ALMANAC作物模型参数的敏感性分析

Sensitivity Analysis on Parameters of ALMANAC Crop Model

为了方便模型数据库的组建,降低模拟结果的不确定性,本文根据山东禹城综合试验站2000-2003年的田间试验资料,进行AL-MANAC模型模拟冬小麦和夏玉米的验证。在此基础上采用OTA（即每次只改变其中1个参数）方法,对模型的土壤参数和作物参数进行敏感性分析。验证结果表明,ALMANAC模型能够较好地模拟冬小麦和夏玉米的产量和叶面积指数的动态变化,冬小麦和夏玉米模拟产量的相对误差（RE）为-8.6%~6.0%、-3.5%~7.2%,叶面积指数的RE为-13.1%~14.8%、-13.0%~12.2%;敏感性分析显示,土壤参数中的径流曲线数、土壤容重、田间持水量和土层厚度对模拟结果影响显著,其次为初始含水量和凋萎湿度,再次为粉粒含量、砂粒含量和土壤反射率;作物参数中的收获指数、光能利用率、热量单元指数、叶面积增长期占生长期的比例,对模拟结果影响显著,其次为作物生长最适温度、消光系数、作物生长下限温度、最大根深、最大叶面积指数、群体动态参数,再次为光能利用降低参数、叶面积指数动态曲线参数、叶面积指数衰减速率。

The data of field experiments for winter wheat（ Triticum aestivum L. ）and summer maize （Zea mays L. ） from 2000 to 2003 in Yucheng County of Shandong Province were used to validate the simulation of the model ALMANAC and calibrate the crop parameters, in order to build model database conveniently and reduce the uncertainty of the model simulation. The One-at-a Time method （OTA） was adopted to analyze sensitivities of the soil and crop parameters. The validation results showed that the model ALMANAC could preferably simulate the dynamic changes of the yields and leaf area indexes of wheat and maize. The relative error of simulated yields for wheat and maize was - 8.6% - 6. 0% and - 3.5% - 7. 2% respectively, while the relative error of simulated leaf area indexes for wheat and maize was - 13.1% - 14.8% and - 13.0% - 12.2% respectively. The results of the sensitivity analysis showed that the runoff curve number, bulk density, field capacity and soil thickness among all of soil parameters had the most significant influence on the simulation results, while the initial soil water content and wilting point were in the next place, and the silt content, sand content and soil albedo were in the third place. The harvest index,biomass-energy ratio, potential heat unit, fraction of leaf area increment season to growing season among crop parameters had the most significant influence on the simulation results, while the optimal temperature, extinction coefficient, ambient temperature, maximum root depth, maximum LAI, plant population parameter were in the next place, and the decline rate of the biomass-energy ratio, leaf area development curve, decline rate of the leaf area index were in the third place.