关键词: 改进的综合气象干旱指数CI new, 综合气象干旱指数CI, 动态监测

Abstract:  Aiming at the "unreasonable drought aggravate" problem of the comprehensive meteorological drought index CI, using linear decreasing precipitation and potential evapotranspiration accumulating methods, an improved comprehensive meteorological drought index, CI new, was put forward in the paper. Comparing with CI, applicability characteristics of CI new was analyzed from the aspects of describing ability of drought course, draught frequency features and hysteresis effect. The results showed that: (1) CI new decreased steadily during no precipitation period, therefore, CI new effectively avoided the "unreasonable drought aggravate" problem of CI, and was able to describe occurrence, development and end of drought process with rich details. (2) There was no statistical significant difference between drought frequency derived from CI new and that from CI, however, since statistical period of new relative moisture index MI 90new extended to 90 days, CI new was enabled to show hysteresis of drought season beginning month (November) to less rain season beginning month (October). The paper provides a reference when CI new is popularized to other places of China.
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Key words: Improved comprehensive meteorological drought index CI new, CI, Dynamic monitoring