1. Ahmadi Akhurmeh, M., Nohegar, A., Soleimani Motlagh, M., Taei Semiromi, M., 2015. Evaluation of groundwater drought using SPI and GRI indicators in the aquifer of Marvdasht Fars Kharameh. Irrigation & Water Engineering Journal 6, 105-107. 2. Ashraf A and Ahmad Z, 2008. Regional groundwater flow modelling of Upper Chaj Doab of Indus Basin, Pakistan using finite element model (Feflow) and geoinformatics. Geophysical Journal International. 173: 17–24. 3. Babaei Fini, A., Alijani, A., 2013. Spatial analysis of long-term drought in Iran. Journal of Geographical Studies 45:3, 1-12. 4. Barker LJ, Hannaford J, Chiverton A, Svensson C, 2015. From meteorological to hydrological drought using standardised indicators. Hydrol Earth Syst Sci 12:12827–12875. 5. Chamanpira, Gh.R., Ahmadi, H., Malekian, A., 2014. The effect of drought on groundwater resources in order to manage optimally, Case study: Plain Aleshtar. Journal of Engineering and watershed management 6: 1, 10-20. 6. Dracup JA, Lee KS and Paulson EG, 1980. On the definition of droughts. Water Resources Research 16(2): 297-302. 7. Karamouz, M., Araghinejad, Sh., 2005. Advanced Hydrology. Amirkabir University Press. 8. Khan S, Gabriel HF and Rana T, 2008. Standard precipitation index to track drought and assess impact of rainfall on watertables in irrigation areas. Irrigation and Drainage Systems. 22: 159–177. 9. Korani, A., Khaje, M., 2014. Evaluation the drought trend and decline in groundwater levels (Case study: Plain Darab). The Journal of Spatial Planning 18:2, 57-80. 10. Malekinejad, H., Soleimani Motlagh, M., 2011. Evaluate the severity of meteorological and hydrological droughts in the Chaghalvandi basin. Iran Water Research Journal 5: 9, 61-72. 11. McKee TB, Doesken NJ and Kleist J, 1993. The relation of drought frequency and duration to time scales. Pp. 179- 184. Proceedings of the Eighth Conference on Applied Climatology. Conference Location Anaheim, California. American Meterological Society, Boston. 12. Mendicino G, Senatore A and Versace P, 2008. A Groundwater Resource Index (GRI) for drought monitoring and forecasting in a Mediterranean climate. Journal of Hydrology 357(3): 282-302. 13. Mohamadi Ghaleney, M., Ebrahimi, K., Araghinejad, Sh. 2012. The effects of climatic factors on the loss of groundwater resources (case study: Saveh aquifer). Journal of Soil and Water Conservation 19:4, 189- 200. 14. Naderi Homami, J. 2011. Quantitative and qualitative study of the groundwater resources of the northern Mahyar plain aquifer using the Visual MODFLOW computer code, M.S.C Thesis. Faculty of Natural sciences, University of Tabriz. 15. Naderianfar, M., Ansari, H., 2011. Evaluate the effects of severity and duration drought in different time scale on groundwater level fluctuation (case study: Naishabur plain). Journal of Water Resources Engineering 4, 1-15. 16. Panda DK, Mishra A, Jena SK, James BK and Kumar A, 2007. The influence of drought and anthropogenic effects on groundwater levels in Orissa, India. Journal of Hydrology. 343: 140– 153. 17. Raziei, T., Daneshkar, P., Akhtari, R., Saghafian, B., 2007. Evaluation of meteorological drought in Sistan and Baluchestan province using SPI index and Markov Chain Model. Journal of Water Resources Iran 3: 1, 25-35. 18. Redmond KT, 2002. The depiction of drought. Bulletin of the American Meteorological Society. 83: 1143–1147. 19. Rezaei, M., Morid, S., Delavar, M., 2013. Assess the impact of climate change on hydrometeorological variables on Siminehrood basin. Journal of water and soil 27: 6, 1247- 1259. 20. Seif, M., Mosaedi, A., Mohamadzade, H., 2013. "Investigation of hydrogeological Drought in the aquifer Fasa plain using GRI Index". 15 th Congress of geosocie. Tehran. 21. Shahid SH and Hazarika MK, 2009. Groundwater Drought in the Northwestern District of Bangladesh. Water Resources Management. 24(10): 1989-2006. 22. Shakiba, A., Mirbagheri, B., Kheiri, A., 2010. Drought and its impact on groundwater resources in the East of Kermanshahprovince by using SPI index. Geography journal 8:25, 105- 124. 23. Soleimani Motlagh, M., 2011. Optimal management of the exploitation of groundwater resources in drought conditions by using MODFLOW (case study: Aleshtar plain). M.Sc. thesis, University of Yazd. 146 pp. 24. Vicente-Serrano SM and Lopez- Moreno JI, 2005. Hydrological response to different time scales of climatological drought: an evaluation of the Standardized Precipitation Index in a mountainous Mediterranean basin. Hydrology and. Earth System Sciences. 9: 523–533. 25. Vicente-Serrano, SM., Chura, O., López-Moreno, JI and Azorin-Molina, C. 2014. Spatio-temporal variability of droughts in Bolivia: 1955–2012. International Journal of Climatology. 35(10): 3024–3040.