Composition-dependent bedrock erosion parameters in fastscape

include/aspect/mesh_deformation/fastscape.h

@@ -453,6 +453,11 @@ namespace aspect
          */
         double sediment_deposition_g;
 
+        /**
+         * Flag for allowing chemical compositions to have different erosional parameters for bedrock
+         */
+        bool use_compositional_erosion_bedrock;
+
         /**
          * Function of bedrock river incision rate (kf) for the stream power law.
          * Represents the parameter `kf` in the FastScape landscape evolution equation.
@@ -475,7 +480,7 @@ namespace aspect
          * otherwise, the units are ${m^(1-2drainage_area_exponent)/s}$. Then a time scale factor will be applied to
          * convert it into  ${m^(1-2drainage_area_exponent)/yr}$ for Fastscape.
          */
-        double constant_bedrock_river_incision_rate;
+        std::vector<double> constant_bedrock_river_incision_rate;
 
         /**
          * Sediment river incision rate for the stream power law.
@@ -509,7 +514,7 @@ namespace aspect
          * convert it into  ${m^2/yr}$ for Fastscape.
          * This function is only used only if use_kf_distribution_function is false.
          */
-        double constant_bedrock_transport_coefficient;
+        std::vector<double> constant_bedrock_transport_coefficient;
 
         /**
          * Sediment transport coefficient for hillslope diffusion.