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运用遥感动态监测与地理信息系统技术相结合的方法,以2005年和2009年遥感解译数据、土地侵蚀数据及环境统计数据为数据源,依据《生态环境状况评价技术规范(试行)》(HJ/T192-2006),对山东省17个城市生态环境质量现状及动态变化趋势进行了评价。结果表明:2009年17个城市生态环境状况指数在59.81~78.08之间,生态环境质量状况总体良好;2005-2009年17城市生态环境状况指数变化值在0.06~3.5之间,生态环境质量状况基本稳定。 相似文献
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通过对曲阜市地理位置和自然资源现状、湿地类型和面积、湿地植被、湿地动物、湿地水生生物等基本情况的详细调查,客观地做出了曲阜市的湿地生态环境评价,提出了做好宣传唤起公众参与保护的意识,兼顾保护和利用并重,加大科技支持力度等湿地保护建议,以保持湿地生态平衡,促进社会经济与生态环境的协调发展。 相似文献
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西气东输工程塔里木气田开发建设区生物多样性(植被)及其影响评价 总被引:3,自引:0,他引:3
西气东输塔里木气源工程的开发建设行为势必对该地脆弱生态环境下的各类生物尤其是对植被产生较大影响。过去的很多研究表明该地的植被对土地资源的保护功能是极其重要的。因此,评价油气田开发对植被的影响也是开发前期必须的工作。 相似文献
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根据生态系统的分类,分别计算了山东省植被生态环境需水量、河流生态环境需水量、湖泊生态环境需水量、水库生态环境需水量和城市生态环境需水量,山东省生态环境需水量为上述各类型生态环境需水量之和。计算结果表明,山东省2000~2005年生态环境需水总量为342.64~345.01亿m^3。山东省2000~2005年生态环境需水保证率均小于50%,生态环境用水无法得到保证,且丰枯年份之间变化明显。 相似文献
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Puglisi E Nicelli M Capri E Trevisan M Del Re AA 《Journal of environmental quality》2003,32(2):466-471
In this work we analyzed the sterol content of agricultural soils. Three eukaryotic sterols, cholesterol, beta-sitosterol, and ergosterol were chosen as representative of the animal, plant, and fungal kingdoms, while coprostanol was validated as a marker of human fecal matter contamination. Three soils subjected to different treatments (sewage sludge application, irrigation by saline waters, and contamination by industrial and municipal wastes) were sampled and their sterol content was measured and compared with adjacent untreated soils. The effects of time, location, and treatment were evaluated by means of a number of statistical techniques. Beta-sitosterol concentration varied from 0.9 to 30 mg kg(-1). Lesser values were measured in Cremona (2.1 mg kg(-1)) than in Bari (4.0 mg kg(-1)) and Naples (10.9 mg kg(-1)) soils. No significant effects were detected for cholesterol and ergosterol. Coprostanol was present after sewage sludge disposal and contamination by industrial and municipal wastes, while it was absent in the soil treated with saline water and in the adjacent untreated soil. Coprostanol concentration did not vary much within site and time of sampling, with a mean value of 0.2 mg kg(-1). We confirmed coprostanol as a useful persistent marker of human fecal matter contamination. Multivariate analysis highlighted a clear distinction between the eukaryotic sterols and coprostanol. In addition, a different behavior between ergosterol and cholesterol on one side and beta-sitosterol on the other was detected. This preliminary work suggests that sterols deserve a deeper study of their use as indicators in agricultural soils. 相似文献
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VINCENT KAKEMBO 《Environmental management》2001,28(1):39-46
Spatial and temporal variations in vegetation are examined in relation to land tenure, population increase, and rainfall variation
in a part of Peddie district, Eastern Cape. Sequential aerial photographs between 1938 and 1988 are analyzed to determine
trends in vegetation and population change in three different land-tenure units. The areal extent at each date of four distinct
vegetation categories is determined using PC ARC/INFO GIS. Long-term annual rainfall trends for the area are analyzed and
juxtaposed with vegetation changes. Extensive ground-truthing exercises are carried out to verify the present condition of
vegetation condition in terms of cover and species composition. Differences in land-tenure systems are discerned as the dominant
factor controlling variations in vegetation degradation. The study also reveals that neither population changes nor rainfall
variations can explain the observed trends in vegetation degradation. Earlier injudicious land-use practices, sustained since
the turn of the last century, may provide plausible explanations for the trends and present status of vegetation degradation
in the area. 相似文献
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Hobbs R 《Journal of environmental management》2009,90(9):2857-2865
In the latter half of the 20th century, native pine woodlands in Scotland were restricted to small remnant areas within which there was little regeneration. These woodlands are important from a conservation perspective and are habitat for numerous species of conservation concern. Recent developments have seen a large increase in interest in woodland restoration and a dramatic increase in regeneration and woodland spread. The proximate factor enabling this regeneration is a reduction in grazing pressure from sheep and, particularly, deer. However, this has only been possible as a result of a complex interplay between ecological, political and socio-economic factors. We are currently seeing the decline of land management practices instituted 150-200 years ago, changes in land ownership patterns, cultural revival, and changes in societal perceptions of the Scottish landscape. These all feed into the current move to return large areas of the Scottish Highlands to tree cover. I emphasize the need to consider restoration in a multidisciplinary framework which accounts not just for the ecology involved but also the historical and cultural context. 相似文献
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Forest Cover Change,Physiography, Local Economy,and Institutions in a Mountain Watershed in Nepal 总被引:2,自引:0,他引:2
This study assessed changes in forest cover in a mountain watershed in central Nepal between 1976 and 2000 by comparing classified satellite images coupled by GIS analyses, and examined the association of forest change with major physiographic, economic, and local forest governance parameters. The results showed an increase in forested area (forest plus shrublands) by 7.6% during 1976–2000. Forest dynamism (changes including improvement, deterioration, gain, and loss) was highest in low-elevation, south-facing and less-steep slopes that were closer to roads. Proportionately the highest net improvement and gain to forested area also took place in those locations. Forest degradation occurred at twice the rate of improvement in high elevation areas (> 2300 m). Forests located in urban and semiurban areas (i.e., a market-oriented economy) experienced a proportionately higher amount of net improvement and gain than forests in rural areas (i.e., a subsistence economy). Among the three governance arrangements, proportionately the highest net improvement and gain took place in semigovernment forests (forested area legally under the forest department but with de facto control and claim of ownership by local communities and/or municipality) followed by formalized community forests (including leasehold). Government forests, which were mostly found in the southern high mountains and had virtually open access, remained relatively stable during the study period. Over 50% of the watershed forests have not come under community-based management despite favorable policy and more than two decades of government intervention with continuous donor support. The findings indicate that the present one size fits all approach of community forest handover policy in Nepal needs rethinking to accommodate biophysical and socioeconomic variations across the country. 相似文献
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This study examines the role of neighborhood effects in the spatial distributions of selected bird species in Navarre, Spain. We employed a geographic information system (GIS) to organize the data on bird distributions and relevant environmental variables and to analyze their spatial patterns. Three bird species were selected for analysis: the European honey-buzzard (Pernis apivorus), the Eurasian hobby (Falco subbuteo), and the European pied flycatcher (Ficedula hypoleuca). Selected environmental variables of the study area were digitized to create a comprehensive data base and logistic regression models were used to evaluate the significance of each variable in the spatial distribution. The spatial patterns of bird distributions were used to extract topological relationships and to identify neighborhood effects. Although all the selected species illustrate a pattern of positive spatial autocorrelation in their distributions, the significance of neighborhood effects varies from species to species. Among the selected species, neighborhood effects are most evident in the distribution of the European pied flycatcher and are significant for the Eurasian hobby. The distribution of the European honey-buzzard is not much affected by neighborhood effects. The results suggest that examination of neighborhood effects is a prerequisite for modeling bird distributions. 相似文献
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This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 +/- 4.6, 30.2 +/- 8.9, and 59.3 +/- 26.1 mg kg(-1) in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 +/- 3.0 mg kg(-1)) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg(-1) of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized. 相似文献
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Waite DT Cessna AJ Grover R Kerr LA Snihura AD 《Journal of environmental quality》2004,33(5):1616-1628
Herbicides are the most commonly used group of agricultural pesticides on the Canadian Prairies and, in 1990, more than 20000 Mg of herbicides were applied in the provinces of Alberta, Saskatchewan, and Manitoba. The present paper reports on environmental concentrations of five herbicides currently used in the prairie region. The herbicides bromoxynil [3,5-dibromo-4-hydroxy-benzonitrile], dicamba [3,6-dichloro-o-anisic acid], diclofop [(RS)-2-[4-(2,4-dichlorophenoxy)-phenoxy]propanoic acid], MCPA [(4-chloro-2-methylphenoxy)acetic acid], and trifluralin [alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-isopropyl-p-toluidine] were measured in the atmosphere, bulk atmospheric deposits, surface film, and dugout (pond) water at two sites near Regina, Saskatchewan, during 1989 and 1990. All five herbicides were detected in air and surface film and all but trifluralin were detected in the bulk atmospheric deposits and dugout water. Trifluralin was most frequently detected in air (79% of samples) whereas bromoxynil was present in maximum concentration (4.2 ng m(-3)). MCPA was present in maximum levels in bulk atmospheric (wet plus dry) deposits (2350 ng m(-2) d(-1)), surface film (390 ng m(-2)), and dugout water (330 ng L(-1)), whereas dicamba was most frequently detected in surface film (47%) and dugout water (97%). The highest quantities of the herbicides tended to be present during or immediately after the time of regional application. 相似文献
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This study was performed to investigate mercury (Hg) tolerance, accumulation, and translocation within the genus Salix for the potential use of this plant to remediate Hg-contaminated sites. Six clones of willow (Salix spp.) were tested on tolerance to Hg by treating plants grown in solution culture with 0 to 15 microM HgCl(2). Results showed that willow had a large variation in its sensitivity to Hg. However, the accumulation and translocation of Hg to shoots was similar in the eight tested willow clones as shown by cold vapor atomic absorption spectrometry analysis when plants were treated with 0.5 microM HgCl(2) in a nutrient solution. The majority of total Hg accumulated was localized to the roots, whereas only 0.45 to 0.62% of the total Hg accumulated via roots was translocated to the shoots. Thus, the root system is the main tissue of willow that accumulates Hg and the majority of the Hg in the root system (80%) was bound in the cell wall. 相似文献
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Zdravka Kostova 《The Environmentalist》1989,9(2):85-90
Summary Educational reforms in Bulgaria over recent years, have permitted a new and definitive environmental education programme to be introduced. This programme is particularly related to nature conservation. The programme has had an important impact on the whole secondary school curriculum and has also influenced the patterns of teacher training.Dr Zdravka Kostova is a Senior Research Associate at the Educational Research Institute in Sofia, Bulgaria. 相似文献