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start:hype_model_description:hype_human_water [2018/09/10 09:35]
cpers [Links to file description]
start:hype_model_description:hype_human_water [2018/11/15 09:39] (current)
cpers
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 ^Parameter/​Data ^File ^ ^Parameter/​Data ^File ^
-|//​lrwet_area,​ lrwet_dep, lrwet_part//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]| +|//​lrwet_area,​ lrwet_dep, lrwet_part, mrwet_area, mrwet_dep, mrwet_part//​|[[start:​hype_file_reference:​geodata.txt|GeoData.txt]]| 
-|//​mrwet_area,​ mrwet_dep, mrwet_part//​|:::​|+
  
  
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 For non-submerged crops, the calculations are based on the FAO-56 crop coefficient methods (Allen et al., 1998). The dual crop coefficient method is used because it is more specific than the single crop coefficient method, and more suitable for daily water balance models. Since transpiration is of primary interest in estimating crop water demand, the irrigation routine focuses on estimating potential transpiration (<​m>​T_P</​m>​) with the basal crop coefficient (<​m>​K_{CB}</​m>​) and the reference potential crop evapotranspiration (<​m>​ET_0</​m>​): ​ For non-submerged crops, the calculations are based on the FAO-56 crop coefficient methods (Allen et al., 1998). The dual crop coefficient method is used because it is more specific than the single crop coefficient method, and more suitable for daily water balance models. Since transpiration is of primary interest in estimating crop water demand, the irrigation routine focuses on estimating potential transpiration (<​m>​T_P</​m>​) with the basal crop coefficient (<​m>​K_{CB}</​m>​) and the reference potential crop evapotranspiration (<​m>​ET_0</​m>​): ​
  
-<m> T_P=K_{CB}×ET_0 ​</m>+<m> T_P=K_{CB}*ET_0 </m>
  
 ET0 follows the dynamics described above (<​m>​ET_0 = epot</​m>​ here following Wisser et al. (2008)). KCB depends on crop type and phenological stage, which is defined in CropData.txt. KCB is constant during the initial development stage, then increases linearly during the development stage until it reaches the mid-season stage during which it is again constant. Finally, <​m>​K_{CB}</​m>​ decreases linearly from the end of the mid-season stage until the end of the season. The dynamics of <​m>​ET_0</​m>​ and <​m>​K_{CB}</​m>​ produces a dynamic <​m>​T_P</​m>​ profile (Figure 1). Allen et al. (1998) provide indicative values for <​m>​K_{CB}</​m>​ (cf. their Table 17). ET0 follows the dynamics described above (<​m>​ET_0 = epot</​m>​ here following Wisser et al. (2008)). KCB depends on crop type and phenological stage, which is defined in CropData.txt. KCB is constant during the initial development stage, then increases linearly during the development stage until it reaches the mid-season stage during which it is again constant. Finally, <​m>​K_{CB}</​m>​ decreases linearly from the end of the mid-season stage until the end of the season. The dynamics of <​m>​ET_0</​m>​ and <​m>​K_{CB}</​m>​ produces a dynamic <​m>​T_P</​m>​ profile (Figure 1). Allen et al. (1998) provide indicative values for <​m>​K_{CB}</​m>​ (cf. their Table 17).
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-<m> if H <(S_{SW}×P_{SSWCORR}×AWC) right irrigate </m>+<m> if H <(S_{SW}*P_{SSWCORR}*AWC) right irrigate </m>
  
 H is the plant-available soil moisture (i.e. soil water above //wcwp1// and //wcwp2// in soil layers 1 and 2 respectively). //AWC// is the maximum plant-available water content in soil layers 1 and 2 (i.e. the sum of //fc1// and //fc2//). <​m>​S_{SW}</​m>​ is a fraction of //AWC// (defined upwards from //wcwp//). Below <​m>​S_{SW}</​m>​ the crop experiences water stress, creating a need for irrigation. <​m>​S_{SW}</​m>​ varies from day to day and depends on the crop type and <​m>​T_P</​m>:​ H is the plant-available soil moisture (i.e. soil water above //wcwp1// and //wcwp2// in soil layers 1 and 2 respectively). //AWC// is the maximum plant-available water content in soil layers 1 and 2 (i.e. the sum of //fc1// and //fc2//). <​m>​S_{SW}</​m>​ is a fraction of //AWC// (defined upwards from //wcwp//). Below <​m>​S_{SW}</​m>​ the crop experiences water stress, creating a need for irrigation. <​m>​S_{SW}</​m>​ varies from day to day and depends on the crop type and <​m>​T_P</​m>:​
  
-<m> S_{SW}=1-(DL_{ref}+0.04×(5-{{T_P}/​0.95})) </m>+<m> S_{SW}=1-(DL_{ref}+0.04*(5-{{T_P}/​0.95})) </m>
  
 <​m>​DL_{ref}</​m>​ is a crop-type specific reference depletion level (essentially the fraction of //AWC// that can be depleted before stress occurs, defined downwards from //wcfc//). Allen et al. (1998) provide indicative values for <​m>​DL_{ref}</​m>​ (cf. their Table 22). The <​m>​S_{SW}</​m>​ equation is a slightly modified form of the original FAO-56 equation to account for the fact that only <​m>​T_P</​m>​ is used here. A typical <​m>​S_{SW}</​m>​ profile is shown in Figure 3.1. By default, <​m>​S_{SW}</​m>​ is limited to the range 0.2 – 0.9, but it can be further refined with the parameter <​m>​P_{SSWCORR}</​m>​ (//​sswcorr//​ in par.txt) to maximum 1. <​m>​DL_{ref}</​m>​ is a crop-type specific reference depletion level (essentially the fraction of //AWC// that can be depleted before stress occurs, defined downwards from //wcfc//). Allen et al. (1998) provide indicative values for <​m>​DL_{ref}</​m>​ (cf. their Table 22). The <​m>​S_{SW}</​m>​ equation is a slightly modified form of the original FAO-56 equation to account for the fact that only <​m>​T_P</​m>​ is used here. A typical <​m>​S_{SW}</​m>​ profile is shown in Figure 3.1. By default, <​m>​S_{SW}</​m>​ is limited to the range 0.2 – 0.9, but it can be further refined with the parameter <​m>​P_{SSWCORR}</​m>​ (//​sswcorr//​ in par.txt) to maximum 1.
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 (3) Up to a defined fraction of <​m>​S_{SW}</​m>​ (<​m>​P_{iwdfrac}</​m>,​ //iwdfrac// in par.txt): ​ (3) Up to a defined fraction of <​m>​S_{SW}</​m>​ (<​m>​P_{iwdfrac}</​m>,​ //iwdfrac// in par.txt): ​
  
-<​m>​W_{I,​D,​j}=min[(S_{SW}×P_{SSWCORR}×AWC-H)×P_{iwdfrac},​(AWC-H)]</​m>​+<​m>​W_{I,​D,​j}=min[(S_{SW}*P_{SSWCORR}*AWC-H)*P_{iwdfrac},​(AWC-H)]</​m>​
  
 The fraction can be larger than 1. For example, to irrigate to a level 10% above <​m>​S_{SW}</​m>,​ <​m>​P_{iwdfrac}</​m>​ =1.1. <​m>​W_{I,​D,​j}</​m>​ is, however, limited to <​m>​AWC</​m>​. The fraction can be larger than 1. For example, to irrigate to a level 10% above <​m>​S_{SW}</​m>,​ <​m>​P_{iwdfrac}</​m>​ =1.1. <​m>​W_{I,​D,​j}</​m>​ is, however, limited to <​m>​AWC</​m>​.
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 If the <​m>​W_{L,​D,​s}</​m>​ volume is available at the source, the demanded water is withdrawn. Otherwise, only the available volume (<​m>​V_s</​m>​) is withdrawn. The withdrawal can also be scaled with the user-defined parameter <​m>​P_{I,​S}</​m>​ (//pirrs// in par.txt): ​ If the <​m>​W_{L,​D,​s}</​m>​ volume is available at the source, the demanded water is withdrawn. Otherwise, only the available volume (<​m>​V_s</​m>​) is withdrawn. The withdrawal can also be scaled with the user-defined parameter <​m>​P_{I,​S}</​m>​ (//pirrs// in par.txt): ​
  
-<m> W_{L,​A,​s(1)}=min(W_{L,​D,​s},​V_{s1})×P_{I,S} </m>+<m> W_{L,​A,​s(1)}=min(W_{L,​D,​s},​V_{s1})*P_{I,S} </m>
  
 <m> W_{L,​D,​s2}=W_{L,​D,​s}-{W_{L,​A,​s(1)}}/​{P_{I,​S}} </​m> ​ <m> W_{L,​D,​s2}=W_{L,​D,​s}-{W_{L,​A,​s(1)}}/​{P_{I,​S}} </​m> ​
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 If any groundwater demand exists, the model withdraws a user-specified fraction of <​m>​W_{L,​D,​g}</​m>​ from an unlimited source outside the model domain or if an aquifer is simulated connected to the subbasin from this aquifer. The first case conceptually represents a large deep aquifer source, which is currently outside of the model domain. <​m>​W_{L,​a,​g}</​m>​ is the abstracted groundwater and <​m>​P_{I,​G}</​m>​ (//pirrg// in par.txt) is the groundwater withdrawal fraction: If any groundwater demand exists, the model withdraws a user-specified fraction of <​m>​W_{L,​D,​g}</​m>​ from an unlimited source outside the model domain or if an aquifer is simulated connected to the subbasin from this aquifer. The first case conceptually represents a large deep aquifer source, which is currently outside of the model domain. <​m>​W_{L,​a,​g}</​m>​ is the abstracted groundwater and <​m>​P_{I,​G}</​m>​ (//pirrg// in par.txt) is the groundwater withdrawal fraction:
  
-<m> W_{L,​A,​g}=W_{L,​D,​g}×P_{I,G} </m>+<m> W_{L,​A,​g}=W_{L,​D,​g}*P_{I,G} </m>
  
 To simulate a more dynamic conjunctive use of groundwater and surface water sources, the model allows for compensation of remaining surface water demands from the groundwater source. This compensation is only allowed if both groundwater and surface water sources are used (//​0<​gw_part<​1//​),​ and if the //irrcomp// parameter is >0. The //irrcomp// parameter defines the degree of compensation allowed, i.e. the fraction of the residual surface water demand which can be met through source compensation. The compensation algorithm is as follows: if any surface water demand remains (<​m>​W_{L,​D,​s,​1}</​m>​ > 0) and the groundwater is not depleted, the groundwater withdrawal cycle is calculated once more using the scaled residual surface water demand. Finally, after possible source compensation,​ the remaining (surface) water demand at the sub-basin scale (<​m>​W_{L,​D,​1}</​m>​) is calculated. To simulate a more dynamic conjunctive use of groundwater and surface water sources, the model allows for compensation of remaining surface water demands from the groundwater source. This compensation is only allowed if both groundwater and surface water sources are used (//​0<​gw_part<​1//​),​ and if the //irrcomp// parameter is >0. The //irrcomp// parameter defines the degree of compensation allowed, i.e. the fraction of the residual surface water demand which can be met through source compensation. The compensation algorithm is as follows: if any surface water demand remains (<​m>​W_{L,​D,​s,​1}</​m>​ > 0) and the groundwater is not depleted, the groundwater withdrawal cycle is calculated once more using the scaled residual surface water demand. Finally, after possible source compensation,​ the remaining (surface) water demand at the sub-basin scale (<​m>​W_{L,​D,​1}</​m>​) is calculated.
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 The total water demand from the regional source (<​m>​W_{R,​D}</​m>​) is then calculated as the sum of the demand from each connected sub-basin, scaled by a parameter controlling the strength of the regional connection (<​m>​P_regirr</​m>,​ //regirr// in par.txt): The total water demand from the regional source (<​m>​W_{R,​D}</​m>​) is then calculated as the sum of the demand from each connected sub-basin, scaled by a parameter controlling the strength of the regional connection (<​m>​P_regirr</​m>,​ //regirr// in par.txt):
  
-<m> W_{R,D}= (sum{i=1}{N}{W_{R,​D,​i}} )×P_{regirr} </m>+<m> W_{R,D}= (sum{i=1}{N}{W_{R,​D,​i}} )*P_{regirr} </m>
  
 The regional demand can be met from two sources in sub-basin <​m>​D_R</​m>:​ the olake and the main river. If the regional source sub-basin has an olake, and if the //irrdam// input variable is set to 1 for that sub-basin, the model attempts to withdraw <​m>​W_{R,​D}</​m>​ first from the olake and then the residual from the main river. If not, the model only attempts to withdraw <​m>​W_{R,​D}</​m>​ from the main river. The regional abstraction (<​m>​W_{R,​a}</​m>​) is limited by the volume available at the source (<​m>​V_r</​m>​) and the scaling parameter <​m>​P_{I,​S}</​m>:​ The regional demand can be met from two sources in sub-basin <​m>​D_R</​m>:​ the olake and the main river. If the regional source sub-basin has an olake, and if the //irrdam// input variable is set to 1 for that sub-basin, the model attempts to withdraw <​m>​W_{R,​D}</​m>​ first from the olake and then the residual from the main river. If not, the model only attempts to withdraw <​m>​W_{R,​D}</​m>​ from the main river. The regional abstraction (<​m>​W_{R,​a}</​m>​) is limited by the volume available at the source (<​m>​V_r</​m>​) and the scaling parameter <​m>​P_{I,​S}</​m>:​
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 <m> W_{R,​D2}=W_{R,​D}-{W_{R,​A1}}/​{P_{I,​S}} </​m> ​ <m> W_{R,​D2}=W_{R,​D}-{W_{R,​A1}}/​{P_{I,​S}} </​m> ​
  
-<m> W_{R,​A2}=min(W_{R,​D2},​V_{r2} )×P_{I,S} </m>+<m> W_{R,​A2}=min(W_{R,​D2},​V_{r2} )*P_{I,S} </m>
  
 <m> W_{R,​A}=W_{R,​A1}+ W_{R,A2} </m> <m> W_{R,​A}=W_{R,​A1}+ W_{R,A2} </m>
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 The concentrations of the withdrawn water are the same as that of the irrigation water source. If the water originates from several sources, the volume-weighted concentration is calculated. If desired, the model can simulate sedimentation tanks, in which a defined fraction of the particulate phosphorous (//pp//) and organic nitrogen (//on//) settles: The concentrations of the withdrawn water are the same as that of the irrigation water source. If the water originates from several sources, the volume-weighted concentration is calculated. If desired, the model can simulate sedimentation tanks, in which a defined fraction of the particulate phosphorous (//pp//) and organic nitrogen (//on//) settles:
  
-<m> C_{a,​pp}=C_{src,​pp}×(1-P_{cirrsink} ) </m>+<m> C_{a,​pp}=C_{src,​pp}*(1-P_{cirrsink} ) </m>
  
-<m> C_{a,​on}=C_{src,​on}×(1-P_{cirrsink} ) </m>+<m> C_{a,​on}=C_{src,​on}*(1-P_{cirrsink} ) </m>
  
 where <​m>​C_{,​a}</​m>​ is the concentration of the abstracted water after settling, <​m>​C_{src}</​m>​ is the concentration of the source, and <​m>​P_{cirrsink}</​m>​ is the concentration reduction fraction (//​cirrsink//​ parameter in par.txt). To use sedimentation tanks in a region, the concentration reduction fraction needs to be set in par.txt (//​0<​cirrsink≤1//​). where <​m>​C_{,​a}</​m>​ is the concentration of the abstracted water after settling, <​m>​C_{src}</​m>​ is the concentration of the source, and <​m>​P_{cirrsink}</​m>​ is the concentration reduction fraction (//​cirrsink//​ parameter in par.txt). To use sedimentation tanks in a region, the concentration reduction fraction needs to be set in par.txt (//​0<​cirrsink≤1//​).
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 The regionally abstracted water (<​m>​W_{R,​A}</​m>​) is first distributed to each connected sub-basin (i) according to their proportional demand, and then scaled to the local scale using the respective regional efficiency: The regionally abstracted water (<​m>​W_{R,​A}</​m>​) is first distributed to each connected sub-basin (i) according to their proportional demand, and then scaled to the local scale using the respective regional efficiency:
  
-<m> W_{R,​A,​i}=W_{R,​A}× {W_{R,D,i}×P_{regirr}}/​{W_{R,​D}}×E_{R,i} </m>+<m> W_{R,​A,​i}=W_{R,​A}{W_{R,D,i}*P_{regirr}}/​{W_{R,​D}}*E_{R,i} </m>
  
 For a given sub-basin, the total amount of abstracted water available at the local scale (<​m>​W_{L,​A,​i,​tot}</​m>​) is calculated and then scaled, using the local efficiency, to represent the water applied to the soil (<​m>​W_{I,​A,​i}</​m>​):​ For a given sub-basin, the total amount of abstracted water available at the local scale (<​m>​W_{L,​A,​i,​tot}</​m>​) is calculated and then scaled, using the local efficiency, to represent the water applied to the soil (<​m>​W_{I,​A,​i}</​m>​):​
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 <m> W_{L,​A,​i,​tot}=W_{L,​A,​i}+W_{R,​A,​i} </m> <m> W_{L,​A,​i,​tot}=W_{L,​A,​i}+W_{R,​A,​i} </m>
  
-<m> W_{I,​A,​i}=W_{L,​A,​i,​tot}×E_{L,i} </m>+<m> W_{I,​A,​i}=W_{L,​A,​i,​tot}*E_{L,i} </m>
  
 <​m>​W_{I,​A,​i}</​m>​ is then distributed onto each irrigated class in proportion to its water demand: <​m>​W_{I,​A,​i}</​m>​ is then distributed onto each irrigated class in proportion to its water demand:
  
-<m> W_{I,​A,​j}=W_{I,​A,​i}×{W_{I,​D,​j}}/​{W_{I,​D}} </m>+<m> W_{I,​A,​j}=W_{I,​A,​i}*{W_{I,​D,​j}}/​{W_{I,​D}} </m>
  
 <​m>​W_{I,​A,​j}</​m>​ is added to the soil water of class j as additional infiltration. <​m>​W_{I,​A,​j}</​m>​ is divided between the top two soil layers according to the epotdist function, beginning with the second layer. For unlimited irrigation: <​m>​W_{I,​A,​j} =  W_{I,​D,​j}</​m>​ , <​m>​P_{I,​S} =1</​m>​ and <​m>​P_{I,​G} = 1</​m>​. <​m>​W_{I,​A,​j}</​m>​ is added to the soil water of class j as additional infiltration. <​m>​W_{I,​A,​j}</​m>​ is divided between the top two soil layers according to the epotdist function, beginning with the second layer. For unlimited irrigation: <​m>​W_{I,​A,​j} =  W_{I,​D,​j}</​m>​ , <​m>​P_{I,​S} =1</​m>​ and <​m>​P_{I,​G} = 1</​m>​.
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 |:::​|//​subid,​ receiver, flow//|:::| |:::​|//​subid,​ receiver, flow//|:::|
 |:::​|//​dwtr//​|[[start:​hype_file_reference:​xobs.txt|Xobs.txt]]| |:::​|//​dwtr//​|[[start:​hype_file_reference:​xobs.txt|Xobs.txt]]|
 +
 ==== Links to relevant procedures in the code ==== ==== Links to relevant procedures in the code ====
  
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 |:::​|water_transfer_from_outlet_lake| ::: | |:::​|water_transfer_from_outlet_lake| ::: |
  
 +===== Dams =====
  
 +Regulation of flow through dams is described in the Chapter about [[start:​hype_model_description:​hype_routing| Rivers and lakes]]. Dams of different purposes and regulation management can be simulated. See details in the sections on [[start:​hype_model_description:​hype_routing#​simple_outlet_lake_or_dam_olake| Simple outlet lake or dam]] and the special case of an [[start:​hype_model_description:​hype_routing#​outlet_lake_with_two_outlets| Outlet lake with two outlets]].
start/hype_model_description/hype_human_water.1536564925.txt.gz · Last modified: 2018/09/10 09:35 by cpers