GCMs降尺度及其在讨赖河上游径流预报中的应用

在气候变化和人类活动影响下,内陆河流域出山径流变异程度提升,研究径流预测及其对气候变化响应具有理论和实践的双重意义。以讨赖河流域上游为研究区,采用Delta降尺度及权重集成方法对14种GCMs在3种RCP情景下的气温和降水进行优化,预测分析了该区未来径流变化和水资源供需平衡。结果表明:由气候-生态联合驱动的径流预测模式在讨赖河流域适用性良好,气温对出山径流总体呈负减效应,降水和NDVI表现为正增效应。未来气温和降水呈增加趋势,增温主要发生在河谷地带,降水增加在分水岭周边更为显著。流域出山径流总体增加,不同子区径流变幅从小到大依次为OL06＜OL04＜OL05＜OL01＜OL03＜OL02。尽管未来出山径流有所增加,但从水资源满足度来看,平、枯水年讨赖河流域仍存在水资源短缺问题。

Application of GCMs Downscaling to Mountainous Discharges Forecasting in the Upper Reaches of Taolai River Basin

Affected by climate change and human activities, mountainous discharge has undergone dramatic variability in inland river basins. Forecasting mountainous discharge and investigating its response to climate change are of great significance in both research and practice. The future runoff change and the supply-demand balance of water resources in Taolai River Basin were predicted and analyzed by optimizing 14 of the GCMs (Global Climate Models) outputs under three RCP scenarios to determine future air temperature and precipitation using the Delta downscaling and weight-based integration methods. The calibrated climate-ecological driving module is suitable for the mountainous discharge simulation in Taolai River Basin. Negative impacts of air temperature and positive impacts of precipitation and NDVI are also found. GCMs outputs indicate an overall increase of mountainous air temperature and precipitation, of which the former is mainly found in valleys while the latter more remarkable near the drainage divide. Mountainous discharge in the studied basin displays an overall increasing trend, and the variation amplitude in different sub-areas follow the sequence of OL06, OL04, OL05, OL01, OL03 and OL02 from small to large. Despite the increase of mountainous discharge, water shortage still exists during normal and dry hydro-years under the three RCP scenarios.