基于空间距离模型的综合干旱监测建模及在东北地区应用

Comprehensive drought monitoring model based on spatial distance model and its application in Northeast China

综合大气-土壤-植被等因素,采用空间距离模型(SDM),结合条件降水指数(PCI)、能量指数(MEI)和条件植被指数(VCI)构建综合干旱监测模型,PCI,MEI,VCI分别表征大气降水亏缺、土壤水分盈缺和植被生长状况,其指标为综合干旱指数(CDI),并利用粮食单产、作物受灾面积和标准化降水蒸散指数(SPEI)对CDI适用性进行验证.结果表明,CDI可反映农业、气象干旱信息,其与粮食单产相关系数绝对值均大于0.66(P<0.05),最高可达0.82(P<0.01);黑、吉、辽三省的CDI与作物受灾面积的相关系数分别为0.75,0.74和0.74,且通过了P<0.05的显著性检验;CDI与SPEI的相关系数绝对值为0.67~0.80(P<0.01).此外,基于CDI对东北地区2018年春夏连旱事件进行监测,结果与实际旱情切合,较好地反映了旱情的时空演变情况.

The comprehensive drought monitoring model was built by combining the factors of precipitation condition index(PCI),modified energy index(MEI)and vegetation condition index(VCI)with spatial distance model(SDM),which was based on comprehensive drought index(CDI).The PCI,MEI and VCI represent atmospheric precipitation deficit,soil moisture surplus and deficiency,and vegetation growth,respectively.The applicability of CDI was verified by using grain yield per unit area,crop disaster area and standardized precipitation evapotranspiration index(SPEI).The results show that the CDI can reflect agricultural and meteorological drought information.The absolute value of correlation coefficients between CDI and grain yield per unit area is all exceeding 0.66(P<0.05),and the highest is 0.82(P<0.01).The absolute value of correlation coefficients between CDI and crop di-saster area in Heilongjiang,Jilin and Liaoning provinces are 0.75,0.74 and 0.74,respectively,which passes the significance test(P<0.05).The correlation coefficients between CDI and SPEI are between 0.67 to 0.80(P<0.01).In addition,based on the CDI,the continuous drought events in spring and summer of 2018 in Northeast China are monitored,and the results are consistent with the actual drought situation,which better reflects the temporal and spatial evolution of the drought situation.