【摘要】 近30多年来,由于农田灌溉条件的迅速改善,得到的土壤墒情资料已不能反映自然状态下的土壤墒情变化规律。利用土壤水分平衡方程和Penman公式等计算各旬土壤水分相对盈亏程度并对照2001~2003年在不浇水条件下得到的各旬土壤墒情资料,建立拟和方程,确定了干旱指标,恢复了1970~2003年的逐旬实际干旱序列。结果表明,模拟的逐旬干旱序列较好地滤出了灌溉因素,与实际自然土壤自然干旱程度接近。更多还原

【Abstract】 Owing to the improvement of farmland irrigation in the recent 30 years,the present soil moisture data cannot reflect the variation regularity of natural soil moisture.The variation(gain and loss) of soil moisture is calculated on a ten-day base by using the soil moisture balance equation and the Penman formula.Compared to the soil moisture data without irrigation from 2001 to 2003,the fitting equation and drought index are established and the drought series from 1970 to 2001 on a ten-day base is reconstructed.The results show that the effect of irrigation is well filtrated out in the calculated drought series,which is very close to the natural soil moisture.更多还原