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991.
Stone, Wesley W. and Robert J. Gilliom, 2012. Watershed Regressions for Pesticides (WARP) Models for Predicting Atrazine Concentrations in Corn Belt Streams. Journal of the American Water Resources Association (JAWRA) 48(5): 970‐986. DOI: 10.1111/j.1752‐1688.2012.00661.x Abstract: Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region‐specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP‐CB) were developed for annual maximum moving‐average (14‐, 21‐, 30‐, 60‐, and 90‐day durations) and annual 95th‐percentile atrazine concentrations in streams of the Corn Belt region. The WARP‐CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model‐development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model‐development sites. The WARP‐CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine‐use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP‐CB models. The WARP‐CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine‐use intensities of 17 kg/km2 of watershed area or greater.  相似文献   
992.
对南京市在污染源普查过程中采取的质控措施进行了探讨,分析出普查质控工作的不足,并提出了几点建议。为提高以后普查的质量拓宽思路。  相似文献   
993.
Kenney, Melissa A., Peter R. Wilcock, Benjamin F. Hobbs, Nicholas E. Flores, and Daniela C. Martínez, 2012. Is Urban Stream Restoration Worth It? Journal of the American Water Resources Association (JAWRA) 48(3): 603-615. DOI: 10.1111/j.1752-1688.2011.00635.x Abstract: Public investment in urban stream restoration is growing, yet little has been done to quantify whether its benefits outweigh its cost. The most common drivers of urban stream projects are water quality improvement and infrastructure protection, although recreational and aesthetic benefits are often important community goals. We use standard economic methods to show that these contributions of restoration can be quantified and compared to costs. The approach is demonstrated with a case study in Baltimore, Maryland, a city with a legal mandate to reduce its pollutant load. Typical urban stream restoration costs of US$500-1,200 per foot are larger than the cost of the least expensive alternatives for management of nitrogen loads from stormwater (here, detention ponds, equivalent to $30-120 per foot of restored stream) and for protecting infrastructure (rip-rap armoring of streambanks, at $0-120 per foot). However, the higher costs of stream restoration can in some cases be justified by its aesthetic and recreational benefits, valued using a contingent valuation survey at $560-1,100 per foot. We do not intend to provide a definitive answer regarding the worth of stream restoration, but demonstrate that questions of worth can be asked and answered. Broader application of economic analysis would provide a defensible basis for understanding restoration benefits and for making restoration decisions.  相似文献   
994.
以黑龙江黑土为对象,研究了冻融循环及有机肥配施量对黑土中镉形态分布的影响。对配施不同有机肥的土壤样品进行5次冻融循环,采用电感耦合等离子质谱仪(ICP-MS)分析土壤样品中镉的赋存形态。结果表明,冻融循环数及有机肥的配施有助于降低黑土中的总镉量;冻融循环会促使黑土中的镉由交换态、碳酸盐结合态、有机结合态向铁锰氧化物结合态和残渣态转化,而增加有机肥配施量会使黑土中的镉由交换态向其他形态转化。因此,冻融循环及有机肥配施有助于降低土壤中镉的生物有效性,进而降低其环境风险。  相似文献   
995.
Abstract: In the United States multispecies habitat conservation plans were meant to be the solution to conflicts between economic development and protection of biological diversity. Although now widely applied, questions exist concerning the scientific credibility of the conservation planning process and effectiveness of the plans. We used ants to assess performance of one of the first regional conservation plans developed in the United States, the Orange County Central‐Coastal Natural Community Conservation Plan (NCCP), in meeting its broader conservation objectives of biodiversity and ecosystem‐level protection. We collected pitfall data on ants for over 3 years on 172 sites established across a network of conservation lands in coastal southern California. Although recovered native ant diversity for the study area was high, site‐occupancy models indicated the invasive and ecologically disruptive Argentine ant (Linepithema humile) was present at 29% of sites, and sites located within 200 m of urban and agricultural areas were more likely to have been invaded. Within invaded sites, native ants were largely displaced, and their median species richness declined by more than 60% compared with uninvaded sites. At the time of planning, 24% of the 15,133‐ha reserve system established by Orange County NCCP fell within 200 m of an urban or agricultural edge. With complete build out of lands surrounding the reserve, the proportion of the reserve system vulnerable to invasion will grow to 44%. Our data indicate that simply protecting designated areas from development is not enough. If habitat conservation plans are to fulfill their conservation promise of ecosystem‐level protection, a more‐integrated and systematic approach to the process of habitat conservation planning is needed.  相似文献   
996.
Principles of good practice for collaborative resource management were derived from the literature and their use studied in a range of integrated catchment management processes. Desk-based reviews and interviews with participants allowed the principles to be refined and described within a framework that illustrates the interrelationships between core principles, enabling principles, precursors to a project and the influence of external factors on such collaborative processes. The findings illustrate the importance of these relationships in understanding how success is defined and under what conditions successful outcomes can be achieved. Understanding how these procedural aspects influence outcomes contributes to the wider literature on collaborative resource management that often treats processes separately from their context.  相似文献   
997.
阐述了农业面源污染的主要来源及危害,指出农业面源污染是当前农业可持续发展的主要障碍之一。由于我国农村过量和不合理地使用农药、化肥、地膜等,造成了农业面源不同程度的污染,给农业生产和农民生活带来了隐患,直接关系到农业可持续发展,应该采取有效措施加以解决。  相似文献   
998.
This study investigated if atmospheric ammonia (NH3) pollution around a sheep farm influences the photosynthetic performance of the lichens Evernia prunastri and Pseudevernia furfuracea. Thalli of both species were transplanted for up to 30 days in a semi-arid region (Crete, Greece), at sites with concentrations of atmospheric ammonia of ca. 60 μg/m3 (at a sheep farm), ca. 15 μg/m3 (60 m from the sheep farm) and ca. 2 μg/m3 (a remote area 5 km away). Lichen photosynthesis was analysed by the chlorophyll a fluorescence emission to identify targets of ammonia pollution. The results indicated that the photosystem II of the two lichens exposed to NH3 is susceptible to this pollutant in the gas-phase. The parameter PIABS, a global index of photosynthetic performance that combines in a single expression the three functional steps of the photosynthetic activity (light absorption, excitation energy trapping, and conversion of excitation energy to electron transport) was much more sensitive to NH3 than the FV/FM ratio, one of the most commonly used stress indicators.  相似文献   
999.
运用多元统计中的主成分分析法和系统聚类法对我国东部地区工业污染的治理投资完成情况进行了分析。根据主成分分析结果,对选取的11个省市进行分类,并在此基础上提出加强各区域环境污染治理的几点建议。  相似文献   
1000.
新疆油田污染减排措施与效果分析   总被引:1,自引:1,他引:0  
针对新疆油田公司的污染减排目标,结合油田实际,剖析了当前制约新疆油田污染减排的主要因素,通过有针对性地实施技术改造、结构调整、清洁生产等措施,取得了显著的污染减排效果,为今后污染减排工作提供了有益的建议。  相似文献   
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