In this work, the climatology, observed trends, and future projections of temperature and precipitation extremes are analysed in the drainage area of the Belo Monte Hydropower Plant in the Xingu River basin. Observed data come from gridded information for the period 1980–2013. The climate projections until the end of the 21st century are provided by the regional climate model Eta-20 km nested to the global climate model MIROC5. Seventeen climate indicators were selected for this assessment, and statistical tests were used to evaluate the significance and magnitude of trends. A tropical climate predominates in the whole basin but with differences in the climatology of extreme temperature. The average annual rainfall (PRCPTOT) presents values between 1,500 and 2,200 mm. Remarkable contrasts of consecutive dry days (CDD) can also be seen. We found a warming signal during the examined period in much of the Xingu River basin, with an increase in the frequency of extremely warm days and nights. In the northern (south-central) area of the basin, there is an increase (reduction) in precipitation. There is a contrasted and local distribution of detected trends in all climate extremes indices related to rainfall. CDD has displayed a considerable elevation in the south-central area over the last decades. The study area exhibits statistically significant warming projections to the future climate. As for the precipitation projections, future changes are toward a dryer climate. We also found that dry periods may last longer in the following decades. Thus, heatwaves can be excited by subsequent days without precipitation in the basin in the future climate. The impacts of climate change on the balance of different environmental and socioeconomic sectors in this area must be wholly investigated.

中文翻译：

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对贝洛蒙特水电站 - 巴西亚马逊东部的观测和预测气候极端温度和降水的综合分析

在这项工作中，分析了新古河流域贝洛蒙特水电站流域的气候学、观测趋势以及极端温度和降水的未来预测。观察到的数据来自 1980-2013 年期间的网格化信息。到 21 世纪末的气候预测由嵌套在全球气候模型 MIROC5 中的区域气候模型 Eta-20 km 提供。该评估选择了 17 个气候指标，并使用统计测试来评估趋势的重要性和幅度。全流域以热带气候为主，但极端气温气候学差异较大。年平均降雨量 (PRCPTOT) 的值介于 1,500 和 2,200 毫米之间。还可以看到连续干燥天数 (CDD) 的显着对比。在新谷河流域的大部分地区，我们在检查期间发现了一个变暖信号，极端温暖的白天和夜晚的频率有所增加。在流域北部（中南部）地区，降水量增加（减少）。在与降雨相关的所有气候极端事件指数中，检测到的趋势存在对比和局部分布。在过去的几十年中，CDD 在中南部地区显示出相当大的海拔。该研究区域显示出对未来气候具有统计显着性的变暖预测。至于降水预测，未来的变化是气候干燥。我们还发现，在接下来的几十年里，干旱期可能会持续更长时间。因此，在未来的气候中，热浪可能会在流域没有降水的情况下被随后几天激发。