Merge pull request #29 from vcorcoro/master

updated automatic irrigation

Author: vcorcoro

src/rhizosphere/waterbalance.jl

@@ -26,7 +26,7 @@ Transpiration
         soil_table[Symbol(soil_class)].wilting_point
     end ~ preserve(parameter, u"mm")
 
-    
+   
     # "Irrigation"
     # irrigation => 0 ~ preserve(parameter, u"mm/hr")
 
@@ -174,22 +174,32 @@ Transpiration
     #    (field_capacity / soil_depth) 
     #end~ track
 
-    "Irrigation control parameters"
-    irrigation_start(WP, soil_depth) => WP / soil_depth ~ preserve(parameter) # Irrigation start point VWC- wilting point
-    irrigation_end(field_capacity, soil_depth) => field_capacity / soil_depth ~ preserve(parameter) # Irrigation end point VWC - field capacity
+       "Irrigation control parameters"
+    irrigation_start_level => 1 ~ preserve(parameter) # as percent of ASW + WP
+    irrigation_end_level => 1 ~ preserve(parameter) # as percent of ASW + WP
     irrigation_rate => 0.5 ~ preserve(parameter, u"mm/hr") # Irrigation rate mm/hr
 
+    irrigation_start(irrigation_start_level, field_capacity, WP, soil_depth) => begin
+        (irrigation_start_level * (field_capacity - WP) + WP) / soil_depth 
+    end ~ preserve(parameter) # Irrigation start point VWC
+    
+    irrigation_end(irrigation_end_level, field_capacity, WP, soil_depth) => begin
+        (irrigation_end_level * (field_capacity - WP) + WP) / soil_depth 
+    end ~ preserve(parameter) # Irrigation end point VWC 
+    
     "Update irrigation status based on VWC"
-    irrigation(VWC, irrigation_rate, irrigation_start, irrigation_end) => begin
-        if VWC < irrigation_start
+    flag_irrigation(VWC, irrigation_start, irrigation_end, flag_irrigation) => begin
+        (VWC < irrigation_start) || (VWC < irrigation_end && flag_irrigation)
+    end ~ flag
+    
+    irrigation(irrigation_rate, flag_irrigation) => begin
+        if flag_irrigation
             irrigation_rate
-        elseif VWC > irrigation_end
-            0
         else
-            irrigation_rate
+            0
         end
     end ~ track(u"mm/hr")
-
+    
     # Relative drought factor from CROPGRO. Used for N_uptake_conversion_factor.
     # Captures water stress due to both drought and water logging through reduction in stomatal conductance
     "Relative water stress factor"