Quantifying salinization trends and drivers in river basins worldwide using a new global salinity dataset
Abstract
Salinization of freshwater resources is a growing problem, threating freshwater security for agricultural, domestic and industrial purposes, as well as biodiversity, in many parts of the world. Although it is generally recognized that salinity changes are driven by both natural (primary salinization) and human processes (secondary salinization), a comprehensive assessment of the spatio-temporal salinity trends and contributing drivers are still lacking. Here we here present a new global surface and groundwater salinity dataset, including more than 16.3 million harmonized measurements over the 1980-2019 period and provide a cross-regional assessment of riverine salinity trends and its drivers. Seasonal Mann-Kendall trend tests were performed to assess salinity trends across and within several regional river basins across the world (Mississippi, Ebro, Rhine, Danube, Orange, Mekong and Murray-Darling). Contributions of 28 environmental and anthropogenic drivers to observed salinity trends were then quantified by using a Random Forest (RF) machine learning approach. Our quantifications show regions characterized by significant increasing salinization and freshening, sometimes across small spatial distances. Main drivers were shown to differ with different salinity trends, and the strength of the relationship also varied between river locations showing an increasing salinity trend, vs. those showing a decreasing trend. Our global, open-source salinity monitoring dataset and analyses of spatio-temporal trends in river basins across the world have potential for tackling several salinity-related research questions at cross-regional to global scales.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH100...09T
- Keywords:
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- 0496 Water quality;
- BIOGEOSCIENCES;
- 1831 Groundwater quality;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY