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| DOI：10.13522/j.cnki.ggps.2017.12.018 |
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| Application of the Copula Function in Frequency Analysis of Drought in Weihe River Basin |
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FENG Xing, SUN Dongyong, HU Weideng, GUO Jianqing
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Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang’an University, Xi’an 710054, China; College of Hydrology and Water Resource, Hohai University , Nanjing 210098, China
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| Abstract: |
| In order to reveal the change of drought, by constructing multivariate joint distribution for drought and analysis. There drought variables, i.e., drought duration, drought severity and drought peak, were selected from long sequence of (1950—2010) daily rainfall data for 22 meteorological stations in the Weihe river basin in China. Fitting degrees were evaluated to select Gumbel-Hougaard Copula、 Frank Copula and Clayton Copula and two-dimension joint distributions of drought variables were analyzed based on them include of drought duration, drought severity and drought peak in Weihe river basin. The Archimedean Copulas of two dimensions can describe the joint probability of drought and multi variables well, and the fitting effect is very good; the drought trend change significantly,the frequency is high of the drought lasted a long time in Weihe river basin, so local relevant units should strengthen drought forecast as well as management. |
| Key words: river basin; joint distribution; Copulas function; goodness of fit; return period |
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