Monitoring and forecasting of groundwater drought in Shahrekord plain using Groundwater Resource Index (GRI) and Markov chain model

Ground water resources management is of particular importance in arid and semi-arid areas. In this research, groundwater droughts in Shahrekord plain were investigated using GRI index. For this purpose, monthly water level measured in 32 piezometric wells in Shahrekord plain during the 31 year period (1984-1394) were used. In order to predict the GRI index values in Shahrekord plain for the next months, the first, second and third- order Markov chain models were used and the performance of these models were evaluated based on contingency table method. After forming the contingency table for the results of first, second and third- order Markov chain models, the values of CSI, POD and FAR statistics were calculated. The results showed that the Markov chain method had good accuracy in prediction of GRI values for the next 1, 2 and 3 months, so it can be used for forecasting groundwater drought in Shahrekord plain. In general, the severe droughts that have occurred in recent years due to reduce atmospheric precipitation, along with the overexploitation of groundwater have caused the severe decline in groundwater levels, which leads to groundwater quality degradation and land subsidence in the Shahrekord plain.