Chapter 5 (2) Classification of soil erosion Precipitation/water erosion(Russians) Washing, wearing(Kozmenko, 1954) Sheetrill),gully(Sobolev, 1948) Normal, accelerated( surface, rill, linear/gully Sus 1949) Water erosion(French) Washing: downpour, sheet, layer or strip, rill, wearing Mass removal: landslides, underground, mud flows, creeping 2021/2/22 Assessment of climate/Change Impacts 6of56
Chapter 5 2021/2/22 Assessment of Climate/Change Impacts 6 of 56 (2) Classification of soil erosion • Precipitation/water erosion (Russians) ➢ Washing, wearing (Kozmenko, 1954) ➢ Sheet(rill), gully (Sobolev, 1948) ➢ Normal, accelerated (surface, rill, linear/gully Sus, 1949) • Water erosion (French) ➢ Washing: downpour, sheet, layer or strip, rill, wearing ➢ Mass removal: landslides, underground, mud flows, creeping
Chapter 5 (2) Classification of soil erosion By erosion intensity Harmless/normal erosion Compensative erosion Tolerance erosion Harmful erosion(sheet, gully No erosion, insignificant erosion Slight erosion Moderate erosion Severe erosion Ⅴ ery severe erosion Catastrophic erosion 2021/2/22 Assessment of climate/Change Impacts 7of56
Chapter 5 2021/2/22 Assessment of Climate/Change Impacts 7 of 56 (2) Classification of soil erosion By erosion intensity • Harmless/normal erosion ➢ Compensative erosion ➢ Tolerance erosion • Harmful erosion (sheet, gully) ➢ No erosion, insignificant erosion ➢ Slight erosion ➢ Moderate erosion ➢ Severe erosion ➢ Very severe erosion ➢ Catastrophic erosion
Chapter 5 (2) Classification of soil erosion Compensative erosion Erosion in which the rate of destruction equals that of soil formation Soil formation rate 90cm thick soil layer, 16,000a; Icm/178a (Kohnke and Bertrand 1959) 3cm/200-1000a,lcm/240a( Bennett195) Icm/100a (Kukal, 1964) Soil loss rate Normal erosion: 0. 1-0. 6 acre a(0r/ a, 25-128t/km-a)
Chapter 5 2021/2/22 Assessment of Climate/Change Impacts 8 of 56 (2) Classification of soil erosion Compensative erosion • Erosion in which the rate of destruction equals that of soil formation • Soil formation rate 90cm thick soil layer, 16,000a; 1cm/178a (Kohnke and Bertrand, 1959) 2-3cm/200-1000a, 1cm/240a (Bennett, 1955) 1cm/100a (Kukal, 1964) • Soil loss rate Normal erosion: 0.1-0.6 t/acre a (0.25-1.48t/ha a, 25-128t/km2 a)
Chapter 5 (2) Classification of soil erosion Permissible/tolerance erosion 1. 24-14.84t/ha a(Smith and Stamey, 1965) 6.75 t/ha a(Kohnke and Bertrand, 1959) 2021/2/22 Assessment of climate/Change Impacts 9of56
Chapter 5 2021/2/22 Assessment of Climate/Change Impacts 9 of 56 (2) Classification of soil erosion Permissible/tolerance erosion 1.24-14.84t/ha a (Smith and Stamey, 1965) 6.75 t/ha a (Kohnke and Bertrand, 1959)
Chapter 5 (2) Classification of soil erosion By erosion development Depending on different erosion form Sheet Gull Intrasoil wash Tunnel Darst 2021/2/22 Assessment of climate/Change Impacts 10of56
Chapter 5 2021/2/22 Assessment of Climate/Change Impacts 10 of 56 (2) Classification of soil erosion By erosion development • Depending on different erosion form ➢ Sheet ➢ Gully ➢ Intrasoil wash ➢ Tunnel ➢ Darst