TY - JOUR
T1 - Analysis of spatiotemporal variation in dissolved organic carbon concentrations for streams with cropland-dominated watersheds
AU - Tian, Yong Q.
AU - Yu, Qian
AU - Carrick, Hunter J.
AU - Becker, Brian L.
AU - Confesor, Remegio
AU - Francek, Mark
AU - Anderson, Olivia C.
N1 - Funding Information:
This study is supported by a collaborative National Science Foundation , United State Grant ( 1025547 , PI, Q. Yu; 1025546 , PI: Y.Q. Tian). Authors would like to thank Ashley Blunden (Lowran) for completing the bulk of the field sampling as part of her graduate work at CMU and Donald Uzarski for making his laboratory services available to process our DOC samples. This paper is contribution number xxx, Institute for Great Lakes Research at Central Michigan University. All supporting data have been listed in a pdf file that can be downloaded at: http://people.se.cmich.edu/tian2y/onlinedata.pdf .
Funding Information:
This study is supported by a collaborative National Science Foundation, United State Grant (1025547, PI, Q. Yu; 1025546, PI: Y.Q. Tian). Authors would like to thank Ashley Blunden (Lowran) for completing the bulk of the field sampling as part of her graduate work at CMU and Donald Uzarski for making his laboratory services available to process our DOC samples. This paper is contribution number xxx, Institute for Great Lakes Research at Central Michigan University. All supporting data have been listed in a pdf file that can be downloaded at: http://people.se.cmich.edu/tian2y/onlinedata.pdf.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/2/25
Y1 - 2023/2/25
N2 - It remains a challenge to understand how dissolved organic carbon (DOC) is cycled from farmlands to rivers due to the complex interaction between farming practices, the baseflow hydrology of predominantly flat lowlands, and seasonal environmental influences such as snowpack. To address this, field DOC concentrations were measured monthly throughout the year at sub-basin scales across the Chippewa River Watershed, which falls within the Corn Belt of the Midwestern United States. These DOC dynamics in stream water from croplands were benchmarked against the data sampled from hilly forested areas in the Connecticut River Watershed. The Soil Water Assessment Tool (SWAT) simulation was applied to provide potential predictive variables associated with daily baseflow. Our study outlines a framework using the combination of primary field data, hydrological modeling, and knowledge-based reclassification of Land Use/Land Cover (LULC) data to analyze the viability of modeling the spatial and temporal variations of cropland stream DOC concentrations. Calibration of the SWAT model resulted in the overall daily Nash–Sutcliffe model efficiency coefficient (NSE) of 0.67 and the corresponding R2 = 0.89. Our main results show: 1) baseflow DOC concentrations from croplands were substantially higher throughout the year relative to other landcover areas, especially for spring runoff/snowmelt scenarios, 2) an empirical analysis explained ~82 % of the spatial gradient of annual mean observed DOC concentrations, and 3) with the addition of hydrological simulated variables, a linear model explained ~81 % of monthly and 54 % of daily variations of observed DOC concentrations for cropland sub-basins. Our study identified key factors regulating the spatiotemporal DOC concentrations in cropland streamflow; the contribution here promotes to strengthen future analytical models that link watershed characteristics to carbon cycling processes in a large freshwater ecosystem.
AB - It remains a challenge to understand how dissolved organic carbon (DOC) is cycled from farmlands to rivers due to the complex interaction between farming practices, the baseflow hydrology of predominantly flat lowlands, and seasonal environmental influences such as snowpack. To address this, field DOC concentrations were measured monthly throughout the year at sub-basin scales across the Chippewa River Watershed, which falls within the Corn Belt of the Midwestern United States. These DOC dynamics in stream water from croplands were benchmarked against the data sampled from hilly forested areas in the Connecticut River Watershed. The Soil Water Assessment Tool (SWAT) simulation was applied to provide potential predictive variables associated with daily baseflow. Our study outlines a framework using the combination of primary field data, hydrological modeling, and knowledge-based reclassification of Land Use/Land Cover (LULC) data to analyze the viability of modeling the spatial and temporal variations of cropland stream DOC concentrations. Calibration of the SWAT model resulted in the overall daily Nash–Sutcliffe model efficiency coefficient (NSE) of 0.67 and the corresponding R2 = 0.89. Our main results show: 1) baseflow DOC concentrations from croplands were substantially higher throughout the year relative to other landcover areas, especially for spring runoff/snowmelt scenarios, 2) an empirical analysis explained ~82 % of the spatial gradient of annual mean observed DOC concentrations, and 3) with the addition of hydrological simulated variables, a linear model explained ~81 % of monthly and 54 % of daily variations of observed DOC concentrations for cropland sub-basins. Our study identified key factors regulating the spatiotemporal DOC concentrations in cropland streamflow; the contribution here promotes to strengthen future analytical models that link watershed characteristics to carbon cycling processes in a large freshwater ecosystem.
KW - Agricultural landscape
KW - Anthropogenic activity
KW - Baseflow
KW - Crop residue management
KW - Dissolved organic carbon
KW - Inland water
KW - SWAT model
UR - http://www.scopus.com/inward/record.url?scp=85145607596&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2022.160744
DO - 10.1016/j.scitotenv.2022.160744
M3 - Article
C2 - 36493833
AN - SCOPUS:85145607596
VL - 861
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 160744
ER -