SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Attribution of climate change, vegetation restoration, and engineering measures to the reduction of suspended sediment in the Kejie catchment, southwest China 
Authors:Ma, X., X.X. Lu, M. van Noordwijk, J.T. Li and J.C. Xu 
Journal:Hydrology and Earth System Sciences 
Article ID: 
URL (non-DOI journals):http://www.hydrol-earth-syst-sci.net/18/1979/2014/hess-18-1979-2014.html 
Broad Application Category:hydrologic & pollutant 
Primary Application Category:land use change and climate change 
Secondary Application Category:sediment loss and transport 
Watershed Description:1,755 km^2 Kejie, located in western Yunnan Province in southwest China 
Calibration Summary: 
Validation Summary: 
General Comments:As of June 12, 2014 the Doi for this article does not work (but the URL works). 
Abstract:Suspended sediment transport in rivers is controlled by terrain, climate, and human activities. These variables affect hillslope and riverbank erosion at the source, transport velocities and sedimentation opportunities in the river channel, and trapping in reservoirs. The relative importance of those factors varies by context, but the specific attribution to sediment transfer is important for policy making, and has wide implications on watershed management. In our research, we analyzed data from the Kejie watershed in the upper Salween River (Yunnan Province, China), where a combination of land cover change (reforestation, as well as soil and water conservation measures) and river channel engineering (sand mining and check dam construction) interact with a changing climate. Records (1971–2010) of river flow and suspended sediment loads were combined with five land-use maps from 1974, 1991, 2001, 2006 and 2009. Average annual sediment yield decreased from 13.7 t ha−1 yr−1 to 8.3 t ha−1 yr−1 between the period 1971–1985 and the period 1986–2010. A distributed hydrological model (Soil and Water Assessment Tools, SWAT) was set up to simulate the sediment sourcing and transport process. By recombining landuse and climate data for the two periods in model scenarios, the contribution of these two factors could be assessed with engineering effects derived from residual measured minus modeled transport. Overall, we found that 47.8% of the decrease was due to land-use and land cover change, 19.8% to climate change, resulting in a milder rainfall regime, 26.1% to watershed engineering measures, and the remaining 6.3% was due to the simulation percent bias. Moreover, mean annual suspended sediment yield decreased drastically with the increase of forest cover, making diverse forest cover one of the most effective ecosystems to control erosion. For consideration of stakeholders and policymakers, we also discuss at length the modeling uncertainty and implications for future soil and water conservation initiatives in China.