minor changes to Fei's commit (to avoid segfault)

sample_inputs/param.nml

@@ -457,7 +457,7 @@
 !-----------------------------------------------------------------------
   ihconsv = 0 !heat exchange option
   isconsv = 0 !evaporation/precipitation model
-! Min depth for applying heat/salt exchange (i.e. off if the local water depth h<hmin_airsea_ex)
+! Min total water depth for applying heat/salt exchange (i.e. off if the local water depth <hmin_airsea_ex)
   hmin_airsea_ex = 0.2 ![m]
 
 !-----------------------------------------------------------------------

src/Hydro/schism_init.F90

@@ -460,7 +460,7 @@ subroutine schism_init(iorder,indir,iths,ntime)
       iadjust_mass_consv0=0 !Enforce mass conservation for a tracer 
       ipre2=0
       ielm_transport=0; max_subcyc=10
-      hmin_airsea_ex=-2.d0
+      hmin_airsea_ex=0.2d0
 
       !Output elev, hvel by detault
       iof_hydro(1)=1; iof_hydro(25)=1

src/Hydro/schism_step.F90

@@ -6151,7 +6151,8 @@ subroutine schism_step(it)
         if(isconsv/=0) then
 !$OMP     do 
           do i=1,nea
-            if( idry_e(i)==1 .or. (ze(nvrt,i)-ze(kbe(i),i))<hmin_airsea_ex ) cycle
+            if(idry_e(i)==1) cycle
+            if(ze(nvrt,i)-ze(kbe(i),i)<hmin_airsea_ex) cycle
 
             if(impose_net_flux/=0) then !imposed net 
               precip=sum(fluxprc(elnode(1:i34(i),i)))/real(i34(i),rkind) !P-E
@@ -6169,7 +6170,8 @@ subroutine schism_step(it)
         if(ihconsv/=0) then
 !$OMP     do 
           do i=1,nea
-            if( idry_e(i)==1 .or. (ze(nvrt,i)-ze(kbe(i),i))<hmin_airsea_ex ) cycle
+            if(idry_e(i)==1) cycle
+            if(ze(nvrt,i)-ze(kbe(i),i)<hmin_airsea_ex) cycle
 
 !           Wet element (not shallow)
 !           Surface flux