Exploring wastewater nitrogen and phosphorus flows in urban and rural areas in China for the period 1970 to 2015.

China has experienced rapid population growth and increasing human N and P discharge from point sources. This paper presents a new spatial and temporal model-based, province-scale inventory of N and P in wastewater using detailed information on the location and functioning of 4436 WWTPs covering China for the period 1970-2015. China's nutrient discharge to surface water increased 22-fold from 177 to 3908 Gg N yr and 29-fold from 20 to 577 Gg P yr in urban areas between 1970 and 2015.

Inland Waters Increasingly Produce and Emit Nitrous Oxide.

Nitrous oxide (NO) is a long-lived greenhouse gas and currently contributes ∼10% to global greenhouse warming. Studies have suggested that inland waters are a large and growing global NO source, but whether, how, where, when, and why inland-water NO emissions changed in the Anthropocene remains unclear. Here, we quantify global NO formation, transport, and emission along the aquatic continuum and their changes using a spatially explicit, mechanistic, coupled biogeochemistry-hydrology model.

Exploring Spatially Explicit Changes in Carbon Budgets of Global River Basins during the 20th Century.

Rivers play an important role in the global carbon (C) cycle. However, it remains unknown how long-term river C fluxes change because of climate, land-use, and other environmental changes. Here, we investigated the spatiotemporal variations in global freshwater C cycling in the 20th century using the mechanistic IMAGE-Dynamic Global Nutrient Model extended with the Dynamic In-Stream Chemistry Carbon module (DISC-CARBON) that couples river basin hydrology, environmental conditions, and C delivery with C flows from headwaters to mouths.