Predicting soil erosion for alternative land uses.

Published online

Journal Article

The APEX (Agricultural Policy-Environmental eXtender) model developed in the United States was calibrated for northwestern China's conditions. The model was then used to investigate soil erosion effects associated with alternative land uses at the ZFG (Zi-Fang-Gully) watershed in northwestern China. The results indicated that the APEX model could be calibrated reasonably well (+/-15% errors) to fit those areas with >50% slope within the watershed. Factors being considered during calibration include runoff, RUSLE (Revised Universal Soil Loss Equation) slope length and steepness factor, channel capacity flow rate, floodplain saturated hydraulic conductivity, and RUSLE C factor coefficient. No changes were made in the APEX computer code. Predictions suggest that reforestation is the best practice among the eight alternative land uses (the status quo, all grass, all grain, all grazing, all forest, half tree and half grass, 70% tree and 30% grain, and construction of a reservoir) for control of water runoff and soil erosion. Construction of a reservoir is the most effective strategy for controlling sediment yield although it does nothing to control upland erosion. For every 1 Mg of crop yield, 11 Mg of soil were lost during the 30-yr simulation period, suggesting that expanding land use for food production should not be encouraged on the ZFG watershed. Grass species are less effective than trees in controlling runoff and erosion on steep slopes because trees generally have deeper and more stable root systems.

Full Text

Duke Authors

Cited Authors

  • Wang, E; Xin, C; Williams, JR; Xu, C

Published Date

  • March 2006

Published In

Volume / Issue

  • 35 / 2

Start / End Page

  • 459 - 467

PubMed ID

  • 16455846

Pubmed Central ID

  • 16455846

International Standard Serial Number (ISSN)

  • 0047-2425

Digital Object Identifier (DOI)

  • 10.2134/jeq2005.0063

Language

  • eng

Conference Location

  • United States