Chapter 3 Multiply method--f(w) 孙慧南: REO R< EO F(W) REO < runoff <1 R〓E0> runoff R: rainfall En: evaporation from water 2021/2/22 Assessment of Climate/Change Impacts 11 of 46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 11 of 46 Multiply method—f(w) 孙慧南: R/E0 R< E0 F(w) ＝ 1 R -E0 ≤runoff < 1 R -E0 >runoff R: rainfall E0 : evaporation from water
Chapter 3 Multiply method-f(w) 李世奎: (1 DR/ETm(1O股xErm f(w)= (1-CR> ET C: runoff coefficient 0.2 R: rainfall ETm crop water requirement m 2021/2/22 Assessment of Climate/Change Impacts 12of46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 12 of 46 Multiply method—f(w) 李世奎： (1-C)R/ETm (1-C)R < ETm f(w)＝ 1 (1-C)R > ETm C: runoff coefficient, 0.2 R: rainfall ETm: crop water requirement
Chapter 3 Multiply method-f(w) FAO: F(W)=K·(1-ET2/ETm Ky: crop yield coefficient responding to water supply ET: actual evaportranspiration ETm: crop water requirements 2021/2/22 Assessment of Climate/Change Impacts 13of46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 13 of 46 Multiply method—f(w) FAO: F(w) ＝Ky .（1-ETa / ETm） Ky : crop yield coefficient responding to water supply ETa : actual evaportranspiration ETm: crop water requirements
Chapter 3 AEz method Yp=|Ff(Y0)°Y0+(1-F)(Yc)°Ycl CL CN.Hlof(w) Yo: potential net dry matter in clear sky Yc: potential net dry matter in overcast F: modifying function for radiation f(Yo f(Yc): modifying function of temperature 2021/2/22 Assessment of Climate/Change Impacts 14of46
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 14 of 46 AEZ method Yp=[F•f(Y0 )•Y0+(1-F)•f(Yc)•Yc]} •CL•CN•HI•f(w) =========== Y0 : potential net dry matter in clear sky Yc: potential net dry matter in overcast F: modifying function for radiation f(Y0 )、f(Yc): modifying function of temperature
Chapter 3 AEz method CL: modifying coefficient for leaf area indeXed CN: modifying coefficient for respiration HI: harvest index ratio of economic yield to biomass f(w): modifying function of water balance 2021/2/22 Assessment of Climate/Change Impacts
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 15 of 46 AEZ method CL: modifying coefficient for leaf area index(LAI) CN: modifying coefficient for respiration HI: harvest index(ratio of economic yield to biomass f(w): modifying function of water balance