User Tools

Site Tools


start:hype_model_description:processes_above_ground

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Next revision Both sides next revision
start:hype_model_description:processes_above_ground [2018/08/10 15:41]
cpers [Precipitation adjustments]
start:hype_model_description:processes_above_ground [2018/10/02 10:28]
cpers [Input to alternative potential evaporation models]
Line 6: Line 6:
  
 ==== Temperature adjustments ==== ==== Temperature adjustments ====
-Subbasin air temperatures (//tempi//) in the input file are normally assumed to be for the subbasin’s average elevation (//elev//).+Subbasin air temperatures (<​m>​T_i<​/m>) in the input file are normally assumed to be for the subbasin’s average elevation (//elev//). The same adjustments are made for maximum and minimum temperatures if available.
    
 (1) If data with other reference height is used it is possible to adjust for that. The subbasin temperature can be adjusted depending on subbasin elevation with general parameter //​tcelevadd//​ (//° / 100m//). This adjustment assumes observations are located at sea level. ​ (1) If data with other reference height is used it is possible to adjust for that. The subbasin temperature can be adjusted depending on subbasin elevation with general parameter //​tcelevadd//​ (//° / 100m//). This adjustment assumes observations are located at sea level. ​
  
-(2) Alternatively it can be adjusted based on the difference between subbasin elevation and temperature observation elevation by general parameter //​tcobselev//​ (//° / 100m//). The temperature observation elevation (//obselev//) then need to be supplied to the model. ​+(2) Alternatively it can be adjusted based on the difference between subbasin elevation and temperature observation elevation by general parameter //​tcobselev//​ (//° / 100m//). The temperature observation elevation (<​m>​elev_obs<​/m>) then need to be supplied to the model. ​
  
 (3) It can be adjusted based on month with the monthly dependent parameter //​monthlapse//​ (//° / 100m//)). These three subbasin elevation adjustments should not be used together. ​ (3) It can be adjusted based on month with the monthly dependent parameter //​monthlapse//​ (//° / 100m//)). These three subbasin elevation adjustments should not be used together. ​
 Subbasin temperature can be adjusted equally over all subbasins within a region with the parameter region dependent parameter //​tempcorr//​. Subbasin temperature can be adjusted equally over all subbasins within a region with the parameter region dependent parameter //​tempcorr//​.
  
-<​m> ​tempgc ​tempi + tempcorr - tcelevadd * elev/100 - tcobselev * (elev-obselev)/100 - monthlapse*elev/​100 </m>+<​m> ​T_gc T_i + tempcorr - tcelevadd * elev/100 - tcobselev * (elev - elev_obs)/100 - monthlapse*elev/​100 </m>
  
-The temperature can also be adjusted for each class depending on their deviation from the subbasin average elevation (//deltah//). The class-dependent temperature (//temp//) is calculated using the parameter //tcalt//. The temperature lapse rate often has a value of 0.6 (//° / 100m//​). ​+The temperature can also be adjusted for each class depending on their deviation from the subbasin average elevation (<​m>​{Delta}h<​/m>). The class-dependent temperature (//T//) is calculated using the parameter //tcalt//. The temperature lapse rate often has a value of 0.6 (//° / 100m//​). ​
  
-<​m> ​temp tempgc ​- tcalt*deltah/100 </m>+<​m> ​T_gc - tcalt*{{Delta} h}/100 </m>
  
 ==== Precipitation adjustments ==== ==== Precipitation adjustments ====
-Subbasin input precipitation (//preci//) can be adjusted equally over all subbasins with the general parameter //pcaddg// or for some subbasins with the parameter region dependent parameter //​preccorr//​. Additionally it is possible to adjust precipitation for undercatch with different parameters (//​pcurain,​pcusnow//​) depending on if the precipitation falls as snow or rain. +Subbasin input precipitation (<​m>​P_i<​/m>) can be adjusted equally over all subbasins with the general parameter //pcaddg// or for some subbasins with the parameter region dependent parameter //​preccorr//​. Additionally it is possible to adjust precipitation for undercatch with different parameters (//​pcurain,​pcusnow//​) depending on if the precipitation falls as snow or rain. 
  
-Subbasin precipitation (//precgc//) is for subbasin average elevation (//basinelev//), but can be adjusted for elevation variations within the subbasin. The precipitation of a class (//prec//) is adjusted for classes where the class average elevation is greater than a threshold (general model parameter //​pcelevth//​). The adjustment is determined by a general parameter (//​pcelevadd//​) that is the correction per 100m. The class elevation adjustment can alternatively be determined from the basin standard deviation of elevation (//​stdbasinelev//​) and a parameter //​pcelevstd//​. The class height adjustment is limited by a general parameter //​pcelevmax//​. The precipitation of a class can additionally be adjusted with land-use dependent parameter //pcluse//, e.g. for interception evaporation.  ​+Subbasin precipitation (<​m>​P_gc<​/m>) is for subbasin average elevation (//elev//), but can be adjusted for elevation variations within the subbasin. The precipitation of a class (//P//) is adjusted for classes where the class average elevation is greater than a threshold (general model parameter //​pcelevth//​). The adjustment is determined by a general parameter (//​pcelevadd//​) that is the correction per 100m. The class elevation adjustment can alternatively be determined from the basin standard deviation of elevation (<​m>​elev_std<​/m>) and a parameter //​pcelevstd//​. The class height adjustment is limited by a general parameter //​pcelevmax//​. The precipitation of a class can additionally be adjusted with land-use dependent parameter //pcluse//, e.g. for interception evaporation.  ​
  
-<​m> ​precgc=preci*(1+pcaddg)*(1+preccorr)*(1+(pcurain*(1-snowfraction)+pcusnow*snowfraction)) </m>+<​m> ​P_gc=P_i*(1+pcaddg)*(1+preccorr)*(1+(pcurain*(1-snfrac)+pcusnow*snfrac)) </m>
  
-<​m> ​pcorr_{height}=delim{lbrace}{ ​+<​m> ​pc_{height}=delim{lbrace}{ ​
 matrix{2}{2}{ matrix{2}{2}{
-    0 {basinelev+deltah<​pcelevth} +    0 {elev+{Delta}h<​pcelevth} 
-    {MIN({basinelev+deltah-pcelevth}/​{100}*pcelevadd+{stdbasinelev}/​{100}*pcelevstd,​pcevelmax)}  else+    {MIN({{elev+{Delta}h-pcelevth}/​{100}}*pcelevadd+{{elev_std}/{100}}*pcelevstd,​pcelevmax)}  else
    }}{} </m>    }}{} </m>
  
-<​m> ​prec=precgc*(1+pcorr_{height} )*(1-pcluse) </m>+<​m> ​P=P_gc*(1+pc_{height} )*(1-pcluse) </m>
  
-Where //​deltah// ​is a class'​s elevation deviation from the subbasin average elevation and //snowfraction// is the average fraction of precipitation that falls as snow calculated from subbasin temperature (tempgc) and class-dependent ​temperature ​threshold ​or from input.+Where <​m>​{Delta}h<​/m> is a class'​s elevation deviation from the subbasin average elevation and //snfrac// is the average fraction of precipitation that falls as snow calculated from subbasin temperature (<​m>​T_i</​m>​) and temperature ​thresholds (see equation below), ​or from input.
 ==== Rainfall and snowfall calculation ==== ==== Rainfall and snowfall calculation ====
-The rain/snow fraction of precipitation is calculated based on temperature or given as an input time series. When the air temperature (//temp//) is around the threshold temperature for mixed precipitation (land-use dependent parameter //ttmp// plus general parameter //ttpd//) both rain and snow. The interval for mixed precipitation is given by the parameter //ttpi//. For temperature below threshold minus //ttpi//, the precipitation is assumed to be in solid form only and is added to the snowpack ​(//snow//). If the air temperature is greater than the threshold temperature plus //ttpi//, the precipitation is assumed to be solely in liquid form. For intermediate temperatures,​ the precipitation is assumed to be a mixture of liquid and solid forms i.e. as both rain and snow. The proportion (//arain//) of precipitation (//prec//), which falls as rain depends linearly on the temperature. ​+The rain/snow fraction of precipitation is calculated based on temperature or given as an input time series. Different temperatures can be used in the equation, i.e. basin average or class temperature. When the air temperature (//T//) is around the threshold temperature for mixed precipitation (land-use dependent parameter //ttmp// plus general parameter //ttpd//) both rain and snow. The interval for mixed precipitation is given by the parameter //ttpi//. For temperature below threshold minus //ttpi//, the precipitation is assumed to be in solid form only and is added to the snowpack. If the air temperature is greater than the threshold temperature plus //ttpi//, the precipitation is assumed to be solely in liquid form. For intermediate temperatures,​ the precipitation is assumed to be a mixture of liquid and solid forms i.e. as both rain and snow. The proportion (<​m>​a_rain<​/m>) of precipitation (//P//) that falls as rain depends linearly on the temperature. ​
  
  
 <m> a_{rain}=delim{lbrace}{ ​ <m> a_{rain}=delim{lbrace}{ ​
 matrix{3}{2}{ matrix{3}{2}{
-    0 {temp<​ttmp+ttpd-ttpi} +    0 {T<​ttmp+ttpd-ttpi} 
-    1 {temp>​ttmp+ttpd+ttpi} +    1 {T>​ttmp+ttpd+ttpi} 
-    {{(temp-(ttmp+ttpd-ttpi))}/​{(2*ttpi)}} ​ else+    {{(T-(ttmp+ttpd-ttpi))}/​{(2*ttpi)}} ​ else
    }}{} </m>    }}{} </m>
  
-Alternatively snowfall fraction (//​sffrac//​) may be read from input file+Alternatively snowfall fraction (//​sffrac//​) may be read from input file and <​m>​a_rain</​m>​ calculated as: 
  
 <m> a_{rain}=1-sffrac </m> <m> a_{rain}=1-sffrac </m>
Line 56: Line 56:
 <m> rainfall=prec*a_{rain} </m> <m> rainfall=prec*a_{rain} </m>
 <m> snowfall=prec*(1-a_{rain} ) </m> <m> snowfall=prec*(1-a_{rain} ) </m>
 +
 +
 +
 +==== Links to file reference ====
 +
 +^Section ^Symbol ^Parameter/​Data ^File ^
 +|Temperature adjustments|<​m>​T_i</​m>​| |[[start:​hype_file_reference:​tobs.txt|Tobs.txt]]|
 +|:::​|//​elev//​|//​elev_mean//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::​|<​m>​{Delta}h</​m>​|//​dhslc_nn//​|:::​|
 +|:::​|<​m>​elev_obs</​m>​|//​tobselev//​|[[start:​hype_file_reference:​forckey.txt|ForcKey.txt]]|
 +|:::| |//​tcelevadd,​ tcobselev, monthlapse, tempcorr, tcalt//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|Precipitation adjustments|<​m>​P_i</​m>​| |[[start:​hype_file_reference:​pobs.txt|Pobs.txt]]|
 +|:::| |//pcaddg, preccorr, pcurain, pcusnow, pcelevth, pcelevadd, pcelevstd, pcelevmax, pcluse//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|:::​|<​m>​{Delta}h</​m>​|//​dhslc_nn//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::​|<​m>​elev_std</​m>​|//​elev_std//​|:::​|
 +|:::​|//​snfrac//​|calculated based on <​m>​T_i</​m>​ or from |[[start:​hype_file_reference:​sfobs.txt|SFobs.txt]]|
 +|Rainfall and snowfall calculations| |//ttmp, ttpd, ttpi//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|:::​|//​sffrac//​| |[[start:​hype_file_reference:​sfobs.txt|SFobs.txt]]|
  
  
Line 76: Line 94:
 ===== Evaporation ===== ===== Evaporation =====
  
-Potential evaporation (//epot// in mm) is calculated based on the temperature if it is not read in from file (Xobs.txt). Alternative PET models exist, and is described [[start:​hype_model_description:​processes_above_ground#​alternative_potential_evaporation_models|below]]. When the air temperature (//temp//) is greater than the threshold temperature //ttmp// evaporation is assumed to occur. Snow melting, snow density and evaporation use the same threshold temperature. The basic potential evapotranspiration (<​m>​epot_base</​m>​) depends on the land use dependent rate parameter //cevp//.+Potential evaporation (//epot// in mm) is calculated based on the temperature if it is not read in from file (Xobs.txt). Alternative PET models exist, and is described [[start:​hype_model_description:​processes_above_ground#​alternative_potential_evaporation_models|below]]. When the air temperature (//T//) is greater than the threshold temperature //ttmp// evaporation is assumed to occur. Snow melting, snow density and evaporation use the same threshold temperature. The basic potential evapotranspiration (<​m>​epot_base</​m>​) depends on the land use dependent rate parameter //cevp//.
  
 <m> cseason = 1 + cevpam*sin(2*pi*(dayno-cevpph)/​365) </m> <m> cseason = 1 + cevpam*sin(2*pi*(dayno-cevpph)/​365) </m>
  
-<m> epot_{base} = (cevp * cseason) * (temp-ttmp) </m>+<m> epot_{base} = (cevp * cseason) * (T-ttmp) </m>
  
 A seasonal factor //cseason// adjusts the potential evaporation rate (//cevp//) e.g. making it higher in the spring when the air is often dry, and lower in autumn when the air is often more humid than in spring. The factor is sinusoidal with two parameters //cevpam// and //cevpph//. It is not used if //cevpam// is zero. A //cevpph// around 45 days give a maximum correction in mid May (dayno=45+91=136). The minimum correction will then be a half year later in September (dayno=136+182). For an earlier maximum, reduce //​cevpph//​. ​ A seasonal factor //cseason// adjusts the potential evaporation rate (//cevp//) e.g. making it higher in the spring when the air is often dry, and lower in autumn when the air is often more humid than in spring. The factor is sinusoidal with two parameters //cevpam// and //cevpph//. It is not used if //cevpam// is zero. A //cevpph// around 45 days give a maximum correction in mid May (dayno=45+91=136). The minimum correction will then be a half year later in September (dayno=136+182). For an earlier maximum, reduce //​cevpph//​. ​
Line 90: Line 108:
 Evaporation from soil is assumed to occur from the two upper layers. The potential evaporation is assumed to decrease exponentially with depth (depending on the parameter //​epotdist//​). The potential evaporation is divided between the two layers (//​epotfrac//​) with the distribution depending on the potential evaporation in the midpoint of each soil layer (figure 1). This is then used by approximating to a rectangle. Since soil layers differ between classes, the evaporation distribution do to. Evaporation from soil is assumed to occur from the two upper layers. The potential evaporation is assumed to decrease exponentially with depth (depending on the parameter //​epotdist//​). The potential evaporation is divided between the two layers (//​epotfrac//​) with the distribution depending on the potential evaporation in the midpoint of each soil layer (figure 1). This is then used by approximating to a rectangle. Since soil layers differ between classes, the evaporation distribution do to.
  
-<m> epot1 = EXP(-epotdist*soillayerdepth(1){/​}2) </m>+<m> epot1 = EXP(- epotdist*soillayerdepth(1){/​}2) </m>
  
-<m> epot2 = EXP(-epotdist*(soillayerdepth(1)+{soillayerdepth(2)-+<m> epot2 = EXP(- epotdist*(soillayerdepth(1)+{soillayerdepth(2)-
           soillayerdepth(1)}/​2)) </m>           soillayerdepth(1)}/​2)) </m>
           ​           ​
Line 130: Line 148:
 The actual evaporation is set to zero for temperatures below the threshold temperature and for negative potential evaporation estimates (condensation). The soil evapotranspiration reduction is calculated as: The actual evaporation is set to zero for temperatures below the threshold temperature and for negative potential evaporation estimates (condensation). The soil evapotranspiration reduction is calculated as:
  
-<m> factor = 1-e^(-tredA*(soiltemp-ttrig)^tredB) </m>+<m> factor = 1-e^( - tredA*(soiltemp-ttrig)^tredB) </m>
  
 <m> evapp = evapp*factor </m> <m> evapp = evapp*factor </m>
Line 142: Line 160:
  
 === Model 0 (default) ===  === Model 0 (default) === 
-As described above; evapotranspiration depends on the rate parameter //cevp// and air temperature (//temp//) above a threshold //ttmp//. If //epot// is given in Xobs.txt those values are used.+As described above; evapotranspiration depends on the rate parameter //cevp// and air temperature (//T//) above a threshold //ttmp//. If //epot// is given in Xobs.txt those values are used.
  
-<m> epot_{base} = (cevp * cseason) * (temp-ttmp) </m>+<m> epot_{base} = (cevp * cseason) * (T-ttmp) </m>
  
 === Model 1 === === Model 1 ===
Line 150: Line 168:
  
 === Model 2 - Modified Jensen-Haise/​McGuiness === === Model 2 - Modified Jensen-Haise/​McGuiness ===
-The modified Jensen-Haise/​McGuiness model follow Oudin et al. (2005). The potential evaporation depends on extraterrestrial radiation (//​radext//​),​ latent heat of vaporization (<​m>​lambda</​m>​) and temperature (//temp//). Two general parameters (//jhtadd// and //​jhtscale//​) are used and one land use dependent (crop coefficient //kc2// or //kc//).+The modified Jensen-Haise/​McGuiness model follow Oudin et al. (2005). The potential evaporation depends on extraterrestrial radiation (//​radext//​),​ latent heat of vaporization (<​m>​lambda</​m>​) and temperature (//T//). Two general parameters (//jhtadd// and //​jhtscale//​) are used and one land use dependent (crop coefficient //kc2// or //kc//).
  
-<m> epot_{base} = {kc/​jhtscale} * MAX(0,​{radext/​lambda}*(temp+jhtadd)) </m>+<m> epot_{base} = {kc/​jhtscale} * MAX(0,​{radext/​lambda}*(T+jhtadd)) </m>
  
 === Model 3 - Modified Hargreaves-Samani === === Model 3 - Modified Hargreaves-Samani ===
-The Hargreaves-Samani evaporation is modified to limit the "​turbidity-factor"​. The potential evaporation depends on extraterrestrial radiation (//​radext//​),​ latent heat of vaporization (<​m>​lambda</​m>​),​ temperature (//temp//) and turbidity (//​turbidity//​). One general parameter (//krs//) is used and one land use dependent (crop coefficient //kc3// or //kc//).+The Hargreaves-Samani evaporation is modified to limit the "​turbidity-factor"​. The potential evaporation depends on extraterrestrial radiation (//​radext//​),​ latent heat of vaporization (<​m>​lambda</​m>​),​ temperature (//T//) and turbidity (//​turbidity//​). One general parameter (//krs//) is used and one land use dependent (crop coefficient //kc3// or //kc//).
  
-<m> epot_{base} = MAX(0,​kc*0.0023 * {radext/​lambda}*{turbidity/​krs}*(temp+17.8)) </m>+<m> epot_{base} = MAX(0,​kc*0.0023 * {radext/​lambda}*{turbidity/​krs}*(T+17.8)) </m>
  
 === Model 4 - Priestly-Taylor === === Model 4 - Priestly-Taylor ===
Line 165: Line 183:
  
 === Model 5 - FAO Penman-Monteith === === Model 5 - FAO Penman-Monteith ===
-The FOA Penman-Monteith potential evaporation depends on net downward radiation (//​netrad//​),​ slope of saturated vapour pressure curve (//​dsatvap//​),​ saturated and actual vapour pressure (//satvap// and //​actvap//​),​ temperature (//temp//), wind speed (//wind//) and a psychrometric constant (<​m>​gamma</​m>​). One land use dependent parameter (crop coefficient //kc5// or //kc//) is used.+The FOA Penman-Monteith potential evaporation depends on net downward radiation (//​netrad//​),​ slope of saturated vapour pressure curve (//​dsatvap//​),​ saturated and actual vapour pressure (//satvap// and //​actvap//​),​ temperature (//T//), wind speed (//wind//) and a psychrometric constant (<​m>​gamma</​m>​). One land use dependent parameter (crop coefficient //kc5// or //kc//) is used.
  
-<m> epot_{base} = MAX(0,​kc*{0.408 * dsatvap*netrad + gamma*{{900}/​{temp+273}}*wind*(satvap-actvap)}/​{dsatvap+gamma*(1+0.34*wind)}) </m>+<m> epot_{base} = MAX(0,​kc*{0.408 * dsatvap*netrad + gamma*{{900}/​{T+273}}*wind*(satvap-actvap)}/​{dsatvap+gamma*(1+0.34*wind)}) </m>
  
 ==== Input to alternative potential evaporation models ==== ==== Input to alternative potential evaporation models ====
  
-Summary of alternative input to PET models: +Summary of alternative input to PET models, and link to file reference. 
-^ Model ^ Parameters ^ Static data ^ Forcing data ^+^ Model ^ Parameters ​([[start:​hype_file_reference:​par.txt|par.txt]])^ Static data ([[start:​hype_file_reference:​geodata.txt|GeoData.txt]])^ Forcing data ([[start:​hype_file_reference#​observation_data_files|files]])^
 | 0 | cevp, ttmp | | Xobs:repo, Tobs | | 0 | cevp, ttmp | | Xobs:repo, Tobs |
 | 1 | cevp, ttmp | | Tobs | | 1 | cevp, ttmp | | Tobs |
Line 190: Line 208:
  
 === Actual vapour pressure === === Actual vapour pressure ===
-Actual vapour pressure (//​actvap//​) is calculated following FAO recommended procedure and function/​data priority. Depending on availability of minimum, mean and maximum relative humidity (//rh//) and minimum, mean and maximum air temperature (//temp//) equations with different combinations of saturated vapour pressure (calculated from temperature) times relative humidity is used. For example:+Actual vapour pressure (//​actvap//​) is calculated following FAO recommended procedure and function/​data priority. Depending on availability of minimum, mean and maximum relative humidity (//rh//) and minimum, mean and maximum air temperature (<​m>​T_min,​ T, T_max</m>) equations with different combinations of saturated vapour pressure (calculated from temperature) times relative humidity is used. For example:
  
-<m> actvap = {satvap(temp_max)*rh_min+satvap(temp_min)*rh_max}/2 </m>+<m> actvap = {satvap(T_max)*rh_min+satvap(T_min)*rh_max}/2 </m>
  
-<m> actvap = satvap(temp_min)*rh_max </m>+<m> actvap = satvap(T_min)*rh_max </m>
  
-<m> actvap = satvap(temp)*rh_mean </m>+<m> actvap = satvap(T)*rh_mean </m>
  
-<m> actvap = satvap(temp_min)*1 </m>+<m> actvap = satvap(T_min)*1 </m>
  
 In case not enough data is available, minimum temperature is calculated from turbidity and a general parameter (//krs//) and the last equation of those above is used. In case not enough data is available, minimum temperature is calculated from turbidity and a general parameter (//krs//) and the last equation of those above is used.
  
-<​m> ​temp_min ​temp_mean ​- 0.5*(turbidity/​krs)^2 </m>+<​m> ​T_min - 0.5*(turbidity/​krs)^2 </m>
  
 Eventually actual vapour pressure is limited by the calculated saturated vapour pressure. ​ Eventually actual vapour pressure is limited by the calculated saturated vapour pressure. ​
Line 222: Line 240:
  
 === Latent heat of vaporization === === Latent heat of vaporization ===
-Latent heat of vaporization (<​m>​lambda</​m>​) is a function of temperature (//temp//).+Latent heat of vaporization (<​m>​lambda</​m>​) is a function of temperature (//T//).
  
-<m> lambda = 2.501-0.002361*temp </m>+<m> lambda = 2.501-0.002361*</m>
  
 === Net downward radiation === === Net downward radiation ===
-The net downward radiation (//​netrad//​) is used explicitly for PET model 4 and 5 (Priestly-Taylor and FAO Penman-Monteith). The net radiation is calculated following FAO recommended procedure. It is calculated as net shortwave radiation minus net longwave radiation. Net shortwave radiation (<​m>​net_short</​m>​) is calculated from the shortwave radiation (//swrad//) and the land use dependent albedo parameter (//alb//). Net longwave radiation (<​m>​net_long</​m>​) is calculated using temperature (//tmintmaxor tmean//), actual vapour pressure (//​actvap//​) and relative shortwave radiation (//relsh//) if those are available, otherwise it is set to zero. The relative shortwave radiation is shortwave radiation in relation to clear sky shortwave radiation.+The net downward radiation (//​netrad//​) is used explicitly for PET model 4 and 5 (Priestly-Taylor and FAO Penman-Monteith). The net radiation is calculated following FAO recommended procedure. It is calculated as net shortwave radiation minus net longwave radiation. Net shortwave radiation (<​m>​net_short</​m>​) is calculated from the shortwave radiation (//swrad//) and the land use dependent albedo parameter (//alb//). Net longwave radiation (<​m>​net_long</​m>​) is calculated using temperature (<​m>​T_minT_maxT</m>), actual vapour pressure (//​actvap//​) and relative shortwave radiation (//relsh//) if those are available, otherwise it is set to zero. The relative shortwave radiation is shortwave radiation in relation to clear sky shortwave radiation.
  
 <m> net_short = swrad*(1-alb) </m> <m> net_short = swrad*(1-alb) </m>
  
-<m> net_long = 4.903*10^9*{{(temp_max+273.15)^4+(temp_min+273.15)^4}/​2}*(0.34-0.14*actvap^0.5)*(1.35*relsh-0.35) </m>+<m> net_long = 4.903*10^9*{{(T_max+273.15)^4+(T_min+273.15)^4}/​2}*(0.34-0.14*actvap^0.5)*(1.35*relsh-0.35) </m>
  
 <m> relsh = turbidity/​clearturb </m> <m> relsh = turbidity/​clearturb </m>
Line 262: Line 280:
 where //elev// is subbasin elevation in meter above sea level. If no shortwave radiaton time series are given, but time series of daily minimum and maximum temperature are, the turbidity is calculated as in the "​ordinary"​ Hargreaves-Samani turbidity function: where //elev// is subbasin elevation in meter above sea level. If no shortwave radiaton time series are given, but time series of daily minimum and maximum temperature are, the turbidity is calculated as in the "​ordinary"​ Hargreaves-Samani turbidity function:
  
-<m> turbidity = krs*SQRT(Tmax Tmin) </m>+<m> turbidity = krs*SQRT(T_max T_min) </m>
  
 but still limited by the minimum turbidity value and the calculated clearsky turbidity. but still limited by the minimum turbidity value and the calculated clearsky turbidity.
  
 === Wind speed === === Wind speed ===
-Wind speed is used in PET model 5 - FAO Penman-Monteith. Wind speed (//wind//) may be given as a constant general parameter (//mwind//) or as a forcing data time series. The time serie wind is given for each subbasin (//windi//). It is possible to adjust the time serie wind speed to different height than observations. If the general parameters //zwind//, //zwish//, //​roughness//,​ and //zpdh// is set, wind speed is adjusted with the transformation factor //​windtrans//​.+Wind speed is used in PET model 5 - FAO Penman-Monteith. Wind speed (//wind//) may be given as a constant general parameter (//mwind//) or as a forcing data time series. The time serie wind is given for each subbasin (<​m>​U_i<​/m>). It is possible to adjust the time serie wind speed to different height than observations. If the general parameters //zwind//, //zwish//, //​roughness//,​ and //zpdh// is set, wind speed is adjusted with the transformation factor //​windtrans//​.
  
-<m> wind=windi*windtrans </m>+<m> wind=U_i*windtrans </m>
  
 <m> windtrans = {ln(zwind-zpdh)-ln(roughness)}/​{ln(zwish-zpdh)-ln(roughness)} </m> <m> windtrans = {ln(zwind-zpdh)-ln(roughness)}/​{ln(zwish-zpdh)-ln(roughness)} </m>
 +
 +==== Links to file reference ====
 +
 +^Section ^Symbol ^Parameter/​Data ^File ^
 +|Evaporation| |//cevp, ttmp, cevmam, cevpph, cevpcorr, epotdist, lp, ttrig, tredA, tredB// |[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|:::​|//​wp//​|calculated from //wcwp, wcwp1, wcwp2, wcwp3// and soillayerdepth|:::​|
 +|:::​|//​fc//​|calculated from //wcfc, wcfc1, wcfc2, wcfc3// and soillayerdepth|:::​|
 +|:::​|//​soillayerdepth//​| |[[start:​hype_file_reference:​geoclass.txt|GeoClass.txt]]|
 +|Alternative potential evaporation models|//​epot//​| |[[start:​hype_file_reference:​xobs.txt|Xobs.txt]]|
 +|:::| |//jhtadd, jhtscale, kc, kc2, kc3, kc4, kc5, krs, alfapt//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|Input to alternative potential evaporation models| |//alb, mwind, zwind, zwish, roughness, zpdh//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|:::​|<​m>​U_i</​m>​| |[[start:​hype_file_reference:​uobs.txt|Uobs.txt]]|
 +|:::​|//​swrad//​|calculated or from |[[start:​hype_file_reference:​swobs.txt|SWobs.txt]]|
 +|:::​|//​elev//​|//​elev_mean//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::| |//​latitude//​|:::​|
 +
 +
 ==== Links to relevant procedures in the code ==== ==== Links to relevant procedures in the code ====
  
Line 312: Line 347:
 Alternatively wet deposition of phosphorus on water surfaces can be specified by a general model parameter (//​wetdepspl//​) as a load. Monthly load of IN atmosperic depostion on water surfaces can be specified in GeoData.txt for each subbasin. Alternatively wet deposition of phosphorus on water surfaces can be specified by a general model parameter (//​wetdepspl//​) as a load. Monthly load of IN atmosperic depostion on water surfaces can be specified in GeoData.txt for each subbasin.
  
 +==== Links to file reference ====
 +
 +^Section ^Parameter/​Data ^File ^
 +|Wet deposition|//​cpT1,​ cpIN, cpSP//​|[[start:​hype_file_reference:​xobs.txt|Xobs.txt]]|
 +|:::​|//​wetdep_n//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::​|//​wetdepsp,​ aloadconst//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|Atmospheric deposition to the soil|//​drydep_n1,​drydep_n2//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::​|//​drydepPP,​ ponatm//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +|Atmospheric deposition to rivers and lakes|//​drydep_n3,​ deploadn1-deploadn12//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]|
 +|:::​|//​drydepPP,​ wetdepspl//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
  
 ==== Links to relevant procedures in the code ==== ==== Links to relevant procedures in the code ====
start/hype_model_description/processes_above_ground.txt · Last modified: 2024/02/21 08:54 by cpers