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161.
Hagström, Johannes A., Mario R. Sengco, and Tracy A. Villareal, 2010. Potential Methods for Managing Prymnesium parvum Blooms and Toxicity, With Emphasis on Clay and Barley Straw: A Review. Journal of the American Water Resources Association (JAWRA) 46(1):187-198. DOI: 10.1111/j.1752-1688.2009.00402.x Abstract: Harmful algal bloom (HAB) control and mitigation is a complex problem in ecosystem management. Phytoplankton play an important role in aquatic ecosystems as primary producers and food sources for many commercially important shellfish and there are limited options for targeting just a single species within the community. Chemical treatments (e.g., algaecides), rotting barley straw, nitrogen and phosphorus manipulation, and clay and/or flocculants are but a few techniques tested or used to reduce fish kills or shellfish contamination during a HAB event. Prymnesium parvum control has focused on the use of chemicals, nutrient manipulation, and clay flocculation. However, many HAB control methods have been rejected due to their effects on ecosystems, high costs, or limited effects on target organisms. For example, rotting barley straw (Hordeum vulgare) is considered to be an environmentally friendly alternative, but has been found to have very different results on the phytoplankton community depending on the dominating taxa and is ineffective against P. parvum and dinoflagellate blooms. Clay flocculation is a useful control/mitigation technique during fish kills in marine aquaculture sites in South Korea and can be effective in freshwater if the correct combination of clay and flocculent is used. Toxins produced by P. parvum and Karenia brevis also bind to phosphatic clay, thereby removing and/or neutralizing the toxins, but there is concern that the clay will have a negative effect on sessile organisms. Some shellfish suffer high mortalities and significant impacts on somatic and reproductive tissue growth at high clay loads; however, benthic communities appear to be unchanged after five years of clay treatment in South Korea. There are likely site-specific and ecosystem-specific characteristics that make generalizations about control options difficult and require careful assessment of options at each location.  相似文献   
162.
Procopio, Nicholas A., 2010. Hydrologic and Morphologic Variability of Streams With Different Cranberry Agriculture Histories, Southern New Jersey, United States. Journal of the American Water Resources Association (JAWRA) 46(3):527-540. DOI: 10.1111/j.1752-1688.2010.00432.x Abstract: The creation of reservoirs and the modification of stream channels are common practices used to facilitate the efficient production of cranberries. The potential impacts to hydrologic and geomorphic aspects of streamflow and channel structure have not been adequately assessed. In this study, the streamflow regime of 12 streams and the channel morphologies of 11 streams were compared for study sites in the Pinelands region of New Jersey with upstream active-cranberry bogs, upstream abandoned-cranberry bogs, and basins with no apparent agricultural history. Flow regime metrics included measures of low-flow, median-flow, and bankfull discharge, two measures of streamflow variability (spread and a modified Richards-Baker Flashiness index), and the frequency of overbank flooding. Stream-channel morphology metrics included average bank slope, average bankfull width, average bankfull depth, average bankfull width-to-depth ratio, and average bankfull area. No significant differences between stream types were apparent for any of the metrics. Basin-area normalized streamflow values of all 12 study sites were highly correlated to each other. Significant relationships existed between some of the flow-regime and channel-morphology metrics. Due to the lack of significant differences between stream types, it appears that neither historic nor current cranberry agricultural practices considerably influence flow regimes or the channel morphology of streams in the New Jersey Pinelands.  相似文献   
163.
This work deals with the application of a Life Cycle Assessment approach for evaluating the environmental and energy impacts ascribed to the production of photovoltaic (PV) cells of first and second generations. PV technologies based on silicon and CuInSe2 (CIS) thin films were taken into account herein. PV systems prepared with amorphous silicon (a-Si) showed a low environmental impact and short energy payback time when compared to those ones obtained using crystalline silicon (c-Si). PV technologies associated with mono-crystal (mono-Si) and polycrystalline silicon (multi-Si) showed large emissions of CO2, nitrogen oxides, non-methane volatile organic compounds, particulates, and SO2 into air per square meter of PV panel processed. In addition, these technologies displayed a significant fossil fuel demand, biological oxygen demand, and global warming potential, which make them eco-unfriendly. Ribbon silicon (ribbon-Si) and CIS thin films showed intermediate impact scores, but further improvements in their production chain are needed before these devices are commercially used. The technologies examined herein were categorized in first- and second-generation technologies in order to compare their environmental impact and conversion efficiency. Much attention was also paid to the development of third-generation PV cells with improved conversion efficiencies and lower environmental impacts.  相似文献   
164.
In mountains of the western United States, channel incision has drawn down the water table across thousands of square kilometers of meadow floodplain. Here climate change is resulting in earlier melt and reduced snowpack and water resource managers are responding by investing in meadow restoration to increase springtime storage and summer flows. The record‐setting California drought (2012–2015) provided an opportunity to evaluate this strategy under the warmer and drier conditions expected to impact mountain water supplies. In 2012, 0.1 km2 of meadow floodplain was reconnected by filling an incised channel through Indian Valley in the central Sierra Nevada Mountains of California. Despite sustained drought conditions after restoration, summer baseflow from the meadow increased 5–12 times. Before restoration, the total summer outflow from the meadow was 5% more than the total summer inflow. After restoration, total summer outflow from the meadow was between 35% and 95% more than total summer inflow. In the worst year of the drought (2015), when inflow to the meadow ceased for at least one month, summer baseflow was at least five times greater than before restoration. Groundwater levels also rose at four out of five sites near the stream channel. Filling the incised channel and reconnecting the meadow floodplain increased water availability and streamflow, despite unprecedented drought conditions.  相似文献   
165.
A city's spatial footprint is covered by extensive impervious building roofs and paved surfaces, which contribute to greater storm-water runoff, more surface pollutants, and less carbon sequestration, hence, worse ecosystem services. This research conducts an empirical study on the ecological and economic impacts of a citywide adoption of green roofs and permeable pavements in Corvallis, OR. The effects on ecosystem services of using green roofs and pervious pavements for a low impact development are modelled using Integrated Value of Ecosystem Services Trade-offs and compared to those from the City's current conventional development without green roofs and pervious pavements. The differences are analysed for ecological impact by storm-water yield, storm-water purification, and carbon sequestration and economic impact by a cost-benefit comparison. The results indicate that low impact development, especially intensive green roofs on commercial/industrial buildings and permeable pavements for parking lots, plays a significant role, even with a higher initial implementation cost, for long-term urban sustainability.  相似文献   
166.
In spring 2011, an unprecedented flood hit the complex eastern United States (U.S.)–Canada transboundary Lake Champlain–Richelieu River (LCRR) Basin, destructing properties and inducing negative impacts on agriculture and fish habitats. The damages, covered by the Governments of Canada and the U.S., were estimated to C$90M. This natural disaster motivated the study of mitigation measures to prevent such disasters from reoccurring. When evaluating flood risks, long‐term evolving climate change should be taken into account to adopt mitigation measures that will remain relevant in the future. To assess the impacts of climate change on flood risks of the LCRR basin, three bias‐corrected multi‐resolution ensembles of climate projections for two greenhouse gas concentration scenarios were used to force a state‐of‐the‐art, high‐resolution, distributed hydrological model. The analysis of the hydrological simulations indicates that the 20‐year return period flood (corresponding to a medium flood) should decrease between 8% and 35% for the end of the 21st Century (2070–2099) time horizon and for the high‐emission scenario representative concentration pathway (RCP) 8.5. The reduction in flood risks is explained by a decrease in snow accumulation and an increase in evapotranspiration expected with the future warming of the region. Nevertheless, due to the large climate inter‐annual variability, short‐term flood probabilities should remain similar to those experienced in the recent past.  相似文献   
167.
针对黑龙江、松花江航道疏浚工程对水生生物环境影响问题,提出了疏浚工程对水生生物的影响,包括对浮游植物的影响、对浮游动物的影响、对底栖动物的影响和对水生植物的影响,将产生泥沙、悬浮物、噪音、底质改变及机械废水、固体垃圾等,进而对鱼类资源的影响分析,包括施工噪音对鱼类的影响,如对鱼类栖息地的影响、对鱼类摄食生长的影响、对鱼类产卵行为的影响、悬浮物对鱼类生存的影响、对鱼类卵、苗的影响和对鱼类洄游通道的影响。  相似文献   
168.
The paper argues that corporate environmental management should be based on significant environmental aspects that result in significant environmental impacts. The Finnish forest industry has substantially reduced its emissions but, being heavy industry, it still causes significant environmental impacts. This paper presents expert views on environmental impacts and their measurement. They were gathered through semi-structured theme interviews. The most frequently mentioned environmental impacts and significant environmental impacts related to water, energy and air. Positive environmental impacts resulted from recycling, forest industry products and use of energy. Traditional emission measurement was considered a well-measured issue. The target subjects of the measurement and especially environmental impact measurement require improvement. The contribution of this research is concerned with the development of measurement and two issues arising from the research are emphasised. First, environmental impact measurement should be further developed. Second, the measurement of the production chain that is physically outside the boundaries of forest industry mills should also be developed.  相似文献   
169.
Watershed characteristics such as land‐use and land‐cover affect stream condition at multiple scales, but it is widely accepted that conditions in close proximity to the stream or survey site tend to have a stronger influence. Although spatially weighted watershed metrics have existed for years, nonspatial lumped landscape metrics (i.e., areal mean or percentage) are still widely used because relatively few technical skills are needed to implement them. The Inverse Distance Weighted Percent Land Use for Streams (IDW‐Plus) custom ArcGIS toolset provides the functionality to efficiently calculate six spatially explicit watershed metrics which account for the Euclidean or flow length distance to the stream or outlet, as well as the probability for overland runoff. These include four distance‐weighted metrics, those being inverse Euclidean distance to the stream or outlet, and the inverse flow length to the stream or outlet. Two tools are also included to generate hydrologically active (i.e., runoff potential), inverse flow length to the stream or outlet metrics. We demonstrate the tools using real data from Southeast Queensland, Australia. We also provide detailed instructions, so readers can recreate the examples themselves before applying the tools to their own data.  相似文献   
170.
In this paper we quantify the additional water quality benefits that can be achieved through coordinated cumulative impact management. To do this we simulate coordinated and un-coordinated revegetation investments and compare their impact on achieving regional water quality goals. Our results show that coordination between multiple mining companies achieves additional benefits since prioritization is enabled across a broader range of investment opportunities. Additionally, when coordinated investment is permitted beyond the boundaries of coal mining leases, results show that additional benefits are greatly enhanced since these regions provide more rewarding investment opportunities. Results illustrate (a) how regional coordination may influence reputational benefits of investments, and (b) that coordination is beneficial when investment opportunities are unevenly distributed across the landscape. When additional benefits are achievable, we suggest that mining companies should develop collective investment projects with an understanding of how coordination influences project costs. Similarly, investment projects should be developed with an understanding of investment tradeoffs and how these may adversely impact on regional stakeholders and hence industry reputation. The mining industry has significant potential to contribute to regional wellbeing; however, land management policies must be flexible and promote incentives to enable companies to invest beyond compliance.  相似文献   
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