# Quantifying erosion-induced carbon emissions from SOC decomposition across sediment pathways in the yellow river basin

## TL;DR

This study quantifies carbon emissions from soil erosion in the Yellow River Basin, showing significant CO2 release due to soil organic carbon decomposition during transport.

## Contribution

The study introduces a novel integration of the CSLE and TLSD models to track erosion-induced carbon emissions across sediment pathways.

## Key findings

- 28.50 ± 4.43% of eroded SOC decomposed during transport, releasing 2.48 ± 0.11 × 108 t CO2 from 1990 to 2020.
- The upper reaches showed a much higher SOC decomposition ratio (49.66 ± 4.40%) compared to the middle reaches (22.96 ± 10.35%).
- Shanxi, Shaanxi, Shandong, Qinghai, and Gansu had the highest carbon emission rates between 1990 and 2020.

## Abstract

Soil erosion not only leads to soil loss but also redistributes soil organic carbon (SOC) and releases carbon dioxide (CO2) that contributes significantly to regional carbon emissions. Great efforts have been made to prevent soil erosion in the Yellow River Basin (YRB) in China in the past decades. Only few studies have paid attention to carbon emissions from soil loss. This study integrates the China Soil Loss Equation (CSLE) with a transport-limited sediment delivery (TLSD) model to quantify sediment redistribution and associated carbon emissions across five depositional processes (slope, reservoir, plain, river channel, and regional output) in the YRB.

The CSLE-TLSD model calibrated to a significantly improved Nash-Sutcliffe efficiency of 0.5690, compared to 0.5628 for the CSLE model. Results reveal that 28.50 ± 4.43% of eroded SOC was decomposed during transport, releasing 2.48 ± 0.11 × 108 t CO2 in the YRB from 1990 to 2020. Striking spatial disparities emerged in different regions: the upper reaches exhibited a SOC decomposition ratio of 49.66 ± 4.40%, in sharp contrast to 22.96 ± 10.35% in the middle reaches. The five provinces with the highest carbon emission rate from 1990 to 2020 were Shanxi (15.45 t CO2/km2), Shaanxi (14.23 t CO2/km2), Shandong (13.10 t CO2/km2), Qinghai (11.98 t CO2/km2), and Gansu (11.25 t CO2/km2).

These findings underscore the necessity of incorporating erosion-driven carbon flux dynamics into terrestrial carbon accounting frameworks, particularly in basins undergoing intensive anthropogenic modification.

The online version contains supplementary material available at 10.1186/s13021-025-00380-7.