汾河上游水文干旱与气象干旱的关系

Relationship between Hydrologic Drought and Meteorological Drought in the Upstream of Fenhe River

为分析汾河上游水文干旱与气象干旱的关系,基于汾河上游4个气象站1956~2000年月降水量、月平均气温资料建立流域标准化降水指数(SPI)和标准化降水蒸散指数(SPEI),并根据4个水文站同期月径流资料建立各水文站标准化径流指数(SRI);对1、3、6、12个月4个时间尺度的指数进行趋势分析,然后分析各水文站4个时间尺度的SRI与流域SPI、SPEI的相关性,最后采用时移互相关分析、回归分析研究水文干旱对气象干旱的滞后性。结果表明,汾河上游呈干旱化趋势;各站水文干旱与气象干旱间的相关系数随时间尺度的增加而增加,都通过了显著性检验;相同时间尺度下,4个水文站水文干旱与气象干旱相关程度差异较弱;SRI与SPEI的相关程度较SRI与SPI更为紧密;12个月时间尺度下,汾河水库、寨上、兰村SRI表征的水文干旱滞后于以SPEI表征的气象干旱约1个月。

To explore relationship between hydrological drought and meteorological drought in the upstream of Fenhe River, Standardized Precipitation Index and Standardized Precipitation Evapotranspiration Index were established on the basis of monthly precipitation, monthly average temperature data of four meteorological stations during 1956-2000 in the upstream of Fenhe River. Standardized Runoff Index was built according to the monthly runoff data of four hydrological stations in the same period. The trend analysis of the above indexes for four time scales （1, 3, 6 and 12 months） was carried out. Then the four time scales S RI of four hydrological stations were respectively tried on correlation analysis with S PI and S PEI of the basin. Finally, time shift cross correlation analysis and regression analysis were used to study the hysteresis relationship between hydrological drought and meteorological drought. The results show that there is a drought trend in the upstream of Fenhe River, the correlation coefficients between hydrological drought and meteorological drought increase with the raise of time scale, and the significance test has been passed; For the same time scale, the eorrelation coefficients between hydrological drought and meteorological drought at four hydrological stations have a slight difference, the correlation degree between S RI and S PEI is more higher than that of S RI and S PI; In the 12 month scale, the hydrologic drought characterized by S RI at Fenhe Reservoir station, Zhaishang station and Lancun station lags behind the meteorological drought represented by S PEI about 1 month.