English references
1- Ali Hassan Musa, Fundamentals of Climate Science, Dar Al-Fikr for Printing, Damascus, 1st Edition, 1994, p. 39.
2- Ali Sahib Talib Al-Musawi, Spatial Relationships between Climatic Characteristics in Iraq and Choosing the Appropriate Irrigation Method and Method, PhD thesis in Geography, (unpublished), College of Arts, University of Baghdad, 1996.
3- Noman Shehadeh, Climate Science, Dar Al-Safaa for Publishing and Distribution, Amman, 1st edition, 2009.
4- Abd al-Zahra Ali al-Janabi, pg. 129.
5- McKee, T. B. Doesken, N.J& Kleist, J. "The Relationship of Drought Freguency and Duration to Time Seales. Preprints", Eight conf. on Applied Climatology, "Anaheim California, USA" .
6- Radia Abdullah Jassim, Determining the Drought Phenomenon in the Kurdistan Region of Iraq, Master Thesis (unpublished), Salahaddin University, pg. 353, 2012.
7- Youssef Abdul-Majid Fayed, Geography, Climate and Plants, 1st Edition, Dar Al-Nahda Al-Arabiya for Printing and Publishing, p. 291, 2002.
8- Nazir Ahmed Ali Muhaimid Al-Obaidi, Observing the Creeping and Manifestations of Desertification in Al-Shirqat District, Master Thesis (unpublished), College of Education for Human Sciences, University of Tikrit, p. 87, 2014.
9- Iyad Abdullah Khalaf, Jassem Khalaf Shalal, Computation of NDVI values and botanical indices to assess the state of rangeland degradation using remote sensing techniques, Tikrit University Journal of Agricultural Sciences, Volume (13), Issue (1), p. 266, 2013.
10- Ati. Alaa Salih, Ibrahim Abdulghafour, Jubair Amel Radhi, Relationship between the Normalized Difference Vegetation Index (NDVI) and Some Soil Characteristics in the North of Iraq, IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS), Volume 7, Issue 10.