JWSS - Journal of Water and Soil Science

Groundwater is a major source of drought. Karstic aquifers are important sources of groundwater in the West and Kermanshah province. This study was performed to investigate the effects of the meteorological drought on the karstic aquifer with different conditions of development. The studied areas in this research included two karstic aquifers, Bistoon-Parau and Patagh mountain in Kermanshah province. In this study, we used monthly precipitation and springs discharge during a period of 20 years.  Accordingly, the SPI and SDI indices were used to investigate the different states of meteorological and hydrological droughts, respectively. To determine the relationship between meteorological droughts and groundwater, Pearson correlation was used; aalso, to determine the time delay, the correlation between the different time conditions (no delay and delay 1 to 6 months) of the SDI index and the SPI index was investigated. The results of the relationship between the meteorological drought and groundwater showed that both had a significant correlation (p-value: 0.01). Also,  based on the results of the correlation between different time conditions (no delay and delay 1 to 6 months) ,the SDI index was compared to the SPI index, showing that the time delay between the occurrence of meteorological drought and groundwater in the studied areas without time delay or a maximum one-month delay had happened. Based on the results, Pearson correlation coefficients between the SPI and SDI indices in the Bistoon-Parav region were more than those of the Patagh mountain region indicating the development of the Bistoon-Parav karst region, as compared with the Patagh Mountain.

The purpose of this study was to investigate the relationship between time and spatial features of meteorological, hydrological and agricultural droughts in Karoon 1 Dam basin. Meteorological and statistical data were accordingly selected to evaluate the drought situation between 1993 and 2016. The results showed that hydrological droughts occurred in the meteorological drought and had a very high correlation with this year's meteorological drought. The most severe droughts occurred between 2006 and 2011. Studies also showed that every three years, the basin was accompanied by a meteorological drought and then a hydrological drought. The results also showed that the highest correlation was observed with the 12-month meteorological index, with a delay of 3 months, and the 6-month meteorological and hydrological index with a delay of 3 months and a three-month hydrological drought index with a delay of two months. Therefore, it could be concluded that hydrological droughts showed a delay of almost two to three months in the entire catchment area; since this period was 4 months or more, the correlation between these two indicators was eliminated and decreased. Also, due to drought zones, during the period from 1993 to 2009, most of the droughts were caused by rainfall reduction in the southwest of the province, and this was associated with a reduction in runoff in its hydrometric stations. Of course, in 2009-2012, the runoff status had been temporarily improved, and from 2012 to 2017, the drought situation had again returned spatially to the previous routine.