@article{MAKHILLOJES20071425369,
    title = {Analysis of Sudan Vegetation Dynamics-Using NOAA-AVHRR NDVI Data from 1993-2003},
    journal = {Online Journal of Earth Sciences},
    volume = {1},
    number = {4},
    pages = {163-169},
    year = {2007},
    issn = {1991-7708},
    doi = {ojesci.2007.163.169},
    url = {https://makhillpublications.co/view-article.php?issn=1991-7708&doi=ojesci.2007.163.169},
    author = {Habib Aziz Salim,Xiaoling Chen and},
    keywords = {NOAA-AVHRR,NDVI time series,drought,rainfall,Sudan},
    abstract = {Long term observation of space-borne remote sensing data provides a means to explore temporal variation on the Earth’s surface. This improved understanding of variability is required by numerous global change studies to explain annual and inter-annual trends and to separate those from individual events. This study  employs  daily  8  km  NOAA-AVHRR  data  of  the  Pathfinder  program  to  study  changes  in the annual  variability  of  vegetation  in Sudan, during the time period from 1993-2003. The daily data were processed  to  improve  15  day  composites using an iterative approach including metadata and robust statistical  techniques.  Examination  of  this  time  series  reveals  that  the  period  1994-2003,  marked  by a trend  towards  wetter  conditions  with   region-wide   above   normal   NDVI  conditions  with  maximum  in  1994 and  1999.  This  study  employs GIS to examine the relationship between rainfall and the Normalized Difference  Vegetation  Index  (NDVI)  in  the  context  of  the Sudan and the value of NDVI is taken as a tool for  drought  monitoring.  The  relationship  between  rainfall  and  NDVI  during  1993-2003  in Sudan is examined using spatial analysis methods and a strong positive correlation is found. The correlation is strongest during years of heaviest rainfall, indicating that  the  relationship between rainfall and NDVI is not a simple linear one.}
    }