Spectral contributions of the components of seawater to the beam attenuation coefficient in surface waters of the Mediterranean Sea

We compute model spectra of the beam attenuation coefficient in surface waters of the Mediterranean Sea. These spectra are used to determine the contribution of the components of seawater (suspended matter, yellow substance, pigments of phytoplankton, and pure water) to the beam attenuation coefficient in different types of seawater. For the surface waters, we establish the relationship between the light scattering coefficient and the attenuation coefficient at a wavelength of 547 nm and determine the background (limiting minimum) value of the coefficient of absorption by the yellow substance in waters of the Mediterranean Sea. It is compared with the values of the same parameter for some other basins (Black Sea, Lake Baikal, Baltic Sea, and oceanic waters).     

Structural changes in macrozoobenthic communities due to summer hypoxia in Gamak Bay,Korea

The purpose of this study was to examine the structural changes that macrozoobenthic communities underwent as a result of the annual summer hypoxia at the northern part of Gamak Bay, Korea. During this study period, summer hypoxia occurred at the northern part of Gamak Bay in July. Under hypoxic conditions, both the number of species and population density decreased rapidly. Species diversity also manifested lower values during this hypoxic period. Faunal composition changed seasonally with Capitella capitata dominant at the hypoxic sites in spring but disappearing in summer. The health condition of the benthic faunal community assessed by the composition of functional groups within community also changed due to the summer hypoxia from a slightly polluted condition to a highly polluted condition. From these results it has been shown that the recent macrozoobenthic community structure in Gamak Bay has returned to a state similar to what it was before dredging works commenced.     

旅游废弃物的环境库兹涅茨效应分析——以黄山风景区为例

旅游废弃物的资源消耗性与环境吸纳性, 是其产生环境与生态影响的根本原因。文章以黄山风景区为例, 利用1979-2010 年的固态、液态、气态3 类6 种旅游废弃物的排放量指标的时间序列数据, 进行旅游废弃物的环境库兹涅茨曲线拟合检验及其效应分析。结果表明:(1) 固态与液态旅游废弃物的排放量与旅游发展之间具有环境库兹涅茨倒U型曲线关系, 而气态废弃物则不具有。(2) 固体废弃物排放量的倒U型曲线的转折点为4596.01 t, 液态的污水与粪便的转折点分别为731491.46 t, 15866.43 t, 转折点时间在2015 年。(3) 科技应用对改善景区空气质量的作用较大, 万元旅游收入的能耗每下降1%, SO₂、NO₂、PM₁₀ 值分别下降3.38%、4.25%、0.78%;环保规制对景区水体的质量控制作用明显, 污水达标排放率每提高1%, 地表水的COD值下降3.41%。(4) 旅游废弃物的排放不一定必然造成风景区环境质量的下降, 调整产业结构、加大科技应用与强化环保规制, 是控制旅游废弃物环境污染与生态影响的关键手段。     

基于遥感反演参数与双约束空间聚类算法的湖泊营养物生态分区

中国湖泊营养物水平和富营养化效应存在显著区域分异特征,开展湖泊营养物生态分区研究,是实现湖泊分区控制的前提和基础。本文以云贵高原亚热带湿润区为案例区,通过遥感反演得到研究区域湖泊水体的叶绿素a(Chl-a)、总氮(TP)和总磷(TN)含量,从自然地理要素、生态系统和人类活动3 方面建立指标体系;根据研究区域 DEM数据划分小流域,将各指标因子投影到小流域;在小流域尺度上,采用数理统计方法定量分析各指标分别对 Chl-a/P 与Chl-a/N 的作用,计算两种湖泊营养物生态分区评价分值;采用双约束空间聚类算法对小流域尺度上两种湖泊营养物生态分区评价分值共同进行聚类,形成湖泊营养物生态分区结果。研究发现：①通过遥感反演模型可以将少数呈点状分布的监测数据推演到面上,这在一定程度上弥补了有限的野外监测数据量难以支撑湖泊营养物生态分区的不足;②通过构建各指标因子分别与湖泊水体中Chl-a/P、Chl-a/N 的定量关系,实现了湖泊营养物生态分区中湖泊水体微观指标与湖泊流域宏观指标的有机结合;③采用双约束空间聚类进行湖泊营养物生态分区,保证了分区结果在空间上的连续性和评价分值上的接近性;④根据自然地理条件、土地利用和人类活动强度的不同,将云贵高原亚热带湿润区分为4 个区：北云南高原湖区、滇南河谷山原湖区、桂西-滇东-黔南岩溶湖区、贵州高原东北部湖区。本文提出的基于双约束空间聚类的湖泊营养物生态分区方法也可以作为其它地区乃至国家尺度湖泊营养物生态分区的借鉴。     

无人机核线影像的稀疏匹配与稠密匹配

无人机影像转化为水平核线影像后,能够有效地减少同名点的搜索空间。在此基础上,本文使用SIFT算子进行了稀疏匹配,并用BP算法进行了稠密匹配。结果表明：①SIFT算子获取的同名点比较少,但是计算方法简单,同名点空间坐标精确,适用于大范围获取简要的空间三维信息;②BP算法计算复杂度高,可以获取地物大量的同名点,适用于小范围的地物三维重建。总体而言,两者各有优缺点,在实际的应用中可互补。     

内蒙古阿巴嘎旗白音图嘎地区晚石炭世花岗岩地球化学特征、锆石U-Pb定年及其地质意义

内蒙古白音图嘎地区位于西伯利亚板块东南缘晚古生代陆缘增生带,地处二连—贺根山板块对接带西北侧,该区发育大量晚古生代花岗岩,主要岩石类型为斑状二长花岗岩和碱长花岗岩。本文对该区花岗岩进行了LA-ICP-MS锆石U-Pb测年和岩石地球化学测试。结果表明:斑状二长花岗岩和碱长花岗岩锆石U-Pb年龄分别为302.8±1.3Ma(MSWD=1.4)和301.1±0.6 Ma(MSWD=0.84),属于晚石炭世;岩石地球化学数据显示,岩体属钾玄岩系,具有高硅(SiO_2=70.83%~75.01%),富碱(Na_2O+K_2O=11.58%~13.20%),贫钙(CaO=0.50%~1.22%)和镁(MgO=0.11%~0.33%)特征。铝饱和指数A/CNK=0.81~1.01,为准铝—弱过铝质花岗岩。岩体整体富集Rb、Th、U等大离子亲石元素(LILEs),亏损Ba、Sr以及高场强元素(HFSEs)Nb、Ta、P、Ti;LERR富集,HERR相对亏损,具有明显的负Eu异常(δEu=0.11~0.43)。初始岩浆温度(759.33℃~801.81℃)和岩石地球化学分析表明,白音图嘎花岗岩具有A型花岗岩特征。同时,低的Nb/Ta(7.38~19.50)、Zr/Hf(29.61~35.26)和Sm/Nd(0.22~0.32)比值指示其源岩为壳源。综合研究表明,白音图嘎花岗岩为陆壳变杂砂岩部分熔融的产物,形成于晚石炭世早期西伯利亚板块和华北板块后碰撞作用的板内伸展环境,为兴蒙造山带晚古生代构造岩浆演化及古亚洲洋闭合的时限提供了新的约束和佐证实例。     

Spatial and temporal evolution of community resilience to natural hazards in the coastal areas of China

With the accelerating progress of industrialization, urbanization and population growth in recent decades, community resilience, the ability of communities to function effectively and recover successfully in the aftermath of disasters and shocks, has received great attentions. A number of studies had been conducted focusing on community resilience. This article applied community resilience framework to the coastal areas of China, which are the most densely populated and economically developed areas in China with the most frequent marine disasters. City-level social and economic data were used to construct a community resilience index (CRI). Using factor analysis and the global principal component analysis method, 55 city-level indexes were reduced into 15 factors that explain 73.99% of the variance. Getis–Ord G* Statistics were used to depict the high-value clusters and low-value clusters of the CRI. Clearly identified spatial and temporal variations of the CRI showed that both the overall level and regional differences of the CRI increased from 2003 to 2013; the overall spatial agglomeration characteristic of community resilience was not significant. Our findings also highlighted the key elements to improving community resilience: a robust and developed economic system; excellent education programs and training to improve consciousness on disaster prevention and mitigation; adequate investment on critical infrastructure, especially transportation and communication; proper environmental policies to protect ecosystems and water rouses; and extra attention and disaster risk budgets for vulnerable populations.     

铼-锇同位素体系定年研究综述

铼-锇(Re-Os)同位素体系以其特殊的地球化学性质为确定岩石的形成时间、演化过程及其地球动力学背景提供了重要参数。随着测试技术和超净化实验室的发展,Re-Os同位素的应用领域不断扩大,测试对象种类也随之扩展。然而,不同测试对象的Re-Os同位素赋存形式、活动特征及其体系封闭性有所差异。文章总结了以辉钼矿、普通硫化物、地幔橄榄岩包体、富有机质沉积岩以及灰岩作为Re-Os同位素体系定年对象的基本原理和研究进展,并对存在问题进行简要地评述,最后对其未来的发展方向作了展望,以期推动Re-Os同位素体系在地质科学中的研究和应用。     

Understanding of the Common Land Model performance for water and energy fluxes in a farmland during the growing season in Korea

The Common Land Model (CLM) is one of the most widely used land surface models (LSMs) due to the practicality of its simple parameterization scheme and its versatility in embracing a variety of field datasets. The improved assessment of land surface water and energy fluxes using CLM can be an alternative approach for understanding the complex land–atmosphere interactions in data‐limited regions. The understanding of water and energy cycles in a farmland is crucial because it is a dominant land feature in Korea and Asia. However, the applications of CLM to farmland in Korea are in paucity. The simulations of water and energy fluxes by CLM were conducted against those from the tower‐based measurements during the growing season of 2006 at the Haenam site (a farmland site) in Korea without optimization. According to the International Geosphere–Biosphere Programme (IGBP) land cover classification, a homogeneous cropland was selected initially for this study. Although the simulated soil moisture had a similar pattern to that of the observed, the former was relatively drier (at 0·1 m³ m^?3) than the latter. The simulated net radiation showed good agreement with the observed, with a root mean squared error (RMSE) of 41 W m^?2, whereas relatively large discrepancies between the simulation and observation were found in sensible (RMSE of 66 W m^?2) and latent (RMSE of 60 W m^?2) heat fluxes. On the basis of the sensitivity analysis, soil moisture was more receptive to land cover and soil texture parameterizations when compared to soil temperature and turbulent fluxes. Despite the uncertainty in the predictive capability of CLM employed without optimization, the initial performance of CLM suggests usefulness in a data‐limited heterogeneous farmland in Korea. Further studies are required to identify the controls on water and energy fluxes with an improved parameterization. Copyright © 2010 John Wiley & Sons, Ltd.     

Temporal dynamics of phytoplankton communities in a semi-enclosed mariculture pond and their responses to environmental factors

Variations in physical-chemical factors, species composition, abundance and biomass of nano- and micro-phytoplankton assemblages, as well as their responses to environmental factors, were investigated over a complete cycle (6 months) in a semi-enclosed shrimp-farming pond near Qingdao, northern China. The aim was to establish the temporal patterns of phytoplankton communities and to evaluate protists as suitable bioindicators to water quality in mariculture systems. A total of 34 taxa with nine dominant species were identified, belonging to six taxonomic groups (dinoflagellates, diatoms, cryptophyceans, chlorophyceans, euglenophyceans and chrysophyceans). A single peak of protist abundance occurred in October, mainly due to chlorophyceans, diatoms and chrysophyceans. Two biomass peaks in July and October were primarily due to dinoflagellates and diatoms. Temporal patterns of the phytoplankton communities significantly correlated with the changes in nutrients, temperature and pH, especially phosphate, either alone or in combination with NO₃-N and NH₃-N. Species diversity, evenness and richness indices were clearly correlated with water temperature and/or salinity, whereas the biomass/abundance ratio showed a significant correlation with NO₃-N. The results suggest that phytoplankton are potentially useful bioindicators to water quality in semi-enclosed mariculture systems.