Reservoir yield intercomparison of large dams in Jaguaribe Basin-CE in climate change scenarios

ABSTRACT Climate changes can have different impacts on water resources. Strategies to adapt to climate changes depend on impact studies. In this context, this study aimed to estimate the impact that changes in precipitation, projected by Global Circulation Models (GCMs) in the fifth report by the Intergovernmental Panel on Climate Change (IPCC-AR5) may cause on reservoir yield (Q90) of large reservoirs (Castanhão and Banabuiú), located in the Jaguaribe River Basin, Ceará. The rainfall data are from 20 GCMs using two greenhouse gas scenarios (RCP4.5 and RCP8.5). The precipitation projections were used as input data for the rainfall-runoff model (SMAP) and, after the reservoirs’ inflow generation, the reservoir yields were simulated in the AcquaNet model, for the time periods of 2040-2069 and 2070-2099. The results were analyzed and presented a great divergence, in sign (increase or decrease) and in the magnitude of change of Q90. However, most Q90 projections indicated reduction in both reservoirs, for the two periods, especially at the end of the 21th century.

摘要：气候变化对水资源可产生多元影响，气候变化适应策略的制定有赖于影响评估研究。在此背景下，本研究旨在评估政府间气候变化专门委员会第五次评估报告（IPCC-AR5）中，全球环流模式（Global Circulation Models, GCMs）所预估的降水变化，对位于塞阿拉州雅瓜里贝河流域的两座大型水库（卡斯塔尼奥水库与巴纳比尤水库）的水库供水量（Q90）造成的影响。本次研究的降水数据来自20个采用两种温室气体排放情景（RCP4.5与RCP8.5）的全球环流模式。将上述降水预估结果作为降雨径流模型（SMAP）的输入数据，在生成水库入库流量后，于AcquaNet模型中模拟2040-2069年与2070-2099年两个时段的水库供水量。研究结果经分析后显示，Q90的变化在趋势（增加或减少）与变化幅度上均存在显著差异；不过在两个预估时段内，多数模拟结果均表明两座水库的Q90均出现下降，且该下降趋势在21世纪末尤为明显。