Y干旱指数在冀东春旱监测中的应用

利用唐山地区3个国家基准站1971—2000年的春季逐日降水、日最高气温资料，从干旱实时监测气象服务的需要出发，考虑了近期降水、土壤底墒（前期降水）和气温三种要素，计算Y干旱指数，并制定了干旱等级标准。对Y干旱指数与土壤湿度干旱指数、降水百分率干旱指数进行了同期对比分析；利用没有参加干旱指标划分的2006、2007年春季的土壤湿度资料对制定的干旱指标进行检验。结果表明，Y干旱指数对冀东春旱具有很好的监测能力，Y干旱指数能够客观的反映唐山地区春季各月的干旱状况，并填补了土壤湿度监测的盲区，能较好的划分唐山地区春季干旱趋势和等级；在一段时间内降水时空分布均匀的情况下，用降水距平百分率干旱指数进行监测，效果较好。在2006—2007年的检验中，Y干旱指数与土壤干旱指数表现一致，在没有土壤测墒的地区和时段，利用Y干旱指数可代替土壤湿度监测，实现干旱无缝隙监测。

Application of Y Drought Index in Spring Drought Monitoring in East Hebei Province

Based on the data of the daily precipitation and daily maximum air temperature in 1971 -2000 in three national benchmark stations in Tangshan, the Y drought index was calculated in consideration of three factors, including precipitation in recent period, the soil moisture preceding rainfall and air temperature. The drought severity degree was determined. The Y drought index was compared with the soil humidity drought index and precipitation anomaly percent at the same time. The verifications of Y drought index had done with the soil humidity data in the spring of 2006 and 2007. The results showed that the Y drought index was consistent with the soil drought index. The Y drought index could be used in the drought monitoring to replace the soil drought index.