title: Effects of vegetation cover of natural grassland on runoff and sediment yield in loess hilly region of China.
abstract: BACKGROUND
  The effects of vegetation cover (VC) on runoff and sediment yield were investigated from rainfall simulation experiments in the Loess Plateau of China. Five VCs from 0% to 80% and three different rainfall intensities (I₂.₀, ₁.₅, ₀.₇₅) were implemented.
  
  
  RESULTS
  The results indicated that runoff and sediment yields in slopes were significantly affected by I and VC, and when the VC amounted to 40% there occurred obvious benefits of runoff and sediment reductions and then amplitude decreased with the increase of VC. The runoff reduction benefits at I₁.₅ and I₀.₇₅ were much greater than that at I₂.₀, while the sediment reduction benefits had no significant difference among different rainfall intensities. At I₂.₀, the natural grassland slopes with high VC exhibited the characteristics of high runoff but low sediment production. There existed a power function relationship between cumulative runoff and sediment yield. The increase in cumulative sediment yield was less than the increase in cumulative runoff with increasing VC, and the sediment reduction benefit was greater than runoff reduction on natural grassland slopes.
  
  
  CONCLUSIONS
  The ratio of runoff reduction to sediment reduction can be used as a comprehensive index for assessing the benefits of runoff and sediment reduction in natural grassland.
authors.affiliation: Institute of Soil and Water conservation, Northwest A&F University, Yangling, Shaanxi, 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, 712100, Shaanxi, China; Institute of Water Saving Agriculture in Arid Regions of China, Northwest A&F University, Shaanxi, 712100, China; Department of Agricultural and Biosystems Engineering, Iowa State University, IA, 50011, USA.
authors.forename: Xining
authors.initials: X
authors.lastname: Zhao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.forename: Pute
authors.initials: P
authors.lastname: Wu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Helmers
mesh_terms: D002681:China; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments; D006109:Poaceae; D011891:Rain; D012987:Soil; D014867:Water
chemical_list: D012987:Soil; D014867:Water
keywords: loess hilly region of China; natural grassland; rainfall intensity; runoff and sediment yield; vegetation cover