Nature not solely to blame for severe droughts

Drought researchers and managers must include human activity when looking at severe droughts, according to scientists from the University of Birmingham.

Changes to the way people use the water and landscape contribute to extreme water shortages in places such as China, Brazil and the US, with human activity just as detrimental to drought as natural forces, said researchers.

Dr Anne Van Loon, from the University of Birmingham said: “Society is not a passive victim of drought; it responds to water shortages and these responses again influence water levels in reservoirs, aquifers and rivers.

“Managing drought effectively means we must acknowledge that human influence is as integral to drought as natural climate variability. The traditional approach to drought research - focussing on natural phenomena - leads to poor prediction and management of this complex interdisciplinary phenomenon.”

The researchers also propose broadening the definition of drought to include water shortages due to human activity.

The current drought in California has affected both the environment and economy. Evaporation rates have been increased by storing water in reservoirs and extracting groundwater, making the drought worse.

Water abstraction, building reservoirs and transferring water are examples where humans have influenced drought conditions. Indirect effects such as changes made to the land can affect the rate at which drought occurs through altering hydrological processes.

In summer 2015, Europe suffered a severe drought that saw agricultural and hydropower production decrease.

Drought impact databases are currently being complied for Europe and the US to help solve this issue.

Dr Van Loon said: “While human activity can contribute to worsening drought, society can also play its part in tackling water shortages. However, we can only begin to take positive global action against drought when evaluating the relationship between nature and people and its impact."