| Based on analysis of the meteorological data at 137 meteorological stations in Northwest China from 1961 to 2003, the corrected Palmer drought severity index (PDSI) and Z index were calculated and analyzed.The results showed that the Z index was more condign than PDSI in monsoon, while the PDSI is more objective and hypersensitive in comparison with Z index in dryness monitoring in the Northwest.The PDSI is more hypersensitive in light dryness monitoring in the Northwest, but the Z index is more hypersensitive in grievous dryness.The PDSI and the Z index were uniform in medium dryness. |