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941.
We present conceptual and quantitative models that predict changes in fertilizer‐derived nitrogen delivery from rowcrop landscapes caused by agricultural conservation efforts implemented to reduce nutrient inputs and transport and increase nutrient retention in the landscape. To evaluate the relative importance of changes in the sources, transport, and sinks of fertilizer‐derived nitrogen across a region, we use the spatially explicit SPAtially Referenced Regression On Watershed attributes watershed model to map the distribution, at the small watershed scale within the Upper Mississippi‐Ohio River Basin (UMORB), of: (1) fertilizer inputs; (2) nutrient attenuation during delivery of those inputs to the UMORB outlet; and (3) nitrogen export from the UMORB outlet. Comparing these spatial distributions suggests that the amount of fertilizer input and degree of nutrient attenuation are both important in determining the extent of nitrogen export. From a management perspective, this means that agricultural conservation efforts to reduce nitrogen export would benefit by: (1) expanding their focus to include activities that restore and enhance nutrient processing in these highly altered landscapes; and (2) targeting specific types of best management practices to watersheds where they will be most valuable. Doing so successfully may result in a shift in current approaches to conservation planning, outreach, and funding.  相似文献   
942.
Turnaround maintenance (TAM) is a usual plant shutdown that is done by process industries to perform asset inspections, repairs, and overhauls. TAM engineering projects are needed on a periodic basis to optimize a plant's performance. Process industrial plants usually don't have enough in-house manpower to carry out needed TAM jobs; it is not uncommon for a process industrial plant to outsource its TAM manpower supply to external contractors. This will create a peculiar management challenge regarding how to assure orientation of safety practices for the newly hired labor. Although accidents during process plant shutdowns may have severe consequences, the safety management systems in place for many companies only cover normal operations and few explicitly address TAM projects. Usually, contractors are evaluated from a safety perspective after handling the project by monitoring safety indicators such as number of injuries, incidents, etc. This paper emphasizes safety attributes to be included in selecting contractors at the bidding stage to assure loss prevention and better safety orientation during TAM implementation. The paper starts with reviewing TAM literature and defining main needed safety attributes to prequalify contractors. It develops an analytic hierarchy process (AHP) model that is applied to rank TAM contractors' selection. A case study is presented for a petrochemical plant in Saudi Arabia to demonstrate the AHP model.  相似文献   
943.
Theories in risk, psychology, and communication suggest aiming to inform the public about basic ecological facts may not be enough to influence knowledge of risks or behaviors to mitigate water quality risks. The risk information‐seeking and processing model and the theory of planned behavior suggest several additional variables that are likely to influence risk‐mitigating behaviors. We used data from a survey of watershed residents in Ohio to explore a model of behavioral intentions to positively impact stream health. Residents' informational norms, or the perceived pressure to know about local stream health, strongly predicted their information‐seeking behaviors. Active‐seeking behaviors predicted positive attitudes toward behaviors impacting stream health, which predicted intentions to positively impact stream health. Implications for outreach include couching communication in terms of risk found important to the local community, here wildlife were seen as negatively influenced by water quality, as opposed to plain reports typically provided by utility companies. Increasing social pressure to feel informed by emphasizing the existing knowledge of stream ecology among residents could change the norm for the less informed. A low response rate limits the generalizability of findings here, but leveraging these findings in outreach efforts could prove more successful in engaging the public to improve stream health and support policies to improve stream health.  相似文献   
944.
Green infrastructure (GI) is quickly gaining ground as a less costly, greener alternative to traditional methods of stormwater management. One popular form of GI is the use of rain gardens to capture and treat stormwater. We used life cycle assessment (LCA) to compare environmental impacts of residential rain gardens constructed in the Shepherd's Creek watershed of Cincinnati, Ohio to those from a typical detain and treat system. LCA is an internationally standardized framework for analyzing the potential environmental performance of a product or service by including all stages in its life cycle, including material extraction, manufacturing, use, and disposal. Complementary to the life cycle environmental impact assessment, the life cycle costing approach was adopted to compare the equivalent annual costs of each of these systems. These analyses were supplemented by modeling alternative scenarios to capture the variability in implementing a GI strategy. Our LCA models suggest rain garden costs and impacts are determined by labor requirement; the traditional alternative's impacts are determined largely by the efficiency of wastewater treatment, while costs are determined by the expense of tunnel construction. Gardens were found to be the favorable option, both financially (~42% cost reduction) and environmentally (62‐98% impact reduction). Wastewater utilities may find significant life cycle cost and environmental impact reductions in implementing a rain garden plan.  相似文献   
945.
Headwater streams have a significant nexus or physical, chemical, and/or biological connection to downstream reaches. Generally, defined as 1st‐3rd order with ephemeral, intermittent, or perennial flow regimes, these streams account for a substantial portion of the total stream network particularly in mountainous terrain. Due to their often remote locations, small size, and large numbers, conducting field inventories of headwater streams is challenging. A means of estimating headwater stream location and extent according to flow regime type using publicly available spatial data is needed to simplify this complex process. Using field‐collected headwater point of origin data from three control watersheds, streams were characterized according to a set of spatial parameters related to topography, geology, and soils. These parameters were (1) compared to field‐collected point of origin data listed in three nearby Jurisdictional Determinations, (2) used to develop a geographic information system (GIS)‐based stream network for identifying ephemeral, intermittent, and perennial streams, and (3) applied to a larger watershed and compared to values obtained using the high‐resolution National Hydrography Dataset (NHD). The parameters drainage area and local valley slope were the most reliable predictors of flow regime type. Results showed the high‐resolution NHD identified no ephemeral streams and 9 and 65% fewer intermittent and perennial streams, respectively, than the GIS model.  相似文献   
946.
Streamside management zone (SMZ) breakthroughs were identified and characterized to determine frequency and potential causes, in order to provide enhanced guidance for future water quality protection. Ten kilometers of SMZs were carefully examined for partial or complete breakthroughs. With partial breakthroughs the SMZ trapped sediment before it reached the stream, while complete breakthroughs appeared to have allowed sediment to have passed through with minimal restriction. A total of 41 breakthroughs occurred (33 complete, 8 partial) across 16 sites, averaging 1 complete breakthrough per 0.3 km of SMZ length. The most common complete breakthroughs were caused by stream crossings (42%), reactivation of legacy agricultural gullies (27%), and harvest related soil disturbances near/within SMZs (24%). Pearson correlations of site characteristics at breakthroughs indicated no strong relationships between breakthrough sites, representing the variable nature of these unique circumstances. Stream crossings are an intentional breakthrough for access purposes, but resulting environmental impacts can be reduced with best management practice implementation. Current recommendations for SMZs tend to work in most situations, yet further research is needed to identify causal factors and quantify breakthrough severity.  相似文献   
947.
The tsunami that struck the coasts of India on 26 December 2004 resulted in the large‐scale destruction of fisher habitations. The post‐tsunami rehabilitation effort in Tamil Nadu was directed towards relocating fisher settlements in the interior. This paper discusses the outcomes of a study on the social effects of relocation in a sample of nine communities along the Coromandel Coast. It concludes that, although the participation of fishing communities in house design and in allocation procedures has been limited, many fisher households are satisfied with the quality of the facilities. The distance of the new settlements to the shore, however, is regarded as an impediment to engaging in the fishing profession, and many fishers are actually moving back to their old locations. This raises questions as to the direction of coastal zone policy in India, as well as to the weight accorded to safety (and other coastal development interests) vis‐à‐vis the livelihood needs of fishers.  相似文献   
948.
根据在某老工业区第1批28块场地环境调查的实践,对污染场地管理中存在的问题进行了分析并提出了相应改进建议:①获取准确的场地资料难度很大,建议研究制定场地全过程档案管理制度;②工业企业关闭搬迁会产生新的环境污染风险,工业企业关闭搬迁应该成为污染场地管理的重要环节,环保部门应该在工业企业搬迁前介入,严格监管整个过程中的环境污染;③大量区域由于其中污染严重、风险高的场地缺乏修复资金而难以再开发利用,建议结合规划优先启动资金投入低的污染较轻区域修复,并同时对风险较高的污染场地进行风险管控,当区域开发取得一定规模、成就和收益后,可以整合资金力量和资源开展污染较重区域的修复。  相似文献   
949.
论述环境影响评价在中国环境管理中的作用,并结合实际工作分析,指出其存在如环境影响分析预测不准确、环保措施实施效果欠佳、监测计划作用发挥不到位、自身局限性等问题.针对存在问题并提出五点建议,即实现环境主管部门全过程监管、加强政府各部门的积极配合、建设环境信息共享平台、全民提高自觉环境保护意识、环评工作者加强自身专业知识培养,以调动全民积极主动性,充分发挥环境影响评价的作用.  相似文献   
950.
中国城市环境管理模式虽然有了很大进步,但存在资金的较大压力,使城市环境的运营能力薄弱、工作质量不佳等问题,这些问题阻碍了城市环境污染治理工作.尤其是起步较晚的市场化管理模式,虽然已能够实现城市环境污染治理与社会管理,但管理水平还处于较低的现状,建议通过加强城市环境的法制建设、建立激励政策、加强对运营机构的监管,采取双赢机制,来提高环境污染治理与社会运营管理的市场化.  相似文献   
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