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start:hype_model_description:hype_np_riv_lake [2020/02/14 11:20]
cpers [Primary production and mineralization]
start:hype_model_description:hype_np_riv_lake [2020/04/30 09:12] (current)
cpers [Macrophyte uptake]
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 ===== Basic assumptions ===== ===== Basic assumptions =====
  
-Transformations of nutrients take place in lakes and rivers. For lakes, which are divided into fast (FLP) and slow (SLP) lake parts, the process is performed only in SLP (Fig. 1). For rivers, which hold delayed water in a queue and in the damping box, the processes is performed only in the damping box.  +Transformations of nutrients take place in lakes and rivers. For lakes, the whole water volume take par. For rivers, which hold delayed water in a queue and in the damping box, the processes is performed only in the damping box. 
- +
-|{{:​start:​hype_model_description:​nutrientflowinlake.png?​400|}}| +
-|Figure 1: Nutrient flows in a lake that is affected by nutrient processes.|+
  
 The processes of denitrification,​ primary production and mineralization have been implemented for both rivers and lakes. For particulate phosphorus (PP) there is an exchange with the river sediments. The rivers dimensions are used in the calculation of these processes. The width and depth of the watercourse are calculated from a number of empirical equations (for more information on these equations see "​Modelling phosphorus transport and retention in river networks"​ by Jörgen Rosberg). The processes of denitrification,​ primary production and mineralization have been implemented for both rivers and lakes. For particulate phosphorus (PP) there is an exchange with the river sediments. The rivers dimensions are used in the calculation of these processes. The width and depth of the watercourse are calculated from a number of empirical equations (for more information on these equations see "​Modelling phosphorus transport and retention in river networks"​ by Jörgen Rosberg).
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 ===== Denitrification ===== ===== Denitrification =====
  
-Denitrification,​ a sink for inorganic nitrogen in lakes and rivers, is a function of the bottom area, the IN concentration (//conc//) in water volume, water temperature (<​m>​T_w</​m>​) and a rate parameter. The dependence on concentration is formulated as a half saturation equation. In the concentration function, the half saturation parameter (//​par<​sub>​half</​sub>//​) is a general parameter, but it was in earlier HYPE versions a constant equal to 1.5 mg/L. Denitrification (//​denitr//,​ //kg/day//) is limited to a maximum of 50% of the available IN pool (i.e. in SLP).+Denitrification,​ a sink for inorganic nitrogen in lakes and rivers, is a function of the bottom area, the IN concentration (//conc//) in water volume, water temperature (<​m>​T_w</​m>​) and a rate parameter. The dependence on concentration is formulated as a half saturation equation. In the concentration function, the half saturation parameter (//​par<​sub>​half</​sub>//​) is a general parameter, but it was in earlier HYPE versions a constant equal to 1.5 mg/L. Denitrification (//​denitr//,​ //kg/day//) is limited to a maximum of 50% of the available IN pool.
  
 <m> tmpfcn=delim{lbrace}{ ​ <m> tmpfcn=delim{lbrace}{ ​
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 <m> TPfcn = {TP-lim} / {(TP-lim) + hsatTP} </m> <m> TPfcn = {TP-lim} / {(TP-lim) + hsatTP} </m>
  
-For lakes, the process is acting only in lake part SLP, while the processes are active throughout the watercourse volume. ​The estimated production/​mineralization (//​minprodNpot//,​ kg / day) is the potential transformation,​ and may be limited by the availability of nutrients. Only 50% of the available IN the pool (at the primary production) or 50% of the ON-pool (for mineralization) can be transformed. The potential phosphorus conversion (//​minprodPpot//​) is calculated in the same way, but with its own parameter (//​wprodp//​) and a factor for phosphorus/​nitrogen ratio (//​NPratio//​ = 1/7.2). Similarly, there is a restriction against transforming maximum 50% of the SP and PP pools. The parameters //wprodn// and //wprodp// is generic or can be specified for each lake. The area is equal to lake area for lakes and bottom area for rivers (width multiplied by the length of the watercourse,​ see [[start:​hype_model_description:​hype_np_riv_lake#​basic_assumptions|Basic assumptions]],​ or if the river is a class, the class' area). The water depth (//depth//) is the SLP lake part, and for the river the depth calculated [[start:​hype_model_description:​hype_np_riv_lake#​basic_assumptions|above]].+The estimated production/​mineralization (//​minprodNpot//,​ kg / day) is the potential transformation,​ and may be limited by the availability of nutrients. Only 50% of the available IN the pool (at the primary production) or 50% of the ON-pool (for mineralization) can be transformed. The potential phosphorus conversion (//​minprodPpot//​) is calculated in the same way, but with its own parameter (//​wprodp//​) and a factor for phosphorus/​nitrogen ratio (//​NPratio//​ = 1/7.2). Similarly, there is a restriction against transforming maximum 50% of the SP and PP pools. The parameters //wprodn// and //wprodp// is generic or can be specified for each lake. The area is equal to lake area for lakes and bottom area for rivers (width multiplied by the length of the watercourse,​ see [[start:​hype_model_description:​hype_np_riv_lake#​basic_assumptions|Basic assumptions]],​ or if the river is a class, the class' area). The water depth (//depth//) is the SLP lake part, and for the river the depth calculated [[start:​hype_model_description:​hype_np_riv_lake#​basic_assumptions|above]].
  
  
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 ^Symbol ^Parameter/​Data ^File ^ ^Symbol ^Parameter/​Data ^File ^
-|<​m>​par_prod</​m>​|//​prodPP,​ prodSP//​|[[start:​hype_file_reference:​par.txt|par.txt]]|+|<​m>​par_prod</​m>​|//​prodPP,​ prodSP//​|[[start:​hype_file_reference:​lakedata.txt|LakeData.txt]]|
  
  
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 |:::​|internal_lake_load| |:::​|internal_lake_load|
  
 +=====Macrophyte uptake=====
 +
 +For shallow waters in lakes macrophytes can grow and take up inorganic nutrients (IN and SP). The nutrients are lost to the model. Macrophyte uptake are controlled by a temperature function (//​tmpfcn//​) and a concentration function (//TPfcn//) for total phosphorus. The temperature function is composed of two parts; one exponential and one dependent on the water temperature (//Tw//) above the average temperature of the last twenty days (//T20//). The concentration function is the same half-saturation function as for production and mineralisation [[start:​hype_model_description:​hype_np_riv_lake#​primary_production_and_mineralization|above]].
 +
 +<m> tmpfcn = (Tw/20)^0.3 * (Tw-T20)/5, Tw>0 and tempfcn>​0 </m>
 +
 +The lake area (//​fracarea//​) that is shallower than a production depth (//​proddep//,​ general parameter //​muptdep//​) is assumed to be active with macrophyte uptake. The lake is for this purpose assumed to be decreasing linearly with depth until twice the average depth of the lake. 
 +
 +<m> fracarea = {proddep / (2*vol/​area)} * area </m>
 +
 +The uptake (//upt//) is limited to maximum 50% of the available nutrients and the whole equation becomes:
 +
 +<m> upt = uptpar * tmpfcn * TPfcn * fracarea </m>
 +
 +The uptake rate parameters (//​uptpar//​),​ different for IN and SP, are general (//muptn, muptp//). The process is similar to the [[start:​hype_model_description:​hype_human_water#​wetland_nutrient_processes1|modelled macrophyte uptake in wetlands]].
 +
 +==== Links to file reference ====
 +
 +^Symbol^Parameter/​Data ^File ^
 +|//​uptpar//​|//​muptn,​muptp//​|[[start:​hype_file_reference:​par.txt|par.txt]] or [[start:​hype_file_reference:​lakedata.txt|LakeData.txt]]|
 +|//​proddep//​|//​muptdep//​|[[start:​hype_file_reference:​par.txt|par.txt]]|
 +
 +
 +==== Links to relevant procedures in the code ====  ​
 +
 +^Modules (file) ^Procedures ^
 +|[[http://​hype.sourceforge.net/​doxy-html/​namespacenpc__surfacewater__processes.html|npc_surfacewater_processes (np_sw_proc.f90)]]|np_processes_in_lake |
 +|:::​|macrophyte_uptaked|
  
start/hype_model_description/hype_np_riv_lake.1581675656.txt.gz · Last modified: 2020/02/14 11:20 by cpers