Time Lag Analysis Between Climate Time And Lag Correlation Analysis Between Climate Drought And Hydrological Drought In Hashtgerd Plain

Groundwater resources in most parts of the world have a special place in terms of water supply for human needs. The quantity of these resources is affected by nutrition (mostly rainfall) and depletion. Drought as a considered natural disaster has profound economic and environmental effects on a large scale. To investigate the temporal effects of climatic drought on hydrological drought in groundwater resources, the present study was conducted in Hashtgerd plain. In this study, SPI was standardized as an indicator of climatic drought and GRI was evaluated as an indicator of groundwater resources. After analyzing the data, this index has a high correlation of 99% in the stations. Then, the weighted average monthly rainfall was employed to study its correlation with the groundwater index. Finally, to determine the relationship between SPI with different time bases and GRI, Pearson correlation with delays of zero to 150 months between these two indicators was applied. The Man-Kendall test was also adopted to check the potential trends in the data. The results showed that the temporal relationship between SPI and GRI not only it is dependent on the relationship between the time frame of the drought index and the time delay of the two indexes, but It also depends on the interrelationship between delay and time frame. Subsequently, the behavioral pattern of each piezometer led to the grouping of piezometers into three diverse groups. Consequently, by continuously examining the correlation between SPIs with various time bases and time delays between them, it was found that the correlations increase with decreasing latency and increasing the time base. However, this reaction was more observed in the first behavioral pattern and led to the creation of a northeast-southwest region with high correlation, while the correlation has increased from the southwest to the northeast.