Evaluating the Effect of Recent Droughts on Changes in Groundwater Resources Level (Case Study: Bandar Abbas Plains)

By definition, drought is a period of dryness especially when prolonged that causes extensive damage to crops or prevents their successful growth and has a negative impact on water resources (groundwater resources). The Standardized Precipitation Index (SPI) is a widely used index to characterize meteorological drought on a range of timescales. The SPI can be related to groundwater and reservoir storage. For this purpose, the SPI index was evaluated at 3, 6, 9, 12, 18 and 24 months scales in relation to groundwater level changes in Bandar Abbas plains Hormozgan Province.

The Bandar Abbas plains, including the Isin, Shamil-Takht, Gnu, Choch Dehno, and Sarakhoon plains play an important role in agricultural production and development in the region. In order to investigate the impact of recent droughts on groundwater levels of the above-mentioned plains, meteorological data were obtained from Bandar Abbas Synoptic Station during the period 2001-2005.

The results showed that in all the plains during the years studied, the SPI index is getting worse, that is, the drought is expanding and intensifying. Concomitant to this situation, groundwater levels are also falling. The average water level drop for the whole region was 3.35 m. Changes in the groundwater level were more consistent with the long-term effects of drought so that the highest correlation with changes in groundwater level occurred in the 24-month series.

Drought has a great effect on the groundwater level drop and changes in the groundwater level were more consistent with the long-term effects of drought.