Prediction and Trend of Future Potential Evapotranspiration in the Heihe River Basin Based on CMIP5 Models
Evapotranspiration is the main dissipation of water resources in arid inland river basin.Future potential evapotranspiration (ET0) prediction can provide basic data for water resources optimization and management under climate change in the Heihe River Basin (HRB).Three processes could be classified in this study.Firstly, ET0 was calculated by FAO-56 Penman-Monteith equation based on metrological data from 1960 to 2014 in HRB.Secondly, future ET0 was predicted by statistical downscaling and deviation regulation based on NCEP reanalysis data from 1960 to 2014, and CMIP5 CNRM-CM5 model from2006 to 2100 under RCP4.5 and RCP8.5 pathways.Finally, three subareas were divided by rotated empirical orthogonal function (REOF) and future trends were analyzed by Mann-Kendall tests for the three subareas and whole HRB.The conclusions showed that: (1) The stepwise regression statistical downscaling models built by NCEP reanalysis data and calculated ET0 from 1960 to 2014 were suitable for predicting future ET0 of HRB by CNRM-CM5 model simulation and deviation regulation. (2) Annual average ET0 of 2021-2050, 2071-2100 would increase 3.49％, 6.11％than that of 1971-2000 separately under RCP4.5 pathway, while the percentage were4.64％, 10.07％ under RCP8.5 pathway.The increasing amplitude of RCP8.5 was greater than that of RCP4.5. (3) Three subareas of future ET0 were divided by REOF under both pathways.Insignificantly decreasing trend was detected for area I under RCP4.5 pathway, while the trend under RCP8.5 pathway was significant.Significantly increasing trends were detected for area II, III and whole HRB under both pathways.
NETL
NSTL
万方数据
维普
