Building national eco-cultural protection areas and the Xiangxi practice in Hunan Province

Journal of Geographical Sciences - Since 2007, the Chinese government has initiated the building of national eco-cultural protection areas (NECPAs), thereby embarking on a significant...     

一种污水排海的近远区计算与控制方法──以大亚湾水容量计算及污水排海为例

针对点容量计算中混合区限制的要求，采用了动量积分法、经验公式法和有限差分法，分别对污水排放后可能引起的近区、过渡区和远区的污水浓度变化进行了模拟预测，并就一定的限制性条件对容量点近区、高浓度混合区及容量点远区影响范围进行了分析。在大亚湾水容量计算及污水排海规划中的应用表明，该法具有计算机时较省、精度相对较高等优点。     

中国东南沿海老红砂研究综述

老红砂是中国东南沿海独具特色的第四纪沉积物。本文回顾了老红砂的研究历史，综述了所取得的关于老红砂的成因，年代和红化作用等主要研究成果及其存在问题，并提出了今后进一步工作的意义。     

1998年夏季南海水团分析

根据 1 998年夏季“南海季风试验 ( SCSMEX)”期间所获的 CTD资料 ,使用系统聚类、Fuzzy模式聚类、Bayes判别分析和 Fuzzy分析等水团分析方法 ,对南海水体的结构和水团配置状况等进行了分析 ,划出了南海存在的 9个主要水团 ,并对各水团的温、盐度特征进行了初析。在调查期间 ,南海本地水 (南海水 )几乎控制了整个调查海区 ,而黑潮水仅出现在台湾岛的西南海域 ;海水强烈混合发生在吕宋海峡附近 ;在中南半岛以东和吕宋岛以西海域 ,表层水明显下沉 ;在南海东南部可能有来自苏禄海的海水 ,其温、盐度特征类似于吕宋海峡中的黑潮水     

ARGO剖面浮标数据质量控制过程剖析

ARGO计划的观测目标是能取得精度分别为0．5℃和0．01PSU的海水温度和盐度资料。然而，由于目前海水盐度是采用海水电导率间接导出的，而测量海水电导率的传感器很容易产生偏差。因此，必须对获得的ARGO数据进行质量控制。文章详细介绍了ARGO剖面浮标资料实时质量控制模式和延时质量控制模式及其采用的质量控制方法等。     

新一代区域海-气-浪耦合台风预报系统

依托国家重点基础研究（973）计划项目"上层海洋对台风的响应和调制机理研究",中国气象局上海台风研究所联合国家海洋局的相关单位,通过实施近海台风的外场观测科学试验、加强台风边界层（特别是海气相互作用）物理过程诊断分析及参数化方案等的研究,建立并改进了台风强度预报的海-气-浪耦合预报模式系统,并在此基础上发展了台风强度的集合预报技术,在历史典型台风个例和2016-2017年台汛期的业务化测试中表现出良好的预报性能。     

中国近海生态环境变化的同位素示踪研究

同位素在确定物质来源、指示生物地球化学循环路径、定量生物地球化学过程速率等方面具有独特的优势,本文以近海生态环境变化研究中常用的稳定同位素（13C、15N、18O）和放射性核素（14C、234Th、232Th、230Th、228Th、210Po、210Pb、137Cs、226Ra、228Ra、224Ra、223Ra）为对象,介绍它们在揭示海洋有机质来源、食物网结构、水体缺氧机制、氮循环过程、颗粒动力学、海底地下水输入、有机地球化学过程、沉积年代学等方面的应用,侧重于总结我国近海生态环境研究中同位素示踪取得的进展。伴随着我国经济的发展,近百年来我国近海生态环境也发生了明显的变化,基于同位素示踪揭示的近海富营养化和沉积环境的演变规律表明,我国近海生态环境自20世纪50年代起经历持续的变化,特别是在过去20~30年时间里,近海生态环境的变化尤为剧烈,反映出人类活动是我国近海生态环境变化的主要驱动力。未来需要通过发展新的同位素技术及拓展更广泛的应用,围绕近海海洋生态环境变化的突出问题,重点揭示近海生态环境变化的响应特征、变化速率和作用机制,从而系统地掌握近海生态环境的时空变化规律。     

Extreme Flood Events over the Past 300 Years Inferred from Lake Sedimentary Grain Sizes in the Altay Mountains,Northwestern China

Understanding the temporal variations of extreme floods that occur in response to climate change is essential to anticipate the trends in flood magnitude and frequency in the context of global warming. However, long-term records of paleofloods in arid regions are scarce, thus preventing a thorough understanding of such events. In this study, a reconstruction of paleofloods over the past 300 years was conducted through an analysis of grain sizes from the sediments of Kanas Lake in the Altay Mountains of northwestern China. Results showed that grain parameters and frequency distributions can be used to infer possible abrupt environmental events within the lake sedimentary sequence, and two extreme flood events corresponding to ca. 1736–1765 AD and ca. 1890 AD were further identified based on canonical discriminant analysis(CDA) and coarse percentile versus median grain size(C-M) pattern analysis, both of which occurred during warmer and wetter climate conditions by referring to tree-ring records. These two flood events are also evidenced by lake sedimentary records in the Altay and Tianshan mountains. Furthermore, through a comparison with other records, the flood event from ca. 1736–1765 AD in the study region seems to have occurred in both the arid central Asia and the Alps in Europe, and thus may have been associated with changes in the North Atlantic Oscillation(NAO) index.     

Spatio-temporal Variation of Soil Respiration and Its Driving Factors in Semi-arid Regions of North China

Soil respiration (SR) is the second-largest flux in ecosystem carbon cycling. Due to the large spatio-temporal variability of environmental factors, SR varied among different vegetation types, thereby impeding accurate estimation of CO₂ emissions via SR. However, studies on spatio-temporal variation of SR are still scarce for semi-arid regions of North China. In this study, we conducted 12-month SR measurements in six land-use types, including two secondary forests (Populus tomentosa (PT) and Robinia pseudoacacia (RP)), three artificial plantations (Armeniaca sibirica (AS), Punica granatum (PG) and Ziziphus jujuba (ZJ)) and one natural grassland (GR), to quantify spatio-temporal variation of SR and distinguish its controlling factors. Results indicated that SR exhibited distinct seasonal patterns for the six sites. Soil respiration peaked in August 2012 and bottomed in April 2013. The temporal coefficient of variation (CV) of SR for the six sites ranged from 76.98% to 94.08%, while the spatial CV of SR ranged from 20.28% to 72.97% across the 12-month measurement. Soil temperature and soil moisture were the major controlling factors of temporal variation of SR in the six sites, while spatial variation in SR was mainly caused by the differences in soil total nitrogen (STN), soil organic carbon (SOC), net photosynthesis rate, and fine root biomass. Our results show that the annual average SR and Q₁₀ (temperature sensitivity of soil respiration) values tended to decrease from secondary forests and grassland to plantations, indicating that the conversion of natural ecosystems to man-made ecosystems may reduce CO₂ emissions and SR temperature sensitivity. Due to the high spatio-temporal variation of SR in our study area, care should be taken when converting secondary forests and grassland to plantations from the point view of accurately quantifying CO₂ emissions via SR at regional scales.