文献类型：期刊文献

英文题名：Watershed Urbanization Stimulates Riverine Ch4 and Co2 Emissions Controlled by Nutrients Input

作者：Cui, Panpan[1] Cui, Lijuan[2] Zheng, Yunlong[1] Su, Fangli[1,3,4]

第一作者：Cui, Panpan

机构：[1] College of Water Conservancy, Shenyang Agricultural University, Shenyang, 110866, China; [2] Institute of Wetland Research, Chinese Academy of Forestry, Beijing, 100091, China; [3] Liaoning Panjin Wetland Ecosystem National Observation and Research Station, Shenyang, 110866, China; [4] Liaoning Shuangtai Estuary Wetland Ecosystem Research Station, Panjin, 124112, China

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240178109)

语种：英文

外文关键词：Carbon - Carbon dioxide - Nutrients - Rivers - Rural areas - Urban growth - Watersheds

摘要：Urban rivers are strongly influenced by human activities and have been hotspots for CH4 and CO2 emissions. However, evaluating land use and urbanization controls on carbon emissions across rural-urban rivers at the watershed scale have received less attention. In this study, a seasonal in situ survey was conducted on a typical rural-urban river in northern China to elucidate the spatial and temporal variations of CH4 and CO2, as well as the relationship with urbanization and its potential controlling factors. The results showed that CH4 emissions were higher in fall than in other seasons, while CO2 emissions peaked in summer. The average CH4 and CO2 fluxes at the water-gas surface were 1387.22±2474.98 μmol·m?2·d?1 and 52.78±54.44 mmol·m?2·d?1, respectively. Fluxes of CH4 and CO2 increased significantly in the urban section of the river, and the spatial heterogeneity of CH4 and CO2 emissions was closely related to the proportion of built-up area around the sampling sites. The proportion of built-up area explained 41% and 53% of the spatial variation of CH4 and CO2 concentrations, respectively. Water parameters explained 80.49% of the total variation of carbon concentrations and fluxes. Structural equation models were constructed based on the water parameters and the proportion of built-up land area, and TN, TP, DTC and conductivity directly affected riverine CH4 and CO2 emissions, with standardized direct effects of 0.502 and 0.486, respectively. The results of the pathway model indicated that urbanization indirectly control riverine CH4 and CO2 emissions by altering riverine nutrients input. We suggest that land use management and control of nutrients input are effective ways to reduce riverine CH4 and CO2 emissions. ? 2024, The Authors. All rights reserved.