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1.
Characteristic levels of metal ions in post dredged sediment and dredged sediments materials of a municipal creek in the Niger Delta show that significant concentrations of heavy metals are found to be accumulated more on the surface (0–15cm depth) of the dredged material as compared to the sub surface (15–30cm) and post dredged sediments. The distribution patterns were in the following order Fe > Mn > Zn > Cu > Pb > Ni > Cd and Fe > Mn > Zn > Pb > Cu > Ni > Cd for the post dredged sediment and dredged sediment materials respectively. The levels of the various metals were far below the EPA screening levels for open water disposal, consequently total levels of heavy metal found in these sediments pose no problem by open-water or upland disposal  相似文献   

2.
Dredged material levees in coastal Louisiana are normally associated with pipeline canals or, more frequently, canals dredged through the wetlands to allow access to drilling locations for mineral extraction. The hydrologic impact on marshes behind the levee is of concern to coastal resource managers because of the potential impact on sediment transport and deposition, and the effect on estuarine organism access to valuable nursery habitat. This study examined the effects of gaps in dredged material levees, compared to continuous levees and natural channel banks, on these two aspects of marsh function. Field studies for sediment deposition were conducted biweekly for a year, and nekton samples were collected in spring and fall. Variation in nekton density among study arears and landscape types was great in part because of the inherent sampling gear issues and in part because of differences in characteristics among areas. Nekton densities were generally greater in natural compared to leveed and gapped landscapes. Differences in landscape type did not explain patterns in sediment deposition. The gaps examined appear to be too restrictive of marsh flooding to provide efficient movements of floodwaters onto the marsh during moderate flooding events. The “trapping” effect of the levees increases sediment deposition during extreme events. Gapping material levees may be an effective method of partially restoring upper marsh connection to nekton, but this method may work best in lower elevation marshes where nekton use is greater.  相似文献   

3.
3 and C4 plant species consumed by animals. Sheep sample vegetation continuously throughout a year, and as their wool grows it integrates and stores information about their diet. In subtropical and tropical rangelands the majority of grass species are C4. Since sheep prefer to graze, and their wool is an isotopic record of their diet, we now have the potential to develop a high resolution index to the availability of grass from a sheep's perspective. Isotopic analyses of wool suggest a new direction for monitoring grazing and for the reconstruction of past vegetation changes, which will make a significant contribution to traditional rangeland ecology and management. It is recommended that isotopic and other analyses of wool be further developed for use in rangeland monitoring programs to provide valuable feedback for land managers.  相似文献   

4.
/ Roxborough State Park in Colorado's Front Range was established in 1975 following a history of cattle and sheep ranching by private ownership. Survey work conducted from 1979 to 1995 resulted in the documentation of 93 species of butterflies. A variety of factors are responsible for the composition of the butterfly community: (1) overgrazing and its effect on the presence or absence of specific butterfly host plants; (2) habitat differences resulting from topographical and geological features; and (3) ecological and historical biogeography. This study provides data on community sampling adequacy, along with estimates of effort needed to monitor trends in abundance by using a community self-similarity curve and power analysis. An annual monitoring plan is proposed to assess trends in community composition. The plan includes collection of presence/absence and abundance data for select butterflies based on natural history information.KEY WORDS: Butterfly communities; Grazing; Inventory; Monitoring; Natural history  相似文献   

5.
通过有效运行的环境监测质量管理体系和实施监测全过程质量管理对虹口区环境监测站质量管理现状进行分析,提出了对策及建议,结果,通过建立数学分析模型对监测数据进行综合分析,实验室工作逐步做到熟练地应用测量不确定度,使环境监测站质量管理水平进一步提高,更好的为环境管理服务.  相似文献   

6.
Remote sensing has emerged as one of the major techniques for the analysis and delineation of large floods. This analysis can provide data invaluable for the hydrological management of large river systems. A need for information on the extent of floodplain inundation for the lower reaches of the largest river in the UK was met by a search through Landsat images of floods and the analysis of the best example recorded. Automated classification of the Landsat imagery of this flood on the river Severn in 1977 was used to provide estimates of the extent and spatial distribution of inundation. Flood images were generated using the Plessey IDP 3000 image processor, and the maps derived accorded well with aerial photography and qualitative flood information. Three distinct floodplain environments were delineated and flood images produced by different spectral bands compared. Specific questions prompted by flood hazard management and concerning the processes and extent of flooding were answered by the Landsat data analysis. Management of the flood risk of large rivers is expensive and remote sensing data is a relatively cheap and effective way of monitoring control works and providing data for the prediction of the effects of future hydrological works. Remote sensing is a practical way in which spatial information concerning the behavior of large dynamic systems can be obtained both quickly and relatively cheaply.  相似文献   

7.
《环境质量管理》2018,27(4):163-171
In order to examine the forms, sources, and pollution of heavy metals—arsenic (As), aluminum (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)—in Daechung Lake, Korea, sediment samples were collected in November 2014. Daechung Lake was constructed to supply water for human consumption, agricultural use, and industrial use as well as to generate electric power. The lake is stratified in the summer and surrounded mostly by agricultural and mining areas. Our results indicate that the heavy metals (except As and Cd) displayed similar concentrations at all of the sampling stations. As and Cd were high in locations where fine sediments had built up. Based on the enrichment factor of the metals, the sediments collected from all of the sampling stations were highly polluted by As and Cd. Therefore, deposition of heavy metals in Daechung Lake is possibly controlled by grain size and anthropogenic activity, such as drainage from abandoned mines, agricultural activities, and/or the release of wastewater. The most dominant forms for all of the metals were oxide and silicate forms. This suggests that the sediments of Daechung Lake are not highly sulfidic. However, the sediment samples were collected after the collapse of seasonal stratification. Therefore, future studies should include elucidation of major sources for As and Cd and the collection of sediments during months of stratification.  相似文献   

8.
Monitoring the effectiveness of management activities within reserves is always a complicated task. When the focus of management activities is mammals, it is difficult to monitor their populations in a way that is rapid, effective, and inexpensive. We report on a mammal survey of a reserve in southwest China using remote-trip cameras. We surveyed 329 locations over 2 field seasons in 2002 and 2003. Sixteen species of mammals were detected with these cameras, with four species documented for the first time. After accounting for variation due to slope, aspect, elevation, and habitat type, the distribution of six species was positively associated with the location of conservation stations and/or patrolling routes. Species of medium-sized mammals are excellent candidates for monitoring programs based on these cameras, due to their relative abundance, sufficient size to be detected by the camera units, and sensitivity to human activity. The distribution of mammals relative to management efforts is a relatively rapid means to assess reserve effectiveness. The repeat use of the cameras as part of a monitoring plan should provide a quantifiable measure of reserve effectiveness.  相似文献   

9.
Use of wood frames from sustainable forestry instead of non-wood frames in multi-storey buildings can reduce primary energy use and carbon dioxide emissions in construction. However, construction actors might have different perceptions towards wood frames than towards steel and concrete frames. Such perceptions may influence the actors’ decision to adopt wood frames. In this study we use a web-based questionnaire to assess Swedish architects’ perceptions, attitudes and interest towards steel, concrete and wood frames in multi-storey buildings (n = 412). Results indicate that the responding architects find concrete the most suitable frame material in buildings of 3-8 storeys, mainly because of the performance of concrete with regards to the engineering aspects (e.g. stability and fire safety) that were considered important in the choice of frame material. Although wood is considered the least suitable frame material, the overall attitude towards, and interest in, using wood is positive and related to the perceived environmental benefits of wood. This may derive from an increased discussion of and information about the environmental impact of buildings. Wood may be perceived as new and innovative while not considered as adequately proven as steel and concrete with regards to engineering aspects.  相似文献   

10.
何爱兰 《四川环境》2005,24(3):49-51
无公害产品产地农业生态环境质量是影响无公害产品质量的重要因子之一,对丽水市庆元县甜桔柚基地农业环境质量的调查和监测表明,庆元县无公害甜桔柚基地符合无公害产品的环境质量要求。  相似文献   

11.
朱培瑜  魏轲 《四川环境》2014,(3):99-101
YSI 6600-V2多功能水质自动监测仪采用荧光原理快速测定水体中浮游植物蓝绿藻的密度,梅梁湖夏季水华高发期时,湖体中的浮游植物几乎全部是蓝绿藻。传统的浮游植物监测前处理方面就需要24~48 h,最终要数天后才有镜检结果,导致浮游植物数据滞后,不能很好的应用到预警监测中。通过比对相关性验证,保证荧光法数据的可信度,提高工作效率,为预警监测提供有力的支持。  相似文献   

12.
A protocol was developed with the purpose of assessing the main costs implied in the set-up, operation and maintenance of a waste gas-treating conventional biofilter. The main operating parameters considered in the protocol were the empty bed residence time and the gas flow rate. A wide variety of investment and operating costs were considered. In order to check its reliability, the protocol was applied to a number of scenarios, with biofilter volumes ranging from 8.3 to 4000 m3. Results show that total annualized costs were between 20?000 and 220?000 €/year and directly dependent, among other factors, on the size of the system. Total investment and operating costs for average-size compost biofilters were around 60?000 € and 20?000 €/year, respectively, which are concordant with actual costs. Also, a sensitivity analysis was performed in order to assess the relative influence of a series of selected costs. Results prove that operating costs are those that influence the total annual costs to a higher extent. Also, packing material replacement costs contribute significantly to the total yearly costs in biofilters with a volume higher than 800 m3. Among operating costs, the electricity consumption is the main influencing factor in biofilters with a gas flow rate above 50?000 m3/h, while labor costs are critical at lower gas flow rates. In addition, the use of a variety of packing materials commonly employed in biofiltration was assessed. According to the results obtained, special attention should be paid to the packing material selected, as it is the main parameter influencing the medium replacement costs, and one of the main factors affecting investment costs.  相似文献   

13.
One of the most important endemic tree species of Chile and at the same time one of the most endangered ones is Araucaria araucana (Mol.) C. Koch, the monkey‐puzzle tree. It grows in the Andes Mountains, homeland of the indigenous Mapuche Pewenche people who depend on this tree. This paper is based on field research that investigated the ecological knowledge, uses and management of the Araucaria araucana forest by indigenous Mapuche Pewenche people based on the socio‐cultural, spiritual and ecological relationships they have with the Araucaria forest, to find out how indigenous people and their knowledge could contribute to sustainable Araucaria forest management. A Mapuche Pewenche community located in the IX region of Chile contributed to this study. Based on the analyses this paper illustrates the nature of indigenous ecological knowledge of Araucaria araucana on the one hand, and its utility in native forest management on the other. The research shows that the Mapuche Pewenche hold ecological knowledge and conduct practices to manage their Araucaria forest in a balanced way. They conserve and use forest biodiversity at one and the same time. This paper provides recommendations for sustainable Araucaria forest management and conservation strategies ex‐situ and in‐situ incorporating indigenous knowledge and scientific knowledge and for promoting a collaborative natural resources management.  相似文献   

14.
The coal mining industries influence hydro-geological parameters, which affect the aquifer recharge in the coal mining areas. This research aimed to evaluate the impact of various hydro-geological parameters on fluctuation of groundwater level in the study area. The various hydro-geological parameters such as soil, geology, drainage pattern, elevation and slope have been considered to accomplish the objective. A comparative analysis was performed by comparing the groundwater level fluctuation (WLF) map with the GIS-based various hydro-geological parameter maps to assess the combined influence of different hydro-geological parameters on groundwater level fluctuation. A total of eighty-six (86) dug-wells were chosen to monitor the level of the groundwater for around ten blocks of Singrauli coalfield, and these wells were examined during the months of dry and wet seasons for 2016. Based on the comparative analysis between the WLF map and thematic maps of various hydro-geological parameters, it has been found that WLF in the south-western and some portions of the north-eastern showed moderate to a higher value. This may be because most of the non-hilly areas come under gentle to moderate slope category, with lower elevation in the area forming the suitable hydro-geological condition for recharging groundwater. It was observed that the northwest, south-east and central part of the study area showed lower WLF, which may be due to the presence of overburden dump, presence of higher elevation and steep slope. Thus, the combined effect of slope, elevation, geology, drainage and mining activities on the WLF in the study region is moderate.  相似文献   

15.
Field reconnaissance of the Ebocha-8 oil spill-affected site at Obiobi/Obrikom in the Niger Delta region of Nigeria was carried out to assess the extent of damage to the terrestrial ecosystem and delimit the epicenter of oil spillage. Following three successive reconnaissance surveys, the area to be sampled was delimited (200 x 200 m2), and soil samples were collected using the grid method from three replicate quadrats at two depths, surface (0-15 cm) and subsurface (15-30 cm). A geographically similar area located 50 m adjacent to the oil-polluted area was used as a reference (control) site. Total hydrocarbon content (THC) and heavy metal concentrations were later determined in the laboratory by extraction and spetrophotemetric techniques. Generally, the THC of soils at surface and subsurface depths of the oil-polluted plots was 2.06 x 10(4) +/- 4.97 x 10(3) mg/kg and 1.67 x 10(3) +/- 3.61 x 10(2) mg/kg soil, respectively, (no overlap in standard errors at 95% confidence limit) while concentrations of heavy metals(Pb, Cd, V, Cu and Ni) were enhanced, especially at the surface. The high levels of THC and heavy metals may predispose the site, which hitherto served as arable agricultural land, to impaired fertility and possible conflagration. When concentrations of heavy metals reach the levels obtained in this study, they may become toxic to plants or possibly bio-accumulate, thus leading to toxic reactions along the food chain. While the spilled-oil may have contributed to the enhanced levels of the metals in the affected soils, physico-chemical properties of the soils, mobility of metals, and the intense rainfall and flooding that preceded the period of study may have also contributed in part to their enhanced concentrations. The presence of high hydrocarbon content may cause oxygen deprivation, which may result in the death of soil fauna by asphyxiation. There is, therefore, an urgent need to clear the affected site of these excess hydrocarbon deposits so as to enhance the rehabilitation process of the affected mat layer of soils. Other appropriate mitigating measures, such as subsequent monitoring of hydrocarbon levels at suitable intervals after the clean up activities, are also recommended, with reference to the findings of this study, for effective management of the affected area.  相似文献   

16.
When planning interventions, water and land resource managers increasingly need to take the opinions of stakeholders into account. In the present study, stakeholders’ concerns in a multifunctional water system are assessed, with a focus on the debate about the sustainability of irrigation projects in stressed and competing water contexts. The selected case study pertains to the Segarra‐Garrigues irrigation canal (Spain), the promotion of which has generated social debate and mobilization, as well as pronouncements from European authorities for ensuring its environmental sustainability. Data was collected through semi‐structured interviews and analysed by means of a new codification system for identifying the affinities and conflicts arising from existing water demands. Results show that sustainability concepts are more present in civil society than in public administration and private services or the rural community. However, social sustainability and environmental sustainability are a priority for most stakeholders, while the economic perspective of sustainable development has been conditioned by the first two. These results can be used by relevant authorities as a first step in customizing their interventions, as they provide a clear initial idea of what stakeholder priorities are in the framework of sustainable development.  相似文献   

17.
This discussion addresses some aspects of a recent paper appearing in this journal which investigates cost effective coastal water management based on different assumptions of the probability distributions (normal and log-normal) of pollutant transport. We also suggest an alternative approach to overcome the technical problems of using the theoretical correct distribution for characterising environmental data (log-normal) within a probabilistic programming framework.  相似文献   

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