基于神经网络模型的千岛湖清洁水体叶绿素a遥感反演研究

叶绿素a浓度值是水体水质评价的重要指标,研究基于高分一号(GF-1)卫星遥感影像,利用神经网络模型,选用6节点的隐含层设置,构建了千岛湖清洁水体叶绿素a浓度反演模型,对其叶绿素a浓度值时空特征进行分析,并与其他常规反演方法精确度进行比较.研究结果表明,利用神经网络模型对千岛湖清洁水体叶绿素a浓度值进行反演是可行的,且与其他常规方法相比,该模型对于叶绿素a含量低的内陆清洁水体反演有着更高的相关性(R2 = 0.921 8);在空间分布上,千岛湖区域水体叶绿素a浓度整体较低,高叶绿素a浓度区域主要集中易受人类活动干扰的西南及东北区域;年际变化分析表明,千岛湖区域水体叶绿素a浓度稳定,且波动较小,平均叶绿素a浓度值皆维持在1.70～1.75 pg/L之间,清洁水体特征显著.     

鄱阳湖蝶形湖泊水体氮磷等的变化及污染初步评价

分别于2014年夏季7月和冬季12月对鄱阳湖蝶形水域的9个湖泊进行了采样,并对湖泊水质基础性指标TN、TP、NH_3-N、NO_3~--N、NO_2~--N、溶解性磷酸盐、TOC、COD_(Mn)和叶绿素a进行了测定与分析。据此同时运用单因素评价法、均值型指数综合评价法和营养状态指数法对鄱阳湖蝶形水域的地表水水环境的污染现状和污染程度进行了评价,以更全面和准确地反映鄱阳湖蝶形水域的水质状况。结果显示:(1)鄱阳湖蝶形水域水质总体符合GB3838-2002III类水标准;(2)7月水质总体优于12月水质。12月总氮含量和总磷含量基本都高于7月,叶绿素a含量除中湖池12月值略低于7月外,其它点位12月值均高于7月。7月总氮值为0.6~1.3 mg/L,总磷值为0.02~0.15 mg/L,叶绿素a为2.2~6.7 mg/L;12月总氮值为0.6~2.0 mg/L,总磷值为0.04~0.19 mg/L,叶绿素a为3.8~34.7 mg/L;(3)7月和12月水质营养状态介于中营养和轻度富营养,水体主要污染物质为总氮和总磷。7月蚌湖营养状态为轻度富营养,其它点位为中营养,12月除常湖、梅溪湖和大汊湖营养状态为中营养,其它点位均为轻度富营养;(4)位于南部的象湖、常湖、白沙湖和大汊湖水质整体较其它蝶形湖泊差,主要是受到工业废水、生活污水和农业面源污染的赣江和饶河的污染输入影响所致。基于以上调查测试结果提出保护和改善鄱阳湖水环境的可行性措施,以促进鄱阳湖蝶形水域水资源的开发利用,实现经济与环境及资源的协调可持续发展。     

淀山湖浮游植物叶绿素a粒径组成及其与水质因子相关性

于2005年6月至2006年5月对淀山湖小型(20～200μm)、微型(2～20μm)和微微型(<2μm)浮游植物叶绿素a和水质因子进行逐月调查研究。结果表明:小型和微型浮游植物是淀山湖水体年均叶绿素a的主要贡献者,二者贡献率之和为74.79%。淀山湖叶绿素a粒径组成百分比的季节变动与水体浮游植物群落结构季节演替密切相关:小型浮游植物叶绿素a浓度所占百分比春季最高,而微型、微微型的则分别在秋、冬季最高。相关性分析显示,小型、微型浮游植物叶绿素a浓度百分比与NH3-N含量分别呈显著正、负相关,微微型浮游植物叶绿素a百分比与BOD5呈极显著负相关。对应滤食性鱼类等水生动物的食性粒级,探讨了运用非经典生物操纵技术防治淀山湖富营养化的可行性。     

阳澄西湖叶绿素a的时空分布及其与环境因子的关系

根据2015年3月~2016年2月对阳澄西湖水体叶绿素a和水质理化因子的逐月监测结果表明,阳澄西湖叶绿素a浓度存在着明显的季节变化,其全年变化范围为11.93μg/L~66.67μg/L,平均值为27.54μg/L±20.34μg/L。最小值出现在2016年1月,最大值出现在2015年8月。叶绿素a在空间分布上也存在着差异,叶绿素a在断面Ⅰ浓度最高,其次是断面Ⅱ和断面Ⅳ,断面Ⅲ最低。根据综合营养状态指数法计算阳澄西湖营养状态,得出综合营养状态指数范围为50.7~59.3,年平均值为55.6,水体总体处于"轻度富营养"状态。综合pearson相关系数和逐步回归方程,结果表明叶绿素a与水温呈极显著正相关,与溶解氧呈极显著负相关,与透明度呈极显著负相关。结合生产实践对阳澄西湖总氮(TN)、总磷(TP)和氮磷比(N/P)取对数进行pearson相关性分析并建立一元线性回归方程,结果表明叶绿素a浓度与总氮无相关关系,与总磷呈极显著正相关,与氮磷比呈极显著负相关,阳澄西湖可能是一定程度的磷限制湖泊。     

次级河流回水区叶绿素a与影响因子的多元分析——以临江河为例

为了对次级河流回水区富营养化进行深入研究，把长江次级河流之一的临江河回水区为研究对象，根据2007年10月至2008年9月临江河回水区中游叶绿素a含量及其水质理化指标的监测数据，分析了临其叶绿素a浓度的时间分布，对叶绿素a浓度及影响因子进行相关分析，找出与叶绿素a显著相关的环境因子并建立多元逐步回归模型。结果表明：临江河回水区叶绿素a浓度峰值主要集中在5月上旬至9月下旬，变化范围为227～661 mg/m3。临江河回水区叶绿素a浓度变化受多个环境因子共同影响，与水温、流速、透明度、COD、总磷之间显著相关，而与总氮相关性不显著。经过叶绿素a及其影响因子的相关分析，建立了以水温、流速和总磷为自变量，叶绿素a浓度为应变量的逐步线性回归模型，模型初步验证结果表明：多元逐步回归模型可以用来描述临江河回水区叶绿素a浓度的变化。通过对临江河回水区叶绿素a及其影响因子的分析，控制临江河回水区水体中磷含量应是其富营养化防治工作的重点，防治工作应主要在春末和整个夏季，尤其是在5、6月份。     

云南高原典型湖泊水样氮磷含量随低温储存时间的变化

总氮(TN)、总磷(TP)是评价湖泊水体富营养化的主要指标,而实验分析中的总氮、总磷含量的测定结果受诸多因素(如水样储存方式、储存时间和氮磷赋存状态等)的影响,易造成分析数据的不稳定性。对于云南典型喀斯特地区湖泊水体氮磷含量分析而言,特别是在采样点距实验室距离远、样品数量多的情况下,不能按实验分析标准要求时间完成分析。该研究针对云南九大高原典型湖泊的特殊性和在大批量样品采集、远距离搬运、实验分析需要一定时间的实际情况,选择3个氮磷含量差异较大的抚仙湖、阳宗海和滇池为研究对象,对采样后样品在低温储存条件下随测定时间而发生变化进行分析,探讨样品TN、TP和溶解态氮(DN)、溶解态磷(DP)含量的变化特征,以确定最佳的实验分析时间。研究结果表明:(1)采样后即进行氮磷含量分析结果显示:3个湖泊水样氮磷含量差别明显,同时存在状态不相一致,滇池样品中氮磷含量最高,其TN含量为2.44 mg/L,DN含量为1.47 mg/L,占总氮的60%,TP含量为0.13 mg/L,DP含量为0.02 mg/L,占总磷的15%;阳宗海次之,其中TN含量为0.73 mg/L,DN含量为0.60 mg/L,占总氮的82%,TP含量为0.04 mg/L,DP含量为0.03 mg/L,占总磷的75%;抚仙湖最低,其中TN含量为0.32 mg/L,DN含量为0.28 mg/L,占总氮的90%,TP含量为0.02 mg/L,DP含量为0.01 mg/L,占总磷的50%;(2)样品在低温室(3℃～4℃)随着静置时间的增长,TN、TP含量均呈现降低趋势,说明静置时间对其有影响;其中滇池和阳宗海水样总氮总磷含量降低幅度较大,而抚仙湖较小;(3)样品经过滤后,滇池阳和宗海的水样氮磷含量呈现降低趋势,而抚仙湖则无明显变化。样品储存时间、过滤处理对氮磷含量低的湖泊水样影响较小,对氮磷含量大的湖泊影响较大,尤其是颗粒态氮磷含量较高的样品。由于水样中氮磷存在多种形态,湖泊营养程度不同,在对水样进行氮磷含量测定时,应当考虑水样储存时间和氮磷赋存状态等因素。     

金头闭壳龟野外生存环境及资源现状调查

为弄清金头闭壳龟野外生存环境及资源现状，2008年7月20日至8月5日，对安徽省南部的黟县、泾县等地进行了调查。调查结果显示：黟县的清溪河和泾县的漕溪河、汀溪河和孤峰河的河流水质清新，未发生富营养化，水化指标范围：pH 5.5～7.0，水温24℃～29℃，DO 6.887～10.421 mg/L，硬度0.42～1.76 mmol/L，总磷0047～3.014 mg/L，亚硝酸盐氮0.009～0.104 mg/L，氨氮0.022～0.043 mg/L，除总磷和氨氮指标外，其他指标均符合Ⅰ或Ⅱ类水质标准；主要分布区域河流的浮游生物量较少，以绿藻门和硅藻门为主，其中绿藻门占浮游植物总属数的35%以上，硅藻门占浮游植物总属数的28%以上，主要分布区域河流底部有大量的螺蛳；2000~2008年，共捕获和销售金头闭壳龟约20只，野外生存量已不足100只。分析认为：金头闭壳龟资源已经处于极度濒危状态，野外生存环境已遭到严重的影响，但原产地的水质及饵料生物条件尚好，需进行连续的资源调查，积极开展人工繁殖，开展资源保护，筹建保护区，拯救这一濒危物种。〖     

淀山湖浮游植物叶绿素a粒径组成及其与水质因子相关性

于2005年6月至2006年5月对淀山湖小型（20～200 μm）、微型（2～20 μm）和微微型（<2 μm）浮游植物叶绿素a和水质因子进行逐月调查研究。结果表明：小型和微型浮游植物是淀山湖水体年均叶绿素a的主要贡献者，二者贡献率之和为7479%。淀山湖叶绿素a粒径组成百分比的季节变动与水体浮游植物群落结构季节演替密切相关：小型浮游植物叶绿素a浓度所占百分比春季最高，而微型、微微型的则分别在秋、冬季最高。相关性分析显示，小型、微型浮游植物叶绿素a浓度百分比与NH3 N含量分别呈显著正、负相关，微微型浮游植物叶绿素a百分比与BOD5呈极显著负相关。对应滤食性鱼类等水生动物的食性粒级，探讨了运用非经典生物操纵技术防治淀山湖富营养化的可行性。〖     

基于光合色素的化学分类法在淡水藻类研究中的应用

采用反相高效液相色谱技术(RP HPLC)系统研究了我国主要淡水藻类--蓝藻、绿藻、硅藻、甲藻、金藻、裸藻和隐藻等的光合色素，在8种纯培养藻类中共确定类胡萝卜素、叶绿素及其衍生物19种。分离到的主要标志性色素按洗脱时间分别为脱植基叶绿素a、19′ 丁酰氧岩藻黄素、叶绿素c、脱镁叶绿素a、多甲藻素、甲基脱植基叶绿素a、岩藻黄素、新黄质、紫黄质、蓝藻叶黄素、硅甲藻黄素、硅藻黄质、叶黄素、玉米黄素、叶绿素b异构体、叶绿素b、叶绿素a异构体、叶绿素a和β 胡萝卜素；其中在纯培养的铜绿微囊藻中首次鉴定到19′ 丁酰氧岩藻黄素；通过官桥基地的实际监测，证实了该技术应用的可行性，为基于HPLC分析技术的浮游植物化学分类法提供了理论依据。     

淀山湖叶绿素a的高光谱遥感监测研究

为实现淀山湖水体叶绿素a的快速监测, 于2006年春季对淀山湖进行了现场光谱测量和同步的采样、实验室分析,通过分析叶绿素a和光谱数据之间的关系,建立了多个基于高光谱数据的叶绿素a浓度的估算模型。结果表明：利用归一化反射率建立的模型中精度最高的是采用708 nm反射率的一元二次模型,R2为0.608;利用R710nm/R667nm反射比建立模型精度得到提高,R2接近0.68;利用695.5 nm一阶微分建立的指数模型精度进一步提高,其R2达到了0.76;分别利用708 nm和667 nm的归一化反射率对数作自变量进行多元回归得到的模型精度最高,R2接近0.8,可以用来实现对叶绿素a的定量估算,实现叶绿素a的快速监测。     

WSSD 2002, Latin America and Brazil: Biodiversity and Indigenous People

Latin America comprehends notable variations in terms of natural environment, availability of natural resources, living standards, and demographic patterns. Latin America is a mosaic of cultures, post- and pre-Columbian. The rich variety of life forms discovered and described by chroniclers and traveling naturalists in the Neotropics contributed to the proposal, in mid-XVIIIth century, of a new system of classification and a scientific code of nomenclature for all organisms. Biodiversity was, for many centuries, a source of resources to be exploited in natura. In scientific circles, its inventory became the domain of taxonomists. But modern technology showed how important the miriad of life forms really are as sources of chemical molecules to be engineered as drugs and reassembled as novel manufactured products. We are on the brink of a new agricultural and medical revolution, thanks to the techniques of genetic engineering, which will lead eventually to the elimination of hunger and malnutrition.In this essay, the Brazilian environmental and social heterogeneity will serve as an example to illustrate some key points, which have influenced sustainability policies. The Amazon deforestation and indigenous knowledge (IK), subjects often associated with areas of high biodiversity, are usually the focus of environmental debates. The importance of IK in integrating development, reducing poverty and sustainability are considered together with the intellectual property rights of native populations.In the World Summit on Sustainable Development (WSSD) Implementation Plan, a few paragraphs were dedicated to Latin America, because of the pre-existing Action Platform on the Road to Johannesburg 2002, approved in Rio de Janeiro in October 2001. This paper calls attention to the need to draw up specific environmental policies for a region which shows an extremely high cultural and biological diversity, associated with a high availability of forests and water, among other resources.     

The Phenomenon of Pseudoviviparity in Alpine and Arctomontane Grasses (DeschampsiaBeauv., FestucaL., and PoaL.)

It is known that pseudoviviparous plant taxa are most numerous in the Arctic and high mountain regions, where they sometimes account for a noticeable part of the local flora and play an important phytocenotic role. The complex of pseudoviviparous taxa is an interesting model for investigating the processes of hybridogenic speciation, as various mechanisms stabilizing the hybrid genetic systems proved to be effective in them. In particular, this concerns vast and taxonomically complex groups such as the genera Deschampsia, Festuca, and Poa.In this paper, published data on the taxonomy, chromosome numbers, and distribution of pseudoviviparous grasses in the Arctic regions and subarctic mountain systems are reviewed.     

Conservation, commercialisation and confusion: harvesting of Ischyrolepis in a coastal forest, South Africa

Harvesting of non-timber forest products is an integral component of rural livelihoods throughout the developing world. At times this is at odds with conservation objectives. Reconciliation of the two requires examination of local level contexts and needs. This paper reports on the harvesting needs for Ischyrolepis by a rural community in South Africa, against the setting that they had recently been prohibited from harvesting by the local conservation officials. Interviews were conducted with conservation officials to understand the reasoning for the prohibition. Local demand for Ischyrolepis was assessed by household surveys, as well as in-depth interviews with traders. The density and size class distribution of Ischyrolepis was determined using transects. The total annual demand for Ischyrolepis was determined to be approximately only 2.7% of the standing crop. The bulk of the annual demand was for small-scale trade, the income from which was a primary source of income for the few harvesters. Very little evidence could be found indicating that harvesting was damaging the resource or its habitat, and local knowledge suggested that the abundance of the species was stimulated by harvesting. Even if market demand were to increase, the size of the shoots required means that less than 20% of the standing crop could be harvested annually. Current regulations around harvesting are in a state of revision, and hence confusion prevails regarding if harvesting is permissible, and if so, under what conditions, which is detrimental to both conservation and livelihoods. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Radionuclide content of building materials and associated gamma dose rates in Egyptian dwellings

Studies have been carried out to determine the natural radioactivity in some building materials (bricks, tiles, marble and ceramics) and their associated radiation hazard. The radioactivity concentrations of ²²⁶Ra ²³²Th and ⁴⁰K were measured using a gamma spectrometer with a Hp–Ge detector. The activities of ²³⁸U and ²³⁴U were measured using an alpha-spectrometer with a surface barrier detector after applying a radiochemical procedure. The ²³⁴U/²³⁸U isotopic ratios were calculated. The radium equivalent activities and the radiation hazard index associated with the natural radionuclides were calculated. A computer program was developed and applied to calculate the dose rate a person will receive from the walls of a room constructed from the studied building materials.     

Education for Sustainable Development: The Johannesburg Summit and Beyond

The World Summit on Sustainable Development (WSSD), held in Johannesburg during 26 August and 4 September 2002, was a truly remarkable event, not least because it identified and committed the world community to what has to be done to realise Agenda 21 objectives. Discussion begins with the "means of implementation" of the Johannesburg Plan of Implementation (JPI). Education for, and raising awareness of, sustainable development are the key commitments in the "means of implementation". The issues central to these commitments are discussed. The crucial role of moral philosophy in education for sustainable development is then discussed. Defining the "problem" as lack of progress (in fact negative progress between Rio and Johannesburg) towards global sustainable development, a cause–effect relationship of the "problem" is developed based on a systematic and logical analysis. It shows that the "cause" is West's profoundly materialistic, environment-degrading and exploitative attitude and activities to satisfy grossly unsustainable, hedonistic and insatiably avaricious Western life-styles – life-styles that are held up by the West as "ideal" fruits of economic "development" to be aspired by all. The "effects" are pollution of air, water and soil; mounting loss of biodiversity, ecosystems and species; relentlessly widening north–south divide, etc. It is argued that while science and technology can address some of the "effects", they cannot address the "cause". Only moral philosophy can by fundamentally re-orienting moral values genuinely to respect nature and the environment. Based on sound and tested principles of Educational Psychology, a proposal is then made for including moral philosophy in the formal curricula (content and pedagogy) of primary, secondary and higher education for instilling in children and young people genuinely environment-respecting moral values. To this end a generic syllabus for the secondary level is proposed. Finally, it is argued that if the scientific community really believes that science or technology alone can radically change the pervasive environment-degrading moral values to those that genuinely respect the environment, thus paving the way to real global sustainability, then it must demonstrate how this could be done and explain why, despite their abundant science and technology, the developed nations are the biggest polluters and consumers with grossly unsustainable life-styles. Certainly, examples would be much more convincing than rhetoric or tired old clichés about how science and technology alone could deliver global sustainable development.     

Do nanoparticles present ecotoxicological risks for the health of the aquatic environment?

Nanotechnology is a major innovative scientific and economic growth area, which may present a variety of hazards for environmental and human health. The surface properties and very small size of nanoparticles and nanotubes provide surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive radicals. There is a wealth of evidence for the harmful effects of nanoscale combustion-derived particulates (ultrafines), which when inhaled can cause a number of pulmonary pathologies in mammals and humans. However, release of manufactured nanoparticles into the aquatic environment is largely an unknown. This review addresses the possible hazards associated with nanomaterials and harmful effects that may result from exposure of aquatic animals to nanoparticles. Possible nanoparticle association with naturally occurring colloids and particles is considered together with how this could affect their bioavailability and uptake into cells and organisms. Uptake by endocytotic routes are identified as probable major mechanisms of entry into cells; potentially leading to various types of toxic cell injury. The higher level consequences for damage to animal health, ecological risk and possible food chain risks for humans are also considered based on known behaviours and toxicities for inhaled and ingested nanoparticles in the terrestrial environment. It is concluded that a precautionary approach is required with individual evaluation of new nanomaterials for risk to the health of the environment. Although current toxicity testing protocols should be generally applicable to identify harmful effects associated with nanoparticles, research into new methods is required to address the special properties of nanomaterials.     

Household water in rural asia: a case study of the construction of a piped water system in Bangui,Ilocos Norte,Philippines

In early 1980 an extension agent was assigned to the rural municipality of Bangui, Ilocos Norte, Philippines to work on development projects – in particular the improvement of the supply of safe water for drinking and sanitation. After many months of visiting spring sites and meeting with community leaders, a small part of the municipality was selected to build a gravity fed piped water system. Although the system took many months to plan, identify funding and construct, the 600 community members were ultimately rewarded with house to house connections that enabled them to achieve per capita water consumption levels above the minimum levels recommended by the World Health Organization. Of course, money was critical to ensure the project’s success, but many other factors played an equally critical role. For instance, without the active participation of the community and the unwavering support of the community leadership the project would not have survived the initial planning stage. Also, the extension agent played a critical role by acting as a conduit between funding agencies, the Bureau of Public Works and the community. The primary lesson to be learned from this experience is that the success of rural development projects is largely driven by the synergy between the community, technical support, financial support, and agents of change such as extension agents. If any of these ingredients had been lacking, the project result would likely have been far different.