Investigating meteorological/groundwater droughts by copula to study anthropogenic impacts

Area of Science:

• Hydrology and Water Resources Management
• Environmental Science
• Climate Change Studies

Background:

• Lake Urmia faces a severe water crisis, necessitating a comprehensive investigation into its meteorological (Met) and groundwater (GW) droughts.
• Understanding anthropogenic impacts and resilience is crucial for effective water resource management in the basin.

Purpose of the Study:

• To conduct a basin-wide investigation of Met and GW droughts using a data-driven modeling strategy.
• To discern anthropogenic impacts on groundwater droughts and assess basin resilience patterns.
• To derive return periods for Met and GW droughts and analyze their spatial distribution.

Main Methods:

• Utilized 21 years of monthly data to transform time series into Met/GW indices.
• Extracted drought duration and severity metrics.
• Applied the copula method to derive return periods of maximum drought events.

Main Results:

• Generated basin-wide spatial distributions of Met and GW drought return periods across four zones.
• Statistically significant results indicate that aquifer depletions are primarily due to mismanagement, not Met droughts.
• Identified undermining of basin resilience through subsidence and altered aquifer-hydrograph connectivity.

Conclusions:

• Basin resilience is compromised, evidenced by physical changes and migration.
• Mismanagement of aquifers is the primary driver of depletion, exacerbating drought impacts.
• Urgent need for a proactive planning system to mitigate damages and manage water resources effectively.