Monitoring the meteorological drought in the middle reaches of Heihe River basin based on TRMM precipitation data

摘要

Tropical Rainfall Measurement Mission (TRMM) is an useful data for different application, whereas the data was less used in monitoring the meteorological drought in arid regions. In this study, we investigated the spatial-temporal process of a meteorological drought event (occurred at middle reach of Heihe River basin from May 2009 to September 2009) use TRMM 3B43 precipitation data product and observed precipitation anomaly. Some of the conclusions can be drawn from our study. Firstly, when the cumulative effects of pre-precipitation were taken into account, the meteorological drought monitoring results represented by the precipitation anomaly percentage index coincide with the actual situation. Secondly, the spring wheat in our study area experienced a constantly aggravating to gradually easing meteorological drought during May 2009 to September 2009. The drought approached severest at April 2009 and the core areas of drought were mainly distributed in the regions of Middle reach of Heihe River basin. At the end of April 2009, with the multiple effects of precipitation, the drought pressure in our study area greatly relieved. Thirdly, due to the better temporal and spatial continuity than the ground-based meteorological observation, TRMM precipitation data shown good application potential in drought monitoring at national or regional scale.