

    申文娟

    2016-01-01

    文中以蔬菜供应链为研究对象,从内部风险和外部风险两个维度分析出蔬菜供应链风险的影响因素,并初步选出了41个风险指标;借助SPSS软件对初始数据进行处理,运用主成分分析法对相关性比较强的指标进行筛选,最终构建了由27个风险指标组成的蔬菜供应链风险评估指标体系。%This paper take vegetable supply chain as the research object,and the author analyze the vegetable supply chain risk factors from two dimensions of the internal risk and external risk and preliminary chose 41 risk indicator;Then the author use principal component analysis to compare strong correlation index screening software of SPSS,finally construct the 27 risk indicator composed of vegetable supply chain risk evaluation index system.

  2. Reflection statistics of weakly disordered optical medium when its mean refractive index is different from an outside medium

    OpenAIRE

    Pradhan, Prabhakar; Park, Daniel John; Capoglu, Ilker; Subramanian, Hariharan; Damania, Dhwanil; Cherkezyan, Lusik; Taflove, Allen; Backman, Vadim

    2015-01-01

    Based on the difference between mean background of an optical sample refractive index n_0 and an outside medium, n_out, different than n_0, we study the reflection statistics of a one-dimensional weakly disordered optical medium with refractive index n(x)=n_0+dn(x). Considering dn(x) as color noise with the exponential spatial correlation decay length l_c and k as the incident wave vector, our results show that for the small correlation length limit, i.e. k*l_c

  3. Soil contamination by phthalate esters in Chinese intensive vegetable production systems with different modes of use of plastic film.

    Science.gov (United States)

    Wang, Jun; Luo, Yongming; Teng, Ying; Ma, Wenting; Christie, Peter; Li, Zhengao

    2013-09-01

    The concentrations of six priority phthalic acid esters (PAEs) in intensively managed suburban vegetable soils in Nanjing, east China, were analyzed using gas chromatography-mass spectrometry (GC-MS). The total PAE concentrations in the soils ranged widely from 0.15 to 9.68 mg kg(-1) with a median value of 1.70 mg kg(-1), and di-n-butyl phthalate (DnBP), bis-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) were the most abundant phthalate esters. Soil PAE concentrations depended on the mode of use of plastic film in which PAEs were incorporated as plasticizing agents and both the plastic film and poultry manure appeared to be important sources of soil PAEs. Vegetables in rotation with flooded rice led to lower concentrations of PAEs in soil. The results indicate that agricultural plastic film can be an important source of soil PAE contamination and further research is required to fully elucidate the mechanisms of PAE contamination of intensive agricultural soils with different use modes of use of plastic film.

  4. Fractal Characteristics of Soil Retention Curve and Particle Size Distribution with Different Vegetation Types in Mountain Areas of Northern China.

    Science.gov (United States)

    Niu, Xiang; Gao, Peng; Wang, Bing; Liu, Yu

    2015-12-03

    Based on fractal theory, the fractal characteristics of soil particle size distribution (PSD) and soil water retention curve (WRC) under the five vegetation types were studied in the mountainous land of Northern China. Results showed that: (1) the fractal parameters of soil PSD and soil WRC varied greatly under each different vegetation type, with Quercus acutissima Carr. and Robina pseudoacacia Linn. mixed plantation (QRM) > Pinus thunbergii Parl. and Pistacia chinensis Bunge mixed plantation (PPM) > Pinus thunbergii Parl. (PTP) > Juglans rigia Linn. (JRL) > abandoned grassland (ABG); (2) the soil fractal dimensions of woodlands (QRM, PPM, PTP and JRL) were significantly higher than that in ABG, and mixed forests (QRM and PPM) were higher than that in pure forests (PTP and JRL); (3) the fractal dimension of soil was positively correlated with the silt and clay content but negatively correlated with the sand content; and (4) the fractal dimension of soil PSD was positively correlated with the soil WRC. These indicated that the fractal parameters of soil PSD and soil WRC could act as quantitative indices to reflect the physical properties of the soil, and could be used to describe the influences of the Return Farmland to Forests Projects on soil structure.

  5. Anti-bacterial activity and brine shrimp lethality bioassay of methanolic extracts of fourteen different edible vegetables from Bangladesh

    Institute of Scientific and Technical Information of China (English)

    MObayedUllah; MahmudaHaque; KanizFatimaUrmi; AbuHasanatMdZulfiker; ElicheaSynthiAnita; MomtajBegum; KaiserHamid

    2013-01-01

    Objective: To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh. Methods: The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria (both gram positive and gram negative). The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations (LC50) were determined at 95% confidence intervals by analyzing the data on a computer loaded with “Finney Programme”. Results: All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains (zone of inhibition=5-28 mm). The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis (zone of inhibition=6-21 mm). All extracts exhibited considerable general toxicity towards brine shrimps. The LC50 value of the tested extracts was within the range of 8.447 to 60.323 µg/mL with respect to the positive control (vincristine sulphate) which was 0.91 µg/mL. Among all studied extracts, Xanthium indicum displayed the highest cytotoxic effect with LC50 value of 8.447 µg/mL. Conclusions: The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.

  6. Anti-bacterial activity and brine shrimp lethality bioassay of methanolic extracts of fourteen different edible vegetables from Bangladesh

    Institute of Scientific and Technical Information of China (English)

    M.Obayed; Ullah; Mahmuda; Haque; Kaniz; Fatima; Urmi; Abu; Hasanat; Md.Zulfiker; Elichea; Synthi; Anita; Momtaj; Begum; Kaiser; Hamid

    2013-01-01

    Objective:To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh.Methods:The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria(both gram positive and gram negative).The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations(LC50)were determined at confidence intervals by analyzing the data on a computer loaded with"Finney Programme??Results:All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains(zone of inhibition=5-28 mm).The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis(zone of inhibition=6-21 mm).All extracts exhibited considerable general toxicity towards brine shrimps.The LC50value of the tested extracts was within the range of 8.447 to 60.323μg/mL with respect to the positive control(vincristine sulphate)which was 0.91μg/mL.Among all studied extracts,Xanthium indicum displayed the highest cytotoxic effect with LC50value of 8.447μg/mL.Conclusions:The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.

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

    Directory of Open Access Journals (Sweden)

    Dragoş-Sorin Fota

    2011-05-01

    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.

  8. The Influence of Different Vegetable Oils on Some ω-3 Polyunsaturated Fatty Acids from Thigh and Abdominal Fat of Broilers

    Directory of Open Access Journals (Sweden)

    Dragoş Sorin Fota

    2011-05-01

    Full Text Available Energy sources, especialy vegetable oils, added to the combined fodder can segnificantly modefy the fatty acids profile of the chicken feed, thus through its control the fatty acids profile of the carcases can be modefied, through enrichment in some fatty acids. In this respect an experiment was coduced on broilers, made up of three experimental groups, fed with a combined base fodder (corn and soybean meal in which 2% of different energy sources were added (sunflower oil, soybean oil, linseed oil. At the end of the 42 days growing period, using gaz cromatography, the fatty acids profile, % of fatty acids in 100 g product (EPA,DPA, DHA, Σ SFA, Σ MUFA, Σ PUFA from the studied cut pieces, were determined. The results obtained after statistc processing and interpretation of the data, showed the fact that regarding the fatty acids profile in chicken thigh and abdominal fat we can observe variations, what denotes that the fatty acids profile can be influenced by dietary factors, the quantity being yet determined by the participation % of the energy sources (vegetable oils, but also by the fatty acids content of the participating raw materials.

  9. Fractal Characteristics of Soil Retention Curve and Particle Size Distribution with Different Vegetation Types in Mountain Areas of Northern China

    Directory of Open Access Journals (Sweden)

    Xiang Niu

    2015-12-01

    Full Text Available Based on fractal theory, the fractal characteristics of soil particle size distribution (PSD and soil water retention curve (WRC under the five vegetation types were studied in the mountainous land of Northern China. Results showed that: (1 the fractal parameters of soil PSD and soil WRC varied greatly under each different vegetation type, with Quercus acutissima Carr. and Robina pseudoacacia Linn. mixed plantation (QRM > Pinus thunbergii Parl. and Pistacia chinensis Bunge mixed plantation (PPM > Pinus thunbergii Parl. (PTP > Juglans rigia Linn. (JRL > abandoned grassland (ABG; (2 the soil fractal dimensions of woodlands (QRM, PPM, PTP and JRL were significantly higher than that in ABG, and mixed forests (QRM and PPM were higher than that in pure forests (PTP and JRL; (3 the fractal dimension of soil was positively correlated with the silt and clay content but negatively correlated with the sand content; and (4 the fractal dimension of soil PSD was positively correlated with the soil WRC. These indicated that the fractal parameters of soil PSD and soil WRC could act as quantitative indices to reflect the physical properties of the soil, and could be used to describe the influences of the Return Farmland to Forests Projects on soil structure.

  10. Simulation of the interaction between the atmosphere, vegetation and the Earth's surface in different parameterisation concepts; Simulation der Wechselwirkung zwischen Atmosphaere, Vegetation und Erdoberflaeche bei Verwendung unterschiedlicher Parametrisierungsansaetze

    Energy Technology Data Exchange (ETDEWEB)

    Grabe, F.

    2002-01-01

    The purpose of the present study was to compare two soil vegetation models based on entirely different concepts, namely the ''VEG3D'' model of the Institute of Meteorology and Climate Research of Karlsruhe University and the TERRA model of the German weather service. VEG3D comprises a multilayer soil model which calculates prognostic equations for soil heat and water flows and a vegetation layer in which the vegetation is represented by a single large leaf, in accordance with Deardorff's reference leaf concept (1976). TERRA is a two-layer soil model which calculates soil temperatures by means of the ''Extended Force Restore Method''. TERRA takes account of the vegetation by allowing the properties of the soil surface to change like a vegetation-bearing surface does. [German] Es war das Ziel dieser Arbeit, zwei Bodenvegetationsmodelle mit voellig unterschiedlichen Konzeptionen miteinander zu vergleichen. Bei diesen Modellen handelt es sich um das 'VEG3D' des Instituts fuer Meteorologie und Klimaforschung der Universitaet Karlsruhe und um das 'TERRA' des Deutschen Wetterdienstes. Das VEG3D beinhaltet ein mehrschichtiges Bodenmodell, in dem die prognostischen Gleichungen fuer Bodenwaerme- und Bodenwasserstroeme berechnet werden, sowie eine Bestandsschicht, in der die Vegetation nach dem Referenzblatt-Konzept von Deardorff (1976) durch ein einzelnes, grosses Blatt dargestellt wird. Das TERRA ist ein zweischichtiges Bodenmodell, welches die Bodentemperaturen ueber die 'Extended-Force-Restore Methode' berechnet. Vegetation wird in TERRA beruecksichtigt, in dem die Eigenschaften der Bodenoberflaeche so veraendert werden, dass sie sich verhaelt wie eine bewachsene Oberflaeche. (orig.)

  11. Comparative health care information: consumer quality index (CQI) information on differences between providers.

    NARCIS (Netherlands)

    Damman, O.C.; Stubbe, J.H.; Triemstra, A.H.M.; Spreeuwenberg, P.; Delnoij, D.M.J.

    2007-01-01

    Background: Public reporting on health care performances has become an important quality-improvement instrument. In the Netherlands, consumer quality index (CQI) questionnaires are currently being used to assess patients’ experiences with various domains of the health care system. An important quest

  12. Impersonality of the Connectivity Index and Recomposition of Topological Indices According to Different Properties

    Directory of Open Access Journals (Sweden)

    Yi-Zeng Liang

    2004-12-01

    Full Text Available The connectivity index χ can be regarded as the sum of bond contributions. Inthis article, boiling point (bp-oriented contributions for each kind of bond are obtainedby decomposing the connectivity indices into ten connectivity character bases and thendoing a linear regression between bps and the bases. From the comparison of bp-orientedcontributions with the contributions assigned by χ, it can be found that they are verysimilar in percentage, i.e. the relative importance of each particular kind of bond is nearlythe same in the two forms of combinations (one is obtained from the regression withboiling point, and the other is decided by the constructor of the χ index. This coincidenceshows an impersonality of χ on bond weighting and may provide us another interpretationof the efficiency of the connectivity index on many quantitative structure–activity/property relationship (QSAR or QSPR results. However, we also found that χ’sweighting formula may not be appropriate for some other properties. In fact, there is nouniversal weighting formula appropriate for all properties/activities. Recomposition ofsome topological indices by adjusting the weights upon character bases according todifferent properties/activities is suggested. This idea of recomposition is applied to thefirst Zagreb group index M1 and a large improvement has been achieved.

  13. A comparison of the environmental impact of different AOPs: risk indexes.

    Science.gov (United States)

    Giménez, Jaime; Bayarri, Bernardí; González, Óscar; Malato, Sixto; Peral, José; Esplugas, Santiago

    2014-12-31

    Today, environmental impact associated with pollution treatment is a matter of great concern. A method is proposed for evaluating environmental risk associated with Advanced Oxidation Processes (AOPs) applied to wastewater treatment. The method is based on the type of pollution (wastewater, solids, air or soil) and on materials and energy consumption. An Environmental Risk Index (E), constructed from numerical criteria provided, is presented for environmental comparison of processes and/or operations. The Operation Environmental Risk Index (EOi) for each of the unit operations involved in the process and the Aspects Environmental Risk Index (EAj) for process conditions were also estimated. Relative indexes were calculated to evaluate the risk of each operation (E/NOP) or aspect (E/NAS) involved in the process, and the percentage of the maximum achievable for each operation and aspect was found. A practical application of the method is presented for two AOPs: photo-Fenton and heterogeneous photocatalysis with suspended TiO2 in Solarbox. The results report the environmental risks associated with each process, so that AOPs tested and the operations involved with them can be compared.

  14. A Comparison of the Environmental Impact of Different AOPs: Risk Indexes

    Directory of Open Access Journals (Sweden)

    Jaime Giménez

    2014-12-01

    Full Text Available Today, environmental impact associated with pollution treatment is a matter of great concern. A method is proposed for evaluating environmental risk associated with Advanced Oxidation Processes (AOPs applied to wastewater treatment. The method is based on the type of pollution (wastewater, solids, air or soil and on materials and energy consumption. An Environmental Risk Index (E, constructed from numerical criteria provided, is presented for environmental comparison of processes and/or operations. The Operation Environmental Risk Index (EOi for each of the unit operations involved in the process and the Aspects Environmental Risk Index (EAj for process conditions were also estimated. Relative indexes were calculated to evaluate the risk of each operation (E/NOP or aspect (E/NAS involved in the process, and the percentage of the maximum achievable for each operation and aspect was found. A practical application of the method is presented for two AOPs: photo-Fenton and heterogeneous photocatalysis with suspended TiO2 in Solarbox. The results report the environmental risks associated with each process, so that AOPs tested and the operations involved with them can be compared.

  15. A comparison between different propagative schemes for the simulation of tapered step index slab waveguides

    NARCIS (Netherlands)

    Haes, Jan; Baets, Roel; Weinert, C.M.; Gravert, M.; Nolting, H.P.; Andrade, M. Adelaide; Leite, A.; Bissessur, Hans K.; Davies, J.B.; Ettinger, Robert D.; Ctyroky, Jiri; Ducloux, E.; Ratovelomanana, F.; Vodjdani, N.; Helfert, Stefan; Pregla, Reinholt; Wijnands, F.H.G.M.; Hoekstra, H.J.W.M.; Krijnen, G.J.M.

    1996-01-01

    The performance and accuracy of a number of propagative algorithms are compared for the simulation of tapered high contrast step index slab waveguides. The considered methods include paraxial as well as nonparaxial formulations of optical field propagation. In particular attention is paid to the val

  16. Developing a composite index of spatial accessibility across different health care sectors: A German example.

    Science.gov (United States)

    Siegel, Martin; Koller, Daniela; Vogt, Verena; Sundmacher, Leonie

    2016-02-01

    The evolving lack of ambulatory care providers especially in rural areas increasingly challenges the strict separation between ambulatory and inpatient care in Germany. Some consider allowing hospitals to treat ambulatory patients to tackle potential shortages of ambulatory care in underserved areas. In this paper, we develop an integrated index of spatial accessibility covering multiple dimensions of health care. This index may contribute to the empirical evidence concerning potential risks and benefits of integrating the currently separated health care sectors. Accessibility is measured separately for each type of care based on official data at the district level. Applying an Improved Gravity Model allows us to factor in potential cross-border utilization. We combine the accessibilities for each type of care into a univariate index by adapting the concept of regional multiple deprivation measurement to allow for a limited substitutability between health care sectors. The results suggest that better health care accessibility in urban areas persists when taking a holistic view. We believe that this new index may provide an empirical basis for an inter-sectoral capacity planning.

  17. The Effect of Pre-Exercise Carbohydrate Feeding with Different Glycemic Index on Endurance Exercise Capacity

    Directory of Open Access Journals (Sweden)

    N. Salarkia

    2004-04-01

    Full Text Available Although, it is known that feeding with carbohydrate (CHO during exercise improves endurance performance, the effects of glycemic index (GI of carbohydrate intake are less clear. This study was carried out to assess the effect of glycemic index of pre-exercise carbohydrate feeding on endurance exercise capacity. In a randomized clinical trial 52 endurance – trained men with mean age 21.7 ± 3 years, weight 69.3 ± 9 kg, height 178.4 ± 2 cm and BMI 22.6 ± 2 were studied. Subjects performed exercise treadmill at 70% VO2max after ingestion: Lentil, a low glycemic index; potato, a high glycemic index; glucose and water (as a control one hour before exercise. Blood samples were collected before and one hour after test meal and 30 minutes after exercise. To assess aerobic capacity VO2max (maximum oxygen uptake was measured at the end of the exercise trial. Endurance time was found to be longer after lentil than after the potato, glucose and control respectively (P < 0.05. At the end of exercise, the glucose group and control both gave lower plasma glucose concentrations. Changes of VO2max in lentil. Potato, glucose and control group which were not statistically significant. This study showed that a low GI meal eaten before an event increases endurance capacity during exercise. Furthermore, the low GI meal was found to maintain glucose at higher concentrations during the later stages of exercise.

  18. Glycemic index differences of high-fat diets modulate primarily lipid metabolism in murine adipose tissue

    NARCIS (Netherlands)

    Schothorst, van E.M.; Bunschoten, J.E.; Verlinde, E.; Schrauwen, P.; Keijer, J.

    2011-01-01

    A low vs. high glycemic index of a high-fat (HF) diet (LGI and HGI, respectively) significantly retarded adverse health effects in adult male C57BL/6J mice, as shown recently (Van Schothorst EM, Bunschoten A, Schrauwen P, Mensink RP, Keijer J. FASEB J 23: 1092–1101, 2009). The LGI diet enhanced whol

  19. [Characteristics of soil phosphorus runoff under different rainfall intensities in the typical vegetable plot of Taihu Basin].

    Science.gov (United States)

    Yang, Li-Xia; Yang, Gui-Shan; Yuan, Shao-Feng; Wu, Ye

    2007-08-01

    Experiments of field runoff plots, which were conducted at vegetable plots in Hongsheng town of Wuxi city--the typical region of Taihu Basin, were designed to assess the effects of different rainfall intensities on soil phosphorus runoff loss from vegetable plots by artificial rainfall simulations. Results showed that there was a relationship of power function between initial runoff-generation time and rainfall intensity. Runoff amount slowly increased under small rainfall intensity, but rapidly increased with rainfall intensity increase. The concentrations of total phosphorus (TP) and particulate phosphorus (PP) were higher at the early stage, then gradually decreased with time and finally reached a comparative steady stage under 0.83, 1.17 and 1.67 mm x min(-1). However they indicated no obvious trend except wavy undulation under 2.50 mm x min(-1). In the course of rainfall-runoff, dissolved phosphorus (DP) gently varied and accounted for 20% - 32% of TP. PP was 68% - 80% of TP and its change trend was consistent with TP. Therefore, PP was main loss form of soil phosphorus runoff. Comparison of different phosphorous loss rate under different rainfall intensities suggested that loss rate of TP and DP under 2.50 mm x min(-1) was 20 times and 33 times higher than that under 0.83 mm x min(-1), which showed that loss rate of PP and DP increased with the increase of rainfall intensities. Results indicated that lots of inorganic dissolved phosphorus (DIP) of phosphorous fertilizer was discharged into water environment by using fertilizer in soil surface before rainfall, which increased loss of DP and greatly aggravated degree of water eutrophication.

  20. [Characteristics of soil organic carbon and enzyme activities in soil aggregates under different vegetation zones on the Loess Plateau].

    Science.gov (United States)

    Li, Xin; Ma, Rui-ping; An, Shao-shan; Zeng, Quan-chao; Li, Ya-yun

    2015-08-01

    In order to explore the distribution characteristics of organic carbon of different forms and the active enzymes in soil aggregates with different particle sizes, soil samples were chosen from forest zone, forest-grass zone and grass zone in the Yanhe watershed of Loess Plateau to study the content of organic carbon, easily oxidized carbon, and humus carbon, and the activities of cellulase, β-D-glucosidase, sucrose, urease and peroxidase, as well as the relations between the soil aggregates carbon and its components with the active soil enzymes were also analyzed. It was showed that the content of organic carbon and its components were in order of forest zone > grass zone > forest-grass zone, and the contents of three forms of organic carbon were the highest in the diameter group of 0.25-2 mm. The content of organic carbon and its components, as well as the activities of soil enzymes were higher in the soil layer of 0-10 cm than those in the 10-20 cm soil layer of different vegetation zones. The activities of cellulase, β-D-glucosidase, sucrose and urease were in order of forest zone > grass zone > forest-grass zone. The peroxidase activity was in order of forest zone > forest-grass zone > grass zone. The activities of various soil enzymes increased with the decreasing soil particle diameter in the three vegetation zones. The activities of cellulose, peroxidase, sucrose and urease had significant positive correlations with the contents of various forms of organic carbon in the soil aggregates.

  1. Asians are different from Caucasians and from each other in their body mass index/body fat per cent relationship

    NARCIS (Netherlands)

    Deurenberg, P.; Deurenberg-Yap, M.; Guricci, S.

    2002-01-01

    The objective was to study the relationship between body mass index (BMI) and body fat per cent (BF%) in different population groups of Asians. The study design was a literature overview with special attention to recent Asian data. Specific information is provided on Indonesians (Malays and Chinese

  2. Chemistry of soil solutions under different kinds of vegetation in the vicinity of a thermal power station

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Sanjurjo, M.J.; Alvarez, E.; Vega, V.F.; Garcia Rodeja, E. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola

    1998-12-01

    The paper discusses the influence of atmospheric deposition on the chemical characteristics of soil solutions in a small catchment area in NW Spain. The soils, were sampled from seven sites supporting different forms of vegetation (deciduous and pine forest and heath). Soil solutions were extracted, by the column displacement method, from soil samples collected monthly from March 1992 until November 1993. The most common ions in all horizons were Cl{sup -} and Na{sup +} due to marine influence. In the surface horizons (0-10 cm), relatively high concentrations of SO{sub 4}{sup 2-} (150-380 {mu}mol) and Zn (similar to 2 {mu} mol) were obtained, with good correlation between the two ions. These results, along with the prevalence of inorganic forms of Al(50-90% of total Al), were related to the effects of acidic deposition in the catchment area.

  3. Inversion of Leaf Area Index during Different Growth Stages in Winter Wheat%冬小麦不同生育时期叶面积指数反演方法

    Institute of Scientific and Technical Information of China (English)

    赵娟; 黄文江; 张耀鸿; 景元书

    2013-01-01

    针对当前作物叶面积指数遥感反演过程中,在不同生育时期采用相同的植被指数进行反演存在叶面积指数反演精度较低的问题.以冬小麦为研究对象,选取了对冬小麦覆盖度响应程度不同的六种宽带和四种窄带共10种植被指数,分析比较了在冬小麦整个生育期选用当前广泛使用的归一化植被指数(NDVI)反演冬小麦的LAI和在冬小麦不同生长阶段选用不同的植被指数反演冬小麦LAI的结果差异.在冬小麦整个生育期内使用NDVI反演小麦LAI得到的LAI反演值和真实值之间的R2 =0.558 5,RMSE=0.320 9.改进的比值植被指数(mSR)适合于反演冬小麦生长前期(拔节期之前)的LAI,得到的LAI反演值和真实值之间的相关系数r=0.728 7,均方根误差RMSE=0.297 1;比值植被指数(SR)适于反演冬小麦生长中期(拔节到抽穗前),得到的LAI反演值和真实值之间的R2 =0.654 6,RMSE=0.306 1;NDVI适于反演冬小麦生长后期(抽穗到成熟期)的LAI,得到的LAI反演值和真实值之间的R2=0.679 4,均方根误差RMSE=0.316 4.研究表明:在冬小麦的不同生育时期,根据地表作物覆盖度的变化和反射率的变化,选择不同的植被指数建立冬小麦LAI的反演模型获得的反演精度均高于在冬小麦整个生育期使用NDVI获得的反演结果.说明在冬小麦的不同生育时期选择不同的植被指数构建LAI的分段反演模型可以改善冬小麦LAI的反演精度.%Being orientated to the low prescion of crop leaf area index (LAI) inversion using the same spectral vegetation index during different crop growth stages,the present paper analyzed the precision of LAI inversion by employing NDVI(normalized difference vegetation index).Ten vegetation indices were chosen including six broad-band vegetation indices and four narrowband vegetation indices responding to vegetation cover to inverse LAI in different growth stages.Several conclusions were drawn according to the

  4. STRUCTURE AND COMPOSITION OF THE REGENERATION STRATUM AND ASSOCIATED VEGETATION OF DIFFERENT SUCCESSION STAGES IN EAST OF PARANÁ STATE

    Directory of Open Access Journals (Sweden)

    Marco Antonio Gomes Souto

    2011-09-01

    Full Text Available In recent decades, the human activities caused the overall decline in biodiversity and, to understand the impacts on plant communities, it is necessary to analyze the regenerative potential of the forest. Studies on the floristic composition and the structure of the guild of seedlings in different succession stages and historical conditions can describe the patterns of species replacement and help understand the forest dynamics. Thus, the objective of this study was to compare floristic and structural layer of the regeneration and associated vegetation in two succession stages of two areas with different historical uses located in the city of Campina Grande do Sul, in Paraná state. Seedlings were collected in two fragments of the secondary forest at the initial and at the intermediate stages, with historical use of clear and selective cuts, respectively. One-hundred and six plots of 0,16 m² were delimited and all individual plants with up to 10 - 50 cm high were collected, identified, quantified and divided into two groups: seedlings of tree species and species associated for the phytosociological analysis. The species were also classified according to their habits, dispersion mode and succession stages and the floristic similarity between areas was established by Sorensen’s, Bray & Curtis’ and Morisita-Horn’s indices. The analysis suggests a possible influence of historical use and the successional stages of regeneration and the associated vegetation. The analysis of similarity indicates a gradient of regeneration, in which the intermediate stage of the clear cut area is similar to the early stage of the selective cutting area.

  5. Ingestion, enzymatic digestion and absorption of particles derived from different vegetal sources by the cockle Cerastoderma edule

    Science.gov (United States)

    Arambalza, U.; Urrutia, M. B.; Navarro, E.; Ibarrola, I.

    2010-10-01

    Ingestion, enzymatic digestion and absorption of particulate detrital matter derived from six different vegetal sources by the common cockle Cerastoderma edule was analyzed in a series of seasonal experiments performed in March, May and October 2005. Two green macroalgae: Ulva lactuca and Enteromorpha sp; two vascular plants: Spartina maritima and Juncus maritimus, the red macroalgae Gracilaria gracilis; and the microalgae Isochrysis galbana were used in experiments. Detrital matter was elaborated by freeze-drying, grinding and sieving (< 63 μm) vegetal tissues. Mono-specific detrital diets of similar organic content (≈ 60-70%) were elaborated by mixing detritus with ashed silt. We measured i) the biochemical composition of different detritus, ii) physiological components of the absorptive balance (i.e. clearance, ingestion, rejection and absorption rate and absorption efficiency), iii) the capability of the digestive gland to hydrolyze carbohydrates from different detritus (digestibility), as well as iv) glandular cellulase and xylanase activities. Detritus type, season and the interaction detritus-season exerted significant effects upon all the physiological components of absorptive balance. Effects were light at the pre-absorptive level, however, huge variations associated to absorption efficiency promoted large significant differences in absorption rates (AR) of different kind of detritus: irrespective of season, highest values corresponded to cockles fed the green macroalgae ( Ulva and Enteromorpha) and lowest to those fed the vascular plant Juncus maritimus. Recorded significant differences in enzymatic digestibility among detritus were found to explain ≈ 40% of differences recorded in AR, and the following regression could be fitted: AR = 0.232 (± 0.032) * Digestibility + 0,072 (± 0.015); r 2 = 0.415; F = 51.036; p < 0.001. Digestibility of Ulva and Enteromorpha was found to be significantly correlated with cellulase activity in the digestive gland

  6. Differences in Dietary Patterns among College Students According to Body Mass Index

    Science.gov (United States)

    Brunt, Ardith; Rhee, Yeong; Zhong, Li

    2008-01-01

    Objective and Participants: The authors surveyed 557 undergraduate students aged 18-56 years to assess weight status, health behaviors, and dietary variety. Methods: They used body mass index (BMI) to divide students into 4 weight categories: underweight (BMI less than 19 kg/m2), healthy weight (19 kg/m2 to 24.99 kg/m2), overweight (25 kg/m2 to…

  7. Sex Differences in Peripheral Augmentation Index and Arterial Reservoir Pressure during Upper Limb Postural Shifts

    Directory of Open Access Journals (Sweden)

    Kevin S. Heffernan

    2014-01-01

    Full Text Available We examined the peripheral hemodynamic response to passive arm postural changes in young men and women. Radial artery pulse waveforms were captured using applanation tonometry in 20 men (age 27 ± 2 yrs, BMI 25 ± 1 kg/m2 and 20 women (age 27 ± 2 yrs, BMI 23±1 kg/m2. Arm position was maintained at either heart level or supported 14 cm above/below heart level in a randomized fashion. Systolic augmentation index (sAIx and diastolic augmentation index (dAIx were used as estimates of pressure from wave reflections arriving in systole and diastole, respectively. A novel reservoir-wave separation technique was used to obtain arterial reservoir pressure (pressure generated by arterial capacitance. Women showed a significant reduction in radial diastolic pressure-time integral (DPTI (P0.05 or dAIx (P>0.05 when moving the arm from below to above heart level. Conversely, men showed an attenuated change in radial DPTI (P>0.05 concomitant with significant increases in reservoir pressure (P<0.05, sAIx (P<0.05, and dAIx (P<0.05. Gravity-mediated changes in regional hemodynamics produced by passive arm postural shifts are sex specific. Men demonstrate less change in regional diastolic pressure concomitant with increased augmentation index and arterial reservoir pressure.

  8. First results on enzymatic activities in two salt marsh soils under different hydromorphic level and vegetation

    Directory of Open Access Journals (Sweden)

    Carmen Trasar-Cepeda

    2015-12-01

    Full Text Available Salt-marsh soils are soils characterized by non-permanent hydric saturation that, depending on factors like duration of submersion periods, are dominated by different salt-tolerant plant species. The composition of microbial communities is an essential component in trophic dynamics and biogeochemical processes in salt marshes, and determines the level of enzymatic activities, which catalyze the conversion of complex molecules into simpler ones. Despite of this, the enzymatic activities in marsh-soils has not yet been investigated. The aim of this study was to analyze the enzymatic activities in two soil profiles of marsh-soils under different water saturation level and dominated by different plant species [Juncus maritimus Lam and Spartina maritima (Curtis Fernald (Sp]. In both soils, the enzymatic activities were much lower than the levels typically found in terrestrial ecosystems. The enzymatic activities were measured both in air-dried and in re-moistened and incubated soil samples. In air-dried samples, the enzymatic activities were higher in Juncus than in Spartina soil and tended to decrease with depth, being sharper the decrease in Juncus than in Spartina soil. Re-moistened and pre-incubated soils showed a general increase in all the enzymatic activities and throughout the whole soil profile, especially in Spartina soils. Hydrolase activities showed a strong and positive relationship with organic matter content both in air-dried and in re-moistened soil samples, higher in these latter. In general, oxidoreductase activities only showed this relationship in re-moistened soil samples. More studies, preferably using freshly collected soil samples, are needed to understand the relationship between enzymatic activities and these environmental conditions.

  9. Lactic acid fermentation in vegetable juices supplemented with different content of brewer’s yeast autolysate

    Directory of Open Access Journals (Sweden)

    Rakin Marica B.

    2005-01-01

    Full Text Available The work is concerned with the conditions for lactic acid fermentation in a mixture of beetroot (Beta vulgaris L juice and carrot (Daucus carota L juice and different content of brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748.Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using the higher content of brewer’s yeast autolysate. In these mixtures, L. plantarum A112 has shown better growth and lactic acid production than L. acidophilus NCDO 1748.

  10. A Difference-Index Based Ranking Bilinear Programming Approach to Solving Bimatrix Games with Payoffs of Trapezoidal Intuitionistic Fuzzy Numbers

    Directory of Open Access Journals (Sweden)

    Deng-Feng Li

    2013-01-01

    Full Text Available The aim of this paper is to develop a bilinear programming method for solving bimatrix games in which the payoffs are expressed with trapezoidal intuitionistic fuzzy numbers (TrIFNs, which are called TrIFN bimatrix games for short. In this method, we define the value index and ambiguity index for a TrIFN and propose a new order relation of TrIFNs based on the difference index of value index to ambiguity index, which is proven to be a total order relation. Hereby, we introduce the concepts of solutions of TrIFN bimatrix games and parametric bimatrix games. It is proven that any TrIFN bimatrix game has at least one satisfying Nash equilibrium solution, which is equivalent to the Nash equilibrium solution of corresponding parametric bimatrix game. The latter can be obtained through solving the auxiliary parametric bilinear programming model. The method proposed in this paper is demonstrated with a real example of the commerce retailers’ strategy choice problem.

  11. [Characteristics of soil pH and exchangeable acidity in red soil profile under different vegetation types].

    Science.gov (United States)

    Ji, Gang; Xu, Ming-gang; Wen, Shi-lin; Wang, Bo-ren; Zhang, Lu; Liu, Li-sheng

    2015-09-01

    The characteristics of soil pH and exchangeable acidity in soil profile under different vegetation types were studied in hilly red soil regions of southern Hunan Province, China. The soil samples from red soil profiles within 0-100 cm depth at fertilized plots and unfertilized plots were collected and analyzed to understand the profile distribution of soil pH and exchangeable acidity. The results showed that, pH in 0-60 cm soil from the fertilized plots decreased as the following sequence: citrus orchard > Arachis hypogaea field > tea garden. As for exchangeable acidity content, the sequence was A. hypogaea field ≤ citrus orchard soil (0-40 cm), compared with the deep soil (60-100 cm), and soil pH decreased by 0.55 and 0.17 respectively, but such changes did not occur in citrus orchard. Soil pH in 0-40 cm soil from the natural recovery vegetation unfertilized plots decreased as the following sequence: Imperata cylindrica land > Castanea mollissima garden > Pinus elliottii forest ≥ Loropetalum chinensis forest. As for exchangeable acidity content, the sequence was L cylindrica land Soil pH in surface soil (0-20 cm) from natural forest plots, secondary forest and Camellia oleifera forest were significantly lower than that from P. massoniana forest, decreased by 0.34 and 0.20 respectively. For exchangeable acidity content in 0-20 cm soil from natural forest plot, P. massoniana forest and secondary forest were significantly lower than C. oleifera forest. Compared with bare land, surface soil acidification in unfertilized plots except I. cylindrica land had been accelerated, and the natural secondary forest was the most serious among them, with surface soil pH decreasing by 0.52. However, the pH increased in deep soils from unfertilized plots except natural secondary forest, and I. cylindrica land was the most obvious among them, with soil pH increasing by 0.43. The effects of fertilization and vegetation type on pH and exchangeable acidity decreased with the

  12. [Remote sensing estimation of vegetation coverage in guangzhou based on the correction of atmospheric radiation].

    Science.gov (United States)

    Gong, Jian-Zhou; Xia, Bei-Cheng

    2007-03-01

    Vegetation coverage is a basic parameter in describing landscape ecosystem, and an important index in assessing ecosystem health and security. Based on the four TM images in 1990, 1995, 2000 and 2005, and by using the correction model to deduct atmospheric radiation effect and the spatial operating model for TM image under unsupervised classification, the relationship model between vegetation coverage and normalized vegetation index was established, and the vegetation coverage in different phases in Guangzhou was calculated. The results showed that the vegetation coverage in Guangzhou decreased continuously from 1990 to 2000 but began to increase thereafter, which accorded with the economic development and environmental construction of the city. The model established in this paper could simulate well the dynamics of regional vegetation cover, and have the advantage in describing the dynamics of vegetation coverage more accurately, being available to the assessment of urban eco-environmental quality and its dynamic characters.

  13. The Regularities of Mutagenic Action of gamma-Radiation on Vegetative Bacillus subtilis Cells with Different Repair Genotype

    CERN Document Server

    Boreyko, A V; Krasavin, E A

    2000-01-01

    The regularities of induction of his^-\\to his^+ mutations in vegetative Bacillus subtilis cells with different repair capacity after gamma-irradiation have been studied. The wild type cells, polA1, recE4, recA, recP, add5, recH were used in experiments. It was shown that radiation-induced mutagenesis is determined by a repair genotype of cells. The blocking of different reparation genes is reflected on mutagenesis ratio by the various ways. A frequency of induction mutations in polA strain is higher than in wild type cells and it is characterized by the linearly-quadratic dose curve. The different rec^- strains that belong to various epistatic groups reveal an unequal mutation induction. The add5 and recP strains are characterized by the high-level induction mutations in contrast with the wild type cells. The mutagenesis in recE and recH strains, on the contrary, sharply reduces. The different influence of rec genes inhering to various epistatic groups on mutagenesis in Bacillus subtilis cells probably reflec...

  14. Soil microfungi in two post-mining chronosequences with different vegetation types

    Energy Technology Data Exchange (ETDEWEB)

    Novakova, A. [Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Inst. Soil Biology

    2001-07-01

    Soil microfungi were studied in the Sokolov (Czech Republic) post-mining dumps afforested with Alnus glutinosa and in the Lusatian (Germany) post-mining dumps afforested with Pinus sylvestris or P. nigra. Microfungi were isolated using the soil dilution plate method. Soil microfungi communities of two chronosequences were compared by species composition, frequency of species occurrence, and colony forming units of fungi (CFU-counts). Differences in species occurrence were determined. More species of entomopathogenic microfungi were found from the Sokolov post-mining area in comparison with the Cottbus post-mining area. Absidia glauca, A. cylindrospora, Penicillium glabrum, and P. janthinellum were the most frequently isolated species from the Cottbus post-mining area, while A. glauca, Geomyces pannorum, and Trichoderma koningii predominated at the Sokolov post-mining area.

  15. Fructans and other water soluble carbohydrates in vegetative organs and fruits of different Musa spp. accessions.

    Science.gov (United States)

    Cruz-Cárdenas, Carlos I; Miranda-Ham, María L; Castro-Concha, Lizbeth A; Ku-Cauich, José R; Vergauwen, Rudy; Reijnders, Timmy; Van den Ende, Wim; Escobedo-GraciaMedrano, Rosa M

    2015-01-01

    The water soluble carbohydrates (WSC) glucose, fructose, and sucrose are well-known to the great public, but fructans represent another type of WSC that deserves more attention given their prebiotic and immunomodulatory properties in the food context. Although the occurrence of inulin-type fructo-oligosaccharides (FOS) was proposed in the fruit of some banana accessions, little or no information is available neither on the exact identity of the fructan species, nor on the fructan content in different parts of banana plants and among a broader array of banana cultivars. Here, we investigated the WSC composition in leaves, pulp of ripe fruits and rhizomes from mature banana plants of 11 accessions (I to XI), including both cultivated varieties and wild Musa species. High performance anion exchange chromatography with integrated pulsed amperometric detection (HPAEC-IPAD) showed the presence of 1-kestotriose [GF2], inulobiose [F2], inulotriose [F3], 6-kestotriose and 6G-kestotriose (neokestose) fructan species in the pulp of mature fruits of different accessions, but the absence of 1,1-nystose and 1,1,1 kestopentaose and higher degree of polymerization (DP) inulin-type fructans. This fructan fingerprint points at the presence of one or more invertases that are able to use fructose and sucrose as alternative acceptor substrates. Quantification of glucose, fructose, sucrose and 1-kestotriose and principal component analysis (PCA) identified related banana groups, based on their specific WSC profiles. These data provide new insights in the biochemical diversity of wild and cultivated bananas, and shed light on potential roles that fructans may fulfill across species, during plant development and adaptation to changing environments. Furthermore, the promiscuous behavior of banana fruit invertases (sucrose and fructose as acceptor substrates besides water) provides a new avenue to boost future work on structure-function relationships on these enzymes, potentially leading to

  16. Fructans and other water soluble carbohydrates in vegetative organs and fruits of different Musa spp. accessions

    Directory of Open Access Journals (Sweden)

    Carlos Ivan eCruz Cardenas

    2015-06-01

    Full Text Available The water-soluble carbohydrates (WSC glucose, fructose and sucrose are well-known to the great public, but fructan represents another type of WSC that deserves more attention given their prebiotic and immunomodulatory properties in the food context. Although the occurrence of inulin-type fructo-oligosaccharides (FOS was proposed in the fruit of some banana accessions, little or no information is available neither on the exact identity of the fructan species, nor on the fructan content in different parts of banana plants and among a broader array of banana cultivars. Here, we investigated the WSC composition in leaves, pulp of ripe fruits and rhizomes from mature banana plants of eleven accessions (I to XI, including both cultivated varieties and wild Musa species. High performance anion exchange chromatography with integrated pulsed amperometric detection (HPAEC-IPAD showed the presence of 1-kestotriose [GF2], inulobiose [F2], inulotriose [F3], 6-kestotriose and 6G-kestotriose (neokestose fructan species in the pulp of mature fruits of different accessions, but the absence of 1,1-nystose and 1,1,1 kestopentaose and higher degree of polymerization (DP inulin-type fructans. This fructan fingerprint points at the presence of one or more invertases that are able to use fructose and sucrose as alternative acceptor substrates. Quantification of glucose, fructose, sucrose and 1-kestotriose and principal component analysis (PCA identified related banana groups, based on their specific WSC profiles. These data provide new insights in the biochemical diversity of wild and cultivated bananas, and shed light on potential roles that fructans may fulfil across species, during plant development and adaptation to changing environments. Furthermore, the promiscuous behavior of banana fruit invertases (sucrose and fructose as acceptor substrates besides water provides a new avenue to boost future work on structure-function relationships on these enzymes

  17. 40 shades of black: regional differences in vegetation response to a changing human influence in the Low Countries during the Dark Ages (AD 300-1000).

    Science.gov (United States)

    Gouw-Bouman, Marjolein T. I. J.; Donders, Timme H.; Hoek, Wim Z.

    2016-04-01

    During the Dark Ages, which includes the Late Roman Period (LRP, AD 300-500) and the Early Middle Ages (EMA, AD 500-1000), large scale vegetation development in Northwestern Europe is generally characterized by a forest regeneration. This forest redevelopment phase was not uniformous across the Netherlands. A comparison between existing pollen records shows that forest redevelopment started earlier and was more severe in the southern part of the Netherlands than in the northeastern Netherlands. The prevailing view advocates that the forest redevelopment is the result of a diminishing human influence on the landscape due to the collapse of the Roman Empire. Following this view, regional changes in forest regeneration are explained by varying population densities. However, existing climate-records indicate a colder and wetter climate during the Dark Ages and the geomorphological record points to a changing landscape. How and to what extent these climatic and environmental changes contributed to the changes in vegetation development or even to the decline of the Roman Empire is largely unknown. To understand the relative importance of the factors (climate, environment, economy and demography) influencing vegetation development it is important to accurately map regional differences in vegetation both on a regional and extra-regional scale. For an extra-regional overview all available pollen records in the Netherlands from this period are compiled to show differences in amplitude of the vegetation development during the Dark Ages. On a regional scale, vegetation reconstruction maps have been produced reflecting the influence of geological/geomorphological factors.

  18. Global-scale analysis of vegetation indices for moderate resolution monitoring of terrestrial vegetation

    Science.gov (United States)

    Huete, Alfredo R.; Didan, Kamel; van Leeuwen, Willem J. D.; Vermote, Eric F.

    1999-12-01

    Vegetation indices have emerged as important tools in the seasonal and inter-annual monitoring of the Earth's vegetation. They are radiometric measures of the amount and condition of vegetation. In this study, the Sea-viewing Wide Field-of-View sensor (SeaWiFS) is used to investigate coarse resolution monitoring of vegetation with multiple indices. A 30-day series of SeaWiFS data, corrected for molecular scattering and absorption, was composited to cloud-free, single channel reflectance images. The normalized difference vegetation index (NDVI) and an optimized index, the enhanced vegetation index (EVI), were computed over various 'continental' regions. The EVI had a normal distribution of values over the continental set of biomes while the NDVI was skewed toward higher values and saturated over forested regions. The NDVI resembled the skewed distributions found in the red band while the EVI resembled the normal distributions found in the NIR band. The EVI minimized smoke contamination over extensive portions of the tropics. As a result, major biome types with continental regions were discriminable in both the EVI imagery and histograms, whereas smoke and saturation considerably degraded the NDVI histogram structure preventing reliable discrimination of biome types.

  19. Vegetation shifts observed in arctic tundra 17 years after fire

    Science.gov (United States)

    Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine Janet; Shaver, Gaius

    2012-01-01

    With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensing imagery and ground observations of the burn scar and an adjacent control site. Early-season remotely sensed imagery from the burn scar exhibits a low vegetation index compared with the control site, whereas the late-season signal is slightly higher. The range and maximum vegetation index are greater in the burn scar, although the mean annual values do not differ among the sites. Ground observations revealed a greater abundance of moss in the unburned site, which may account for the high early growing season normalized difference vegetation index (NDVI) anomaly relative to the burn. The abundance of graminoid species and an absence of Betula nana in the post-fire tundra sites may also be responsible for the spectral differences observed in the remotely sensed imagery. The partial replacement of tundra by graminoid-dominated ecosystems has been predicted by the ALFRESCO model of disturbance, climate and vegetation succession.

  20. Decreased vegetation growth in response to summer drought in Central Asia from 2000 to 2012

    Science.gov (United States)

    Xu, Hao-jie; Wang, Xin-ping; Zhang, Xiao-xiao

    2016-10-01

    Climate change scenarios predict that Central Asia may experience an increase in the frequency and magnitude of temperature and precipitation extremes by the end of the 21st century, but the response regularity of different types of vegetation to climate extremes is uncertain. Based on remote-sensed vegetation index and in-situ meteorological data for the period of 2000-2012, we examined the diverse responses of vegetation to climate mean/extremes and differentiated climatic and anthropogenic influence on the vegetation in Central Asia. Our results showed that extensive vegetation degradation was related to summer water deficit as a result of the combined effect of decreased precipitation and increased potential evapotranspiration. Water was a primary climatic driver for vegetation changes regionally, and human-induced changes in vegetation confined mainly to local areas. Responses of vegetation to water stress varied in different vegetation types. Grasslands were most responsive to water deficit followed by forests and desert vegetation. Climate extremes caused significant vegetation changes, and different vegetation types had diverse responses to climate extremes. Grasslands represented a symmetric response to wet and dry periods. Desert vegetation was more responsive during wet years than in dry years. Forests responded more strongly to dry than to wet years due to a severe drought occurred in 2008. This study has important implications for predicting how vegetation ecosystems in drylands respond to climate mean/extremes under future scenarios of climate change.

  1. Remote sensing-based vegetation indices for monitoring vegetation change in the semi-arid region of Sudan

    Science.gov (United States)

    R. A., Majdaldin; Osunmadewa, B. A.; Csaplovics, E.; Aralova, D.

    2016-10-01

    Land degradation, a phenomenon referring to (drought) in arid, semi-arid and dry sub-humid regions as a result of climatic variations and anthropogenic activities most especially in the semi-arid lands of Sudan, where vast majority of the rural population depend solely on agriculture and pasture for their daily livelihood, the ecological pattern had been greatly influenced thereby leading to loss of vegetation cover coupled with climatic variability and replacement of the natural tree composition with invasive mesquite species. The principal aim of this study is to quantitatively examine the vigour of vegetation in Sudan through different vegetation indices. The assessment was done based on indicators such as soil adjusted vegetation index (SAVI). Cloud free multi-spectral remotely sensed data from LANDSAT imagery for the dry season periods of 1984 and 2009 were used in this study. Results of this study shows conversion of vegetation to other land use type. In general, an increase in area covered by vegetation was observed from the NDVI results of 2009 which is a contrast of that of 1984. The results of the vegetation indices for NDVI in 1984 (vegetated area) showed that about 21% was covered by vegetation while 49% of the area were covered with vegetation in 2009. Similar increase in vegetated area were observed from the result of SAVI. The decrease in vegetation observed in 1984 is as a result of extensive drought period which affects vegetation productivity thereby accelerating expansion of bare surfaces and sand accumulation. Although, increase in vegetated area were observed from the result of this study, this increase has a negative impact as the natural vegetation are degraded due to human induced activities which gradually led to the replacement of the natural vegetation with invasive tree species. The results of the study shows that NDVI perform better than by SAVI.

  2. Vegetation Index Models Based on MODIS and Their Application in Grassland Ecosystem%基于MODIS的植被指数模型及其在草地生态系统中的应用

    Institute of Scientific and Technical Information of China (English)

    孙成明; 孙政国; 穆少杰; 杨洪飞; 居为民; 李建龙

    2011-01-01

    为了明确MODIS植被指数模型的类型以及MODIS数据在大尺度上的可用性,在分析MODIS数据优势的基础上,综述了MODIS植被指数、植被指数模型以及MODIS植被指数模型在草地生态系统中的应用.MODIS数据可以直接提取NDVI和EVI2类植被指数,还可以间接计算MSAVI和RVI等多种 植被指数;利用MODIS植被指数可以建立线性回归模型和非线性的多种曲线模型,它们可以用在草地生态系统的净初级生产力估算、草地退化监测等方面.MODIS植被指数还可以在草地面积提取、草地碳储量估算等方面进一步的应用.%In order to define the type of vegetation indices of MODIS and the usability on a larger scale, based on the analysis of the advantages of MODIS data, the vegetation indices of MODIS, vegetation index models and their applications in grassland ecosystem were reviewed. Two kinds of vegetation indices, such as NDVI and EVI could be directly extracted from MODIS data, and other vegetation indices such as MSAVI and RVI could be indirectly calculated from MODIS data too. Using MODIS vegetation indices, the linear regression model and some nonlinear curve models may be established, and they can be used in the estimation of the net primary productivity (NPP) in grassland ecosystem and the monitoring of grassland degradation and so on. And the further applications of MODIS vegetation indices in area extraction and carbon storage estimation of grassland ecosystem were prospected.

  3. Nitrogen–use efficiency in different vegetation type at Cikaniki Research Station, Halimun-Salak Mountain National Park, West Java

    Directory of Open Access Journals (Sweden)

    SUHARNO

    2007-10-01

    Full Text Available A research about nitrogen–use efficiency (NUE and trees identification was conducted at different vegetation type at Cikaniki, Halimun-Salak National Park, West Java. Plot quadrate methods (20 x 50 m was used to analyze trees vegetation and Kjeldahl methods was used to analyze leaf nitrogen. The width and length of the leaf was also measured to obtain the leaf surface area. The result showed that there are 61 individual trees which consisted of 24 species was identified. The species which have 5 highest important value are Altingia excelsa (64,657, Castanopsis javanica (39,698, Platea latifolia (27,684, Garcinia rostrata (21,151, and Schima walichii (16,049. Futhermore Eugenia lineata (13,967, Melanochyla caesa (12,241, Quercus lineata (10,766, platea excelsa (10,766 have lower important value. Other trees have important value less than 10. Morphological and nitrogen content analyze were done on 4 species : Quercus lineata, G. rostrata, A. excelsa, and E. lineata. Among them, Quercus lineata has highest specific leaf area (SLA (0,01153, followed by G. rostrata (0,00821, A. excelsa (0,00579, and E. lineata (0,00984 g/cm2. The highest number of stomata was found on A. excelsa (85,10/mm2, followed by E. lineata (74,40/mm2, Q. lineata (53,70/mm2, and G. rostrata (18,4 /mm2. The emergent species (A. excelsa and Q. lineata have higher nitrogen content than the underlayer species (G. rostrata and E. lineata. A. excelsa have highest nitrogen use efficiency (28,19% compare to E. lineata (23,81% , Q. lineata (19,09%, and G. rostrata (14,87%. Although not significant, emergen species have higher NUE than underlayer species.

  4. Effectiveness of Different Classes of Fungicides on Botrytis cinerea Causing Gray Mold on Fruit and Vegetables

    Directory of Open Access Journals (Sweden)

    Joon-Oh Kim

    2016-12-01

    Full Text Available Botrytis cinerea is a necrotrophic pathogen causing a major problem in the export and post-harvest of strawberries. Inappropriate use of fungicides leads to resistance among fungal pathogens. Therefore, it is necessary to evaluate the sensitivity of B. cinerea to various classes of fungicide and to determine the effectiveness of different concentrations of commonly used fungicides. We thus evaluated the effectiveness of six classes of fungicide in inhibiting the growth and development of this pathogen, namely, fludioxonil, iprodione, pyrimethanil, tebuconazole, fenpyrazamine, and boscalid. Fludioxonil was the most effective (EC₅₀ < 0.1 μg/ml, and pyrimethanil was the least effective (EC₅₀ = 50 μg/ml, at inhibiting the mycelial growth of B. cinerea. Fenpyrazamine and pyrimethanil showed relatively low effectiveness in inhibiting the germination and conidial production of B. cinerea. Our results are useful for the management of B. cinerea and as a basis for monitoring the sensitivity of B. cinerea strains to fungicides.

  5. Reflection statistics of weakly disordered optical medium when its mean refractive index is different from an outside medium

    CERN Document Server

    Pradhan, Prabhakar; Capoglu, Ilker; Subramanian, Hariharan; Damania, Dhwanil; Cherkezyan, Lusik; Taflove, Allen; Backman, Vadim

    2015-01-01

    Based on the difference between mean background of an optical sample refractive index n_0 and an outside medium, n_out, different than n_0, we study the reflection statistics of a one-dimensional weakly disordered optical medium with refractive index n(x)=n_0+dn(x). Considering dn(x) as color noise with the exponential spatial correlation decay length l_c and k as the incident wave vector, our results show that for the small correlation length limit, i.e. k*l_c proportional to l_c. However, the standard deviation of r is proven to be std(r(dn,l_c)) proportional to sqrt(l_c), which is different from the matched case. Applications to light scattering from layered media and biological cells are discussed

  6. Fate of the insecticide lambda-cyhalothrin in ditch enclosures differing in vegetation density.

    Science.gov (United States)

    Leistra, Minze; Zweers, Anton J; Warinton, Jacqui S; Crum, Steven J H; Hand, Laurence H; Beltman, Wim H J; Maund, Stephen J

    2004-01-01

    Use of the insecticide lambda-cyhalothrin in agriculture may result in the contamination of water bodies, for example by spray drift. Therefore, the possible exposure of aquatic organisms to this insecticide needs to be evaluated. The exposure of the organisms may be reduced by the strong sorption of the insecticide to organic materials and its susceptibility to hydrolysis at the high pH values in the natural range. In experiments done in May and August, formulated lambda-cyhalothrin was mixed with the water body of enclosures in experimental ditches containing a bottom layer and macrophytes (at different densities) or phytoplankton. Concentrations of lambda-cyhalothrin in the water body and in the sediment layer, and contents in the plant compartment, were measured by gas-liquid chromatography at various times up to 1 week after application. Various water quality parameters were also measured. Concentrations of lambda-cyhalothrin decreased rapidly in the water column: 1 day after application, 24-40% of the dose remained in the water, and by 3 days it had declined to 1.8-6.5%. At the highest plant density, lambda-cyhalothrin residue in the plant compartment reached a maximum of 50% of the dose after 1 day; at intermediate and low plant densities, this maximum was only 3-11% of the dose (after 1-2 days). The percentage of the insecticide in the ditch sediment was 12% or less of the dose and tended to be lower at higher plant densities. Alkaline hydrolysis in the water near the surface of macrophytes and phytoplankton is considered to be the main dissipation process for lambda-cyhalothrin.

  7. Chemical Composition and Antioxidant Activity in Different Tissues of Brassica Vegetables

    Directory of Open Access Journals (Sweden)

    Shiva Ram Bhandari

    2015-01-01

    Full Text Available This research was conducted to evaluate glucosinolate profiles, vitamin C, total phenol, total flavonoid, and free sugar (glucose, fructose, and sucrose content, fatty acid composition, and antioxidant activity in floret and leaf of six cauliflower and broccoli cultivars. The level of chemical constituents as well as antioxidants significantly varied among crop types, cultivars, and their different parts, in that phytochemicals such as glucosinolate were statistically higher in florets compared with leaves in both broccoli and cauliflower cultivars. In contrast, total flavonoid and free sugar were found at higher levels in the leaf parts. The Asia purple cultivar exhibited statistically higher vitamin C (649.7 mg·100 g−1, total phenol (1345.2 mg·GAE 100 g−1, and total flavonoid (632.7 mg·CE 100 g−1 contents and consequently had the highest antioxidant activity (1.12 mg·mL−1 in its florets, while Baeridom and Bridal had the highest total glucosinolate (9.66 µmol·g−1 and free sugar (318.6 mg·g−1 contents, respectively compared with other cultivars. Likewise, the major fatty acids were palmitic (23.52%–38.42%, linoleic (13.09%–18.97%, and linolenic (26.32%–51.80% acids, which comprised the highest compositional ratio (more than 50% of polyunsaturated fatty acids (PUFAs in most cultivars. Among the antioxidants, total phenol exhibited the most significant positive correlation (r = 0.698 ** with antioxidant activity, followed by vitamin C (r = 0.522 ** and total flavonoid (r = 0.494 **, indicating their significant contributions to total antioxidant activity.

  8. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    Energy Technology Data Exchange (ETDEWEB)

    Ashokkumar, Saranya, E-mail: saras@food.dtu.dk [Accoat A/S, Munkegardsvej 16, 3490 Kvistgard (Denmark); Food Production Engineering, DTU FOOD, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Adler-Nissen, Jens [Food Production Engineering, DTU FOOD, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark); Moller, Per [Department of Materials Science and Engineering, DTU Mechanical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

    2012-12-15

    Graphical abstract: Plot of cos {theta} versus temperature for metal and ceramic surfaces where cos {theta} rises linearly with increase in temperature. Highlights: Black-Right-Pointing-Pointer cos {theta} of olive oil on different surface materials rises linearly with increase in temperature. Black-Right-Pointing-Pointer Slopes are much higher for quasicrystalline and polymers than for ceramics. Black-Right-Pointing-Pointer Increase in surface roughness and surface flaws increases surface wettability. Black-Right-Pointing-Pointer Contact angle values gave information for grouping easy-clean polymers from other materials. Black-Right-Pointing-Pointer Contact angle measurements cannot directly estimate the cleanability of a surface. - Abstract: The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25-200 Degree-Sign C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface materials investigated include stainless steel (reference), PTFE (polytetrafluoroethylene), silicone, quasicrystalline (Al, Fe, Cr) and ceramic coatings: zirconium oxide (ZrO{sub 2}), zirconium nitride (ZrN) and titanium aluminum nitride (TiAlN). The ceramic coatings were deposited on stainless steel with two different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cos {theta} values. Studies of the effect of roughness and surface flaws on wettability revealed that the cos {theta} values increases with increasing roughness and surface flaws. Correlation analysis indicates that the measured contact angle values gave useful information for grouping easy-clean polymer materials from the other materials; for the latter group, there is no direct relation between

  9. Prevalence differences of patients in vegetative state in the Netherlands and vienna, austria: a comparison of values and ethics

    NARCIS (Netherlands)

    Beljaars, D.E.; Valckx, W.J.; Stepan, C.; Donis, J.; Lavrijsen, J.C.M.

    2015-01-01

    OBJECTIVE: Little is known about prevalence of persistent vegetative state/unresponsive wakefulness syndrome and comparisons between countries. The aim of this column was to explore reasons for the comparable count of patients in vegetative state found in prevalence studies in nursing homes in 1 Eur

  10. Refractive index change mechanisms in different glasses induced by femtosecond laser irradiation

    Science.gov (United States)

    Fuerbach, A.; Gross, S.; Little, D.; Arriola, A.; Ams, M.; Dekker, P.; Withford, M.

    2016-07-01

    Tightly focused femtosecond laser pulses can be used to alter the refractive index of virtually all optical glasses. As the laser-induced modification is spatially limited to the focal volume of the writing beam, this technique enables the fabrication of fully three-dimensional photonic structures and devices that are automatically embedded within the host material. While it is well understood that the laser-material interaction process is initiated by nonlinear, typically multiphoton absorption, the actual mechanism that results in an increase or sometimes decrease of the refractive index of the glass strongly depends on the composition of the material and the process parameters and is still subject to scientific studies. In this paper, we present an overview of our recent work aimed at uncovering the physical and chemical processes that contribute to the observed material modification. Raman microscopy and electron microprobe analysis was used to study the induced modifications that occur within the glass matrix and the influence of atomic species migration forced by the femtosecond laser writing beam. In particular, we concentrate on borosilicate, heavy metal fluoride and phosphate glasses. We believe that our results represent an important step towards the development of engineered glass types that are ideally suited for the fabrication of photonic devices via the femtosecond laser direct write technique.

  11. Glycemic index differences of high-fat diets modulate primarily lipid metabolism in murine adipose tissue.

    Science.gov (United States)

    van Schothorst, Evert M; Bunschoten, Annelies; Verlinde, Eline; Schrauwen, Patrick; Keijer, Jaap

    2011-08-16

    A low vs. high glycemic index of a high-fat (HF) diet (LGI and HGI, respectively) significantly retarded adverse health effects in adult male C57BL/6J mice, as shown recently (Van Schothorst EM, Bunschoten A, Schrauwen P, Mensink RP, Keijer J. FASEB J 23: 1092-1101, 2009). The LGI diet enhanced whole body insulin sensitivity and repressed HF diet-induced body and white adipose tissue (WAT) weight gain, resulting in significantly reduced serum leptin and resistin levels and increased adiponectin levels. We questioned how WAT is modulated and characterized the molecular mechanisms underlying the glycemic index-mediated effects using whole genome microarrays. This showed that the LGI diet mainly exerts its beneficial effects via substrate metabolism, especially fatty acid metabolism. In addition, cell adhesion and cytoskeleton remodeling showed reduced expression, in line with lower WAT mass. An important transcription factor showing enhanced expression is PPAR-γ. Furthermore, serum levels of triglycerides, total cholesterol, and HDL- and LDL-cholesterol were all significantly reduced by LGI diet, and simultaneously muscle insulin sensitivity was significantly increased as analyzed by protein kinase B/Akt phosphorylation. Cumulatively, even though these mice were fed an HF diet, the LGI diet induced significantly favorable changes in metabolism in WAT. These effects suggest a partial overlap with pharmacological approaches by thiazolidinediones to treat insulin resistance and statins for hypercholesterolemia. It is therefore tempting to speculate that such a dietary approach might beneficially support pharmacological treatment of insulin resistance or hypercholesterolemia in humans.

  12. Remote sensing of vegetation dynamics in drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y.

    2016-01-01

    Monitoring long-term biomass dynamics in drylands is of great importance for many environmental applications including land degradation and global carbon cycle modeling. Biomass has extensively been estimated based on the normalized difference vegetation index (NDVI) as a measure of the vegetation...... greenness. The vegetation optical depth (VOD) derived from satellite passive microwave observations is mainly sensitive to the water content in total aboveground vegetation layer. VOD therefore provides a complementary data source to NDVI for monitoring biomass dynamics in drylands, yet further evaluations...... based on ground measurements are needed for an improved understanding of the potential advantages. In this study, we assess the capability of a long-term VOD dataset (1992-2011) to capture the temporal and spatial variability of in situ measured green biomass (herbaceous mass and woody plant foliage...

  13. The Oslo Health Study: a Dietary Index estimating high intake of soft drinks and low intake of fruits and vegetables was positively associated with components of the metabolic syndrome.

    Science.gov (United States)

    Høstmark, Arne Torbjørn

    2010-12-01

    A previous finding that soft drink intake is associated with increased serum triglycerides and decreased high-density-lipoprotein (HDL) cholesterol, both components of the metabolic syndrome (MetS), raises the question of whether other aspects of an unhealthy diet might be associated with MetS. Main MetS requirements are central obesity and 2 of the following: increased triglycerides, low HDL, increased systolic or diastolic blood pressure, and elevated fasting blood glucose. Of the 18 770 participants in the Oslo Health Study, there were 13 170 respondents (5997 men and 7173 women) with data on MetS factors (except fasting glucose) and on the components used to determine the Dietary Index score (calculated as the intake estimate of soft drinks divided by the sum of intake estimates of fruits and vegetables). MetSRisk was calculated as the sum of arbitrarily weighted factors positively associated with MetS divided by HDL cholesterol. Using regression analyses, the association of the Dietary Index with MetSRisk, with the number of MetS requirements present, and with the complete MetS was studied. In young, middle-aged, and senior men and women, there was, in general, a positive association (p soft drinks and a low intake of fruit and vegetables was positively and independently associated with aspects of MetS.

  14. Growth index in massai grass under different levels of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Marcos Neves Lopes

    2011-12-01

    Full Text Available This study aimed to evaluate the growth index of massai grass during two regrowth cycles in a greenhouse under five levels of nitrogen (0, 150, 300, 450 and 600 mg N/dm³ of soil and eight growth ages (5, 8, 11, 14, 17, 20, 23 and 26 days in a split-plot design with five replications. The following variables were evaluated: net assimilation rate, herbage growth rate, relative growth rate, leaf area ratio, leaf weight ratio and specific leaf area. The effect of nitrogen was detected on the variables net assimilation rate (regrowths 1 and 2, leaf area ratio (regrowth 1, leaf weight ratio (regrowths 1 and 2, specific leaf area (regrowths 1 and 2 and herbage growth rate (regrowths 1 and 2. The growth ages influenced the relative growth rate (regrowth 2 and the net assimilation rate (regrowth 2. The net assimilation rate presented linear effect, estimated in 0.70 and 2.86 g/m² leaf.day-1 for the 0 and 600 mg N/dm³ soil, respectively (regrowth 1. For each milligram of N/dm³ added, the leaf area ratio was reduced in 0.0000258 m² leaf/g plant (regrowth 1. The herbage growth rate was estimated in 1.38 and 37.02 g/m².day-1 (regrowth 1, and 4.37 and 32.20 g/m².day-1 (regrowth 2 for the 0 and 600 mg N/dm³ soil, respectively. The massai grass' growth is favored by nitrogen fertilization, and little do the growth ages affect the growth index of the plants.

  15. Optimal growth condition of earthworms and their vermicompost features during recycling of five different fresh fruit and vegetable wastes.

    Science.gov (United States)

    Huang, Kui; Xia, Hui; Li, Fusheng; Wei, Yongfen; Cui, Guangyu; Fu, Xiaoyong; Chen, Xuemin

    2016-07-01

    This study aimed to promote vermicomposting performance for recycling fresh fruit and vegetable wastes (FVWs) and to assess microbial population and community of final products. Five fresh FVWs including banana peels, cabbage, lettuce, potato, and watermelon peels were chosen as earthworms' food. The fate test of earthworms showed that 30 g fresh FVWs/day was the optimal loading and the banana peels was harmful for the survival of Eisenia fetida. The followed vermicomposting test revealed lower contents of total carbon and weaker microbial activity in final vermicomposts, relative to those in compared systems without earthworms worked. The leachate from FVWs carried away great amounts of nutrients from reactors. Additionally, different fresh FVWs displayed dissimilar stabilization process. Molecular biological approaches revealed that earthworms could broaden bacterial diversity in their products, with significant greater populations of actinobacteria and ammonia oxidizing bacteria than in control. This study evidences that vermicomposting efficiency differs with the types and loadings of fresh FVWs and vermicomposts are rich in agricultural probiotics.

  16. Developing and comparing two different prognostic indexes for predicting disease-free survival of nonmetastatic breast cancer patients

    OpenAIRE

    TOKATLI, Zehra Füsun; Türe, Mevlüt; Ömürlü, İmran Kurt; ALAS, Ruşen Çoşar; Uzal, Mustafa Cem

    2011-01-01

    To determine 2 different prognostic indexes (PI) for the differentiation of subgroups of nonmetastatic breast cancer patients with the Cox regression analysis and survival tree (ST) methods and the additional usage of the Kaplan-Meier estimates to investigate the predictive power of these methods. Materials and methods: Prognostic factors data were collected for 410 patients. The Cox regression analysis examines the relationship of the survival distribution and covariates. The ST method is ...

  17. Development Of Index To Assess Drought Conditions Using Geospatial Data A Case Study Of Jaisalmer District, Rajasthan, India

    Science.gov (United States)

    Chhajer, Vaidehi; Prabhakar, Sumati; Rama Chandra Prasad, P.

    2015-12-01

    The Jaisalmer district of Rajasthan province of India was known to suffer with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. However flood-like situation prevails in the drought prone Jaisalmer district of Rajasthan as torrential rains are seen to affect the region in the recent years. In the present study, detailed analysis of meteorological, hydrological and satellite data of the Jaisalmer district has been carried out for the years 2006-2008. Standardized Precipitation Index (SPI), Consecutive Dry Days (CDD) and Effective Drought Index (EDI) have been used to quantify the precipitation deficit. Standardized Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Vegetation Health Index (VHI), Normalized Difference Vegetation Index (NDVI) and Modified Soil-Adjusted Vegetation Index 2 have been calculated. We also introduce two new indices Soil based Vegetation Condition Index (SVCI) and Composite Drought Index (CDI) specifically for regions like Jaisalmer where aridity in soil and affects vegetation and water-level.

  18. Post-fire vegetation recovery in Portugal based on spot/vegetation data

    Science.gov (United States)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2010-04-01

    A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

  19. Post-fire vegetation recovery in Portugal based ewline on spot/vegetation data

    Directory of Open Access Journals (Sweden)

    C. Gouveia

    2010-04-01

    Full Text Available A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI, with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation

  20. Thermodynamic study of three pharmacologically significant drugs: Density, viscosity, and refractive index measurements at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: mjiqauchem@yahoo.com; Chaudhry, Mansoora Ahmed [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2009-02-15

    Measurements of density, viscosity, and refractive index of three pharmacologically significant drugs, i.e. diclofenac sodium, cetrizine, and doxycycline have been carried in aqueous medium at T = (293.15 to 313.15) K. An automated vibrating-tube densimeter, viscometer, and refractometer are used in a concentration range from (7.5) . 10{sup -3} to 25 . 10{sup -3}) mol . kg{sup -1}. The precise density results are used to evaluate the apparent molar volume, partial molar volume, thermal expansion coefficient, partial molar expansivity, and the Hepler's constant. Viscosity results are used to calculate the Jones-Dole viscosity B-coefficient, free energy of activation of the solute and solvent, activation enthalpy, and activation entropy. The molar refractive indices of the drug solutions can be employed to calculate molar refraction. It is inferred from these results that the above mentioned drugs act as structure-making compounds due to hydrophobic hydration of the molecules in the drugs.

  1. Gender-Specific Differences in the Association of Adiponectin Gene Polymorphisms with Body Mass Index

    Science.gov (United States)

    Tabatabaei-Malazy, Ozra; Hasani-Ranjbar, Shirin; Amoli, Mahsa M.; Heshmat, Ramin; Sajadi, Mohammadali; Derakhshan, Reza; Amiri, Parvin; Namakchian, Mahsa; Rezazadeh, Ebrahim; Tavakkoly-Bazzaz, Javad; Keshtkar, Abbasali; Larijani, Bagher

    2010-01-01

    OBJECTIVE: Adiponectin gene polymorphisms are associated with obesity, metabolic syndrome and type 2 diabetes (T2D). The study evaluated possible associations of +45T/G and -11391G/A adiponectin gene polymorphisms with body mass index (BMI), waist circumferences (WC), and blood pressure in diabetic and non-diabetic Iranians. METHODS: This cross-sectional study involved two groups of subjects: 243 diabetic patients and 173 non-diabetic subjects recruited from Rafsanjan city in the south-east of Iran. RESULTS: No significant association was found between +45T/G and -11391G/A adiponectin gene polymorphisms and systolic or diastolic blood pressure. However, male carriers of the TT genotype of +45T/G had a significantly higher mean BMI than male GG homozygotes (p = 0.018). Also, male carriers of the GG genotype of -11391G/A had significantly higher mean BMI than male GA or AA homozygotes (p = 0.041). Female carriers of the GG genotype of -11391G/A had significantly higher mean WC than female GA or AA homozygotes (p = 0.038). CONCLUSIONS: We observed a significantly higher BMI in women, and GA or AA carriers of -11391G/A polymorphism. Also, there was a significantly lower WC in females and GG carriers of +45T/G. These results point to a gender-specific impact of the studied genotypes on BMI and WC. PMID:21409316

  2. Individual Differences in Base Rate Neglect: A Fuzzy Processing Preference Index

    Science.gov (United States)

    Wolfe, Christopher R.; Fisher, Christopher R.

    2013-01-01

    Little is known about individual differences in integrating numeric base-rates and qualitative text in making probability judgments. Fuzzy-Trace Theory predicts a preference for fuzzy processing. We conducted six studies to develop the FPPI, a reliable and valid instrument assessing individual differences in this fuzzy processing preference. It…

  3. Ethnic differences in the relationship between body mass index and percentage body fat among Asian children from different backgrounds.

    Science.gov (United States)

    Liu, Ailing; Byrne, Nuala M; Kagawa, Masaharu; Ma, Guansheng; Poh, Bee Koon; Ismail, Mohammad Noor; Kijboonchoo, Kallaya; Nasreddine, Lara; Trinidad, Trinidad Palad; Hills, Andrew P

    2011-11-01

    Overweight and obesity in Asian children are increasing at an alarming rate; therefore a better understanding of the relationship between BMI and percentage body fat (%BF) in this population is important. A total of 1039 children aged 8-10 years, encompassing a wide BMI range, were recruited from China, Lebanon, Malaysia, The Philippines and Thailand. Body composition was determined using the 2H dilution technique to quantify total body water and subsequently fat mass, fat-free mass and %BF. Ethnic differences in the BMI-%BF relationship were found; for example, %BF in Filipino boys was approximately 2 % lower than in their Thai and Malay counterparts. In contrast, Thai girls had approximately 2.0 % higher %BF values than in their Chinese, Lebanese, Filipino and Malay counterparts at a given BMI. However, the ethnic difference in the BMI-%BF relationship varied by BMI. Compared with Caucasian children of the same age, Asian children had 3-6 units lower BMI at a given %BF. Approximately one-third of the obese Asian children (%BF above 25 % for boys and above 30 % for girls) in the study were not identified using the WHO classification and more than half using the International Obesity Task Force classification. Use of the Chinese classification increased the sensitivity. Results confirmed the necessity to consider ethnic differences in body composition when developing BMI cut-points and other obesity criteria in Asian children.

  4. Comparison of Dietary Intakes of Myricetin, Quercetin, Kaempferol, Apigenin and Luteolin from Vegetables and Fruits in Chinese Adults from Four Different Regions

    Institute of Scientific and Technical Information of China (English)

    Wei-na GAO; Ling-ling PU; Jing-yu WEI; Yang LIU; Chang-jiang GUO; Li-ting ZHAO; Ying CAI; Cai-lian WU

    2014-01-01

    Objective To assess the daily flavonoids intakes from vegetables and fruits, and provide an epidemiologic basis for formulating dietary flavonoids intakes in Chinese adults.Methods A total of 932 males aged 16-34 years, from Liaoning, Beijing, Jiangsu and Guangdong, China, participated in this cross-sectional study from April to October 2006. The dietary intakes of total as well as individual of five flavonoids (myricetin, quercetin, kaempferol, apigenin, luteolin) from vegetables and fruits were assessed using the in-home weighting method.Results The mean total daily flavonoids intake was 71.55±21.15 mg/d in Chinese adults. The average intakes of five above flavonoids were 46.43±16.44, 15.09±4.84, 4.85±0.79, 3.23±0.68, and 1.94±0.68 mg/d in order, respectively. The mean total intakes of flavonols (myricetin, quercetin and kaempferol) and flavones (apigenin and luteolin) were 66.37±21.55 and 5.17±1.35 mg/day, respectively. The richest sources of flavonoids were potato, cabbage, and white radish in vegetables, and apple and banana in fruits. The daily intake of luteolin from vegetables in Liaoning was notably higher than that in Jiangsu and Guangdong, while that from all vegetables and fruits was lower in Jiangsu than in Liaoning and Beijing. The daily total intake of myricetin in Guangdong was higher than that in Liaoning. The daily intake of quercetin from vegetables in Guangdong was significantly higher than that in Liaoning and Jiangsu, and the total intake from all vegetables and fruits was the highest among the four regions. The daily intake of total flavonoids in Guangdong was higher than that in Liaoning.Conclusion The daily intakes of flavonoids were significantly different in four regions both in total and individual flavonoids, among which myricetin was the primary contributor.

  5. Response of remotely sensed Normalized Difference Water Deviation Index to the 2006 Drought of eastern Sichuan Basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG WenJiang; LU QiFeng; GAO ZhiQiang; PENG Jian

    2008-01-01

    One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water In-dex (NDWI) for the summers of 2001-2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water Deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more pref-erable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

  6. Comparative analysis of indexes of physical preparedness of footballers of professional commands of different level

    Directory of Open Access Journals (Sweden)

    Shalenko V.V.

    2010-01-01

    Full Text Available This paper deals with results of the research of physical preparedness of professional teams of footballers of different level. The pedagogical testing program of the physical skills level includes control exercised recommended by the scientific-methodical committee of Ukrainian Federation of Football. The article presents indices of physical preparedness of footballers of different playing roles of the top league teams of Ukrainian championship and first league of Ukrainian team championship. Differences of physical preparedness structure of goalkeepers, defenders, halfbacks and forwards are revealed.

  7. Differences in Fine-Root Biomass of Trees and Understory Vegetation among Stand Types in Subtropical Forests.

    Science.gov (United States)

    Fu, Xiaoli; Wang, Jianlei; Di, Yuebao; Wang, Huimin

    2015-01-01

    Variation of total fine-root biomass among types of tree stands has previously been attributed to the characteristics of the stand layers. The effects of the understory vegetation on total fine-root biomass are less well studied. We examined the variation of total fine-root biomass in subtropical tree stands at two sites of Datian and Huitong in China. The two sites have similar humid monsoon climate but different soil organic carbon. One examination compared two categories of basal areas (high vs. low basal area) in stands of single species. A second examination compared single-species and mixed stands with comparable basal areas. Low basal area did not correlate with low total fine-root biomass in the single-species stands. The increase in seedling density but decrease in stem density for the low basal area stands at Datian and the quite similar stand structures for the basal-area contrast at Huitong helped in the lack of association between basal area and total fine-root biomass at the two sites, respectively. The mixed stands also did not yield higher total fine-root biomasses. In addition to the lack of niche complementarity between tree species, the differences in stem and seedling densities and the belowground competition between the tree and non-tree species also contributed to the similarity of the total fine-root biomasses in the mixed and single-species stands. Across stand types, the more fertile site Datian yielded higher tree, non-tree and total fine-root biomasses than Huitong. However, the contribution of non-tree fine-root biomass to the total fine-root biomass was higher at Huitong (29.4%) than that at Datian (16.7%). This study suggests that the variation of total fine-root biomass across stand types not only was associated with the characteristics of trees, but also may be highly dependent on the understory layer.

  8. Differences in Fine-Root Biomass of Trees and Understory Vegetation among Stand Types in Subtropical Forests.

    Directory of Open Access Journals (Sweden)

    Xiaoli Fu

    Full Text Available Variation of total fine-root biomass among types of tree stands has previously been attributed to the characteristics of the stand layers. The effects of the understory vegetation on total fine-root biomass are less well studied. We examined the variation of total fine-root biomass in subtropical tree stands at two sites of Datian and Huitong in China. The two sites have similar humid monsoon climate but different soil organic carbon. One examination compared two categories of basal areas (high vs. low basal area in stands of single species. A second examination compared single-species and mixed stands with comparable basal areas. Low basal area did not correlate with low total fine-root biomass in the single-species stands. The increase in seedling density but decrease in stem density for the low basal area stands at Datian and the quite similar stand structures for the basal-area contrast at Huitong helped in the lack of association between basal area and total fine-root biomass at the two sites, respectively. The mixed stands also did not yield higher total fine-root biomasses. In addition to the lack of niche complementarity between tree species, the differences in stem and seedling densities and the belowground competition between the tree and non-tree species also contributed to the similarity of the total fine-root biomasses in the mixed and single-species stands. Across stand types, the more fertile site Datian yielded higher tree, non-tree and total fine-root biomasses than Huitong. However, the contribution of non-tree fine-root biomass to the total fine-root biomass was higher at Huitong (29.4% than that at Datian (16.7%. This study suggests that the variation of total fine-root biomass across stand types not only was associated with the characteristics of trees, but also may be highly dependent on the understory layer.

  9. Effects of mixed rare earth fertilizer on yield and nutrient quality of leafy vegetables during different seasons

    Institute of Scientific and Technical Information of China (English)

    任艳军; 任学军; 马建军; 闫立英

    2016-01-01

    Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons (spring and autumn), the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theo-retical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments pro-moted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio in-creased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content de-creased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.

  10. Climate contributions to vegetation variations in Central Asian drylands

    DEFF Research Database (Denmark)

    Zhou, Yu; Zhang, Li; Fensholt, Rasmus

    2015-01-01

    Central Asia comprises a large fraction of the world's drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index...... (NDVI) data. In our study, most areas showed an increasing trend during 1982-1991, but experienced a significantly decreasing trend for 1992-2011. Vegetation changes were closely coupled to climate variables (precipitation and temperature) during 1982-1991 and 1992-2011, but the response trajectories...... differed between these two periods. The warming trend in Central Asia initially enhanced the vegetation greenness before 1991, but the continued warming trend subsequently became a suppressant of further gains in greenness afterwards. Precipitation expanded its influence on larger vegetated areas in 1992...

  11. Vegetative impacts upon bedload transport capacity and channel stability for differing alluvial planforms in the Yellow River source zone

    Science.gov (United States)

    Li, Zhi Wei; Yu, Guo An; Brierley, Gary; Wang, Zhao Yin

    2016-07-01

    The influence of vegetation upon bedload transport and channel morphodynamics is examined along a channel stability gradient ranging from meandering to anabranching to anabranching-braided to fully braided planform conditions along trunk and tributary reaches of the Upper Yellow River in western China. Although the regional geology and climate are relatively consistent across the study area, there is a distinct gradient in the presence and abundance of riparian vegetation for these reaches atop the Qinghai-Tibet Plateau (elevations in the study area range from 2800 to 3400 m a.s.l.). To date, the influence of vegetative impacts upon channel planform and bedload transport capacity of alluvial reaches of the Upper Yellow River remains unclear because of a lack of hydrological and field data. In this region, the types and pattern of riparian vegetation vary with planform type as follows: trees exert the strongest influence in the anabranching reach, the meandering reach flows through meadow vegetation, the anabranching-braided reach has a grass, herb, and sparse shrub cover, and the braided reach has no riparian vegetation. A non-linear relation between vegetative cover on the valley floor and bedload transport capacity is evident, wherein bedload transport capacity is the highest for the anabranching reach, roughly followed by the anabranching-braided, braided, and meandering reaches. The relationship between the bedload transport capacity of a reach and sediment supply from upstream exerts a significant influence upon channel stability. Bedload transport capacity during the flood season (June-September) in the braided reach is much less than the rate of sediment supply, inducing bed aggradation and dynamic channel adjustments. Rates of channel adjustment are less pronounced for the anabranching-braided and anabranching reaches, while the meandering reach is relatively stable (i.e., this is a passive meandering reach).

  12. Differences in Perceptions of the Food Environment between African American Men Who Did and Did Not Consume Recommended Levels of Fruits and Vegetables

    Science.gov (United States)

    Griffith, Derek M.; Cornish, Emily K.; McKissic, Sydika A.; Dean, Donnatesa A. L.

    2016-01-01

    African American men have high rates of chronic disease morbidity and mortality associated with their low rates of fruit and vegetable consumption. In an effort to inform tailored behavioral interventions for this demographic, we sought to assess if men with healthier eating practices viewed their environment differently than those who ate less…

  13. Cognitive Strategy Use as an Index of Developmental Differences in Neural Responses to Feedback

    DEFF Research Database (Denmark)

    Andersen, Lau M.; Visser, Ingmar; Crone, Eveline A.;

    2014-01-01

    Developmental differences in dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC) and superior parietal cortex (SPC) activation are associated with differences in how children, adolescents, and adults learn from performance feedback in rule-learning tasks (Crone, Zanolie...... strategy groups except for the best performing one. Strategy use was a mediator and largely explained the relation between age and variance in activation patterns in the DLPFC and the SPC, but not in the ACC. These findings are interpreted vis-à-vis age versus performance predictors of brain development...

  14. Assessing vegetation response to drought in the northern Great Plains using vegetation and drought indices

    Science.gov (United States)

    Ji, Lei; Peters, Albert J.

    2003-01-01

    The Normalized Difference Vegetation Index (NDVI) derived from the Advanced Very High Resolution Radiometer (AVHRR) has been widely used to monitor moisture-related vegetation condition. The relationship between vegetation vigor and moisture availability, however, is complex and has not been adequately studied with satellite sensor data. To better understand this relationship, an analysis was conducted on time series of monthly NDVI (1989–2000) during the growing season in the north and central U.S. Great Plains. The NDVI was correlated to the Standardized Precipitation Index (SPI), a multiple-time scale meteorological-drought index based on precipitation. The 3-month SPI was found to have the best correlation with the NDVI, indicating lag and cumulative effects of precipitation on vegetation, but the correlation between NDVI and SPI varies significantly between months. The highest correlations occurred during the middle of the growing season, and lower correlations were noted at the beginning and end of the growing season in most of the area. A regression model with seasonal dummy variables reveals that the relationship between the NDVI and SPI is significant in both grasslands and croplands, if this seasonal effect is taken into account. Spatially, the best NDVI–SPI relationship occurred in areas with low soil water-holding capacity. Our most important finding is that NDVI is an effective indicator of vegetation-moisture condition, but seasonal timing should be taken into consideration when monitoring drought with the NDVI.

  15. Gender Differences in the Association Between Body Mass Index and Psychopathology

    NARCIS (Netherlands)

    Desai, Rani A.; Manley, Melinda; Desai, Mayur M.; Potenza, Marc N.

    2009-01-01

    Introduction: The objective of the study was to examine gender,differences in the relationship between weight group (under-weight to severely obese), and Axis I and Axis 11 psychopathology. Methods: Data from the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC) were analyzed.

  16. Age Differences in Affective Decision Making as Indexed by Performance on the Iowa Gambling Task

    Science.gov (United States)

    Cauffman, Elizabeth; Shulman, Elizabeth P.; Steinberg, Laurence; Claus, Eric; Banich, Marie T.; Graham, Sandra; Woolard, Jennifer

    2010-01-01

    Contemporary perspectives on age differences in risk taking, informed by advances in developmental neuroscience, have emphasized the need to examine the ways in which emotional and cognitive factors interact to influence decision making. In the present study, a diverse sample of 901 individuals between the ages of 10 and 30 were administered a…

  17. Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sumaira, E-mail: skhanzai@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kolachi, Nida Fatima, E-mail: nidafatima6@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Qadir, E-mail: aqshah07@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kumar, Sham; Shah, Faheem [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-06-15

    The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V{sup 5+} species from soil, vegetable and grass samples using Na{sub 2}CO{sub 3} in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V{sup 5+} and V{sup 4+} determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 {mu}g/g in test and control soil samples, respectively. The contents of V{sup 5+} and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 {mu}g/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P < 0.01). Statistical evaluations indicate that the sum of concentrations of V{sup 5+} and V{sup 4+} species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

  18. Perspectives in using a remotely sensed dryness index in distributed hydrological models at river basin scale

    DEFF Research Database (Denmark)

    Andersen, J.; Sandholt, Inge; Jensen, Karsten Høgh;

    2002-01-01

    Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture......Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture...

  19. Dose optimization for different medical imaging tasks from exposure index, exposure control factor, and MAS in digital radiography.

    Science.gov (United States)

    Zhang, Menglong; Zhao, Bin; Wang, Yaying; Chen, Weixia; Hou, Lixia

    2012-09-01

    In radiographic examination, not all medical imaging tasks require the same level of image quality or diagnostic information. Criteria should be established for different imaging tasks to avoid excessive doses where there is no clear net benefit in the diagnosis or the image quality. An exposure index provided by manufacturers would be a useful tool for this purpose. This study aims to establish an optimum exposure index to be used as a guideline for clinical imaging tasks to minimize radiation exposure for chest digital radiography. A three-level classification of image quality (high, medium, and low) for chest imaging tasks was carried out. An anthropomorphic phantom was employed to establish minimum exposure index and exposure (mAs) for clinical imaging task type I (corresponding to high image quality). The exposures of medium and low quality images derived from it. Thirty patients were exposed consecutively with these optimized exposure factors, and clinical tasks were considered, while another 30 patients were exposed with the exposure factors routinely used in practice. Image quality was assessed objectively by a consensus panel. The optimized exposure provided a significant reduction of the mean exposure index from 1,556 to 1,207 (p < 0.0001) and mean patient's entrance surface dose from 0.168 mGy to 0.092 mGy (p < 0.0001). The results show that a clinical-task-determined radiographic procedure is more conducive to radiation protection of patients. In this study, the posteroanterior chest imaging examination was chosen as an example. This procedure can also apply to other body parts and views.

  20. Vegetable oil basestocks for lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Garces, R.; Martinez-Force, E.; Salas, J.

    2011-07-01

    The use of vegetable biodegradable basestocks for lubricant oils present several advantages over the much more extended mineral bases. These advantages refer to biodegradability, a renewable feedstock of local production, lubricant and viscosity index and lower costs than synthetic lubricant bases. Despite these benefits, their use in industry and motor vehicles is not yet extensive due their lower stability and higher pour points. Vegetable oils are esters of fatty acids and glycerol, and their physicochemical properties rely mainly on the composition of their acyl moieties. Thus, to assure the maximum levels of stability while maintaining acceptable behavior at low temperatures, monounsaturated fatty acids are preferred for this purpose. The presence of natural antioxidants also improves the properties of these vegetable based stocks as lubricants. These oils usually require additives to improve their viscosity value, oxidative stability and properties at low temperatures. In the present work, the different sources of vegetable oils appropriate for biolubricant production were reviewed. Their properties and the future improvement of the oil bases, oil based stock production, uses and additives are discussed. (Author).

  1. [Analysis of body mass index in different sector workers for over ten years].

    Science.gov (United States)

    Perbellini, L; Zonzin, C; Baldo, M

    2010-01-01

    A critical review of the literature on obesity and overweight underlines that a low educational level, a low social-economic status, certain working conditions, the lack of physical activity in leisure time, together with the availability of food, are the main factors favouring increased prevalence of obesity. Certain jobs also contribute significantly to this problem. Automation, the use of machines for heavy works and sedentary activities favour body weight increase. Jobs that are a source of stress, such as work with night shift can cause metabolic disorders leading to an increased prevalence of obesity. The main aim of this article is to study the trend of body weight in different working area during ten years, comparing this parameter to different factors such as job, blood pressure, smoke, alcool and health diseases.

  2. Generic index of aquatic vegetation (IVAM) for a rapid assessment of ecological quality of Spanish rivers: taxonomic resolution and application to Castilla-La Mancha region; Indice Generico de Vegetacion Acuatica (IVAM): Propuesta de evaluacion rapida del estado ecologico de los rios ibericos en aplicacion de la Directiva Marco del Agua

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, J. L.; Navarro, C.; Hera, J. de las

    2005-07-01

    The Water Framework Directive proposes the use of aquatic flora as a valid bio indicator for assessing the ecological status of European rivers. Due to the lack of an aquatic vegetation index for Spanish rivers, we present an index to assess trophic status or eutrophication in rivers and streams. Thus, we calculated tolerance scores and indicator values for tax from nutrient levels. the index is called IVAM (Macroscopic Aquatic Vegetation Index). The index takes into account either macrophyte or microphytes (the latter making up macroscopic growth forms) including briophytes. The IVAM showed the best correlation with nutrients besides other quality indices, indicating a solid tool to assess trophic status or eutrophication. (Author) 15 refs.

  3. ASSOCIATION OF BODY MASS INDEX WITH INTERARM BLOOD PRESSURE DIFFERENCE: A COMPARATIVE AND CROSS SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Namala Surya

    2015-11-01

    Full Text Available The major health problem faced by the 13% of world population is obesity and this obesity and overweight may lead to many health consequences such as cardiovascular diseases, diabetes and some cancers to mention a few. Objective of present study is to find the relation between the increased BMI and the interarm blood pressure difference. MATERIALS AND METHODS The present study was conducted on 180 subjects with age ranging from 18 to 50 years. They were divided into two groups based on the BMI. Subjects with normal BMI (25Kg/M2. The study was conducted in the GSL Medical College and General Hospital, Rajahmundry. RESULTS On comparing the results in overweight subjects in the age group of 40-50 were found to have interarm difference in the mean systolic blood pressure of more than 10mmHg, i.e. Mean value of 13.04+ 2.34(<0.001. CONCLUSION The overweight individuals with age more than 40 years, there is interarm difference in the mean systolic blood pressure, which is an indicator of peripheral vascular disease.

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

    DEFF Research Database (Denmark)

    Hyldig, Grethe; Nielsen, Henrik Hauch; Holm, Jørgen

    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......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...

  5. [Nitrogen Fraction Distributions and Impacts on Soil Nitrogen Mineralization in Different Vegetation Restorations of Karst Rocky Desertification].

    Science.gov (United States)

    Hu, Ning; Ma, Zhi-min; Lan, Jia-cheng; Wu, Yu-chun; Chen, Gao-qi; Fu, Wa-li; Wen, Zhi-lin; Wang, Wen-jing

    2015-09-01

    In order to illuminate the impact on soil nitrogen accumulation and supply in karst rocky desertification area, the distribution characteristics of soil nitrogen pool for each class of soil aggregates and the relationship between aggregates nitrogen pool and soil nitrogen mineralization were analyzed in this study. The results showed that the content of total nitrogen, light fraction nitrogen, available nitrogen and mineral nitrogen in soil aggregates had an increasing tendency along with the descending of aggregate-size, and the highest content was occurred in nitrogen fractions for all aggregate-classes followed in the order of abandoned land soil nitrogen than honeysuckle land. In this study it also showed the nitrogen stockpiling quantity of each aggregate-size class was differed in all aggregate-size classes, in which the content of nitrogen fraction in 5-10 mm and 2-5 mm classes of soil aggregate-size were the highest. And it meant that soil nutrient mainly was stored in large size aggregates. Large size aggregates were significant to the storage of soil nutrient. For each class of soil aggregate-size, the contribution of the nitrogen stockpiling quantity of 0. 25-1 mm class to soil net nitrogen mineralization quantity was the biggest, and following >5mm and 2-5 mm classes, and the others were the smallest. With the positive vegetation succession, the weight percentage of > 5 mm aggregate-size classes was improved and the nitrogen storage of macro-aggregates also was increased. Accordingly, the capacity of soil supply mineral nitrogen and storage organic nitrogen were intensified.

  6. On-Farm Study on Intercropping of Hybrid Maize with Different Short Duration Vegetables in the Charland of Tangail

    Directory of Open Access Journals (Sweden)

    MA Rahaman, MM Rahman, S Roy, M Ahmed, MS Bhuyan

    2015-12-01

    Full Text Available An experiment was conducted in charland at the Multi Location Testing (MLT site Bhuapur, Tangail during 2012-13 and 2013-14 under AEZ-8 to find out the suitable intercropping system of hybrid maize with different short duration vegetables with economic return. The experiment was laid out in RCB design with six dispersed (six farmers’ field replications. The hybrid maize (ver. BARI Hybrid maize-7, potato (Diamant, spinach (local, red amaranth (BARI Lalsak-1, Radish (BARI Mula-1 were used as the planting materials. Five treatment combinations viz. T1= Sole Maize, T2= 100% Maize (maize paired row + Potato (var. Diamant, T3= 100% Maize (maize paired row + Spinach (var. local, T4= 100% Maize (maize paired row + Red amaranth (var. BARI Lalshak-1 and T5= 100% Maize (Maize paired row + Radish (var. BARI Mula-1 were studied. Maize grain yield in intercropped combination varied from 5.59-7.62 t ha-1. But the highest grain yield (8.17 t ha-1 was obtained from sole maize. Maize equivalent yields in the intercrops situation ranged from 11.39-19.68 t ha-1 where highest maize equivalent yield 19.68 t ha-1 was recorded from the treatment T3 (100 % maize + spinach. The same combinations also gave highest gross return (Tk. 373930 ha-1 and gross margin (Tk. 258585 ha-1 as well as benefit cost ratio (3.24. Though highest grain yield was recorded from sole maize but equivalent yield and economic return was much lower than the treatment T3.

  7. Evaluation of different parameters affecting the liquid scintillation spectrometry measurement of gross alpha and beta index in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, M. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain); Villa, M. [Centro de Investigacion, Tecnologia e Innovacion. Servicio Radioisotopos. Universidad de Sevilla (Spain); Casacuberta, N. [Institut de Ciencia i Tecnologia Ambientals-Departament de Fisica, Universitat Autonoma de Barcelona. Spain (Spain); Penalver, A.; Borrull, F. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain); Aguilar, C., E-mail: carme.aguilar@urv.cat [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Tarragona (Spain)

    2011-09-15

    Liquid scintillation spectrometry is a fast