A Modified Palmer’s Drought Index

This paper expounded the principle and the advantage of the Palmer’s drought index and its procedure of computation of the index. Based on the analysis of the observational data from Jinan and Zhengzhou we modified the Palmer’s drought index to fit the observation data. With this modified index we have calculated the drought index for 140 stations in China from Jan. 1951 to Dec. 1980. It is found that the computed drought indices are consistent with the descritions on drought conditions in some official publications and with the actual observations on drought conditions by the authors, we have the opinion that the modified Palmer’s drought index is suitable for use in China