Anthropogenic Drought: Definition, Challenges, and Opportunities

Abstract

Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions and activities, and altered micro-climate conditions due to changes in land and water management. This definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems that drive the development of anthropogenic drought. This process magnifies the water supply demand gap and can lead to water bankruptcy, which will become more rampant around the globe in the coming decades due to continuously growing water demands under compounding effects of climate change and global environmental degradation. This challenge has de facto implications for both short-term and long-term water resources planning and management, water governance, and policymaking. Herein, after a brief overview of the anthropogenic drought concept and its examples, we discuss existing research gaps and opportunities for better understanding, modeling, and management of this phenomenon.Plain Language Summary This article reviews research and progress on the notion of anthropogenic drought broadly defined as drought events caused or intensified by human activities. Most commonly used drought definitions are based on deficit in hydrologic/meteorologic drivers such as precipitation and runoff. Within coupled human-water systems, however, drought must be defined and understood as the complex and interrelated dynamics of both natural and human-induced changes. This anthropogenic drought definition considers the full spectrum of dynamic feedbacks and processes (e.g., land-atmosphere interactions and water and energy balance) within human-nature systems. Ideally, anthropogenic drought and the corresponding human interactions should be incorporated in models that include land-atmosphere interactions, water balance, and energy balance. In this article, we review AGHAKOUCHAK ET AL.

Anthropogenic drought dominates groundwater depletion in Iran

“…Iran has been under a prolonged drying condition since the early twenty-first century, revealing itself by vanishing lakes and wetlands 40 along with excessive water stress across the country 25 . As it was previously shown for the case of surface water availability in Iran 33 , such drought conditions are human-induced and are exemplifiers of "anthropogenic droughts" 41,42 , which refer to water stress caused or intensified by aggressive, short-sighted and unsustainable land and water management 25,[41][42][43] . Here, the condition of anthropogenic drought is manifested by excessive ratios of water withdrawal to available renewable groundwater resources across Iran's major basins.…”

Natural variability vs forced signal in the 2015–2019 Central American drought

“…These two questions will be addressed from a meteorological point of view by looking at the impact of climate change on the precipitation deficit. We realize that this is only the first step in analyzing the drivers of a complex phenomenon like a drought, which is not only caused by large scale circulation anomalies but also by complex interactions of local precipitation, wind, temperature, land use, and water management (Mishra and Singh 2010;AghaKouchak et al 2021).…”

Evaluation of precipitation indices in suites of dynamically and statistically downscaled regional climate models over Florida

“…Recent decades have seen large collaborative efforts to produce downscaled climate datasets to provide information regarding current and future climate. The need for this information is crucial as many studies have suggested changes in the global hydrological cycle in response to global warming, leading to global and regional scale changes in: drought risk and severity (Diffenbaugh et al 2015;Apurv et al 2019;Marvel et al 2019;Alizadeh et al 2020;AghaKouchak et al 2021) on one hand, and more intense and more frequent rainfall on the other (Marvel and Bonfils 2013;Westra et al 2013;Fischer and Knutti 2015;Prein et al 2017;Reidmiller et al 2018;Myhre et al 2019). At the wet end, extreme rainfall events have the potential for producing devastating effects, such as flooding, damage to public infrastructure (e.g., dams, highways etc.…”