updates for Hamon PET method, preventing negative PET

rchlumsk · rchlumsk · commit b2141657828d · 2025-08-19T12:33:28.000-04:00
diff --git a/src/Evaporation.cpp b/src/Evaporation.cpp
@@ -267,7 +267,7 @@ double Hamon1961Evap(const force_struct *F)
 
   abs_hum=216.7*(sat_vap*MB_PER_KPA)/(F->temp_daily_ave+ZERO_CELSIUS);//abs. humidity, g/m3 (may wish to make separate function of T)s
 
-  return 0.0055*4.0*abs_hum*F->day_length*F->day_length*MM_PER_INCH;
+  return max(0.0,0.0055*4.0*abs_hum*F->day_length*F->day_length*MM_PER_INCH);
 }
 
 //////////////////////////////////////////////////////////////////

Original file line number	Diff line number	Diff line change
`@@ -267,7 +267,7 @@ double Hamon1961Evap(const force_struct *F)`
`267`	`267`
`268`	`268`	`abs_hum=216.7(sat_vapMB_PER_KPA)/(F->temp_daily_ave+ZERO_CELSIUS);//abs. humidity, g/m3 (may wish to make separate function of T)s`
`269`	`269`
`270`		`- return 0.00554.0abs_humF->day_lengthF->day_length*MM_PER_INCH;`
	`270`	`+ return max(0.0,0.00554.0abs_humF->day_lengthF->day_length*MM_PER_INCH);`
`271`	`271`	`}`
`272`	`272`
`273`	`273`	`//////////////////////////////////////////////////////////////////`