Simulation and Trend Analysis of the Water Quality Monitoring Daily Data in Nestos River Delta. Contribution to the Sustainable Management and Results for the Years 2000–2002

The transboundary River Nestos in the Balkan Peninsula is a surface water resource shared by Hellas and Bulgaria. The Public Power Corporation of Hellas (DEH) proceeded to the dams' construction of Thesaurus in 1997 and Platanovrissi in 2000, to satisfy the increased needs for power production and irrigation in the Regions of Eastern Macedonia and Thrace in the Hellenic Territory. DEH following the Ministerial Agreement of the Hellenic Parliament ‘`KYA 18492/19—09—1996’' funded a series of Research Projects concerned on the monitoring of the water quantity and quality data of Nestos from the Hellenic-Bulgarian borders to its estuaries in the Thracian sea. ‘`PERSEAS’' Research Group from Aristotle University of Thessaloniki, carried out the research, design, construction, installation, operation and maintenance of the ‘`R.E.MO.S.’' (Remote Environmental MOnitoring System) networks. Three REMOS networks have been installed in the areas of (a) the River Nestos deltaic channel, (b) Thesaurus dam-lake in the intramountainous valley and (c) Potamoi (Despat) and Pagoneri (Nestos) villages close to the borders between Hellas and Bulgaria. They record water level (H), water and air temperature (T), water conductivity (ECw), Redox potential (RP) and dissolved oxygen (DO) on a 24h basis, since the beginning of the year 2000. The research carried out in this paper, is focused on the REMOS station in the final course of Nestos in the deltaic area. The continuous monitoring and the data analysis yield useful results for the quality and quantity of the hydrologic regime of Nestos after the dams' construction, as well as for the trends detected of the quality parameters (ECw, RP and DO) and the water level, using the nonparametric Spearman's criterion. The best fitted model of time trend, for each variable, was chosen. The statistical sample of each one of the quality variables consisted of about 1000 values based on daily measures on a three years monitoring program (1/1/2000—31/12/2002). Further research and analysis for the other network stations of REMOS should provide useful results for the sustainable management of the transboundary River Nestos.     

Temporal and Spatial Variation of Nutrient Levels in the Nemunas River (Lithuania and Belarus)

There are discordant results on trends in nutrient river water quality from the economical transition countries in Europe. The present study assessed the impact of these economical changes on the load and concentration at 17 monitoring stations along the Nemunas River and its major tributaries (Lithuania and Belarus). Three time periods were evaluated: the Soviet rule command system period 1986–1991, the transfer to market economy period 1992–1996 and the post reform period 1997–2002. The most surprising result in this study, was the increased area-specific load of NO₃-N from the first to the third period at almost all the sampling sites. The increase was particularly large (43–78%) at the sites in the Lithuanian part of the river. The corresponding load increase in the Belarussian part of the river was only 1–15%. The statistical analyses of concentration data confirm the strong upward NO₃-N trend at the Nemunas mouth and at 5 of the 6 tributaries in the lower part of Nemunas. Temporal and spatial analysis of nitrates transport in the Nemunas River and its main tributaries revealed that nitrates mainly originate from agricultural areas. The upward trends were most likely an effect of ploughing of pastures and unbalanced crop fertilisation in combination with large storage and accumulation of soil-nitrogen during the Soviet period.On contrary to nitrate-N, the area-specific load of PO₄-P decreased significantly from the first to the third period at all sites along the Nemunas River (31–86%). Seasonal (SMK) and Partial (PMK) Mann-Kendall tests on PO₄-P concentrations also showed significant downward trend at 14 of 16 investigated sites. The decrease of PO₄-P levels was attributed to the reduction of municipal and industrial point source emissions and to the decreased livestock numbers.The NH₄-N load showed the same pattern as PO₄-P. At the river mouth the load was 90 kg km⁻² yr⁻¹ during the first period compared to only 20–30 kg km⁻² yr⁻¹ in the third period. The trend test on NH₄-N concentrations detected significant downward trends at 5 out of 16 sites. The declines were explained by decreased emissions from cities and large animal breeding farms.This study showed that trend analysis at multiple sites in a river basin is crucial for the understanding of the variability in time and space. Such analysis is also important for our interpretation of underlying sources and fluxes in a drainage basin over time. This is particularly important for compounds that have different source origin.     

我国生活垃圾的处理现状及发展趋势

生活垃圾是人类面临的一个普遍性问题,关系着人口、资源、环境是否能协调发展.介绍了城市生活垃圾的处理现状和存在问题,从各角度分析了各种方法的优缺点,介绍每种方法的最新进展.最后指出应根据本地区不同的地理环境、垃圾成分及经济发展水平采用不同的垃圾处理模式.     

我国工业SO2排放趋势及影响因素分析

分析了我国工业SO2排放量的变化趋势,以及其与GDP、工业产值、火电厂发电量等指标的变化关系;利用50个省市1998—2007年的有关数据建立了SO2排放量的影响因素面板数据模型,力求通过定量分析识别影响我国工业SO2排放量的关键因素。研究表明,我国工业SO2排放量与第二产业比重、火力发电比重并无明显关系,而GDP、发电量、一次能源转化效率、SO2去除率存在显著关系,对SO2工业实际排放量起决定作用的是SO2的去除率。     

云南干旱的气候特征及变化趋势研究

以Thornthwaite水分平衡干燥度指数为主和自定义的反映短期降水有效性和异常性特征的有效降水指数为辅构建单站干旱综合指数,并定义了定量描述云南省受旱程度的干旱面积指数和干旱强度指数。采用变率和变差系数作为长期气候特征的定量指标,用云南省1959-2005年的资料,分1-3月、4-6月上旬、6-8月、9-10月、11-12月5个时段对云南省的干旱气候特征及变化趋势进行定量分析研究。结果表明：云南1-3月干旱最严重,平均每年有约2/3的土地受旱;其次是11-12月,有约50%的土地受旱;再次是4-6月上旬,有22%的土地受旱;9-10月干旱较轻,有约5%的土地受旱;6-8月平均受旱面积不到1%,基本不受干旱的影响。云南4-6月上旬和9-10月这两个时段干旱有发展加重的气候变化趋势,且9-10月加重的趋势更明显;1-3月干旱有减轻的趋势;11-12月和6-8月干旱变化趋势不明显。     

中国不同发展阶段地区环境可持续性状态与趋势研究

中国不同地区发展水平存在较大的差异．面临的环境问题和可持续发展的优先领域也不同。因此．可持续发展评价与政策制定需要与区域发晨实际相结合。选取上海、德州和固原三个地区作为中国发达、发展中和欠发达地区的代表．选择可操作和可比性强的指标．基子压力-状态-响应模型．构建了环境可持续性趋势系数．对比不同发展水平地区环境发展的状态、趋势和存在的主要问题。得出以下结论：近20年来．虽然中国总体环境保护能力有了一定的提高．但污染物排放压力持续增长．环境质量普遍恶化的趋势没有得到根本改变;上海、德州和固原环境可持续性趋势系数分别为0．82、0．55和0．45．发达地区环境可持续性最强．发展中地区一般．欠发达地区量差;目前我国环境政策领域往往注重经济发展的“两极”：高度发达地区和欠发达地区,本文的研究结果表明。面积占全国67％、人口占全国40％的发展中地区环境问题最为突出。     

Effects of arsenic on seed germination and physiological activities in wheat seedlings

The effects of arsenic(As)were investigated on seed germination,root and shoot length and their biomass and some other factors to elucidate the toxicity of As.The results showed low concentrations of As(O-1 mg/kg)stimulated seed germination and the growth of root and shoot,however,these factors all decreased gradually at high concentrations of As(5-20 mg/kg).The contents Of O2-,MDA,soluble protein and peroxidase(POD)activity all increased with increasing As concentrations.Soluble sugar content,ascorbate peroxidase(APX),and superoxide dismutase(SOD)activities decreased at low concentrations of As,and increased at high concentrations of As.While acetylsalicylic acid(ASA)and chlorophyll contents,catalase(CAT)activity displayed increasing trend when the concentrations of As was lower than 1 mg/kg,and then decreasing trend.By polyacrylamide gel electrophoresis(PAGE).As induced the expression of POD isozymes of wheat seedlings.As induced the expression of CAT isozymes but inhibited the expression of SOD isozymes of wheat seedlings at concentrations lower than 1 mg/kg.However,As inhibited the expression of CAT isozymes but induced the expression of SOD isozymes at concentrations higher than 5 mg/kg.The results indicated As could exert harmfulness in the early development stage of wheat at inappropriate concentrations.     

上海地区洪涝致灾因子复合概率及未来变化分析

根据上海地区三阶段(1970-2004年,2020-2054年和2060-2094年)四要素(降水、吴淞口风速、太湖流域面雨量、吴淞口潮位)提取年极值时间序列,采用GEV分布首先开展"雨洪风潮"各致灾因子气候变化分析,结果显示:"雨洪风潮"各致灾因子年极值受气候变化影响均呈增加趋势;进而基于Copula联合函数中的三维...     

输变电工程建设的环保要求及其变化趋势分析

从环境敏感区的保护、公众参与、土地占用、施工期环境影响、景观协调性等方面对输变电工程规划、设计和建设过程中的环保要求以及变化趋势进行了较为全面的分析,对输变电工程规划、选址、选线、施工阶段等环节提出环境保护方面的意见和建议.     

自动控制系统在污水处理厂的应用分析

说明了污水处理厂自动控制系统的类型、特点与应用研究现状,介绍了自控系统在国内外污水处理厂的应用研究现状,分析了污水处理厂自控系统广泛应用的限制因素,并指出了今后污水处理厂自控系统的发展趋势。