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1 | Redirecting to URL 'https://iland.boku.ac.at/svn/iland/tags/release_1.0/src/core/watercycle.cpp': |
1 | Redirecting to URL 'https://iland.boku.ac.at/svn/iland/tags/release_1.0/src/core/watercycle.cpp': |
2 | #include "global.h"
|
2 | #include "global.h"
|
3 | #include "watercycle.h"
|
3 | #include "watercycle.h"
|
4 | #include "climate.h"
|
4 | #include "climate.h"
|
5 | #include "resourceunit.h"
|
5 | #include "resourceunit.h"
|
6 | #include "species.h"
|
6 | #include "species.h"
|
7 | #include "model.h"
|
7 | #include "model.h"
|
8 | 8 | ||
9 | WaterCycle::WaterCycle() |
9 | WaterCycle::WaterCycle() |
10 | {
|
10 | {
|
11 | mSoilDepth = 0; |
11 | mSoilDepth = 0; |
12 | mLastYear = -1; |
12 | mLastYear = -1; |
13 | }
|
13 | }
|
14 | 14 | ||
15 | void WaterCycle::setup(const ResourceUnit *ru) |
15 | void WaterCycle::setup(const ResourceUnit *ru) |
16 | {
|
16 | {
|
17 | mRU = ru; |
17 | mRU = ru; |
18 | // get values...
|
18 | // get values...
|
19 | mFieldCapacity = 0.; // on top |
19 | mFieldCapacity = 0.; // on top |
20 | const XmlHelper &xml=GlobalSettings::instance()->settings(); |
20 | const XmlHelper &xml=GlobalSettings::instance()->settings(); |
21 | mSoilDepth = xml.valueDouble("model.site.soilDepth", 0.) * 10; // convert from cm to mm |
21 | mSoilDepth = xml.valueDouble("model.site.soilDepth", 0.) * 10; // convert from cm to mm |
22 | double pct_sand = xml.valueDouble("model.site.pctSand"); |
22 | double pct_sand = xml.valueDouble("model.site.pctSand"); |
23 | double pct_silt = xml.valueDouble("model.site.pctSilt"); |
23 | double pct_silt = xml.valueDouble("model.site.pctSilt"); |
24 | double pct_clay = xml.valueDouble("model.site.pctClay"); |
24 | double pct_clay = xml.valueDouble("model.site.pctClay"); |
25 | mTopLayerWaterContent = xml.valueDouble("model.site.topLayerWaterContent",50); |
25 | mTopLayerWaterContent = xml.valueDouble("model.site.topLayerWaterContent",50); |
26 | if (pct_sand + pct_silt + pct_clay != 100.) |
26 | if (pct_sand + pct_silt + pct_clay != 100.) |
27 | throw IException(QString("Setup Watercycle: soil composition percentages do not sum up to 100. Sand: %1, Silt: %2 Clay: %3").arg(pct_sand).arg(pct_silt).arg(pct_clay)); |
27 | throw IException(QString("Setup Watercycle: soil composition percentages do not sum up to 100. Sand: %1, Silt: %2 Clay: %3").arg(pct_sand).arg(pct_silt).arg(pct_clay)); |
28 | 28 | ||
29 | // calculate soil characteristics based on empirical functions (Schwalm & Ek, 2004)
|
29 | // calculate soil characteristics based on empirical functions (Schwalm & Ek, 2004)
|
30 | // note: the variables are percentages [0..100]
|
30 | // note: the variables are percentages [0..100]
|
31 | mPsi_ref = -exp((1.54 - 0.0095*pct_sand + 0.0063*pct_silt) * log(10)) * 0.000098; // Eq. 83 |
31 | mPsi_ref = -exp((1.54 - 0.0095*pct_sand + 0.0063*pct_silt) * log(10)) * 0.000098; // Eq. 83 |
32 | mPsi_koeff_b = -( 3.1 + 0.157*pct_clay - 0.003*pct_sand ); // Eq. 84 |
32 | mPsi_koeff_b = -( 3.1 + 0.157*pct_clay - 0.003*pct_sand ); // Eq. 84 |
33 | mRho_ref = 0.01 * (50.5 - 0.142*pct_sand - 0.037*pct_clay); // Eq. 78 |
33 | mRho_ref = 0.01 * (50.5 - 0.142*pct_sand - 0.037*pct_clay); // Eq. 78 |
34 | mCanopy.setup(); |
34 | mCanopy.setup(); |
35 | 35 | ||
36 | mPermanentWiltingPoint = heightFromPsi(-4000); // maximum psi is set to a constant of -4MPa |
36 | mPermanentWiltingPoint = heightFromPsi(-4000); // maximum psi is set to a constant of -4MPa |
37 | if (xml.valueBool("model.settings.waterUseSoilSaturation",false)==false) { |
37 | if (xml.valueBool("model.settings.waterUseSoilSaturation",false)==false) { |
38 | mFieldCapacity = heightFromPsi(-15); |
38 | mFieldCapacity = heightFromPsi(-15); |
39 | } else { |
39 | } else { |
40 | // =-EXP((1.54-0.0095* pctSand +0.0063* pctSilt)*LN(10))*0.000098
|
40 | // =-EXP((1.54-0.0095* pctSand +0.0063* pctSilt)*LN(10))*0.000098
|
41 | double psi_sat = -exp((1.54-0.0095 * pct_sand + 0.0063*pct_silt)*log(10.))*0.000098; |
41 | double psi_sat = -exp((1.54-0.0095 * pct_sand + 0.0063*pct_silt)*log(10.))*0.000098; |
42 | mFieldCapacity = heightFromPsi(psi_sat); |
42 | mFieldCapacity = heightFromPsi(psi_sat); |
43 | if (logLevelDebug()) qDebug() << "psi: saturation " << psi_sat << "field capacity:" << mFieldCapacity; |
43 | if (logLevelDebug()) qDebug() << "psi: saturation " << psi_sat << "field capacity:" << mFieldCapacity; |
44 | }
|
44 | }
|
45 | 45 | ||
46 | mContent = mFieldCapacity; // start with full water content (in the middle of winter) |
46 | mContent = mFieldCapacity; // start with full water content (in the middle of winter) |
47 | if (logLevelDebug()) qDebug() << "setup of water: Psi_ref (kPa)" << mPsi_ref << "Rho_ref" << mRho_ref << "coeff. b" << mPsi_koeff_b; |
47 | if (logLevelDebug()) qDebug() << "setup of water: Psi_ref (kPa)" << mPsi_ref << "Rho_ref" << mRho_ref << "coeff. b" << mPsi_koeff_b; |
48 | mLastYear = -1; |
48 | mLastYear = -1; |
49 | }
|
49 | }
|
50 | 50 | ||
51 | /** function to calculate the water pressure [saugspannung] for a given amount of water.
|
51 | /** function to calculate the water pressure [saugspannung] for a given amount of water.
|
52 | returns water potential in kPa.
|
52 | returns water potential in kPa.
|
53 | see http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance */
|
53 | see http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance */
|
54 | inline double WaterCycle::psiFromHeight(const double mm) const |
54 | inline double WaterCycle::psiFromHeight(const double mm) const |
55 | {
|
55 | {
|
56 | // psi_x = psi_ref * ( rho_x / rho_ref) ^ b
|
56 | // psi_x = psi_ref * ( rho_x / rho_ref) ^ b
|
57 | if (mm<0.001) |
57 | if (mm<0.001) |
58 | return -100000000; |
58 | return -100000000; |
59 | double psi_x = mPsi_ref * pow((mm / mSoilDepth / mRho_ref),mPsi_koeff_b); |
59 | double psi_x = mPsi_ref * pow((mm / mSoilDepth / mRho_ref),mPsi_koeff_b); |
60 | return psi_x; // pis |
60 | return psi_x; // pis |
61 | }
|
61 | }
|
62 | 62 | ||
63 | /// calculate the height of the water column for a given pressure
|
63 | /// calculate the height of the water column for a given pressure
|
64 | /// return water amount in mm
|
64 | /// return water amount in mm
|
65 | /// see http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance
|
65 | /// see http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance
|
66 | inline double WaterCycle::heightFromPsi(const double psi_kpa) const |
66 | inline double WaterCycle::heightFromPsi(const double psi_kpa) const |
67 | {
|
67 | {
|
68 | // rho_x = rho_ref * (psi_x / psi_ref)^(1/b)
|
68 | // rho_x = rho_ref * (psi_x / psi_ref)^(1/b)
|
69 | double h = mSoilDepth * mRho_ref * pow(psi_kpa / mPsi_ref, 1./mPsi_koeff_b); |
69 | double h = mSoilDepth * mRho_ref * pow(psi_kpa / mPsi_ref, 1./mPsi_koeff_b); |
70 | return h; |
70 | return h; |
71 | }
|
71 | }
|
72 | 72 | ||
73 | /// get canopy characteristics of the resource unit.
|
73 | /// get canopy characteristics of the resource unit.
|
74 | /// It is important, that species-statistics are valid when this function is called (LAI)!
|
74 | /// It is important, that species-statistics are valid when this function is called (LAI)!
|
75 | void WaterCycle::getStandValues() |
75 | void WaterCycle::getStandValues() |
76 | {
|
76 | {
|
77 | mLAINeedle=mLAIBroadleaved=0.; |
77 | mLAINeedle=mLAIBroadleaved=0.; |
78 | mCanopyConductance=0.; |
78 | mCanopyConductance=0.; |
79 | const double GroundVegetationCC = 0.02; |
- | |
- | 79 | const double ground_vegetationCC = 0.02; |
|
80 | double lai; |
80 | double lai; |
81 | foreach(ResourceUnitSpecies *rus, mRU->ruSpecies()) { |
81 | foreach(ResourceUnitSpecies *rus, mRU->ruSpecies()) { |
82 | lai = rus->constStatistics().leafAreaIndex(); |
82 | lai = rus->constStatistics().leafAreaIndex(); |
83 | if (rus->species()->isConiferous()) |
83 | if (rus->species()->isConiferous()) |
84 | mLAINeedle+=lai; |
84 | mLAINeedle+=lai; |
85 | else
|
85 | else
|
86 | mLAIBroadleaved+=lai; |
86 | mLAIBroadleaved+=lai; |
87 | mCanopyConductance += rus->species()->canopyConductance() * lai; // weigh with LAI |
87 | mCanopyConductance += rus->species()->canopyConductance() * lai; // weigh with LAI |
88 | }
|
88 | }
|
89 | double total_lai = mLAIBroadleaved+mLAINeedle; |
89 | double total_lai = mLAIBroadleaved+mLAINeedle; |
90 | 90 | ||
91 | // handle cases with LAI < 1 (use generic "ground cover characteristics" instead)
|
91 | // handle cases with LAI < 1 (use generic "ground cover characteristics" instead)
|
92 | if (total_lai<1.) { |
92 | if (total_lai<1.) { |
93 | mCanopyConductance+=(GroundVegetationCC)*(1. - total_lai); |
- | |
- | 93 | mCanopyConductance+=(ground_vegetationCC)*(1. - total_lai); |
|
94 | total_lai = 1.; |
94 | total_lai = 1.; |
95 | }
|
95 | }
|
96 | mCanopyConductance /= total_lai; |
96 | mCanopyConductance /= total_lai; |
97 | 97 | ||
98 | if (total_lai < Model::settings().laiThresholdForClosedStands) { |
98 | if (total_lai < Model::settings().laiThresholdForClosedStands) { |
99 | // following Landsberg and Waring: when LAI is < 3 (default for laiThresholdForClosedStands), a linear "ramp" from 0 to 3 is assumed
|
99 | // following Landsberg and Waring: when LAI is < 3 (default for laiThresholdForClosedStands), a linear "ramp" from 0 to 3 is assumed
|
100 | // http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance
|
100 | // http://iland.boku.ac.at/water+cycle#transpiration_and_canopy_conductance
|
101 | mCanopyConductance *= total_lai / Model::settings().laiThresholdForClosedStands; |
101 | mCanopyConductance *= total_lai / Model::settings().laiThresholdForClosedStands; |
102 | }
|
102 | }
|
103 | if (logLevelInfo()) qDebug() << "WaterCycle:getStandValues: LAI needle" << mLAINeedle << "LAI Broadl:"<< mLAIBroadleaved << "weighted avg. Conductance (m/2):" << mCanopyConductance; |
103 | if (logLevelInfo()) qDebug() << "WaterCycle:getStandValues: LAI needle" << mLAINeedle << "LAI Broadl:"<< mLAIBroadleaved << "weighted avg. Conductance (m/2):" << mCanopyConductance; |
104 | }
|
104 | }
|
105 | 105 | ||
106 | /// calculate responses for ground vegetation, i.e. for "unstocked" areas.
|
106 | /// calculate responses for ground vegetation, i.e. for "unstocked" areas.
|
107 | /// this duplicates calculations done in Species.
|
107 | /// this duplicates calculations done in Species.
|
108 | /// @return Minimum of vpd and soilwater response for default
|
108 | /// @return Minimum of vpd and soilwater response for default
|
109 | inline double WaterCycle::calculateBaseSoilAtmosphereResponse(const double psi_kpa, const double vpd_kpa) |
109 | inline double WaterCycle::calculateBaseSoilAtmosphereResponse(const double psi_kpa, const double vpd_kpa) |
110 | {
|
110 | {
|
111 | // constant parameters used for ground vegetation:
|
111 | // constant parameters used for ground vegetation:
|
112 | const double mPsiMin = 1.5; // MPa |
112 | const double mPsiMin = 1.5; // MPa |
113 | const double mRespVpdExponent = -0.6; |
113 | const double mRespVpdExponent = -0.6; |
114 | // see SpeciesResponse::soilAtmosphereResponses()
|
114 | // see SpeciesResponse::soilAtmosphereResponses()
|
115 | double water_resp; |
115 | double water_resp; |
116 | // see Species::soilwaterResponse:
|
116 | // see Species::soilwaterResponse:
|
117 | const double psi_mpa = psi_kpa / 1000.; // convert to MPa |
117 | const double psi_mpa = psi_kpa / 1000.; // convert to MPa |
118 | water_resp = limit( 1. - psi_mpa / mPsiMin, 0., 1.); |
118 | water_resp = limit( 1. - psi_mpa / mPsiMin, 0., 1.); |
119 | // see species::vpdResponse
|
119 | // see species::vpdResponse
|
120 | 120 | ||
121 | double vpd_resp; |
121 | double vpd_resp; |
122 | vpd_resp = exp(mRespVpdExponent * vpd_kpa); |
122 | vpd_resp = exp(mRespVpdExponent * vpd_kpa); |
123 | return qMin(water_resp, vpd_resp); |
123 | return qMin(water_resp, vpd_resp); |
124 | }
|
124 | }
|
125 | 125 | ||
126 | /// calculate combined VPD and soilwaterresponse for all species
|
126 | /// calculate combined VPD and soilwaterresponse for all species
|
127 | /// on the RU. This is used for the calc. of the transpiration.
|
127 | /// on the RU. This is used for the calc. of the transpiration.
|
128 | inline double WaterCycle::calculateSoilAtmosphereResponse(const double psi_kpa, const double vpd_kpa) |
128 | inline double WaterCycle::calculateSoilAtmosphereResponse(const double psi_kpa, const double vpd_kpa) |
129 | {
|
129 | {
|
130 | double min_response; |
130 | double min_response; |
131 | double total_response = 0; // LAI weighted minimum response for all speices on the RU |
131 | double total_response = 0; // LAI weighted minimum response for all speices on the RU |
132 | double total_lai_factor = 0.; |
132 | double total_lai_factor = 0.; |
133 | foreach(ResourceUnitSpecies *rus, mRU->ruSpecies()) { |
133 | foreach(ResourceUnitSpecies *rus, mRU->ruSpecies()) { |
134 | if (rus->LAIfactor()>0) { |
134 | if (rus->LAIfactor()>0) { |
135 | // retrieve the minimum of VPD / soil water response for that species
|
135 | // retrieve the minimum of VPD / soil water response for that species
|
136 | rus->speciesResponse()->soilAtmosphereResponses(psi_kpa, vpd_kpa, min_response); |
136 | rus->speciesResponse()->soilAtmosphereResponses(psi_kpa, vpd_kpa, min_response); |
137 | total_response += min_response * rus->LAIfactor(); |
137 | total_response += min_response * rus->LAIfactor(); |
138 | total_lai_factor += rus->LAIfactor(); |
138 | total_lai_factor += rus->LAIfactor(); |
139 | }
|
139 | }
|
140 | }
|
140 | }
|
141 | 141 | ||
142 | if (total_lai_factor<1.) { |
142 | if (total_lai_factor<1.) { |
143 | // the LAI is below 1: the rest is considered as "ground vegetation"
|
143 | // the LAI is below 1: the rest is considered as "ground vegetation"
|
144 | total_response += calculateBaseSoilAtmosphereResponse(psi_kpa, vpd_kpa) * (1. - total_lai_factor); |
144 | total_response += calculateBaseSoilAtmosphereResponse(psi_kpa, vpd_kpa) * (1. - total_lai_factor); |
145 | }
|
145 | }
|
146 | 146 | ||
147 | // add an aging factor to the total response (averageAging: leaf area weighted mean aging value):
|
147 | // add an aging factor to the total response (averageAging: leaf area weighted mean aging value):
|
148 | // conceptually: response = min(vpd_response, water_response)*aging
|
148 | // conceptually: response = min(vpd_response, water_response)*aging
|
149 | if (total_lai_factor==1.) |
149 | if (total_lai_factor==1.) |
150 | total_response *= mRU->averageAging(); // no ground cover: use aging value for all LA |
150 | total_response *= mRU->averageAging(); // no ground cover: use aging value for all LA |
151 | else if (total_lai_factor>0. && mRU->averageAging()>0.) |
151 | else if (total_lai_factor>0. && mRU->averageAging()>0.) |
152 | total_response *= (1.-total_lai_factor)*1. + (total_lai_factor * mRU->averageAging()); // between 0..1: a part of the LAI is "ground cover" (aging=1) |
152 | total_response *= (1.-total_lai_factor)*1. + (total_lai_factor * mRU->averageAging()); // between 0..1: a part of the LAI is "ground cover" (aging=1) |
153 | 153 | ||
154 | DBGMODE( if (mRU->averageAging()>1. || mRU->averageAging()<0. || total_response<0 || total_response>1.) |
154 | DBGMODE( if (mRU->averageAging()>1. || mRU->averageAging()<0. || total_response<0 || total_response>1.) |
155 | qDebug() << "water cycle: average aging invalid. aging:" << mRU->averageAging() << "total response" << total_response; |
155 | qDebug() << "water cycle: average aging invalid. aging:" << mRU->averageAging() << "total response" << total_response; |
156 | ); |
156 | ); |
157 | 157 | ||
158 | //DBG_IF(mRU->averageAging()>1. || mRU->averageAging()<0.,"water cycle", "average aging invalid!" );
|
158 | //DBG_IF(mRU->averageAging()>1. || mRU->averageAging()<0.,"water cycle", "average aging invalid!" );
|
159 | return total_response; |
159 | return total_response; |
160 | }
|
160 | }
|
161 | 161 | ||
162 | 162 | ||
163 | /// Main Water Cycle function. This function triggers all water related tasks for
|
163 | /// Main Water Cycle function. This function triggers all water related tasks for
|
164 | /// one simulation year.
|
164 | /// one simulation year.
|
165 | /// @sa http://iland.boku.ac.at/water+cycle
|
165 | /// @sa http://iland.boku.ac.at/water+cycle
|
166 | void WaterCycle::run() |
166 | void WaterCycle::run() |
167 | {
|
167 | {
|
168 | // necessary?
|
168 | // necessary?
|
169 | if (GlobalSettings::instance()->currentYear() == mLastYear) |
169 | if (GlobalSettings::instance()->currentYear() == mLastYear) |
170 | return; |
170 | return; |
171 | // preparations (once a year)
|
171 | // preparations (once a year)
|
172 | getStandValues(); // fetch canopy characteristics from iLand (including weighted average for mCanopyConductance) |
172 | getStandValues(); // fetch canopy characteristics from iLand (including weighted average for mCanopyConductance) |
173 | mCanopy.setStandParameters(mLAINeedle, |
173 | mCanopy.setStandParameters(mLAINeedle, |
174 | mLAIBroadleaved, |
174 | mLAIBroadleaved, |
175 | mCanopyConductance); |
175 | mCanopyConductance); |
176 | - | ||
177 | 176 | ||
178 | // main loop over all days of the year
|
177 | // main loop over all days of the year
|
179 | double prec_mm, prec_after_interception, prec_to_soil, et, excess; |
178 | double prec_mm, prec_after_interception, prec_to_soil, et, excess; |
180 | const Climate *climate = mRU->climate(); |
179 | const Climate *climate = mRU->climate(); |
181 | const ClimateDay *day = climate->begin(); |
180 | const ClimateDay *day = climate->begin(); |
182 | const ClimateDay *end = climate->end(); |
181 | const ClimateDay *end = climate->end(); |
183 | int doy=0; |
182 | int doy=0; |
184 | double total_excess = 0.; |
183 | double total_excess = 0.; |
185 | for (; day<end; ++day, ++doy) { |
184 | for (; day<end; ++day, ++doy) { |
186 | // (1) precipitation of the day
|
185 | // (1) precipitation of the day
|
187 | prec_mm = day->preciptitation; |
186 | prec_mm = day->preciptitation; |
188 | // (2) interception by the crown
|
187 | // (2) interception by the crown
|
189 | prec_after_interception = mCanopy.flow(prec_mm, day->temperature); |
188 | prec_after_interception = mCanopy.flow(prec_mm, day->temperature); |
190 | // (3) storage in the snow pack
|
189 | // (3) storage in the snow pack
|
191 | prec_to_soil = mSnowPack.flow(prec_after_interception, day->temperature); |
190 | prec_to_soil = mSnowPack.flow(prec_after_interception, day->temperature); |
192 | // (4) add rest to soil
|
191 | // (4) add rest to soil
|
193 | mContent += prec_to_soil; |
192 | mContent += prec_to_soil; |
194 | 193 | ||
195 | excess = 0.; |
194 | excess = 0.; |
196 | if (mContent>mFieldCapacity) { |
195 | if (mContent>mFieldCapacity) { |
197 | // excess water runoff
|
196 | // excess water runoff
|
198 | excess = mContent - mFieldCapacity; |
197 | excess = mContent - mFieldCapacity; |
199 | total_excess += excess; |
198 | total_excess += excess; |
200 | mContent = mFieldCapacity; |
199 | mContent = mFieldCapacity; |
201 | }
|
200 | }
|
202 | 201 | ||
203 | double current_psi = psiFromHeight(mContent); |
202 | double current_psi = psiFromHeight(mContent); |
204 | mPsi[doy] = current_psi; |
203 | mPsi[doy] = current_psi; |
205 | mWaterDeficit_mm[doy] = mFieldCapacity - mContent; |
- | |
- | 204 | ||
206 | // (5) transpiration of the vegetation (and of water intercepted in canopy)
|
205 | // (5) transpiration of the vegetation (and of water intercepted in canopy)
|
207 | // calculate the LAI-weighted response values for soil water and vpd:
|
206 | // calculate the LAI-weighted response values for soil water and vpd:
|
208 | double combined_response = calculateSoilAtmosphereResponse( current_psi, day->vpd); |
207 | double combined_response = calculateSoilAtmosphereResponse( current_psi, day->vpd); |
209 | et = mCanopy.evapotranspiration3PG(day, climate->daylength_h(doy), combined_response); |
208 | et = mCanopy.evapotranspiration3PG(day, climate->daylength_h(doy), combined_response); |
210 | 209 | ||
211 | mContent -= et; // reduce content (transpiration) |
210 | mContent -= et; // reduce content (transpiration) |
212 | // add intercepted water (that is *not* evaporated) again to the soil (or add to snow if temp too low -> call to snowpack)
|
211 | // add intercepted water (that is *not* evaporated) again to the soil (or add to snow if temp too low -> call to snowpack)
|
213 | mContent += mSnowPack.add(mCanopy.interception(),day->temperature); |
212 | mContent += mSnowPack.add(mCanopy.interception(),day->temperature); |
214 | 213 | ||
215 | // do not remove water below the PWP (fixed value)
|
214 | // do not remove water below the PWP (fixed value)
|
216 | if (mContent<mPermanentWiltingPoint) { |
215 | if (mContent<mPermanentWiltingPoint) { |
217 | et -= mPermanentWiltingPoint - mContent; // reduce et (for bookkeeping) |
216 | et -= mPermanentWiltingPoint - mContent; // reduce et (for bookkeeping) |
218 | mContent = mPermanentWiltingPoint; |
217 | mContent = mPermanentWiltingPoint; |
219 | }
|
218 | }
|
220 | 219 | ||
221 | 220 | ||
222 | //DBGMODE(
|
221 | //DBGMODE(
|
223 | if (GlobalSettings::instance()->isDebugEnabled(GlobalSettings::dWaterCycle)) { |
222 | if (GlobalSettings::instance()->isDebugEnabled(GlobalSettings::dWaterCycle)) { |
224 | DebugList &out = GlobalSettings::instance()->debugList(day->id(), GlobalSettings::dWaterCycle); |
223 | DebugList &out = GlobalSettings::instance()->debugList(day->id(), GlobalSettings::dWaterCycle); |
225 | // climatic variables
|
224 | // climatic variables
|
226 | out << day->id() << mRU->index() << day->temperature << day->vpd << day->preciptitation << day->radiation; |
225 | out << day->id() << mRU->index() << day->temperature << day->vpd << day->preciptitation << day->radiation; |
227 | out << combined_response; // combined response of all species on RU (min(water, vpd)) |
226 | out << combined_response; // combined response of all species on RU (min(water, vpd)) |
228 | // fluxes
|
227 | // fluxes
|
229 | out << prec_after_interception << prec_to_soil << et << mCanopy.evaporationCanopy() |
228 | out << prec_after_interception << prec_to_soil << et << mCanopy.evaporationCanopy() |
230 | << mContent << mPsi[doy] << excess; |
229 | << mContent << mPsi[doy] << excess; |
231 | // other states
|
230 | // other states
|
232 | out << mSnowPack.snowPack(); |
231 | out << mSnowPack.snowPack(); |
233 | //special sanity check:
|
232 | //special sanity check:
|
234 | if (prec_to_soil>0. && mCanopy.interception()>0.) |
233 | if (prec_to_soil>0. && mCanopy.interception()>0.) |
235 | if (mSnowPack.snowPack()==0. && day->preciptitation==0) |
234 | if (mSnowPack.snowPack()==0. && day->preciptitation==0) |
236 | qDebug() << "watercontent increase without precipititaion"; |
235 | qDebug() << "watercontent increase without precipititaion"; |
237 | 236 | ||
238 | }
|
237 | }
|
239 | //); // DBGMODE()
|
238 | //); // DBGMODE()
|
240 | 239 | ||
241 | }
|
240 | }
|
242 | mLastYear = GlobalSettings::instance()->currentYear(); |
241 | mLastYear = GlobalSettings::instance()->currentYear(); |
243 | 242 | ||
244 | }
|
243 | }
|
245 | 244 | ||
246 | 245 | ||
247 | namespace Water { |
246 | namespace Water { |
248 | 247 | ||
249 | /** calculates the input/output of water that is stored in the snow pack.
|
248 | /** calculates the input/output of water that is stored in the snow pack.
|
250 | The approach is similar to Picus 1.3 and ForestBGC (Running, 1988).
|
249 | The approach is similar to Picus 1.3 and ForestBGC (Running, 1988).
|
251 | Returns the amount of water that exits the snowpack (precipitation, snow melt) */
|
250 | Returns the amount of water that exits the snowpack (precipitation, snow melt) */
|
252 | double SnowPack::flow(const double &preciptitation_mm, const double &temperature) |
251 | double SnowPack::flow(const double &preciptitation_mm, const double &temperature) |
253 | {
|
252 | {
|
254 | if (temperature>0.) { |
253 | if (temperature>0.) { |
255 | if (mSnowPack==0.) |
254 | if (mSnowPack==0.) |
256 | return preciptitation_mm; // no change |
255 | return preciptitation_mm; // no change |
257 | else { |
256 | else { |
258 | // snow melts
|
257 | // snow melts
|
259 | const double melting_coefficient = 0.7; // mm/°C |
258 | const double melting_coefficient = 0.7; // mm/°C |
260 | double melt = qMin(temperature * melting_coefficient, mSnowPack); |
259 | double melt = qMin(temperature * melting_coefficient, mSnowPack); |
261 | mSnowPack -=melt; |
260 | mSnowPack -=melt; |
262 | return preciptitation_mm + melt; |
261 | return preciptitation_mm + melt; |
263 | }
|
262 | }
|
264 | } else { |
263 | } else { |
265 | // snow:
|
264 | // snow:
|
266 | mSnowPack += preciptitation_mm; |
265 | mSnowPack += preciptitation_mm; |
267 | return 0.; // no output. |
266 | return 0.; // no output. |
268 | }
|
267 | }
|
269 | 268 | ||
270 | }
|
269 | }
|
271 | 270 | ||
272 | 271 | ||
273 | inline double SnowPack::add(const double &preciptitation_mm, const double &temperature) |
272 | inline double SnowPack::add(const double &preciptitation_mm, const double &temperature) |
274 | {
|
273 | {
|
275 | // do nothing for temps > 0°
|
274 | // do nothing for temps > 0°
|
276 | if (temperature>0.) |
275 | if (temperature>0.) |
277 | return preciptitation_mm; |
276 | return preciptitation_mm; |
278 | 277 | ||
279 | // temps < 0°: add to snow
|
278 | // temps < 0°: add to snow
|
280 | mSnowPack += preciptitation_mm; |
279 | mSnowPack += preciptitation_mm; |
281 | return 0.; |
280 | return 0.; |
282 | }
|
281 | }
|
283 | 282 | ||
284 | /** Interception in crown canopy.
|
283 | /** Interception in crown canopy.
|
285 | Calculates the amount of preciptitation that does not reach the ground and
|
284 | Calculates the amount of preciptitation that does not reach the ground and
|
286 | is stored in the canopy. The approach is adopted from Picus 1.3.
|
285 | is stored in the canopy. The approach is adopted from Picus 1.3.
|
287 | Returns the amount of precipitation (mm) that surpasses the canopy layer.
|
286 | Returns the amount of precipitation (mm) that surpasses the canopy layer.
|
288 | @sa http://iland.boku.ac.at/water+cycle#precipitation_and_interception */
|
287 | @sa http://iland.boku.ac.at/water+cycle#precipitation_and_interception */
|
289 | double Canopy::flow(const double &preciptitation_mm, const double &temperature) |
288 | double Canopy::flow(const double &preciptitation_mm, const double &temperature) |
290 | {
|
289 | {
|
291 | // sanity checks
|
290 | // sanity checks
|
292 | mInterception = 0.; |
291 | mInterception = 0.; |
293 | mEvaporation = 0.; |
292 | mEvaporation = 0.; |
294 | if (!mLAI) |
293 | if (!mLAI) |
295 | return preciptitation_mm; |
294 | return preciptitation_mm; |
296 | if (!preciptitation_mm) |
295 | if (!preciptitation_mm) |
297 | return 0.; |
296 | return 0.; |
298 | double max_interception_mm=0.; // maximum interception based on the current foliage |
297 | double max_interception_mm=0.; // maximum interception based on the current foliage |
299 | double max_storage_mm=0.; // maximum storage in canopy |
298 | double max_storage_mm=0.; // maximum storage in canopy |
300 | 299 | ||
301 | if (mLAINeedle>0.) { |
300 | if (mLAINeedle>0.) { |
302 | // (1) calculate maximum fraction of thru-flow the crown (based on precipitation)
|
301 | // (1) calculate maximum fraction of thru-flow the crown (based on precipitation)
|
303 | double max_flow_needle = 0.9 * sqrt(1.03 - exp(-0.055*preciptitation_mm)); |
302 | double max_flow_needle = 0.9 * sqrt(1.03 - exp(-0.055*preciptitation_mm)); |
304 | max_interception_mm += preciptitation_mm * (1. - max_flow_needle * mLAINeedle/mLAI); |
303 | max_interception_mm += preciptitation_mm * (1. - max_flow_needle * mLAINeedle/mLAI); |
305 | // (2) calculate maximum storage potential based on the current LAI
|
304 | // (2) calculate maximum storage potential based on the current LAI
|
306 | double max_storage_needle = 4. * (1. - exp(-0.55*mLAINeedle) ); |
305 | double max_storage_needle = 4. * (1. - exp(-0.55*mLAINeedle) ); |
307 | max_storage_mm += max_storage_needle; |
306 | max_storage_mm += max_storage_needle; |
308 | }
|
307 | }
|
309 | 308 | ||
310 | if (mLAIBroadleaved>0.) { |
309 | if (mLAIBroadleaved>0.) { |
311 | // (1) calculate maximum fraction of thru-flow the crown (based on precipitation)
|
310 | // (1) calculate maximum fraction of thru-flow the crown (based on precipitation)
|
312 | double max_flow_broad = 0.9 * pow(1.22 - exp(-0.055*preciptitation_mm), 0.35); |
311 | double max_flow_broad = 0.9 * pow(1.22 - exp(-0.055*preciptitation_mm), 0.35); |
313 | max_interception_mm += preciptitation_mm * (1. - max_flow_broad * mLAIBroadleaved/mLAI); |
312 | max_interception_mm += preciptitation_mm * (1. - max_flow_broad * mLAIBroadleaved/mLAI); |
314 | // (2) calculate maximum storage potential based on the current LAI
|
313 | // (2) calculate maximum storage potential based on the current LAI
|
315 | double max_storage_broad = 2. * (1. - exp(-0.5*mLAIBroadleaved) ); |
314 | double max_storage_broad = 2. * (1. - exp(-0.5*mLAIBroadleaved) ); |
316 | max_storage_mm += max_storage_broad; |
315 | max_storage_mm += max_storage_broad; |
317 | }
|
316 | }
|
318 | 317 | ||
319 | // (3) calculate actual interception and store for evaporation calculation
|
318 | // (3) calculate actual interception and store for evaporation calculation
|
320 | mInterception = qMin( max_storage_mm, max_interception_mm ); |
319 | mInterception = qMin( max_storage_mm, max_interception_mm ); |
321 | 320 | ||
322 | // (4) limit interception with amount of precipitation
|
321 | // (4) limit interception with amount of precipitation
|
323 | mInterception = qMin( mInterception, preciptitation_mm); |
322 | mInterception = qMin( mInterception, preciptitation_mm); |
324 | 323 | ||
325 | // (5) reduce preciptitaion by the amount that is intercepted by the canopy
|
324 | // (5) reduce preciptitaion by the amount that is intercepted by the canopy
|
326 | return preciptitation_mm - mInterception; |
325 | return preciptitation_mm - mInterception; |
327 | 326 | ||
328 | }
|
327 | }
|
329 | 328 | ||
330 | /// sets up the canopy. fetch some global parameter values...
|
329 | /// sets up the canopy. fetch some global parameter values...
|
331 | void Canopy::setup() |
330 | void Canopy::setup() |
332 | {
|
331 | {
|
333 | mAirDensity = Model::settings().airDensity; // kg / m3 |
332 | mAirDensity = Model::settings().airDensity; // kg / m3 |
334 | }
|
333 | }
|
335 | 334 | ||
336 | void Canopy::setStandParameters(const double LAIneedle, const double LAIbroadleave, const double maxCanopyConductance) |
335 | void Canopy::setStandParameters(const double LAIneedle, const double LAIbroadleave, const double maxCanopyConductance) |
337 | {
|
336 | {
|
338 | mLAINeedle = LAIneedle; |
337 | mLAINeedle = LAIneedle; |
339 | mLAIBroadleaved=LAIbroadleave; |
338 | mLAIBroadleaved=LAIbroadleave; |
340 | mLAI=LAIneedle+LAIbroadleave; |
339 | mLAI=LAIneedle+LAIbroadleave; |
341 | mAvgMaxCanopyConductance = maxCanopyConductance; |
340 | mAvgMaxCanopyConductance = maxCanopyConductance; |
- | 341 | ||
- | 342 | // clear aggregation containers
|
|
- | 343 | for (int i=0;i<12;++i) mPET[i]=0.; |
|
- | 344 | ||
342 | }
|
345 | }
|
343 | 346 | ||
344 | 347 | ||
345 | 348 | ||
346 | /** calculate the daily evaporation/transpiration using the Penman-Monteith-Equation.
|
349 | /** calculate the daily evaporation/transpiration using the Penman-Monteith-Equation.
|
347 | This version is based on 3PG. See the Visual Basic Code in 3PGjs.xls.
|
350 | This version is based on 3PG. See the Visual Basic Code in 3PGjs.xls.
|
348 | Returns the total sum of evaporation+transpiration in mm of the day. */
|
351 | Returns the total sum of evaporation+transpiration in mm of the day. */
|
349 | double Canopy::evapotranspiration3PG(const ClimateDay *climate, const double daylength_h, const double combined_response) |
352 | double Canopy::evapotranspiration3PG(const ClimateDay *climate, const double daylength_h, const double combined_response) |
350 | {
|
353 | {
|
351 | double vpd_mbar = climate->vpd * 10.; // convert from kPa to mbar |
354 | double vpd_mbar = climate->vpd * 10.; // convert from kPa to mbar |
352 | double temperature = climate->temperature; // average temperature of the day (°C) |
355 | double temperature = climate->temperature; // average temperature of the day (°C) |
353 | double daylength = daylength_h * 3600.; // daylength in seconds (convert from length in hours) |
356 | double daylength = daylength_h * 3600.; // daylength in seconds (convert from length in hours) |
354 | double rad = climate->radiation / daylength * 1000000; //convert from MJ/m2 (day sum) to average radiation flow W/m2 [MJ=MWs -> /s * 1,000,000 |
357 | double rad = climate->radiation / daylength * 1000000; //convert from MJ/m2 (day sum) to average radiation flow W/m2 [MJ=MWs -> /s * 1,000,000 |
355 | 358 | ||
356 | //: Landsberg original: const double e20 = 2.2; //rate of change of saturated VP with T at 20C
|
359 | //: Landsberg original: const double e20 = 2.2; //rate of change of saturated VP with T at 20C
|
357 | const double VPDconv = 0.000622; //convert VPD to saturation deficit = 18/29/1000 |
360 | const double VPDconv = 0.000622; //convert VPD to saturation deficit = 18/29/1000 |
358 | const double latent_heat = 2460000.; // Latent heat of vaporization. Energy required per unit mass of water vaporized [J kg-1] |
361 | const double latent_heat = 2460000.; // Latent heat of vaporization. Energy required per unit mass of water vaporized [J kg-1] |
359 | 362 | ||
360 | double gBL = Model::settings().boundaryLayerConductance; // boundary layer conductance |
363 | double gBL = Model::settings().boundaryLayerConductance; // boundary layer conductance |
361 | 364 | ||
362 | // canopy conductance.
|
365 | // canopy conductance.
|
363 | // The species traits are weighted by LAI on the RU.
|
366 | // The species traits are weighted by LAI on the RU.
|
364 | // maximum canopy conductance: see getStandValues()
|
367 | // maximum canopy conductance: see getStandValues()
|
365 | // current response: see calculateSoilAtmosphereResponse(). This is basically a weighted average of min(water_response, vpd_response) for each species
|
368 | // current response: see calculateSoilAtmosphereResponse(). This is basically a weighted average of min(water_response, vpd_response) for each species
|
366 | double gC = mAvgMaxCanopyConductance * combined_response; |
369 | double gC = mAvgMaxCanopyConductance * combined_response; |
367 | 370 | ||
368 | 371 | ||
369 | double defTerm = mAirDensity * latent_heat * (vpd_mbar * VPDconv) * gBL; |
372 | double defTerm = mAirDensity * latent_heat * (vpd_mbar * VPDconv) * gBL; |
370 | // saturation vapor pressure (Running 1988, Eq. 1) in mbar
|
373 | // saturation vapor pressure (Running 1988, Eq. 1) in mbar
|
371 | double svp = 6.1078 * exp((17.269 * temperature) / (237.3 + temperature) ); |
374 | double svp = 6.1078 * exp((17.269 * temperature) / (237.3 + temperature) ); |
372 | // the slope of svp is, thanks to http://www.wolframalpha.com/input/?i=derive+y%3D6.1078+exp+((17.269x)/(237.3%2Bx))
|
375 | // the slope of svp is, thanks to http://www.wolframalpha.com/input/?i=derive+y%3D6.1078+exp+((17.269x)/(237.3%2Bx))
|
373 | double svp_slope = svp * ( 17.269/(237.3+temperature) - 17.269*temperature/((237.3+temperature)*(237.3+temperature)) ); |
376 | double svp_slope = svp * ( 17.269/(237.3+temperature) - 17.269*temperature/((237.3+temperature)*(237.3+temperature)) ); |
374 | 377 | ||
375 | double div = (1. + svp_slope + gBL / gC); |
378 | double div = (1. + svp_slope + gBL / gC); |
376 | double Etransp = (svp_slope * rad + defTerm) / div; |
379 | double Etransp = (svp_slope * rad + defTerm) / div; |
377 | double canopy_transpiration = Etransp / latent_heat * daylength; |
380 | double canopy_transpiration = Etransp / latent_heat * daylength; |
- | 381 | ||
- | 382 | // calculate PET
|
|
- | 383 | double div_evap = 1 + svp_slope; |
|
- | 384 | double pet_day = (svp_slope*rad + defTerm) / div_evap / latent_heat * daylength; |
|
- | 385 | mPET[climate->month-1] += pet_day; |
|
378 | 386 | ||
379 | if (mInterception>0.) { |
387 | if (mInterception>0.) { |
380 | // we assume that for evaporation from leaf surface gBL/gC -> 0
|
388 | // we assume that for evaporation from leaf surface gBL/gC -> 0
|
381 | double div_evap = 1 + svp_slope; |
- | |
382 | double evap = (svp_slope*rad + defTerm) / div_evap / latent_heat * daylength; |
- | |
383 | evap = qMin(evap, mInterception); |
- | |
384 | mInterception -= evap; // reduce interception |
- | |
385 | mEvaporation = evap; // evaporation from intercepted water |
- | |
- | 389 | pet_day = qMin(pet_day, mInterception); |
|
- | 390 | mInterception -= pet_day; // reduce interception |
|
- | 391 | mEvaporation = pet_day; // evaporation from intercepted water |
|
386 | }
|
392 | }
|
387 | return canopy_transpiration; |
393 | return canopy_transpiration; |
388 | }
|
394 | }
|
389 | 395 | ||
390 | } // end namespace |
396 | } // end namespace |
391 | 397 |