气候波动对海伦市粮食产量影响的风险分析

粮食生产具有不确定性特征,气候波动是影响粮食产量年际变化的主要因素之一。本研究采用风险分析方法,基于海伦市22个乡镇1978～2007年大豆和玉米产量的统计资料,以相对气象产量作为农作物受气候波动影响程度的指标,采用非参数信息扩散方法中正态扩散模型,对各乡镇大豆和玉米产量不同减产程度出现的概率进行了计算,进而获得各乡镇大豆、玉米单产受气候波动影响的风险度。在此基础上,基于海伦市气象站逐日降雨量和气温资料,按照气候干燥度将所有年份分为偏干旱年份、正常年份和偏湿润年份,分别计算不同水热耦合年份下各乡镇粮食产量受气候波动影响的风险程度。结果表明,大豆和玉米极端减产年出现的概率高于极端高产年;北部大豆减产风险小于南部,玉米在总体上呈现出和大豆减产概率空间分布相反的趋势;在不同水热耦合年份中,海伦市旱田农作物生产风险具有空间差异性,其中大豆生产风险空间分布与河网相关性较玉米高。

Risk analysis of climate variability on food production in Hailun, Northeast China

Climate variability is one of the main factors affecting annual changes in crop yield. In this study, a risk analysis method was used to describe the relationship between climate change and crop yield. The results could provide the basis for reducing the risk of food production. Based on available data on yield of soybean and corn in 22 towns of Hailun City for 1978~2007, relative meteorological yield was used as an indicator for the influence degree of climate change on crop yield. Yield reduction probabilities for different crops in each township were calculated using information diffusion method. Furthermore, the risk of crop production affected by climate variability was identified. Using daily rainfall and temperature as aridity index, all years were divided into partially dry, normal and partially wet years. The degree of risk was estimated under different hydrothermal years for each township. Results show that the probability of extremely high-yield years is lower than that of extremely low-yield years. The risk level of production reduction of soybean in north area is lower than that in south area, while the corn shows the contrary spatial tendency. There are spatial differences in risk levels of crop production among the different hydrothermal years. And spatial distribution of soybean production is more relative with rive network than that of corn production.