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start:hype_model_description:hype_np_soil [2019/09/06 09:00]
cpers [Soil erosion]
start:hype_model_description:hype_np_soil [2019/12/19 16:49] (current)
cpers [Soil erosion]
Line 138: Line 138:
 <m> MobilisedSR = {{(sflow*365)^{sreroexp}} * (1-common_{groundcover}) * {1/​{0.5*soilcoh}} * sin(slope/​100)} / 365 </m> <m> MobilisedSR = {{(sflow*365)^{sreroexp}} * (1-common_{groundcover}) * {1/​{0.5*soilcoh}} * sin(slope/​100)} / 365 </m>
  
-All mobilized ​particles is not removed from the field, because sometimes the transport capacity of the particle-bearing water (//eflow//) will not suffice for the task. A //​transportfactor//​ will reduce the particle amount:+All mobilised ​particles is not removed from the field, because sometimes the transport capacity of the particle-bearing water (//eflow//) will not suffice for the task. A //​transportfactor//​ will reduce the particle amount:
    
 <m> transportfactor = MIN(1.0,​(eflow {/} 4)^{1.3}) </m> <m> transportfactor = MIN(1.0,​(eflow {/} 4)^{1.3}) </m>
    
-Eroded ​sediment (kg/km2) is calculated as:+Mobilised ​sediment (kg/km2) is calculated as:
  
-<​m> ​erodedSed ​= 1000 * (MobilisedRain + MobilisedSR) * transportfactor </m>+<​m> ​mobilSed ​= 1000 * (MobilisedRain + MobilisedSR) * transportfactor </m>
   ​   ​
-The alternative erosion model calculates ​eroded ​sediment (//erodedSed// (kg/km2)) based on rainfall (//prec//) and a number of model parameters and subbasin input data.+The alternative erosion model calculates ​mobilised ​sediment (//mobilSed// (kg/km2)) based on rainfall (//rain//) and a number of model parameters and subbasin input data.
  
-<​m> ​erodedSed ​= 1000. * ({slope / 5})^{erodslope} * erodluse * erodsoil * {EI/​erodindex} * prec^{erodexp} </m>+<​m> ​mobilSed ​= 1000. * ({slope / 5})^{erodslope} * erodluse * erodsoil * {EI/​erodindex} * rain^{erodexp} </m>
  
 The parameters //​erodslope//,​ //erodexp// and //​erodindex//​ are general. The parameters //​erodluse//​ and //​erodsoil//​ are land-use and soil type dependent. Subbasin input is needed on //slope//, the subbasins average slope, and an erosion index, //EI//. The parameters //​erodslope//,​ //erodexp// and //​erodindex//​ are general. The parameters //​erodluse//​ and //​erodsoil//​ are land-use and soil type dependent. Subbasin input is needed on //slope//, the subbasins average slope, and an erosion index, //EI//.
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-Eventually the eroded ​PP (kg/km2) is calculated as:+Eventually the mobilised ​PP (kg/km2) is calculated as:
  
-<​m> ​erodedP ​= 0.000001 * erodedSed ​* {{PartP + HumusP}/ {thickness * bulkdensity}} * enrichment </m>+<​m> ​mobilP ​= 0.000001 * mobilSed ​* {{PartP + HumusP}/ {thickness * bulkdensity}} * enrichment </m>
  
-The calculated ​eroded sediment (//​erodedSed//​) and eroded ​phosphorus (//erodedP//) are now available to add to the suspended sediment (SS) or particulate phosphorus (PP) of surface runoff.+The calculated ​mobilised ​phosphorus (//mobilP//) is now available to add to the particulate phosphorus (PP) of surface runoff.
    
-A portion of SS and PP in surface runoff (//sflow//) is filtered out (for example by buffer zones). Filtering (//​srfilt//​) is determined by land use dependent parameters (//​bufferfilt,​ innerfilt, otherfilt//​),​ percentage of agricultural land close to a watercourse (//alfa//), and proportion of agricultural land near the rivers which have a protective buffer zone (//​bufferpart//​).+A portion of PP in surface runoff (//sflow//) is filtered out (for example by buffer zones). Filtering (//​srfilt//​) is determined by land use dependent parameters (//​bufferfilt,​ innerfilt, otherfilt//​),​ percentage of agricultural land close to a watercourse (//alfa//), and proportion of agricultural land near the rivers which have a protective buffer zone (//​bufferpart//​).
  
 <m> srfilt = otherfilt + alfa * (1. + bufferpart * (bufferfilt - 1.)) + innerfilt * (1. - alfa) </m> <m> srfilt = otherfilt + alfa * (1. + bufferpart * (bufferfilt - 1.)) + innerfilt * (1. - alfa) </m>
  
-Similarly, part of the SS and PP which is transported by macropore flow (//mflow//) is filtered away between the soil surface and drainage pipes. The parameter that determines this effect (//​macrofilt//​) is soil dependent. The SS or PP transported (//transp//) by surface runoff and macropore flow is collected in a temporary storage pool (//​relpool//​ (kg/km2)) together with SS and PP in tile runoff (//​tilep//​).+Similarly, part of the PP which is transported by macropore flow (//mflow//) is filtered away between the soil surface and drainage pipes. The parameter that determines this effect (//​macrofilt//​) is soil dependent. The PP transported (//erodedP//) by surface runoff and macropore flow is collected in a temporary storage pool (//​relpool//​ (kg/km2)) together with PP in tile runoff (//​tilep//​).
  
-<​m> ​transp ​= (srfilt*sflow+macrofilt*mflow)*erodedSed/​eflow </m> or +<​m> ​erodedP ​= (srfilt*sflow+macrofilt*mflow)*mobilP/eflow </m>
-<m> transp = (srfilt*sflow+macrofilt*mflow)*erodedP/eflow </m>+
  
 <m> eflow=sflow+mflow </m> <m> eflow=sflow+mflow </m>
  
-<m> relpool = relpool + transp ​+ tilep </m> \\+<m> relpool = relpool + erodedP ​+ tilep </m> \\
  
-From the temporary pool sediment and phosphorus is released (//​release//​ (kg/km2)) and then transported to the local river depending on the size of the total runoff (//runoff// (mm)). The parameters //​pprelmax//​ and //​pprelexp//​ are general.+From the temporary pool phosphorus is released (//​release//​ (kg/km2)) and then transported to the local river depending on the size of the total runoff (//runoff// (mm)). The parameters //​pprelmax//​ and //​pprelexp//​ are general.
  
 <m> release = MIN(relpool,​ relpool *(runoff {/} pprelmax)^{pprelexp}) </m> <m> release = MIN(relpool,​ relpool *(runoff {/} pprelmax)^{pprelexp}) </m>
start/hype_model_description/hype_np_soil.1567753216.txt.gz · Last modified: 2019/09/06 09:00 by cpers