辽西八县由于大气环流、年际降水变率大、土层浅薄、土壤有机质少、生态平衡遭受破坏等原因,经常发生干旱灾害。在干旱威胁下,粮豆产量年际间变异系数很大。其中凌源、建昌、喀左三县产量较高而不稳,建平、阜新、彰武三县产量偏低而较稳,而朝阳、北票二县产量既不高又不稳。经统计分析,发现降水量,蒸发量(力)对粮豆产量都有影响,其中蒸发的影响大于降水。对多数县份的作物,蒸发量(力)的作用要大3—5倍。在各月蒸发量(力)中,初步看来,五月份对禾谷类作物影响最大,七月份对大豆影响最大。 Due to the general circulation of the atmosphere, large annual variability of precipitation, shallow soil layers, little organic matter in the soil and destruction of the ecological balance, the eight counties in western Liaoning Province often suffer from drought disasters. Under the threat of drought, the annual variation coefficient of grain yield is very large. Among them, the output of Lingyuan, Jianchang and Kaizuo three counties was high and unstable. The output of Jianping, Fuxin and Zhangwu counties was low and stable, while that of Chaoyang and Beipiao counties was neither high nor unstable. After statistical analysis, it is found that precipitation and evaporation (force) have an impact on grain yield, of which evaporation is greater than precipitation. For most county crops, the effect of evaporation (force) is 3-5 times greater. In each month of evaporation (force), initially it appears that May has the greatest impact on cereal crops, July has the greatest impact on soybean.