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113 | Werner | 2 | #include "global.h" |
3 | #include "production3pg.h" |
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4 | |||
189 | iland | 5 | #include "resourceunit.h" |
113 | Werner | 6 | #include "species.h" |
226 | werner | 7 | #include "speciesresponse.h" |
8 | #include "model.h" |
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113 | Werner | 9 | |
10 | Production3PG::Production3PG() |
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11 | { |
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226 | werner | 12 | mResponse=0; |
113 | Werner | 13 | } |
14 | |||
146 | werner | 15 | // fake: aggregated response values per month GO to webbrowser!! |
133 | Werner | 16 | const double totalResponses[] = {0., 0.05, 0.4, 0.6, 0.8, 0.8, 0.8, 0.5, 0.5, 0.1, 0. ,0. }; |
113 | Werner | 17 | const double radYear = 3140.; // the sum of radMonth [MJ/m2] |
18 | |||
226 | werner | 19 | /** |
20 | This is based on the utilizable photosynthetic active radiation. |
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21 | @sa http://iland.boku.ac.at/primary+production |
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227 | werner | 22 | The resulting radiation is MJ/m2 */ |
23 | inline double Production3PG::calculateUtilizablePAR(const int month) const |
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226 | werner | 24 | { |
25 | // calculate the available radiation |
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26 | |||
27 | // there is no production outside of the vegetation period |
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28 | if (mResponse->absorbedRadiation()[month]==0.) |
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29 | return 0.; |
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30 | // see Equation (3) |
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31 | double response = mResponse->absorbedRadiation()[month] * |
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32 | mResponse->vpdResponse()[month] * |
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33 | mResponse->soilWaterResponse()[month] * |
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34 | mResponse->tempResponse()[month]; |
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35 | return response; |
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36 | } |
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37 | /** calculate the alphac (=photosynthetic efficiency) for the given month. |
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38 | this is based on a global efficiency, and modified per species. |
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227 | werner | 39 | epsilon is in gC/MJ Radiation |
226 | werner | 40 | */ |
227 | werner | 41 | inline double Production3PG::calculateEpsilon(const int month) const |
226 | werner | 42 | { |
43 | double epsilon = Model::settings().epsilon; // maximum radiation use efficiency |
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44 | epsilon *= mResponse->nitrogenResponse() * |
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45 | mResponse->co2Response(); |
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46 | return epsilon; |
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47 | } |
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48 | |||
227 | werner | 49 | inline double Production3PG::abovegroundFraction() const |
50 | { |
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51 | double harsh = 1 - 0.8/(1 + 2.5 * mResponse->nitrogenResponse()); |
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52 | return harsh; |
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53 | } |
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54 | |||
226 | werner | 55 | /** calculate the alphac (=photosynthetic efficiency) for given month. |
56 | @sa http://iland.boku.ac.at/primary+production */ |
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115 | Werner | 57 | double Production3PG::calculate() |
113 | Werner | 58 | { |
226 | werner | 59 | Q_ASSERT(mResponse!=0); |
60 | // Radiation: sum over all days of each month with foliage |
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228 | werner | 61 | double year_raw_gpp_c = 0.; |
113 | Werner | 62 | for (int i=0;i<12;i++) { |
228 | werner | 63 | mGPP[i] = 0.; mUPAR[i]=0.; |
226 | werner | 64 | } |
65 | double utilizable_rad, epsilon; |
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66 | for (int i=0;i<12;i++) { |
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228 | werner | 67 | mUPAR[i] = calculateUtilizablePAR(i); // utilizable radiation of the month times ... |
226 | werner | 68 | epsilon = calculateEpsilon(i); // ... photosynthetic efficiency ... |
227 | werner | 69 | mGPP[i] =utilizable_rad * epsilon; // ... results in GPP of the month (gC/m2) |
228 | werner | 70 | year_raw_gpp_c += mGPP[i]; // gC/m2 |
113 | Werner | 71 | } |
227 | werner | 72 | // calculate fac |
73 | mRootFraction = 1. - abovegroundFraction(); |
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137 | Werner | 74 | |
75 | // global value set? |
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215 | werner | 76 | double dbg = GlobalSettings::instance()->settings().paramValue("gpp_per_year",0); |
227 | werner | 77 | if (dbg) { |
228 | werner | 78 | year_raw_gpp_c = dbg * 1000. / 2.; // to g Carbon / m2 |
227 | werner | 79 | mRootFraction = 0.4; |
80 | } |
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137 | Werner | 81 | |
228 | werner | 82 | // year GPP/rad: kg Biomass (Carbon) * 2 / (yearly MJ/m2) |
83 | double year_gpp_biomass = year_raw_gpp_c * 2 / 1000.; // conversion from gC/m2 -> kg/m2 |
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84 | mGPPperRad = year_gpp_biomass / radYear; |
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85 | return mGPPperRad; // kg Biomass/MJ |
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113 | Werner | 86 | } |