TY  - JOUR
AV  - public
UR  - https://doi.org/10.1002/2014WR016668
IS  - 11
PB  - Wiley
TI  - Annual water, sediment, nutrient, and organic carbon fluxes in river basins: A global meta?analysis as a function of scale
A1  - Mutema, M
A1  - Chaplot, V
A1  - Jewitt, G
A1  - Chivenge, P
A1  - Bloschl, G
N1  - Data used in the current analyses were
obtained free of charge from cited
literature, and we acknowledge
generating secondary data from
primary sources in some instances to
suit our requirements. The research
leading to these results has received
funding from the European
Community?s Seventh Framework
Programme (FP7/2007-2013) under
the WHaTeR project (Water Harvesting
Technologies Revisited) grant 266360.
We would also like to thank the
Austrian Science Fund (project P
23723-N21) and the ERC Advanced
grant ??Flood Change?? for financial
support. We are also grateful for the
comments and suggestions from the
journal Editors and three anonymous
reviewers.
SN  - 0043-1397
VL  - 51
N2  - Process controls on water, sediment, nutrient, and organic carbon exports from the landscape through runoff are not fully understood. This paper provides analyses from 446 sites worldwide to evaluate the impact of environmental factors (MAP and MAT: mean annual precipitation and temperature; CLAY and BD: soil clay content and bulk density; S: slope gradient; LU: land use) on annual exports (RC: runoff coefficients; SL: sediment loads; TOCL: organic carbon losses; TNL: nitrogen losses; TPL: phosphorus losses) from different spatial scales. RC was found to increase, on average, from 18% at local scale (in headwaters), 25% at microcatchment and subcatchment scale (midreaches) to 41% at catchment scale (lower reaches of river basins) in response to multiple factors. SL increased from microplots (468 g m?2 yr?1) to plots (901 g m?2 yr?1), accompanied by decreasing TOCL and TNL. Climate was a major control masking the effects of other factors. For example, RC, SL, TOCL, TNL, and TPL tended to increase with MAP at all spatial scales. These variables, however, decreased with MAT. The impact of CLAY, BD, LU, and S on erosion variables was largely confined to the hillslope scale, where RC, SL, and TOCL decreased with CLAY, while TNL and TPL increased. The results contribute to better understanding of water, nutrient, and carbon cycles in terrestrial ecosystems and should inform river basin modeling and ecosystem management. The important role of spatial climate variability points to a need for comparative research in specific environments at nested spatiotemporal scales.
SP  - 8949
Y1  - 2015/09//
EP  - 8972
ID  - icrisat10807
KW  - climate
KW  -  spatial scale
KW  -  organic carbon and nutrient erosion
KW  -  sediments
KW  -  water pollution
KW  -  runoff coefficient
KW  -  organic carbon fluxes
KW  -  meta-analysis
KW  -  soil erosion
JF  - Water Resources Research
ER  -