Author(s): Siyu CAI, Weihong Liao, Yinmao Zhao, Jing Wu
Linked Author(s): Siyu CAI
Keywords: Climate change; Extreme precipitation; Ya-lung River Basin; Trend analysis; CREST model;
Abstract: Using the 10 models of NEX-GDDP CMIP5 to perform equal weighted averaging in the RCP4.5 and RCP8.5 scenarios to obtain daily precipitation data under the multi-model set, and based on this, the spatial characteristics of extreme precipitation events in the Ya-lung River Basin from 2020 to 2099 were carried out. After using the Hargreaves-Samani (HS) method to obtain future evaporation data in the future, the CREST model is driven to simulate the future daily runoff of the Ya-lung River Basin, and the precipitation and runoff changes are analyzed from the interdecadal and seasonal. Finally, the multivariate trend analysis of precipitation and runoff is carried out to provide favorable help for the planning, development and utilization of water resources in the Ya-lung River Basin. The results show that: 1. The annual total wet-day precipitation, the number of heavy precipitation days, the simple daily intensity index and the max 5-day precipitation amount in the two scenarios show a significant increase trend, while the consecutive dry days show opposite changes in the two scenarios. Spatially, the indicators vary. 2. CREST model has good applicability in Ya-lung River Basin. The Nash efficiency coefficient (0.83,0.84), deterministic coefficient (0.84,0.85) and relative error (-2.05% and 3.01%) in the calibration and verification period all meet the accuracy requirements. 3. In both scenarios, the increase in precipitation is mainly concentrated in winter, while the increase in runoff is mainly concentrated in summer and autumn. 4. Under the multivariate trend analysis, the future precipitation and runoff in the Ya-lung River Basin show an decreasing trend under both scenarios.