A critical understanding of the water crisis of Lake Urmia is the driver in this paper for a basin-wide investigation of its Meteorological (Met) droughts and Groundwater (GW) droughts. The challenge is to formulate a data-driven modelling strategy capable of discerning anthropogenic impacts and resilience patterns through using 21-years of monthly data records. The strategy includes: (i) transforming recorded timeseries into Met/GW indices; (ii) extracting their drought duration and severity; and (iii) deriving return periods of the maximum drought event through the copula method. The novelty of our strategy emerges from deriving return periods for Met and GW droughts and discerning anthropogenic impacts on GW droughts. The results comprise return periods for Met/GW droughts and their basin-wide spatial distributions, which are delineated into four zones. The information content of the results is statistically significant; and our interpretations hint at the basin resilience is already undermined, as evidenced by (i) subsidence problems and (ii) altering aquifers' interconnectivity with watercourses. These underpin the need for a planning system yet to emerge for mitigating impacts and rectifying their undue damages. The results discern that aquifer depletions stem from mismanagement but not from Met droughts. Already, migration from the basin area is detectable.

A critical understanding of the water crisis of Lake Urmia is the key in this paper for a basin-wide investigation of its Meteorological (Met) droughts and Groundwater (GW) droughts through a data-driven modelling strategy using 21-years of data records. The challenge is to formulate a modelling strategy to discern anthropogenic impacts and resilience patterns. The strategy includes: (i) transforming the recorded timeseries into Met/GW drought indices; (ii) extracting their drought duration and severity; and (iii) deriving return periods of the maximum drought event through the copula method. Our strategy is heuristic and its novelty emerges from deriving return periods for both Met and GW droughts to discern anthropogenic impacts on GW droughts. The results underpin the need for a planning system yet to emerge for mitigating impacts and rectifying ongoing damages before they become irreparable. The collective outcomes of the results and our professional knowledge shed light: on the ways resilience in the basin is undermined in terms of subsidence problems, on impacting the environment by altering interconnectivities between the lake and watercourses, and on discerning the causes for aquifer depletions to be due to mismanagement but not of Met droughts. Already, migration from the basin area can be detected.