基于作物模型的河南省旱稻干旱风险评估

采用作物模型与数理统计相结合的方法,利用长期历史气象资料,以作物模型和地理信息系统技术为工具,系统分析了河南地区旱稻生育期水分盈亏情况。以模型模拟的雨养条件下实际蒸散量相对于潜在条件下的蒸散量(即需水量)的亏缺率,即水分亏缺指数,以雨养条件下产量相对于潜在产量的损失率(即灾损指数)作为产量灾损强度评价指标,从受旱程度和产量损失两个角度构建干旱风险评估模型,进行干旱风险评估。结果表明:河南省旱稻生育期集中在6—9月,水分亏缺最多的阶段为出苗—穗分化阶段,水分亏缺指数变化在0.50~0.60,其次是开花—成熟阶段和穗分化—开花阶段,水分亏缺指数变化在0.11~0.43;全生育期水分亏缺指数在0.36~0.50。出苗—穗分化阶段干旱发生的风险最大,其次是开花—成熟阶段,穗分化—开花阶段的最小。河南旱稻生育期干旱风险呈现为由东南向西北逐渐升高的分布,其中三门峡、济源西部一带风险最高,洛阳南部和南阳西北部一带最低,黄河以北大部地区和豫东、豫南地区风险居中。

Risk Assessment of Drought on Aerobic Rice in Henan Based on Crop Simulation Model

In this paper, combining the method of crop growth simulation and statistics, the drought risk for planting aerobic rice in Henan province was evaluated using the historical weather data. The crop water deficit index (CWDI) building by the potential evaptranspiration and actual rainfed evaptranspiration, and the yield loss index building by the potential yield and actual yield under rainfed condition were selected to construct the evaluating model for drought. Results showed that: the growing season of aerobic rice in Henan province concentrated in the duration from June to September. Water deficit was the most at the stage of emergence to panicle initiation, with the water deficit index ranged from 0.50 to 0.60, then the stage of panicle initiation to flowering and flowering to maturity, with water deficit index ranged from 0.11 to 0.43. For the whole growing season, water deficit index varied between 0.36 and 0.50. Therefore, drought risk was the highest at the stage of emergence to panicle initiation, followed by flowering to maturity and panicle initiation to flowering. The integrated drought risk for aerobic rice presented the gradually increasing trend from the southeast to the northwest. It was the highest in the areas of Sanmenxia and west of Jiyuan, and lowest in the areas of south of Luoyang and north west of Nanyang. Most areas in the north of Yellow River, east and south of Henan belonged to the mid value region.