Abstract: In order to improve the accuracy and timeliness of the agricultural drought monitoring,the crop coefficient and stress coefficient were introduced to calculate the soil moisture according to the theory of Palmer drought severity index and the characteristics of agricultural drought.The duration of agricultural drought was simultaneously revised to shorten the time steps of drought monitoring.Based on the daily meteorological data of 23 stations in Shangdong Province from 1961 to 2007,the palmer drought index for each ten days was built to monitor the agricultural drought.In comparison with the actual situations of agricultural drought,the revised palmer drought index could accurately reflect the variability of the soil moisture.The sensitivity of the short-term dry-wet variation was improved.The whole course of drought variation was basically accordant with the practical situation.

Key words: Palmer drought index, Palmer drought index, Revision, Soil moisture, Agriculture drought monitoring