A modified RUSLE model to estimate sediment yield in the Huangfuchuan watershed
We modified the Revised Universal Soil Loss Equation model (RUSLE) for soil erosion and sediment load simulation by making use of geographic information system and remote sensing techniques.The sediment transport capacity and check dam trapping efficiency modules were added to RUSLE model in order to compute sediment yield from soil loss data.The modified model was applied in the Huangfuchuan Watershed in the northem Loess Plateau as a case study.The simulated monthly sediment load showed good agreement with observations at the Huangfu station,with the Nash-Sutcliffe coefficient (NS) and correlation coefficient (R2) higher than 0.70 during 1991 to 1999 for model calibration; model verification from 2000 to 2009 (no measurement data was available in 2005) displayed relatively worse results with a lower NS and R2.Seasonal dynamics in sediment load can be well simulated in most cases;however,modeled sediment loads presented higher peaks than observation.This may be largely caused by model limitations and not considering detailed soil erosion processes.The most serious soil loss area with annual soil erosion modulus higher than 15 000t/km2/a mostly occurred in the Pisha stone and sandy region due to steep slopes and low vegetation cover.In the flat alluvial plain and high vegetation cover region,annual soil erosion modulus was less than 2 500t/km2/a.The annual soil erosion modulus with the same precipitation conditions,different land use types in the watershed can be ordered as:Pisha stone＞sandy region＞arable land＞grassland＞woodland.The results inferred that check dams in the Huangfuchuan watershed have trapped approximately 42 million t sediment,which is almost equal to the average annual sediment load at Huangfu station from 1955 to 2010.
NETL
NSTL
万方数据
维普
