Abstract
Reliable regional-scale representation of crop growth and yields has been increasingly important in earth system modeling for the simulation of atmosphere-vegetation-soil interactions in managed ecosystems. While the parameter values in many crop models are location specific or cultivar specific, the validity of such values for regional simulation is in question. We present the scale dependency of likely parameter values that are related to the responses of growth rate and yield to temperature, using the paddy rice model applied to Japan as an example. For all regions, values of the two parameters that determine the degree of yield response to low temperature (the base temperature for calculating cooling degree days and the curvature factor of spikelet sterility caused by low temperature) appeared to change relative to the grid interval. Two additional parameters (the air temperature at which the developmental rate is half of the maximum rate at the optimum temperature and the value of developmental index at which point the crop becomes sensitive to the photoperiod) showed scale dependency in a limited region, whereas the remaining three parameters that determine the phenological characteristics of a rice cultivar and the technological level show no clear scale dependency. These results indicate the importance of using appropriate parameter values for the spatial scale at which a crop model operates. We recommend avoiding the use of location-specific or cultivar-specific parameter values for regional crop simulation, unless a rationale is presented suggesting these values are insensitive to spatial scale. Key Points The dependency of parameters of a crop model to spatial scales is examined Parameters representing the yield response to temperature showed the dependency Results indicate the importance of appropriate parameters for regional scale
| Original language | English |
|---|---|
| Pages (from-to) | 527-540 |
| Number of pages | 14 |
| Journal | Journal of Advances in Modeling Earth Systems |
| Volume | 6 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2015 Aug 21 |
| Externally published | Yes |
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Keywords
- large-area crop modeling
- model calibration
- regional crop simulation
ASJC Scopus subject areas
- Global and Planetary Change
- Environmental Chemistry
- Earth and Planetary Sciences(all)
Cite this
Dependency of parameter values of a crop model on the spatial scale of simulation. / Iizumi, Toshichika; Tanaka, Yukiko; Sakurai, Gen; Ishigooka, Yasushi; Yokosawa, Masayuki.
In: Journal of Advances in Modeling Earth Systems, Vol. 6, No. 3, 21.08.2015, p. 527-540.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dependency of parameter values of a crop model on the spatial scale of simulation
AU - Iizumi, Toshichika
AU - Tanaka, Yukiko
AU - Sakurai, Gen
AU - Ishigooka, Yasushi
AU - Yokosawa, Masayuki
PY - 2015/8/21
Y1 - 2015/8/21
N2 - Reliable regional-scale representation of crop growth and yields has been increasingly important in earth system modeling for the simulation of atmosphere-vegetation-soil interactions in managed ecosystems. While the parameter values in many crop models are location specific or cultivar specific, the validity of such values for regional simulation is in question. We present the scale dependency of likely parameter values that are related to the responses of growth rate and yield to temperature, using the paddy rice model applied to Japan as an example. For all regions, values of the two parameters that determine the degree of yield response to low temperature (the base temperature for calculating cooling degree days and the curvature factor of spikelet sterility caused by low temperature) appeared to change relative to the grid interval. Two additional parameters (the air temperature at which the developmental rate is half of the maximum rate at the optimum temperature and the value of developmental index at which point the crop becomes sensitive to the photoperiod) showed scale dependency in a limited region, whereas the remaining three parameters that determine the phenological characteristics of a rice cultivar and the technological level show no clear scale dependency. These results indicate the importance of using appropriate parameter values for the spatial scale at which a crop model operates. We recommend avoiding the use of location-specific or cultivar-specific parameter values for regional crop simulation, unless a rationale is presented suggesting these values are insensitive to spatial scale. Key Points The dependency of parameters of a crop model to spatial scales is examined Parameters representing the yield response to temperature showed the dependency Results indicate the importance of appropriate parameters for regional scale
AB - Reliable regional-scale representation of crop growth and yields has been increasingly important in earth system modeling for the simulation of atmosphere-vegetation-soil interactions in managed ecosystems. While the parameter values in many crop models are location specific or cultivar specific, the validity of such values for regional simulation is in question. We present the scale dependency of likely parameter values that are related to the responses of growth rate and yield to temperature, using the paddy rice model applied to Japan as an example. For all regions, values of the two parameters that determine the degree of yield response to low temperature (the base temperature for calculating cooling degree days and the curvature factor of spikelet sterility caused by low temperature) appeared to change relative to the grid interval. Two additional parameters (the air temperature at which the developmental rate is half of the maximum rate at the optimum temperature and the value of developmental index at which point the crop becomes sensitive to the photoperiod) showed scale dependency in a limited region, whereas the remaining three parameters that determine the phenological characteristics of a rice cultivar and the technological level show no clear scale dependency. These results indicate the importance of using appropriate parameter values for the spatial scale at which a crop model operates. We recommend avoiding the use of location-specific or cultivar-specific parameter values for regional crop simulation, unless a rationale is presented suggesting these values are insensitive to spatial scale. Key Points The dependency of parameters of a crop model to spatial scales is examined Parameters representing the yield response to temperature showed the dependency Results indicate the importance of appropriate parameters for regional scale
KW - large-area crop modeling
KW - model calibration
KW - regional crop simulation
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U2 - 10.1002/2014MS000311
DO - 10.1002/2014MS000311
M3 - Article
VL - 6
SP - 527
EP - 540
JO - Journal of Advances in Modeling Earth Systems
JF - Journal of Advances in Modeling Earth Systems
SN - 1942-2466
IS - 3
ER -