نتایج جستجو برای: شاخص ndvi

تعداد نتایج: 79772  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی ساری - دانشکده منابع طبیعی 1390

گونه های مهاجم با ایجاد تغییرات اکولوژیکی که گاهی برگشت ناپذیرند موفقیت عملیات احیا در حوزه های آبخیز را تهدید و موجب کاهش پتانسیل اکوسیستم ها در ارائه خدمات مورد نیاز جوامع انسانی می شوند. بنابراین ممانعت از هجوم، تشخیص اولیه و حذف این گیاهان کلیدی جهت کنترل و مدیریت آنهاست. تکنیک های سنجش از دور و سامانه اطلاعات جغرافیایی جهت پایش و مدیریت پایدار مراتع به منظور جلوگیری از هجوم، نابودی یا کنتر...

Journal: :Remote Sensing 2017
Shi Peng Jianguang Wen Qing Xiao Dongqin You Baocheng Dou Qiang Liu Yong Tang

Narrowband-to-broadband conversion is a critical procedure for mapping land-surface broadband albedo using multi-spectral narrowband remote-sensing observations. Due to the significant difference in optical characteristics between soil and vegetation, NTB conversion is influenced by the variation in vegetation coverage on different surface types. To reduce this influence, this paper applies an ...

Journal: :Remote Sensing 2011
Athos Agapiou Diofantos G. Hadjimitsis Christiana Papoutsa Dimitrios D. Alexakis George Papadavid

This paper presents the findings of the impact of atmospheric effects when applied on satellite images intended for supporting archaeological research. The study used eleven multispectral Landsat TM/ETM+ images from 2009 until 2010, acquired over archaeological and agricultural areas. The modified Darkest Pixel (DP) atmospheric correction algorithm was applied, as it is considered one of the mo...

Journal: :Journal of environmental quality 2002
Jerry A Griffith Edward A Martinko Jerry L Whistler Kevin P Price

We explored relationships of water quality parameters with landscape pattern metrics (LPMs), land use-land cover (LULC) proportions, and the advanced very high resolution radiometer (AVHRR) normalized difference vegetation index (NDVI) or NDVI-derived metrics. Stream sites (271) in Nebraska, Kansas, and Missouri were sampled for water quality parameters, the index of biotic integrity, and a hab...

Journal: :Remote Sensing 2016
Xavier Blaes Guillaume Chomé Marie-Julie Lambert Pierre Sibiry Traoré Antonius G. T. Schut Pierre Defourny

Soil fertility in smallholder farming areas is known to vary strongly on multiple scales. This study measures the sensitivity of the recorded satellite signal to on-farm soil fertility treatments applied to five crop types, and quantifies this fertilization effect with respect to within-field variation, between-field variation and field position in the catena. Plant growth was assessed in 5–6 p...

2016
JORDAN R. BELL

During the growing season in the central United States, severe thunderstorms frequently occur and produce large hail that damages the underlying vegetation, often in agricultural areas. Satellite remote sensing provides a tool for identifying these damaged areas. Previous studies have used changes in the normalized difference vegetation index (NDVI) to identify and examine these areas of damage...

2008
DONAL BISANZIO GIUSEPPINA AMORE CHARLOTTE RAGAGLI LAURA TOMASSONE LUIGI BERTOLOTTI ALESSANDRO MANNELLI

Host-seeking ticks were collected during monthly dragging sessions from November 2004 throughOctober 2006 inTuscany, central Italy.Normalizeddifference vegetation index (NDVI), which was calculated from Landsat ETM 7 remote sensing data recorded in August 2001, was signiÞcantly correlated with numbers of host-seeking immature Ixodes ricinus L. (Acari: Ixodidae) during periods of relatively low ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Miaogen Shen Zhenzhong Sun Shiping Wang Gengxin Zhang Weidong Kong Anping Chen Shilong Piao

Zhang et al. (1) report that the green-up dates in the Tibetan Plateau (TP) have continuously advanced from 1982 to 2011. They retrieved green-up dates from the multiannual time-series of Normalized Difference Vegetation Index (NDVI) using the method proposed by Piao et al. (2). This method assumes that the nongrowing season NDVI values remain constant among the different years and thus require...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Shuhua Yi Zhaoye Zhou

Using the National Aeronautics and Space Administration (NASA) Global Inventory, Monitoring, and Modeling Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) dataset (1982–2006), Yu et al. (1) found that the trend of advancing spring phenology for alpine steppe and meadow was reversed around 2000, despite the increasing air temperature over the Tibetan Plateau. This phenomenon cannot ...

ژورنال: :مطالعات جغرافیای مناطق خشک 0
محمد بـاعقیده بهلـول علیجـانی پرویز ضیائیان

برای شناسایی شاخص جایگزین به جای شاخص های اقلیمی ارزیابی و پایش خشک سالی ها، آمار بارش ماهانه ی دوره ی رشد (مارس تا سپتامبر) ایستگاه های هواشناسی استان اصفهان و تصاویر ماهواره noaa در دوره ی آماری 1997 تا 2003 تهیه و پردازش شدند. از آمار بارش شاخص spi و از تصاویر ماهواره ای شاخص ndvi محاسبه و استخراج شدند. نواحی پوشش گیاهی استان از روی نقشه ی کاربری، اراضی به صورت مراتع غنی، متوسط، و فقیر تعیین...

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