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601.
602.
Coastal zones are among the planets most threatened ecosystems and effective management of these systems requires spatial
tools at appropriate spatial scales. Here we apply aerial photography with Geographic Information Systems (GIS), to map the
cumulative anthropogenic footprint of an industry in a spatially defined ecologically important region of the British Columbian
coast. Resolution required for such an analysis was made possible through highly detailed aerial photography of the region
taken at an elevation of 305 m, at a 1:3000 scale. The approach applied here was successful in accurately detailing the cumulative
extent of the anthropogenic activity on the foreshore which could have not been achieved at a coarser resolution. Such information
was then effectively applied to visualize and assess the potential impact of an industrial development of the foreshore on
bird distribution within the spatially identified region. The degree of overlap between the anthropogenic footprint and small
estuaries within the region was also successfully assessed. For ecologically important regions such as Marine Protected Areas,
and other such designated sensitive coastal regions, detailed mapping through aerial photography and GIS can aid in first
identifying the true extent of an anthropogenic activity and then secondly used to link to possible ecological consequences.
This in turn greatly enhances our ability to best manage the region of interest such that conservation priorities can be met. 相似文献
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604.
Jen-ni Kuo Alicia Y. Soon Christine Garrett Michael T. K. Wan John P. Pasternak 《Journal of environmental science and health. Part. B》2013,48(4):250-261
The objectives of this study were to determine environmental occurrence and concentrations of selected currently-used-pesticides and some transformation products in agricultural farms in the Okanagan Valley (OKV), and to conduct a simple risk assessment of environmental pesticides levels detected in OKV on non-target aquatic organisms. The OKV is the tree fruit country of the Province of British Columbia where considerable amount of pesticides are applied annually. Water, sediment and soil samples were collected at eleven sites in early June and late September following rainfall events and/or extended periods of irrigation from drainage ditches and/or from small streams. Undisturbed reference sites were also sampled. Study results showed that forty of the eighty chemicals analyzed, including organochlorine, nitrogen-containing and organophosphate pesticides commonly used for OKV crops, were detected in runoff and small stream water samples. Among which, endosulfan-sulfate was the most frequently detected chemical. Also, azinophos-methyl (0.699–25.5 ng/L), diazinon (0.088–214 ng/L) exceeded, and α-, β- endosulfan, endosulfan sulphate approached the guidelines for the protection of aquatic life. 相似文献
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606.
The ecological security of urban surface water is subject to significant risk due to rapid urbanization. Pollutant discharge and accumulation are among the most critical stressors endangering urban surface water and affecting the normal operation of urban aquatic ecosystem services. In this study, we assessed how pollutant accumulation stresses water purification systems, which perform important urban ecosystem services. First, we applied a water environmental capacity model to calculate thresholds of urban surface water environmental capacity under a given water quality target. Second, based on a stepwise regression method, an equation was used to describe the relationship between stressor factors (pollutant accumulation) and measurable socioeconomic indicators. Third, an ecological risk index was used as an assessment endpoint indicator to assess the negative ecological effect of pollutant accumulation. Finally, risk level was classified according to the risk quotient method. Taking Xiamen City as an example, we analyzed the contribution of different sources of pollutants and evaluated the urban ecological risk posed by two major contaminants present in the environment by measuring chemical oxygen demand (COD) and ammonium nitrogen (NH4+-N). The results show that the ecological risk indexes of both COD and NH4+-N are expected to decrease from 2020 to 2030; that of COD is expected to fall from medium to low, whereas that of NH4+-N is expected to fall from high to medium. These findings demonstrate that the ecological risk posed to the surface water in Xiamen City can be reduced by controlling population growth, optimizing industrial structure, and promoting economic development. 相似文献
607.
Urban road network development (RND) plays an important role in social and economic evolution. However, the unlimited expansion of roads leads to great changes in urban landscape patterns, which further affect ecosystems. To better characterize the urban ecological risk (UER) of RND, in this study, RND was considered the stressor and habitat provision the assessment endpoint in a UER assessment. According to the theory of landscape ecology, habitat quality disturbance intensity (HQDI) is used to quantify the negative effect of RND on an urban ecosystem. In particular, we aimed to explore the exposure-response function between road density and HQDI under RND stress. A case study was carried out in Xiamen City to examine this association. In terms of spatial distribution, this study showed that developed areas had the highest HQDI values, whereas low HQDI values were mostly associated with suburban areas. In addition, the probability distribution of HQDIs was uneven and the urban ecosystem showed unequal sensitivities to different types of roads. Based on a multilevel characterization of UER, results of this provide a framework to predict UER under RND stress and may enhance the ability of risk managers to develop scientifically based control measures. 相似文献
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609.
日光温室蔬菜中百菌清残留状况及不同处理对其的影响 总被引:9,自引:0,他引:9
近些年来,食品安全问题逐渐成为人们关注的热点,而农药残留由于其对食品安全和人类健康的影响,引起了广泛的关注.随着越来越多的温室蔬菜出现在人们的生活中,其农药残留势必会对人们的健康产生巨大的影响.本文应用气相色谱法研究两种常见温室蔬菜(黄瓜、番茄)的农药百菌清残留情况及不同处理对其的影响.结果表明,百菌清在这两种温室蔬菜中严重超标,而实验中所采取的类似家庭采用的流水洗净和去皮两种不同处理方式都可以有效降低百菌清的残留量,去皮的效果更为显著. 相似文献
610.
在试验的基础上,分析了声波助清灰技术对除尘效率的影响,并对各种清灰方式单独或组合使用的效果进行比较,最后对下一步的研究提出了一些建议。 相似文献