Research and Application of Meteorological Drought Monitoring Indexes in Northwest China
To monitor drought in Northwest China more effectively, the drought monitoring index for east and west part of NW China was established respectively based on t he principles of Z index and Palmer index. The monthly precipitation data in 138 representative stations of NW China(1961～2000) were used as basic data. A regi onal drought monitoring index was further developed, and the grades for regional drought were also determined. Comparing the computed drought index with some re corded drought situation, it is found that these indexes can reflect the severit y of meteorological drought in NW China. Furthermore, the drought characteristic s were analyzed by using some statistical methods. The result shows that the dro ught in the east part was more severe than in the west in recent decades. In a l ong term, the drought frequency shows an increasing trend in the east part while a decreasing trend in the west. The meteorological drought in the east part fr om March to June has a period of 5 to 10 years, while the periodicity isn't evid ent in the west. These indexes have an obvious meteorology meaning and can be ap plied simply in the drought monitoring practices of NW China.