The evaporative loss from global lakes
(natural and artificial) is a critical
component of the terrestrial water and energy
balance. However, the evaporation volume of
these water bodies—from the spatial distribution
to the long-term trend—is as of yet unknown.
Here, using satellite observations and modeling
tools, we quantified the evaporation volume from
1.42 million global lakes from 1985 to 2018. We
find that the long-term average lake evaporation
is 1500 ± 150 km3 year−1 and it has increased at
a rate of 3.12 km3 year−1. The trend attributions
include an increasing evaporation rate (58%),
decreasing lake ice coverage (23%), and increasing
lake surface area (19%). While only accounting for
5% of the global lake storage capacity, artificial
lakes (i.e., reservoirs) contribute 16% to the
evaporation volume. Our results underline the
importance of using evaporation volume, rather
than evaporation rate, as the primary index for
assessing climatic impacts on lake systems.
Led by Huilin Gao, associate professor in the
Zachry Department of Civil and Environmental
Engineering at Texas A&M University, researchers
created the global lake evaporation volume
(GLEV) dataset. It leverages modeling and
remote sensing to provide the first long-term
monthly time series for 1.42 million individual
natural lakes and artificial reservoirs worldwide.
The researchers published their findings in Nature Communications.
About 87% of fresh surface water in liquid form is
stored in natural and artificial lakes (i.e., reservoirs).
While the evaporation volume from these global lakes
is substantial, little is known about its spatial
distribution and its long-term trend.
From 1985 to 2018, researchers discovered that long-term
average lake evaporation volume has increased at a
rate of 3.12 cubic kilometers per year. The trend
attributions include an increased evaporation rate of
58%, decreased lake ice coverage of 23% and increased
lake surface area of 19%.
“With regard to evaporation loss, this study will be
an invaluable venue to serve water resources researchers
and decision-makers,” Gao said. “Our findings have
significant environmental, societal and economic implications
as the global evaporative loss will be accelerated and
further exacerbated in the future under global warming.
“From a global perspective, the total reservoir evaporation
can be larger than the combined use of domestic and
industrial water. However, even in the United States,
very few lakes/reservoirs have reliable evaporation data.”
Without accurately quantifying the magnitude and trend of
volumetric evaporation loss individually for the millions
of global lakes, researchers say reliable water and
energy resources projections can’t be made. This freely
available dataset can benefit decision-makers and the
wider science community.
“With results for individual water bodies, GLEV can
really help improve reservoir management decision-making
all over the world, especially under increasing drought
events and population growth,” Gao said. “This dataset
helps the science community better understand the role
that these water bodies play in Earth systems, from
global weather forecasting, flood and drought modeling
to Earth system modeling under climate change.”
Provided by the IKCEST Disaster Risk Reduction Knowledge Service System