Estimating the Gross Primary Production and Evapotranspiration of Rice Paddy Fields in the Sub-Tropical Region of China Using a Remotely-Sensed Based Water-Carbon Coupled Model
Abstract
:1. Introduction
2. Study Site and Data Processing
2.1. Study Site
2.2. Eddy Covariance Measurements and Meteorology Data at the Xiangtang Station
2.3. Regional Data
3. The PML-V2 Model
3.1. The Estimation of GPP
3.2. The Estimation of ET
3.3. Biophysical Conductance Model
3.4. Model Calibration and Validation
4. Results
4.1. GPP and ET Fluxes of RICE Paddy Field at the Site-Level
4.2. Seasonal Variations in the Key Parameters of the PML-V2 Model for the Early Rice and Late Rice Ecosystems
4.3. Model Evaluation at the Xiangtang Station
4.4. Regional Estimation of GPP and ET Using the PML-V2 Model
5. Discussion
6. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Periods | Date | Plantation | Growing Stages of Rice |
---|---|---|---|
P1 | 01/10/2016–24/10/2016 | Late Rice | Grouting and ripeness |
P2 | 25/10/2016–23/03/2017 | Chinese milk vetch | |
P3 | 24/03/2017–23/04/2017 | Early Rice | Rice seedling transplant and resume growth |
P4 | 24/04/2017–23/05/2017 | Resume growth before jointing | |
P5 | 24/05/2017–23/06/2017 | Jointing, booting, heading, and blooming | |
P6 | 24/06/2017–14/07/2017 | Grouting and ripeness | |
P7 | 15/07/2017–23/08/2017 | Late Rice | Rice seedling transplant and resume growth |
P8 | 24/08/2017–24/09/2017 | Jointing, booting, heading, and blooming | |
P9 | 25/09/2017–24/10/2017 | Grouting and ripeness | |
P10 | 25/10/2017–23/03/2018 | Chinese milk vetch | |
P11 | 24/03/2018–23/04/2018 | Early Rice | Rice seedling transplant and resume growth |
P12 | 24/04/2018–23/05/2018 | Resume growth before jointing | |
P13 | 24/05/2018–23/06/2018 | Jointing, booting, heading, and blooming | |
P14 | 24/06/2018–14/07/2018 | Grouting and ripeness | |
P15 | 15/07/2018–23/08/2018 | Late Rice | Rice seedling transplant and resume growth |
P16 | 24/08/2018–24/09/2018 | Jointing, booting, heading, and blooming | |
P17 | 25/09/2018–24/10/2018 | Grouting and ripeness | |
P18 | 25/10/2018–31/10/2018 | Chinese milk vetch |
Parameters | Definition | Ranges |
---|---|---|
Vm25 | The notional maximum catalytic capacity of Rubisco per unit leaf area at 25 °C | 10–120 µmol m−2 s−1 |
β | The initial slope of the response curve of assimilation rate of leaves to light (quantum efficiency) | 0.01–0.15 µmol CO2 (µmol PAR) −1 |
η | The initial slope of the response curve of assimilation rate of leaves to CO2 (carboxylation efficiency) | 0.01–0.15 µmol m−2 s−1 (µmol m−2 s−1)−1 |
Dmin | The threshold below which there is no vapor pressure constraint | 0.5–1.5 kPa |
Dmax | The threshold above which there is no assimilation | 3.5–6.5 kPa |
D0 | Water vapor pressure deficit of the air | 0.5–2.0 kPa |
KQ | Extinction coefficient of PAR | 0.1–1 |
KA | Extinction coefficient of available energy | 0.7–0.9 |
Sl | Specific canopy rainfall storage capacity per unit leaf area | 0.01–0.17 |
F0 | The specific ratio of average evaporation rate over average rainfall intensity during storms per unit of canopy cover | 0.01–0.16 |
αs * | Soil evaporation coefficient | 0.8–1.5 |
m | Stomatal conductance coefficient | 2.0–40.0 |
Early Rice | Late Rice | |||||
---|---|---|---|---|---|---|
GPP (gCm−2day−1) | ET (mm/day) | H (mm/day) | GPP (gCm−2day−1) | ET (mm/day) | H (mm/day) | |
2017 | 4.78 | 3.40 | 0.40 | 8.70 | 4.67 | 0.11 |
2018 | 6.02 | 4.06 | 0.42 | 7.91 | 4.96 | 0.06 |
2017 | 2018 | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Early Rice | Late Rice | Early Rice | Late Rice | |||||||||||
Periods | P3 | P4 | P5 | P6 | P7 | P8 | P9 | P11 | P12 | P13 | P14 | P15 | P16 | P17 |
D0 | 0.84 | 0.98 | 0.51 | 0.71 | 0.31 | 1.00 | 0.99 | 0.21 | 0.92 | 0.80 | 0.97 | 1.00 | 0.82 | 0.20 |
kq | 0.72 | 0.98 | 0.83 | 1.00 | 0.76 | 0.68 | 0.44 | 0.99 | 0.12 | 0.94 | 0.90 | 0.15 | 0.88 | 0.12 |
ka | 0.90 | 0.90 | 0.74 | 0.78 | 0.76 | 0.88 | 0.90 | 0.89 | 0.72 | 0.74 | 0.77 | 0.70 | 0.71 | 0.70 |
Sl | 0.01 | 0.02 | 0.03 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.11 | 0.02 | 0.01 | 0.01 | 0.01 | 0.16 |
F0 | 0.05 | 0.02 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.03 |
β | 0.03 | 0.03 | 0.09 | 0.09 | 0.04 | 0.06 | 0.03 | 0.05 | 0.01 | 0.08 | 0.06 | 0.09 | 0.05 | 0.03 |
η | 0.01 | 0.05 | 0.14 | 0.10 | 0.02 | 0.02 | 0.09 | 0.05 | 0.13 | 0.15 | 0.07 | 0.01 | 0.15 | 0.04 |
m | 37.8 | 17.4 | 9.8 | 13.6 | 35.8 | 17.0 | 23.8 | 38.9 | 22.0 | 9.5 | 23.6 | 23.9 | 16.8 | 36.4 |
Vm25 | 36 | 23 | 108 | 81 | 115 | 56 | 23 | 30 | 90 | 119 | 115 | 83 | 26 | 41 |
Dmin | 0.69 | 1.50 | 0.71 | 1.02 | 1.46 | 1.39 | 1.36 | 0.84 | 1.39 | 1.09 | 0.78 | 1.50 | 1.40 | 0.67 |
Dmax | 3.56 | 3.67 | 3.50 | 3.52 | 4.31 | 3.66 | 6.13 | 5.93 | 6.01 | 5.55 | 6.33 | 6.08 | 5.72 | 5.61 |
αs | 0.98 | 1.34 | 1.28 | 1.27 | 1.13 | 1.50 | 0.81 | 1.06 | 0.97 | 1.22 | 0.99 | 0.80 | 1.34 | 1.50 |
Regression Equation | R2 | RMSE | ||
---|---|---|---|---|
Early rice | GPP | 14.14NDVI + 0.08 | 0.93 | 0.41 |
ET | 1.424NDVI + 0.016Rs↓ + 0.16Ta − 47.0 | 0.90 | 0.12 | |
T/ET | 1.068NDVI + 0.006u + 0.134 | 0.98 | 0.02 | |
WUE | 2.822NDVI + 0.165 | 0.82 | 0.14 | |
Late rice | GPP | 14.11NDVI − 0.005Ta | 0.94 | 0.43 |
ET | 2.177NDVI + 0.026 Rs↓ + 0.438u − 2.1 | 0.91 | 0.11 | |
T/ET | 0.933NDVI + 0.0006Ta + 0.03 | 0.97 | 0.02 | |
WUE | 2.418NDVI − 0.0003Ta | 0.87 | 0.11 |
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Gan, G.; Zhao, X.; Fan, X.; Xie, H.; Jin, W.; Zhou, H.; Cui, Y.; Liu, Y. Estimating the Gross Primary Production and Evapotranspiration of Rice Paddy Fields in the Sub-Tropical Region of China Using a Remotely-Sensed Based Water-Carbon Coupled Model. Remote Sens. 2021, 13, 3470. https://doi.org/10.3390/rs13173470
Gan G, Zhao X, Fan X, Xie H, Jin W, Zhou H, Cui Y, Liu Y. Estimating the Gross Primary Production and Evapotranspiration of Rice Paddy Fields in the Sub-Tropical Region of China Using a Remotely-Sensed Based Water-Carbon Coupled Model. Remote Sensing. 2021; 13(17):3470. https://doi.org/10.3390/rs13173470
Chicago/Turabian StyleGan, Guojing, Xiaosong Zhao, Xingwang Fan, Henwang Xie, Weirong Jin, Han Zhou, Yifan Cui, and Yuanbo Liu. 2021. "Estimating the Gross Primary Production and Evapotranspiration of Rice Paddy Fields in the Sub-Tropical Region of China Using a Remotely-Sensed Based Water-Carbon Coupled Model" Remote Sensing 13, no. 17: 3470. https://doi.org/10.3390/rs13173470