水稻高温热害风险评估方法研究

以衡阳地区的水稻生长为研究对象,对ORYZA2000水稻模型的相应参数进行了本地化,模拟了该地区常年气候条件、设定高温条件及各年高温条件下的一季稻产量,并计算了各年实况及设定条件下的产量灾损率,在此基础上建立了两种水稻产量灾损率评估模型。研究发现：46 a来衡阳地区水稻开花灌浆期平均日最高气温为34.98℃,高于水稻生产的最适温度5℃以上;相对常年产量,由高温热害导致的产量灾损率最高为67.2%,历年灾损中2003年的灾损率接近最高值,达67.0%;高温造成的产量灾损率受高温程度及持续时间的共同影响,二者缺一不可;根据多元回归建立的灾损率评估模型,F计算值〉〉F查表值,方程有意义。其趋势预测完全一致,灾损率精确度〉72%;根据高温指标建立的灾损率评估模型通过了46 a的大样本检验,在高温热害风险评估方面具有一定的实际应用价值。

Assessment Method Study on High Temperature Damage to Rice

Hengyang rice-growing region as object of the study, we locakized ORYZA 2000 corre- sponding model parameters, simulated the long-term climatic conditions, the assumptive temperature and actual calendar year conditions rice yield; and calculated yield disaster loss in the assumptive and actual calendar year conditions. On the basis of those, we established two types of rice yield disaster loss assessment model. The results show Hengyang district average daily maximum temperature is 34.98 ℃ , which is higher 5 ℃ than the optimal temperature for rice production within the 46a. Compared with the year - round, the yield disaster loss rate is 67.2% , and the 2003 disaster loss rate 67.0% is close to the maximum value. The yield loss rate is affected by high temperature grade and duration. The disaster loss as- sessment model which established according to the multiple regression is meaningful when F计算值 〉〉 F查表值. The trend forecast results were consistent, and its accuracy is more than 72%. The disaster loss assessment model which established according to the high temperature index is adopted by large sample test, and has a certain practical application value.