Resources Science ›› 2017, Vol. 39 ›› Issue (5): 860-870.doi: 10.18402/resci.2017.05.06

• Orginal Article • Previous Articles     Next Articles

Assessing the delivery of soil erosion control benefits at the watershed level following the WATEM/SEDEM concept

Yu LIU1(), Jiakun TENG1,2   

  1. 1. Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,100101 Beijing,China
    2. School of Environment and Resource,Southwest University of Science and Technology,Mianyang 621010,China
  • Received:2016-10-24 Revised:2017-02-05 Online:2017-05-20 Published:2017-05-20

Abstract:

Soil erosion and sediment delivery occurs widely in terrestrial environments. It has on-site and off-site environmental and social-economic effects. Soil erosion control provides various benefits for human beings,such as prevention of soil productivity loss,and reducing impoundment of reservoirs. For a land plot,the off-site benefits of soil erosion control is equal to the reduction of sediment export. Previously,assessments of off-site benefits of soil erosion control mostly rely on estimation of on-site soil retention,which is equal to the difference between estimated actual soil erosion and soil erosion without any prevention measures,and an invariant sediment delivery ratio (SDR). The scale effect of SDR and its correlation with the spatial and temporal variation of watershed characteristics and driven factors,such as spatial variation of rainfall regime,are often ignored. Consequently,quantitative and spatially explicit evaluations of soil erosion control benefits (SECB)and delivery across space are missing. For these reasons,an approach following the framework of WATEM/SEDEM model combining soil erosion and sediment delivery was developed to assess SECB provision and delivery over watershed. This approach integrates the on-site soil erosion prevention and reduction of sediment delivery. A case study was conducted in the Nianzhuang Watershed on the Loess Plateau. The SECB balance and spatial pattern in this loess watershed in the Hilly and Gully Area of the Loess Plateau was assessed. Based on the grid-cell-based modelling,the SECB import and export for each land use type were quantified and mapped. This approach identifies SECB supply areas and external beneficiary areas. In addition,it has potential to link SECB supply areas with beneficiary areas of SECB in a quantitative and spatially explicit way. Thanks to its spatial explicit feature,this approach is capable of serving the location-specific payments for ecosystem services provision.

Key words: soil erosion, sediment delivery, soil erosion control benefit, WATEM/SEDEM model, Loess Plateau