近百年来长江水下三角洲高分辨率洪水沉积记录及其控制机理

夏季洪涝灾害对长江流域社会经济造成了严重的影响,急需开展多时空尺度流域洪水发生规律和控制机理的研究,但因洪水器测数据年限短和缺少有效的古洪水沉积记录研究方法而难以实现。选取长江水下三角洲YEC1701柱状样顶部100 cm进行高分辨率XRF岩心连续扫描（XRFCS）,粒度、有机碳、N元素、δ13C和210Pb定年分析,并与流域洪水器测或历史记录等进行对比研究,以期建立高效的古洪水沉积记录代用指标。结果表明,长江水下三角洲沉积物中Zr/Rb峰值通常对应粒度粗组分高值和较高的C/N值、偏负的δ13C值,所在层位的沉积年龄与流域洪水事件发生年份有很好的对应关系。由此判断,Zr/Rb值可作为判别长江古洪水沉积的重要代用指标。长江流域于1930—2017年间共发生22次洪水事件,利用XRFCS获得的10 mm和2 mm间隔Zr/Rb值可分别识别出其中的11次和18次,识别率为50%和80%。由此推荐XRFCS样品测试间隔要小于年沉积速率一半以内,以提高古洪水事件的识别率。多源洪水和降雨数据分析表明,长江洪水年际至千年尺度发生规律主要受厄尔尼诺-南方涛动和东亚夏季风、南亚夏季风活动的共同影响。但早期长江洪水资料分辨率较低,长江水下三角洲有较连续的洪水沉积记录,运用XRFCS毫米级分辨率的Zr/Rb值可重建全新世高分辨率的长江古洪水发生历史,更精细地分析气候变化对洪水发生规律的控制机理,为预测全球变化背景下长江洪水演变趋势提供依据。     

江西银山多金属矿床伊利石的形成与流体成矿作用的初步研究

江西银山多金属矿床的热液蚀变粘土矿物主要由伊利石组成,伊利石主要由流体作用过程中长石的伊利石化形成,其结晶度与成矿流体作用密切相关.银山第1期铅锌银成矿作用,水/岩比相对较低,成矿流体以孔隙渗透为主,溶质迁移慢,形成含有少量膨胀层的伊利石;第2期铜金成矿作用,水/岩比相对较高,流体的运移方式以通道式或裂隙式为主,溶质迁移的速度快,形成不含膨胀层的伊利石.研究表明成矿作用过程中的伊利石化主要与铅锌银矿化有关,而绿泥石化与铜金矿化有关.     

我国核电厂设计中考虑的自然灾害综述与建议

我国是目前世界在建核电机组最多的国家,总装机容量世界第三,是名副其实的核大国,核安全是国家安全的重要内容,被提到了前所未有的高度。同时,我国也是世界上自然灾害最严重的国家之一,包括核电厂在内的重大工程建设高度重视自然灾害防御设计。日本311地震海啸引起福岛核事故后,核电厂设计中增强了对超设计基准自然灾害的考虑。本文对核电厂防御自然灾害的必要性、核电厂设计中需考虑的自然灾害及国内外核电厂关于防御自然灾害存在的问题进行研究,提出我国核电厂防御自然灾害的建议。     

Peatland initiation and carbon dynamics in northeast China: links to Holocene climate variability

Throughout northeast China, the widely distributed peatlands have formed a large carbon (C) pool. However, the relationship between peatland initiation and climate controls is still poorly documented and understood. Understanding the responses of these C‐rich ecosystems to past climate change will provide useful insights into projecting the fate of peatland C in the future. In this study, we present a detailed historical reconstruction of peatland development in northeast China based on 312 basal peat dates, and examine the relationship between Holocene peatland dynamics and climate sensitivity. Our results indicate that peatland initiation started in the early Holocene, and that the majority of peatlands were initiated by and developed during the late Holocene. After the most intensive initiation period of 4.2–0.8 ka, the rate of peatland development slowed, which was concomitant with decreasing insolation and monsoon intensity. The widespread peatland initiation in the late Holocene might have been caused by the cool and moist climate patterns. The optimum timing of the peatland development was not uniform across northeast China, and these spatio‐temporal differences indicate the influences of regional climate and terrain on peatland initiation. Peat‐core data show variations in the long‐term apparent rate of C accumulation (LORCA) during the Holocene, with an average rate of 37.2 g C m^?2 a^?1. The peak LORCA occurred during 10.5–9.0 ka, probably in response to higher temperatures and stronger East Asia summer monsoon intensities. Both temperature and humidity are important factors influencing the peatland initiation and C dynamics in this region.     

基于主体功能区约束的大气污染物总量控制目标分配研究

考虑经济发展水平、污染物排放现状、污染物治理水平、空气质量,特别是国家主体功能区环境目标约束等因素,构建大气污染物排放总量分配的指标体系,用改进的等比例分配方法对2015年国家SO2,NOx总量控制目标进行区域分配。分配结果表明:SO2和NOx削减量大的省份主要集中在华北平原及其周围地区,这些地区污染物排放量大、空气质量较差;削减比例较大的地区主要集中在西部地区以及北京、天津2个直辖市,这些地区单位GDP能耗高、工业污染物去除率低、空气质量差;削减量相对较小的地区主要集中在西南和南部一些省份;削减比例较小的地区主要集中在中南部和南部几个省份,这些地区污染物排放量相对较少,空气质量好于其他省份。     

Efficient estimation of flood forecast prediction intervals via single‐ and multi‐objective versions of the LUBE method

Prediction intervals (PIs) are commonly used to quantify the accuracy and precision of a forecast. However, traditional ways to construct PIs typically require strong assumptions about data distribution and involve a large computational burden. Here, we improve upon the recent proposed Lower Upper Bound Estimation method and extend it to a multi‐objective framework. The proposed methods are demonstrated using a real‐world flood forecasting case study for the upper Yangtze River Watershed. Results indicate that the proposed methods are able to efficiently construct appropriate PIs, while outperforming other methods including the widely used Generalized Likelihood Uncertainty Estimation approach. Copyright © 2016 John Wiley & Sons, Ltd.