rewriting of yield impacts

config/default.cfg

@@ -25,7 +25,7 @@ cfg$model <- "main.gms"   #def = "main.gms"
 cfg$input <- c(regional    = "rev4.88_h12_magpie.tgz",
                cellular    = "rev4.88_h12_fd712c0b_cellularmagpie_c200_MRI-ESM2-0-ssp370_lpjml-8e6c5eb1.tgz",
                validation  = "rev4.88_h12_validation.tgz",
-               additional  = "additional_data_rev4.43.tgz",
+               additional  = "additional_data_rev4.45.tgz",
                calibration = "calibration_H12_per_ton_fao_may22_glo_08Aug23.tgz")
 
 # NOTE: It is recommended to recalibrate the model when changing cellular input data
@@ -307,16 +307,14 @@ cfg$gms$s14_limit_calib <- 1       # def = 1
 # NOTE: It is recommended to recalibrate the model when changing this setting!
 cfg$gms$s14_calib_ir2rf <- 1       # def = 1
 
-# * Switch to include yield impacts of land degradation
-# * Exogeneous yield reduction coefficients need to be provided
-# * through f14_degradation_yld_reduc.cs3
+# * Switch to include yield impacts of land degradation.
+# * The state of yield-relevant nature's contributions to people (NCP)
+# * is reported through ./modules/14_yields/input/f14_yld_ncp_report.cs3
+# * based on estimated outcomes for soil loss or pollination sufficiency
+# * per cluster from an existing model run.
 # * options: 1 (yields are reduced based on yield reduction coefficients)
 # *          0 (land degradation is switched off)
 cfg$gms$s14_degradation <- 0      # def = 0
-# * Types of land degradation considered
-# * options:  "soil_loss" (soil loss by water erosion)
-# *           "poll_loss" (insufficient pollination)
-cfg$gms$degrad_type <- "soil_loss, poll_loss"    #def = "soil_loss, poll_loss"
 
 # ***---------------------    15_food    ---------------------------------------
 # * (anthropometrics_jan18): estimates food using scenario dependent regression

modules/14_yields/input/files

@@ -5,3 +5,4 @@ lpj_yields_0.5.mz
 f14_pasture_yields_hist.csv
 f14_ipcc_bce.cs3
 f14_aboveground_fraction.csv
+f14_kcr_pollinator_dependence.csv

modules/14_yields/managementcalib_aug19/input.gms

@@ -10,11 +10,6 @@ $setglobal c14_yields_scenario  cc
 *             nocc      (no climate change)
 *             nocc_hist (no climate change after year defined by sm_fix_cc)
 
-sets
-  degrad_type(degrad_all) land degradation types considered in yield impacts
-       / poll_loss, soil_loss /
-;
-
 scalar s14_limit_calib   Relative managament calibration switch (1=limited 0=pure relative) / 1 /;
 
 scalar s14_calib_ir2rf   Switch to calibrate rainfed to irrigated yield ratios (1=calib 0=not calib) / 1 /;
@@ -23,6 +18,7 @@ scalar s14_degradation   Switch to include yield impacts of land degradation(0=n
 
 scalars
   s14_yld_past_switch  Spillover parameter for translating technological change in the crop sector into pasture yield increases  (1)     / 0.25 /
+  s14_yld_reduction_soil_loss  Land productivity declines by 8 per cent in areas where erosion rates are higher that 11 tons per hectare (1)     / 0.08 /
 ;
 
 scalars
@@ -86,9 +82,17 @@ $offdelim
 ;
 
 $onEmpty
-table f14_degradation_yld_reduc(t_all,j,degrad_all) Yield reduction factors due to land degradation (1)
+table f14_yld_ncp_report(t_all,j,ncp_type14) Share of land with intact natures contributions to people (NCP) (1)
 $ondelim
-$if exist "./modules/14_yields/input/f14_degradation_yld_reduc.cs3" $include "./modules/14_yields/input/f14_degradation_yld_reduc.cs3"
+$if exist "./modules/14_yields/input/f14_yld_ncp_report.cs3" $include "./modules/14_yields/input/f14_yld_ncp_report.cs3"
 $offdelim
 ;
 $offEmpty
+
+parameter f14_kcr_pollinator_dependence(kcr) Share of total yield dependent on crop pollination (1)
+/
+$ondelim
+$include "./modules/14_yields/input/f14_kcr_pollinator_dependence.csv"
+$offdelim
+/
+;

modules/14_yields/managementcalib_aug19/preloop.gms

@@ -165,15 +165,21 @@ i14_yields_calib(t,j,"pasture",w) = i14_yields_calib(t,j,"pasture",w)
 *' @code
 *' Land degradation can negatively affect yields. Soil loss for example can
 *' notably affect land productivity. Similarly, the yield of pollinator-dependent crops
-*' is reduced when there is lack of pollinators. To account for the impacts of degradation,
-*' calibrated yields are multiplied by a reduction coefficient that signifies the yield loss
-*' after degradation.
+*' is reduced when there is a lack of pollinators. To account for the impacts of degradation,
+*' calibrated yields are multiplied by the share of land with intact NCP in each cell and specific
+*' yield reduction coefficients that represent yield loss due to soil erosion and pollination
+*' deficiency on non-intact land.
+
+* set default values in case of missing input file.
+if(sum((t,j,ncp_type14),f14_yld_ncp_report(t,j,ncp_type14)) = 0,
+  f14_yld_ncp_report(t,j,ncp_type14) = 1;
+);
 
 if ((s14_degradation = 1),
-  i14_yields_calib(t,j,kcr,w)       = i14_yields_calib(t,j,kcr,w)
-                                      * (1 - sum(degrad_type, f14_degradation_yld_reduc(t,j,degrad_type)));
-  i14_yields_calib(t,j,"pasture",w) = i14_yields_calib(t,j,"pasture",w)
-                                      * (1 - sum(degrad_type, f14_degradation_yld_reduc(t,j,degrad_type)));
+  i14_yields_calib(t,j,kcr,w) = i14_yields_calib(t,j,kcr,w) * (1 - s14_yld_reduction_soil_loss)
+                                + i14_yields_calib(t,j,kcr,w) * s14_yld_reduction_soil_loss * f14_yld_ncp_report(t,j,"soil_intact");
+  i14_yields_calib(t,j,kcr,w) = i14_yields_calib(t,j,kcr,w) * (1 - f14_kcr_pollinator_dependence(kcr))
+                                + i14_yields_calib(t,j,kcr,w) * f14_kcr_pollinator_dependence(kcr) * f14_yld_ncp_report(t,j,"poll_suff");
 );
 
 *' @stop

modules/14_yields/managementcalib_aug19/sets.gms

@@ -25,13 +25,13 @@ sets
          oilpalm, puls_pro, potato, cassav_sp, sugr_cane, sugr_beet, others,
          foddr, cottn_pro, begr, betr /
 
-   knbe14(kcr) Cropping activities excluding bioenergy plants
+  knbe14(kcr) Cropping activities excluding bioenergy plants
        / tece, maiz, trce, rice_pro, soybean, rapeseed, groundnut, sunflower,
          oilpalm, puls_pro, potato, cassav_sp, sugr_cane, sugr_beet, others,
          foddr, cottn_pro /
 
-  degrad_all all land degradation types
-       / poll_loss, soil_loss /
+  ncp_type14 natures contributions to people (NCP) relevant for agricultural yields
+       / soil_intact, poll_suff /
 
 ;