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241.
归一化植被指数(NDVI)是反映植被状况的重要指标,对植被生长和区域生态状况的研究具有重要意义。为探究辽河三角洲植被生态状况变化特征和未来发展趋势,基于1995—2009年的NOAA/AVHRR NDVI和2009—2020年FY3/MERSI NDVI数据,通过修正拟合和S-G滤波法构建了1995—2020年长时间序列NDVI数据集。利用趋势分析法、变异系数和Hurst指数分析辽河三角洲(盘锦地区)NDVI时空分布特征,重点研究了水田和沼泽湿地的植被生态状况变化规律和未来发展趋势。结果表明:(1)从时间变化上看,26 a间辽河三角洲NDVI呈波动增加趋势,年平均增长率为0.32%;NDVI年内呈典型的单峰型分布,最大值出现在7月下旬或8月上旬。(2)从空间变化上看,区域内NDVI呈西南—东北方向递增,最高值主要分布在水田区,次高值分布在沼泽区。(3)绝大部分水田植被逐年变好,且植被生态状况比较稳定,低波动变化区域占96.72%,未来植被生态状况将持续改善的区域占61.05%。(4)沼泽植被逐年变好的区域占97.67%,变好最明显的区域主要分布在南部沿海地区和双台子河口附近,且该区域未... 相似文献
242.
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. 相似文献
243.
Sileika AS Stålnacke P Kutra S Gaigalis K Berankiene L 《Environmental monitoring and assessment》2006,122(1-3):335-354
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. 相似文献
244.
我国生活垃圾的处理现状及发展趋势 总被引:3,自引:0,他引:3
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. 相似文献
245.
突发性环境事件时间序列特征可表征环境风险管理成效及存在问题。研究表明2000年以来中国突发环境事件预防、控制与管理取得了显著成效,其中,突发性水污染事件、大气污染事件以及噪声振动危害年发生频次呈大幅度降低趋势,但固废污染事件自2003年以来的年发生频次变化不大,而其它突发性环境事件自2002年以来的年发生频次则呈快速增长态势,说明中国在强调突发性水环境和大气环境事件监管的同时,还需加强固废污染事件及其它类型突发环境事件的监控与管理。 相似文献
246.
文中所说“总量控制”,全称是污染物排放总量控制制度。当污染物超出环境容量,总量控制一般以削减现有总量的方式出现,也就是通常所说的“减排”。结构减排在减排中占据主导的核心地位。实践表明,“节能必减排,减排促节能”。节能减排相结合是推动经济发展方式转变、调整经济结构、提高自主创新能力、实现环境与发展“双赢”的一种有效途径,也是科学发展的必然要求。节能减排与应对气候变化密不可分,是应对气候变化的主要支撑面。控制温室气体(以CO2为代表)排放强度,是对污染物排放总量控制制度的深化与发展。 相似文献
247.
Yu-Chi Weng Takeshi Fujiwara Yuzuru Matsuoka 《Journal of Material Cycles and Waste Management》2009,11(2):110-122
Industrialization and urbanization result in significant changes in lifestyle. These lifestyle changes seem to lead to unsustainable
consumption patterns and increase the generation of various kinds of environmental loads, especially the amount of municipal
solid waste (MSW). Taiwan is a small island with scarce natural resources. The economic development in Taiwan has resulted
in the generation of large amounts of MSW. As a result, the Taiwan Environmental Pollution Administration (TEPA) has produced
regulations for waste minimization and has imposed several important policy measures that have successfully reduced the MSW
discard rate in recent years and have established a public recycling network as a part of the MSW collection. Nowadays, the
objective of the MSW policies in Taiwan is to develop a “zero-waste society.” This article aims to review the MSW management
progress in Taiwan and to project future MSW discards up to 2011 based on the national plan and assumed scenarios for socioeconomic
variables. According to the analysis results, a more sustainable consumption pattern can be proposed and the corresponding
MSW management system can be planned so as to develop a low-waste-discard society. 相似文献
248.
Agamuthu Periathamby Fauziah Shahul Hamid Kahlil Khidzir 《Journal of Material Cycles and Waste Management》2009,11(2):96-103
Solid waste generation and its implications for people and the environment are global issues. The complexity of the waste
composition and the ever-increasing percapita waste generation is a challenge for waste managers, particularly in developing
countries. Thus, the need to have a clear policy on waste management and legislation to realize that policy is imperative.
Malaysia is developing rapidly and problems such as the waste generation associated with development and industrialization
are evident. The Solid Waste and Public Cleansing Management Bill, which was approved in August 2007 after a 10-year delay,
is envisaged to have serious consequences in waste management practices and implementation in Malaysia. This article explores
the main features of this all-encompassing bill and its impacts on the waste management scenario in Malaysia. In addition,
a comparative evaluation is also discussed to explore the policies/legislation of selected countries vis-àvis the Malaysian
bill. 相似文献
249.
250.
详细分析了2001-2010年天津市环境空气中铅污染变化趋势,找出了变化趋势的源排放因素及气象因素,探讨了铅污染水平与PM10、TSP、降尘(灰尘自然沉降量)、大气污染源烟尘排放量的相关性. 相似文献