2026-01-13 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/research_news/earth/202601/t20260113_1145654.shtml
- https://www.sciencedirect.com/science/article/pii/S0022169425022292
気候変動は、中国亜熱帯流域における窒素流出への土地利用変化の影響を増幅すると予想される Climate change expected to amplify land-use change impacts on nitrogen export from a subtropical catchment in China
Sanyuan Jiang, Adrian D. Werner, Lu Gao, Michael Rode
Journal of Hydrology Available online: 29 December 2025
DOI:https://doi.org/10.1016/j.jhydrol.2025.134888
Highlights
- DIN export most sensitive to denitrification in the soil and river systems;
- Increase of agricultural land increases river DIN concentration and DIN load;
- Climate change plays a larger role on hydrology than land-use change;
- Climate change amplifies the effects of land-use change on DIN export.
Abstract
Despite numerous modeling investigations of nutrient export, less is known about the effects of changes in climate and land use on dissolved inorganic nitrogen (DIN) export in subtropical catchments, which is needed to develop effective watershed management strategies. This study examines DIN export from a typical subtropical catchment (Yifeng River catchment, southeastern China) to evaluate the primary causes of variations in DIN export and the impacts of expected future changes in climate and land use. Sensitivity analysis and calibration of the Hydrological Predictions for the Environment (HYPE) model was performed using PEST and Differential Evolution Markov Chain algorithm (DE-MC). HYPE reproduced streamflow dynamics (2000–2019) sufficiently well and captured inter-annual variability in DIN export, which appears to be mainly controlled by fertilizer application rate, denitrification in the soil and river systems, causing higher loads in spring and summer. Land-use change alone (i.e. increased arable land by 7.0% and reduced forest areas by 7.5%; from 2015 to 2050) is estimated to increase riverine DIN concentration and load by 12.8% and 19.1%, respectively in response to increased nitrogen inputs. Annual evapotranspiration and runoff kept stable (insignificant change of 0.5%). Climate change (2031–2050) is expected to lead to different trends in runoff in various climate models and emission scenarios (−24.0 to 24.8%), while the average DIN concentration will increase by up to 36.0% compared to the baseline conditions of 2000–2019, depending on specific hydroclimatic variability. In combination, future land-use and climate changes are expected to increase the riverine DIN load by up to 32.6%. The study indicated that climate effect is dominant in runoff and climate change could amplify land-use change impacts on nitrogen pollution in subtropical catchments such as the Yifeng River catchment, mainly due to lower dilution capacity with decreased precipitation and river discharge.
