Our latest paper has been published in Environmental Research Letters, entitled “Re-assessing global water storage trends from GRACE time series“.
Its main message is that linear trend values for short time series should be interpreted carefully, and specifically in this case for hydrological time series from the Gravity Recovery And Climate Experiment (GRACE) satellite mission. We introduce a new metric (Trend to Variability ratio, TVR) for assessing the severity of GRACE trends with regards past variability, and show that GRACE-derived water storage trends are better interpreted when set in the context of historical variability.
Using GRACE data complemented by TVR, we find that several regions thought to be losing water at a moderate rate are more endangered when longer term natural variability is considered, and vice-versa. We also estimate that greater than 3.2 billion people are currently living in regions facing severe water storage depletion, and that over one-third of river catchments that lost water in the last decade have suffered unprecedented losses
A plain language summary of the work is available here.
Full paper: Vishwakarma B.D., Bates, P., Sneeuw, N., Westaway, R.M. and Bamber, J. L. (2020). Re-assessing global water storage trends from GRACE time series. Environmental Research Letters (DOI:10.1088/1748-9326/abd4a9 ).