Climate change is the major global challenge facing water resources managers
because of its impacts on many life fields beginning with agriculture activities to economic
- social regions. In this study, drought in the eastern north of Syria have be
en investigated
(Hasake, Rakka, DerAzzor, Bokmal, Kameshli) using a set of data containing precipitation
data for period from 2000 to 2010, and MODIS time series images for the same period.
This study assure that 2008/2009 described as drought period in the study area, and the
NDVI maps ,which we have, give us an idea about the vegetation status and patterns in the
study area. The study clearly show that NDVI and rainfall was found to be highly
correlated in Rakka with P- Value= 0.003; and medium correlated in the other stations with
P- Value > 0.05.
Results of this study verify needing to use this index (NDVI), along with
precipitation data, in drought monitoring in the eastern north region of Syria. So that,. It
would help managers in making decisions to face drought in this area.
This study was analyzed the temporal variation of Moderate Resolution Imaging
Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) of natural
stands of cedrus libani in the northern humid part and eastern exposure of the Syrian
coastal mountains (Slenfeh, Jawbat Burghal), and its correlation with climatic variables
(temperature and precipitation) during the period of 2004-2014. We examined the
interannual and seasonal variation in NDVI values of Cedrus stands, and accumulative
effects of climatic variables (temperature and precipitation) on stands using simple linear
regression and correlation (Pearson). The NDVI values of Cedrus libani stands showed
significant increase in Slenfeh and Jawbat Burghal (0.006, 0.004 /year) respectively. We
found that the annual mean NDVI was significantly correlated with annual mean
precipitation in Jawbat Burghal (R = 0.689).The significant increase trend of seasonal
mean NDVI was in Slenfeh summer and Jawbat Burghal winter (R = 0.638, R = 0.724)
respectively. The results showed, there were accumulative effects of temperature on
Cedrus libani in Slenfeh and Jawbat Burghal in autumn and winter, while the
accumulative effects of precipitation in autumn and summer were noted.
This research aimed to use space image at certain growth stage for
predicting cotton yield in its direct physio-spectral relationship with
productivity. Timely, at the beginning of August better spectral growth stage is
coincidence with a maximum
leaf area index of cotton plants at Al-Kaltta fields.
Normalized difference vegetation index (NDVI) showed superiority on each of
red and near infrared channels in relation with productivity. Exponential
model was used to predict cotton productivity depending on NDVI values
during stage that maximum LAI.
The aim of the research was to clarify the pre-processing steps required for satellite images
before starting to analyze and extract data from them using the ENVI program.
Radiometric and topographic correction applied to the Landsat image 2017, an
d then we
calculated the NDVI index for this image before and after applying pre-processing.
The results showed a difference in the spectral values of the image before and after the
radiometric correction, especially in near infrared band. The reflection values were
recorded in the original image between (40-50) and (300-3500) in the corrected image. The
difference in the reflection values after the topographical correction was also visible on the
near- infrared and infrared bands, especially in the points where shadows of the terrain.
Differences in the values of NDVI for 2017 were observed before and after the application
of pre-processing on the image, especially in points of good and very good vegetation
coverage with high values of the index.
The study concluded that it is important to follow the minimum number of steps required
for preprocessing steps in order to avoid unnecessary steps and recommend well tested,
readily available, and adequately documented data approaches and data products.
In this study, drought in the eastern region of Syria (Hasake, Rakka,
DerAzzor, Bokmal & Kameshli) has been investigated using SPI, NDVI
indices.
We used a set of data containing precipitation data for period from 1975 to 2010 to calculate Standardized Precipitation Index SPI, and MODIS time series images in April for period from 2000 to 2010 to calculate the Normalized Difference Vegetation Index NDVI.