TY - JOUR
T1 - Effects of climate and land-surface processes on terrestrial dissolved organic carbon export to major U.S. coastal rivers
AU - Yu, Qian
AU - Blunden, Ashley
AU - Tian, Yong
AU - Feig, Anthony D
PY - 2013/1/31
Y1 - 2013/1/31
N2 - This study aims to understand the influences of climate change and land surface processes on the variation
of in-stream DOC concentrations in coastal rivers crossing different climate zones. Monthly observations
spanning multiple years in seven major rivers in four different climate zones within the U.S. were analyzed
for correlations between dissolved organic carbon (DOC) concentration and surface air temperature, precipitation,
land cover and discharge. The major watersheds were the Altamaha River (GA), the Apilachicola
River (FL), the Columbia River (OR), the Delaware River (NJ), the Sacramento and San Joaquin Rivers (CA)
and the Susquehanna River (MD). One minor watershed, the Neponset River (MA) was also analyzed.
Results indicate that temperature is the most important variable for DOC export when the variation of
annual mean temperatures is large (e.g., >5 ◦C) with sufficient precipitation levels. Land-surface characteristics
and discharges are better correlated to DOC concentrations when the variations of annual mean
temperatures are small (e.g. <2 ◦C). However, results from the small watershed (Neponset) showed that
land surface processes can vary annual DOC concentrations about
±1.65 mg/L from mean value. This study
is the first to examine DOC relationships in watersheds in multiple climate zones, and it was determined
that weak correlations between temperature and DOC found in previous studies may be attributable to
the fact that those studies examined small watersheds contained within a single climate zone. DOC flux
per square meter was calculated based on incremental temperature increases. The results indicate that
an increase of 1 ◦C would result in a 0.476 mg/L increase of in-stream DOC in large watersheds. Climate
warming would have a greater impact on riverine DOC yields in cooler climate zones (up to 26% per ◦C)
than on those in warmer climate zones (up to 6% per ◦C).
AB - This study aims to understand the influences of climate change and land surface processes on the variation
of in-stream DOC concentrations in coastal rivers crossing different climate zones. Monthly observations
spanning multiple years in seven major rivers in four different climate zones within the U.S. were analyzed
for correlations between dissolved organic carbon (DOC) concentration and surface air temperature, precipitation,
land cover and discharge. The major watersheds were the Altamaha River (GA), the Apilachicola
River (FL), the Columbia River (OR), the Delaware River (NJ), the Sacramento and San Joaquin Rivers (CA)
and the Susquehanna River (MD). One minor watershed, the Neponset River (MA) was also analyzed.
Results indicate that temperature is the most important variable for DOC export when the variation of
annual mean temperatures is large (e.g., >5 ◦C) with sufficient precipitation levels. Land-surface characteristics
and discharges are better correlated to DOC concentrations when the variations of annual mean
temperatures are small (e.g. <2 ◦C). However, results from the small watershed (Neponset) showed that
land surface processes can vary annual DOC concentrations about
±1.65 mg/L from mean value. This study
is the first to examine DOC relationships in watersheds in multiple climate zones, and it was determined
that weak correlations between temperature and DOC found in previous studies may be attributable to
the fact that those studies examined small watersheds contained within a single climate zone. DOC flux
per square meter was calculated based on incremental temperature increases. The results indicate that
an increase of 1 ◦C would result in a 0.476 mg/L increase of in-stream DOC in large watersheds. Climate
warming would have a greater impact on riverine DOC yields in cooler climate zones (up to 26% per ◦C)
than on those in warmer climate zones (up to 6% per ◦C).
M3 - Article
VL - 54
SP - 192
EP - 201
JO - Ecological Engineering
JF - Ecological Engineering
SN - 0925-8574
ER -