白河流域年径流量对气候变化的响应研究

基于气象和水文观测资料，分析白河流域年径流量与气象要素的关系并建立拟合模型，利用CMIP5模式在不同典型浓度路径（RCPs）下的模拟结果，预估21世纪白河流域年径流量的变化特征。结果表明:1981~2012年白河流域年径流量呈先减少后增加的变化趋势，与气象站观测的年平均最高气温呈显著负相关，与降水量呈显著正相关。以红原、阿坝站的年平均最高气温和年降水量为自变量，唐克站年径流量为因变量，建立了多元线性回归方程，该方程通过了0.01水平的显著性检验，验证期同号率达100%，说明其稳定可靠。对21世纪白河流域年径流量的预估表明，RCP2.6情景下，其年径流量没有明显的变化趋势，可以维持在当前水平；RCP4.5情景下，年径流量呈减少趋势，气候倾向率为?0.28 × 108 m3/10 a， 21世纪中期和末期分别减少17%和19%；RCP8.5情景下，年径流量呈显著减少趋势，气候倾向率为?1.1 × 108 m3/10 a，21世纪前、中、末期分别减少20%、24%和49%。 

Response of Annual Runoff to Climate Change in Baihe River Basin

Based on the meteorological and hydrological observation data, the relationship between annual runoff and meteorological factors in Baihe River Basin is analyzed, and a fitting model is established. The variation characteristics of annual runoff in Baihe River Basin in the 21st century are estimated by using the prediction results of CMIP5 model under different representative concentration pathway (RCPs). The results show that the annual runoff of Baihe River Basin decreased first and then increased from 1981 to 2012, which was negatively correlated with the annual average maximum temperature observed by meteorological stations, and positively correlated with the annual precipitation. A multiple linear regression equation was established with the annual mean maximum temperature and annual precipitation of Hongyuan and Aba stations as independent variables and the annual runoff of Tangke station as dependent variables. The F value test passed the significance test (α = 0.01), and the percentage of the same phase reached 100% in the verification period, indicating that the regression equation was stable and reliable. The prediction of the annual runoff of Baihe River Basin in the 21st century shows that the annual runoff of Baihe River Basin had no obvious change trend under RCP2.6 and could be maintained at the current level. Under the RCP4.5, the annual runoff displayed a decreasing trend of 0.28 × 108m3/10a, which decreased by 17% and 19% in the middle and end of the 21st century, respectively. Under the RCP8.5, the annual runoff displayed a significant decreasing trend of 1.1 × 108m3/10a, and it decreased by 20%, 24% and 49% in the early, middle and late 21st century, respectively.