A new preparation process of coal-based magnetically activated carbon

Fe/C-based magnetically activated carbon （MAC） was obtained by carbonizing and activating its precursor, that was prepared by co-precipitation of anthracite coal impregnated in ferric chloride solution. The effect of the concentrations of FeC13 and pH of solution on BET surface area, pore volume and magnetic properties of the MAC was studied by BET N2 adsorption and VSM method. The results indicated that the magnetization of MAC gradually increases with increasing concentration of FeC13 and pH value of solution, and BET surface area was inclined to fluctuation. The largest BET surface area and magnetization of MAC were 1327.5 m2/g and 35.56 emu/g, respec- tively. The form of magnetic matter in the magnetically activated carbon was mainly Fe3C by X-ray powder diffrac- tion （XRD） and magnetic attraction test.     

基于人工降雨模拟试验的坡面水文连通性

为揭示降水入渗时坡面水文连通性特征以及坡度和雨强等对水文连通性的影响,研究基于人工降雨模拟试验,分别采用结构性指标径流长度（Flowlength,l_F）和功能性指标相对地表连接函数（Relative Surface Connection Function, F_RC）分析不同坡度坡面（5°、15°、25°;面积为150 cm×50 cm）在不同雨强（25 mm/h、50 mm/h、70 mm/h和86 mm/h）条件下的水文连通性。研究结果表明:坡面水文连通结构主要由l_F为0~100 mm的径流路径组成,其栅格频率高达90%以上,而l_F为100~500 mm的栅格频率为3%~8%。水文连通性的迅速发展主要集中在降水事件的开始阶段,而一定阶段以后入渗速率与地表储水速率基本持平,水文连通性呈现出较为稳定的发展趋势。坡度增大整体上有利于水文连通性的发展。5°坡面对应水文连通面积比率整体小于其他坡度。由于雨强增大到一定范围时将增加地表糙率,从而阻碍水文连通性的发展,研究中仅25 mm/h对应水文连通性明显区别于其他雨强,而其他雨强间则在多数情况下水文连通性差别较小。     

江苏淤泥质潮滩剖面演变现场观测

为探究江苏中部沿海双凸型剖面演变特性,在江苏盐城川东港南侧潮间带布设了10个水准观测站,2012年9月至2013年11月对该潮滩剖面演变过程开展了现场观测.结果表明:该潮滩剖面呈现出双凸型特征,平均高、低潮位线附近的滩涂形成淤积率较高的地形凸点;潮间上带受潮流影响小,滩面高程相对稳定;平均高、低潮位之间的区域滩面高程季节性变化明显,总体呈现冲刷状态;潮间下带冲刷显著,滩面坡度增大.全剖面自岸向海呈现"稳定—淤积—稳定—淤积—冲刷"的双凸型剖面特征.     

论气候变暖背景下干旱和干旱灾害风险特征与管理策略简

The drought is a most severe natural disaster worldwide, which leads to great risk in human being. The drought disaster and risk have more prominent because of obvious climatic warming in the last hundred years. At present, the understanding of the internal laws of the occurrence of drought and drought risk is not comprehensive, and the recognition of the characteristics of the drought and drought risk under climatic warming is obscure. In this paper, we summarized systematically the domestic and overseas research progress of the drought and drought disaster risk, introduced the principle of the drought disaster transfer process and the essential features of drought disaster, analyzed synthetically the main characteristics and interactions among the key factors of the drought disaster risk, discussed the effect of climatic warming on drought and drought disaster risk, and probed into the basic requirement of drought disaster risk management. Above all, we provide the main protective measurements of the drought disaster and the main strategy of drought disaster risk management.     

Studies on the Coral Reefs of the South China Sea: From Global Change to Oil-Gas Exploration

Studies on the coral reefs of the South China Sea (SCS) was the theme of the 6th Session of the 3rd Conference on Earth System Science (CESS) in Shanghai, 2014. This session discussed the most recent study developments on the SCS coral reefs, including coral reefs’ responses to global changes, coral reefs’ records on past climatic variations, and the activities about constructions and oil gas explorations in the coral reefs areas of the SCS. Disturbed by intensive anthropogenic activities and global climate warming, coral reefs in the SCS have declined dramatically, reflecting the up to 80% decrease of living coral cover and many areas having less than 20% of living coral cover. Geochemical data of SCS coral skeletons clearly show that since the Industry Revolution, the pollution situation of the SCS have dramatically increased and the seawater pH values have been continuously lowering, i.e. oceanic acidification. All these environmental phenomenon are further stressing the healthy development of the coral reef ecosystem in the SCS. Meanwhile, the poor coral reef ecosystems in the SCS are facing more anthropogenic disturbances such as coastal developments and engineering constructions. Obviously, the SCS coral reefs will be faced with more environmental challenges in the coming future. We therefore suggest that the policy makers should realize the extreme importance and the fragile of the coral reef ecosystems, and scientifically and with great cautions design construction project when in coral reef areas. We initiated the concept of “green engineering” for future developments in coral reef areas. Coral reefs are widely spreading in the whole SCS, and most of them developed since Miocene. Variations in coral reef structures provide good future oil-gas exploration. Because the SCS coral reefs have a long-developing history and a wide spatial distribution, they provide great potential in recording past environmental changes.     

全新世温度研究回顾及对历史人地关系的启示

最新一些研究结果强调了全新世期间的长期增温趋势,综合全球平均海平面、大陆冰盖面积、大气温室气体和太阳辐射证据来看,这比传统观点所认为的全新世期间的长期降温趋势,更具有合理性。回顾历史,结合最新的一些研究进展,发现支持“中全新世大暖期”和“晚全新世降温趋势”的证据存在明显的不确定性,最核心的问题为晚全新世加强的人类活动对代用指标或者证据的强烈扰动,使得其不能准确地反映真实的气候变化过程。鉴于目前全新世温度历史争论的核心关键在于晚全新世,因此有必要加强晚全新世温度变化研究。在人类活动影响较小的地区,或者利用对人类活动不敏感的代用指标开展研究,有望可以获得更可靠的晚全新世温度历史重建结果,为准确认识中华数千年文明的长期温度变化背景,进而理解期间的“人地关系”演化历史,并最终客观认识现今面临的以全球变暖为主要特征的气候环境问题,提供一定的科学基础。     

2001—2020年中国地表温度时空分异及归因分析

地表温度（LST）变化对陆面过程的能量收支平衡与生态系统稳定有着至关重要的影响。本文基于MOD11C3数据,使用回归分析、GIS空间分析、相关性分析及质心模型等方法,分析了中国2001—2020年LST变化及其时空分异格局;运用地理探测器识别中国38个生态地理分区下LST变化的主导因子,进而探寻其形成原因。结果表明：① 中国2001—2020年LST气候平均值为9.6 ℃,整体呈东南及西北干旱区高、东北及青藏高原低,平原高、山区低的基本格局;LST与海拔呈显著负相关,相关系数达-0.66;第一阶梯负相关性最为显著,相关系数达 -0.76,LST递减率为0.57 ℃/100 m;② 中国2001—2020年LST倾向率为0.21 ℃/10 a,升温区占国土面积的78%,整体呈现“多核式升温,轴线式降温”的空间特征;③ 中国LST及变化具有显著的季节性特征,冬、夏两季均温空间分布较其他季节的差异较大且波动更为明显;季节性升/降温区的质心轨迹呈环状,且运动呈现出对应的季节性反向轨迹,降温区质心移动幅度更大,说明降温区的区域差异性和季节变异性较大;④ 中国LST变化由自然影响与人类活动共同驱动,其中自然因素贡献更大,日照时数和海拔是关键因子;两大主导类型在空间分布上与“胡焕庸线”高度吻合,其以东区域多以人类活动强度为主导并与地形因子共同作用,而以西区域则多以自然因素为主,通过与气候、地形、植被等因子的相互耦合从而增强/削弱LST变化幅度。本文可为应对气候变化、解析地表环境模式、保护生态环境等方面提供科学参考。     

地表城市热岛效应的概念内涵与定量刻画

明晰城市热岛（UHI）效应相关概念内涵、厘清其定量刻画方法是有效开展UHI效应研究的重要基础。全球城市化进程使UHI效应越发普遍,相关研究数量迅速增长并出现了UHI效应的多样认知,尤其对具有空间异质性表征优势的地表城市热岛（SUHI）效应开发了多样的定量刻画方法,但目前尚缺乏对其定量刻画方法的系统梳理。因此,本文对城市热岛、城市热岛效应、地表温度和城市热环境等易混淆概念进行了辨析,总结了各类UHI典型空间位置和尺度范围。在SUHI效应定量刻画中,将SUHI范围识别方法归结为城乡温度阈值、温度等级阈值、高斯拟合参数、温度衰减突变四大类,指出当前SUHI范围识别研究侧重于对SUHI影响规模的认知。研究同时对各类范围识别方法所对应的SUHI强度表征指标进行了梳理,认为理解指标本质内涵是掌握指标间潜在差异的前提。未来研究应整合多维度数据以突破单一SUHI监测途径,发展大尺度SUHI定量刻画方法以拓展定量研究的广度,认知连通化SUHI空间形态以挖掘范围识别研究的深度。     

土壤粒径空间预测方法研究综述

土壤粒径（砂粒、粉粒和黏粒）是各种陆表过程和生态系统服务评估等模型的关键参数。作为一种土壤成分数据,土壤粒径的空间预测方法有和为1（或100%）等特殊要求,其空间分布精度受预测方法影响较大。本文针对土壤粒径相较于其他土壤属性的特殊性,提出了土壤粒径空间预测方法框架,综述了土壤粒径数据变换、空间插值和精度验证等系列方法,总结了提升土壤粒径空间预测精度的各种途径,包括通过有效的数据变换改善数据分布、结合数据分布特点选择合适的预测方法、结合辅助变量提升制图精度和分布合理性、使用混合模型提升插值精度、使用多成分联合模拟模型提升预测的系统性等。最后,提出了今后土壤粒径空间预测方法研究的未来方向,包括从考虑数据变换原理和机制角度改善数据分布、发展多成分联合模拟模型和高精度曲面建模方法,以及引入土壤粒径函数曲线并与随机模拟结合等。     

环青海湖地下水溶解性碳的时空变化特征

区域地下水溶解性碳的时空变化特征研究对于认识区域物质循环和能量传递及推动区域生态可持续发展具有重要意义。本研究在青海湖流域冻结期和融化期分别收集了地下水、河水和湖水样品,研究了环青海湖地下水在冻结期和融化期的溶解性碳特征,并探究了不同类型地下水的溶解性碳特征及其对不同冻融时期的响应,最后揭示了环湖区域不同水体的溶解性碳的差异特征及影响因素。结果表明：冻结期地下水、河水和湖水的溶解性无机碳（DIC）均相对高于融化期,溶解性有机碳（DOC）均相对低于融化期。地下水、河水和湖水的溶解性碳均主要以DIC为主,DIC在溶解性碳的占比高达92%。地下水的DIC平均含量在基岩裂隙水、水量中等和浅埋藏的水文地质条件下相对较高,DOC平均含量在基岩裂隙水、水量丰富和浅埋藏的水文地质条件下相对较高。地下水的DIC在湖滨平原砂砾石层、淤泥质砂层潜水和水量中等的水文地质条件下受冻融期影响较大,DOC在基岩裂隙水和水量贫乏的水文地质条件下受冻融期影响较大。湖水的DIC和DOC均远高于河水和地下水。河水的DIC在融化期和冻结期均低于地下水,DOC在融化期高于地下水,在冻结期低于地下水。