土壤相对湿度对冬小麦干热风灾害发生的影响

The Influence of Soil Relative Moisture on Dry-hot Wind Disaster of Winter Wheat

  • 摘要: 以华北黄淮地区高温低湿型冬小麦干热风灾害为研究对象,基于逐日逐时气象资料、分层土壤水分资料、灾情资料等,采用历史灾情反演、独立t检验等方法,将灾情记录中无明确记载和有明确记载土壤相对湿度影响干热风灾害的样本分为A类和B类,基于两类样本相互独立,厘定各土层对干热风灾害有影响的土壤相对湿度阈值,利用随机预留样本验证阈值的合理性。结果表明:分层和整层土壤相对湿度阈值均随土层深度增加而增大,其中整层阈值平均值近似60%;独立样本检验符合率在80%左右。为便于业务应用,选取10~20 cm土层相对湿度60%为土壤相对湿度对冬小麦干热风灾害影响的临界阈值。当土壤相对湿度大于等于60%时,土壤相对湿度对冬小麦干热风灾害影响显著;当土壤相对湿度小于60%时,土壤相对湿度对冬小麦干热风灾害影响较小,独立样本检验符合率达82.5%。该文为量化评估土壤相对湿度对冬小麦干热风灾害的影响提供了科学依据。

     

    Abstract: Based on daily and hourly meteorological data, layered soil moisture data and disaster data, the dry-hot wind disasters of winter wheat accompanying high temperature and low humidity are studied in North China and Huanghuai Region through historical disaster inversion, normal distribution test, soil moisture treatment and independent t-test. These disaster samples are classified:Class A samples are not affected by the relative humidity of soil, while Class B samples are affected by the relative humidity of soil. Thresholds of soil relative humidity on dry-hot wind disaster of wheat are determined according to independence of samples in two groups, and verified by random samples. Relative humidity values of the whole and layered soil layers subject to normal distribution. The relative humidity of Sample A and Sample B in each soil layer is independent. Thresholds of relative humidity affecting dry-hot wind disaster are 58%-65% for the whole soil layer and 56%-75% for layered soil. The mean value of the whole layer is approximately 60% and increases with the depth of the soil layer. The coincidence rate of relative humidity threshold of each soil layer is between 72.5% and 85%with average value about 80%, which could reasonably reflect the influence of soil relative humidity on dry-hot wind disaster of wheat. For convenience in application, 60% of the soil relative humidity in depth of 10-20 cm layer is selected as the critical threshold to determine the influence of soil relative humidity on the dry-hot wind disaster of northern winter wheat, being significant when it is greater than or equal to 60% and ignoral when less than 60%. The conformance rate of independent samples is 82.5%. Results provide a scientific basis for quantifying effects of soil relative humidity on the dry-hot wind disaster of winter wheat.

     

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