User Tools

Site Tools


start:hype_model_description:hype_np_riv_lake

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:hype_np_riv_lake [2018/11/16 15:45]
cpers [Basic assumptions]
start:hype_model_description:hype_np_riv_lake [2019/09/30 10:07]
cpers [Sedimentation/Resuspension]
Line 1: Line 1:
 ====== Nitrogen and phosphorus processes in rivers and lakes ====== ====== Nitrogen and phosphorus processes in rivers and lakes ======
- 
-===== Basic assumptions ===== 
  
 HYPE simulates concentration of inorganic nitrogen (IN), organic nitrogen (ON), soluble reactive phosphorus (SP) and particulate phosphorus (PP) in discharge and other surface waters. As output also the total nitrogen (TN) and phosphorus (TP) concentration can be had. In addition total suspended sediments (TS) can be simulated. It consists of the sum of suspended sediments (SS) and algae (AE) simulated concentrations. HYPE simulates concentration of inorganic nitrogen (IN), organic nitrogen (ON), soluble reactive phosphorus (SP) and particulate phosphorus (PP) in discharge and other surface waters. As output also the total nitrogen (TN) and phosphorus (TP) concentration can be had. In addition total suspended sediments (TS) can be simulated. It consists of the sum of suspended sediments (SS) and algae (AE) simulated concentrations.
 +
 +===== 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, 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. 
Line 92: Line 92:
 ===== Primary production and mineralization ===== ===== Primary production and mineralization =====
  
-Primary production in lakes and rivers is a source of organic nitrogen and particulate phosphorus and a sink for inorganic nitrogen and soluble reactive phosphorus in the model. The reverse is true for mineralization. The processes ​is modelled together and only one is active at the time. Primary production and mineralization are controlled by two temperature functions. The first (//​tmpfcn1//​) is solely dependent on the water temperature (//​T<​sub>​w</​sub>//​). It simulates the increased activity at warmer temperatures. The second (//​tmpfcn2//​) governs the relationship between primary production and mineralization and determines which one dominates. Net primary production is highest in spring (northern hemisphere) and changes into net mineralization when the temperature //T10// is less than the temperature //T20// in autumn. These two temperatures are calculated as the average water temperature of 10 and 20 days. +Primary production in lakes and rivers is a source of organic nitrogen and particulate phosphorus and a sink for inorganic nitrogen and soluble reactive phosphorus in the model. The reverse is true for mineralization. The processes ​are modelled together and only one is active at the time. Primary production and mineralization are controlled by two temperature functions. The first (//​tmpfcn1//​) is solely dependent on the water temperature (//​T<​sub>​w</​sub>//​). It simulates the increased activity at warmer temperatures. The second (//​tmpfcn2//​) governs the relationship between primary production and mineralization and determines which one dominates. Net primary production is highest in spring (northern hemisphere) and changes into net mineralization when the temperature //T10// is less than the temperature //T20// in autumn. These two temperatures are calculated as the average water temperature of 10 and 20 days. 
  
  
Line 134: Line 134:
 ===== Sedimentation/​Resuspension ===== ===== Sedimentation/​Resuspension =====
  
-Sedimentation in lakes is a sink for particulate phosphorus (PP) and organic nitrogen (ON), as well as for suspended sediments (SS) and algae (AE). Sedimentation (//sed//, //m/day//) is calculated as a function of concentration (//conc//) in the lake and lake area (//area//). The sedimentation rate (//​par<​sub>​sed</​sub>//​) is given by parameters (//sedon//, //sedpp//, //sedss//, //sedae//) which are generic, but ON and PP sedimentation can be specified for each lake. The concentration used in the equation may be limited (//lim//) by general parameters (//​limsedON//,​ //​limsedPP//,​ //​limsedSS//​),​ but not for AE (//​lim//​=0).+Sedimentation in lakes is a sink for particulate phosphorus (PP) and organic nitrogen (ON), as well as for suspended sediments (SS) and algae (AE). Sedimentation (//sed//, //kg/day//) is calculated as a function of concentration (//conc//) in the lake and lake area (//area//). The sedimentation rate (//​par<​sub>​sed</​sub>//​) is given by parameters (//sedon//, //sedpp//, //sedss//, //sedae//) which are generic, but ON and PP sedimentation can be specified for each lake. The concentration used in the equation may be limited (//lim//) by general parameters (//​limsedON//,​ //​limsedPP//,​ //​limsedSS//​),​ but not for AE (//​lim//​=0).
  
 <m> sed = par_sed * (conc-lim) * area </m> <m> sed = par_sed * (conc-lim) * area </m>
start/hype_model_description/hype_np_riv_lake.txt ยท Last modified: 2024/01/25 11:37 (external edit)