Impacts of Climate Change on the Hydrological Cycle in the Luan River Basin
Climate change impacts on temporal and spatial patterns of water resources in China' s various regions, especially on water resources engineering and planning, is of importance to climate change impact assessment in China.Uncertainties in climate models, which are major promising tools for the assessment of climate change impact, could introduce uncertainties to runoff simulation and subsequently hydrological response prediction.Many studies have shown that the average result of multiple climate models seems to be better than that from a single model.Therefore, the average simulations from multiple climate models were applied in this study to the Luanhe River basin.The linear regression and Mann-Kendall non-parametric test methods were used to unravel the change characteristics of hydrological and meteorological variables.Results indicate an increasing trend in precipitation, evaporation, as well as temperature, while the runoff decreased in the past years.A distributed hydrological model, Soil and Water Assessment Tool (SWAT), was applied by accounting for digital elevation models, land use and soil types, and other data sources specific to the study river basin.Results suggest efficiency coefficients of 77.2％ and 83.1％ for the calibration period (1961-1990) and validation period (1991-2000), respectively.This indicates that the SWAT model could be applicable to the Luanhe River basin.Then,meteorological data sets based on IPCC AR4 multi-mode climate models under different green house gases (GHG) emission scenarios (SRES-A2, A1B, and B1) in the 21st century were used to drive the SWAT model to simulate the hydrological processes in the future time periods.Finally,annual response processes of precipitation, temperature, runoff, and evaporation during the period 2011-2099 were analyzed with reference to the period 1961-1990.Results show an increasing trend of all hydrological elements under three scenarios during the period 2011-2099.In particular, the precipitation, temperature, and evaporation would increase compared with the baseline period.By the end of the 21 st century, average changes in precipitation, temperature, and evaporation under the three scenarios would be 16.9％, 3.67 oC, and 14.6％, respectively.During the period of the 2020s (2011-2040), the runoff would reduce by 27.69％, 29.88％, and 11.04％ under three scenarios, respectively.During the period of the 2050s (2041-2070), the runoff would still remain less than that in the reference period under scenarios A2 and B1, whereas it would increase by about 3.05％ under scenario A1B.For the period of the 2080s (2071-2099), the runoff would increase by 7.01％, 12.64％, and 4.27％ under scenarios A2, A1B, and B1, respectively, compared with the baseline period.Furthermore, the precipitation and evaporation under scenario A 1B would increase more than that in the other two scenarios.The runoff would increase most in the late 21 st century under scenario A1B.The results would be greatly helpful for providing a basis for water diversion management for the Middle Route of the South-to-North Water Transfer Project and sustainable development of economy and society in North China.
NETL
NSTL
万方数据
维普
