Research of the regional meteorological drought assessment analysis model

In order to cope with the increasingly serious global drought issue, this treatise investigates the relatively complete evaluation and analysis model on the regional meteorological drought. It proposes a three-step evaluation and analysis method, which includes the regional meteorological drought identification, the drought characteristic value calculation and the multivariable analysis on drought characteristics. Taking Weihe River basin as a case study example, the treatise first carries out a rectangular drought evaluation-unit division on the research area, selecting reconnaissance drought index as an evaluation indicator to identify drought conditions in each unit at different time periods in the research area. The result is almost in accordance with the historical record on the years of drought. Then the treatise uses statistical methods such as the distribution fitting, the correlation coefficient, the copulas function to carry out characteristic analysis on the regional drought characteristic values (the drought duration, the drought area, the drought severity and the drought frequency), drawing a series of analytic and comparative results on the univariate, the bivariate and the multivariate characteristics. Based on the distribution function calculation and construction on different distribution functions, the treatise comes to the occurrence conditional probability and recurrence interval of droughts in Weihe Basin, forming a relatively complete evaluation and analysis model on the regional meteorological drought.