按土壤垂向分布的不均匀性将土层分为三层,用三层蒸散发模型计算蒸散发量。参数有流域平均张力水容量WM (mm ),上层张力水容量WUM(mm),下层张力水容量WLM(mm),深层张力水容量WDM(mm),深层蒸散发扩散系数C 。
具体计算为
若P+WU>=EP, 则EU=EP,EL=0,ED=0;
若P+WU
若WL>C*LM,则WL=(EP-EU)WL/LM,ED=0;
若WL=C*(EP-EU),则EL=C*(EP-EU),ED=0;
若WL
用C++部分程序如下:
if(WU[i]+P[i]>=EP[i])
{
EU[i]=EP[i];
EL[i]=0;
ED[i]=0;
}
else
{ EU[i]=WU[i]+P[i];
if(WL[i]>=C*WLM)
{ EL[i]=(EP[i]-EU[i])*WL[i]/WLM;
ED[i]=0;
}
else
{if(WL[i]>=C*(EP[i]-EU[i]))
{
EL[i]=C*(EP[i]-EU[i]);
ED[i]=0;
}
else
{
EL[i]=WL[i];
ED[i]=C*(EP[i]-EU[i])-EL[i];
}
}
}
if(i
{WU[i+1]=WU[i]+P[i]-EU[i];
WL[i+1]=WL[i]-EL[i];
WD[i+1]=WD[i]-ED[i]; } E[i]=EU[i]+EL[i]+ED[i];
按土壤垂向分布的不均匀性将土层分为三层,用三层蒸散发模型计算蒸散发量。参数有流域平均张力水容量WM (mm ),上层张力水容量WUM(mm),下层张力水容量WLM(mm),深层张力水容量WDM(mm),深层蒸散发扩散系数C 。
具体计算为
若P+WU>=EP, 则EU=EP,EL=0,ED=0;
若P+WU
若WL>C*LM,则WL=(EP-EU)WL/LM,ED=0;
若WL=C*(EP-EU),则EL=C*(EP-EU),ED=0;
若WL
用C++部分程序如下:
if(WU[i]+P[i]>=EP[i])
{
EU[i]=EP[i];
EL[i]=0;
ED[i]=0;
}
else
{ EU[i]=WU[i]+P[i];
if(WL[i]>=C*WLM)
{ EL[i]=(EP[i]-EU[i])*WL[i]/WLM;
ED[i]=0;
}
else
{if(WL[i]>=C*(EP[i]-EU[i]))
{
EL[i]=C*(EP[i]-EU[i]);
ED[i]=0;
}
else
{
EL[i]=WL[i];
ED[i]=C*(EP[i]-EU[i])-EL[i];
}
}
}
if(i
{WU[i+1]=WU[i]+P[i]-EU[i];
WL[i+1]=WL[i]-EL[i];
WD[i+1]=WD[i]-ED[i]; } E[i]=EU[i]+EL[i]+ED[i];