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121.
抚顺市大气污染物对降水pH值的影响及预测分析   总被引:1,自引:0,他引:1  
降水 pH值在一定程度上反映了降水和大气的污染状况。研究抚顺市大气污染物对降水 pH值的影响并预测了未来几年降水 pH值的变化趋势。结果表明 :抚顺市的降水酸度是由大气中的SO2 等酸性气体和碱性尘埃共同作用的结果 ,降水 pH值向酸性降水发展。  相似文献   
122.
ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.  相似文献   
123.
完全均匀混合质量平衡水质模型在滇池中的应用   总被引:24,自引:1,他引:23  
介绍了完全均匀混合假设下以质量平衡为基础的湖泊水质模型,运用滇池的实测数据对模型进行了参数率定、验证,给出了模型在滇池水质预测中的应用实测,最后讨论了模型的几个假设条件对滇池的适应性。实例研究表明,该模型可适用于滇池水质有机污染长期浓度预测。   相似文献   
124.
系统总结了当前大气污染物排放调查监测的主要方法及其在全球、区域、局地等不同尺度的典型应用,分析了地面监测、模型模拟与遥感反演3种方法受排放源多样、成分复杂、时空变异显著等因素影响,在尺度效应、成分解析等方面存在的问题。从优化监测方法、改进监测模式、融合监测技术等角度,提出了构建现代化大气污染物排放调查监测网络、开展污染物在不同排放阶段的变化解析研究及在不同圈层间的迁移全过程研究等建议。  相似文献   
125.
东北玉米热量指数预测方法研究(Ⅲ)——GM(1,1)预测方法   总被引:2,自引:0,他引:2  
GM(1,1)是开展时间序列环境要素变化趋势预测的有效方法之一。通过对东北地区玉米热量指数的分析,建立了热量指数时间变化趋势的GM(1,1)预测模型,各模型的平均预测精度虽低于逐步回归统计模型,但也都达91%以上,可以应用该模型的预测结果指导农业生产。  相似文献   
126.
地震人员伤亡快速评估模型研究   总被引:2,自引:0,他引:2  
每年地震都会给社会造成巨大人员伤亡,如果震后能迅速预知地震人员伤亡数量,这对挽救生命损失是十分有意义的。统计了近10年来中国大陆数10次强震、中强震灾害损失,根据影响伤亡的主要因素,用线性回归分析法,建立地震人员伤亡快速评估模型,并对模型进行验证,使之可用于地震预警。  相似文献   
127.

Introduction

The purpose of the current study was to examine differences in factors associated with self-reported collision involvement of three age groups of drivers based on a large representative sample of Ontario adults. Method: This study was based on data from the CAMH Monitor, an ongoing cross-sectional telephone survey of Ontario adults 18 years and older from 2002 to 2005. Three age groups were examined: 18-34 (n = 1,294), 35-54 (n = 2,428), and 55+ (n = 1,576). For each age group sample, a logistic regression analysis was conducted of self-reported collision involvement in the last 12 months by risk factor measures of driving exposure (kilometers driven in a typical week, driving is stressful, and driving on busy roads), consuming five or more drinks of alcohol on one occasion (past 12 months), cannabis use (lifetime, and past 12 months), and driving after drinking among drinkers (past 12 months), controlling for demographics (gender, region, income, and marital status). Results: The study identified differences in factors associated with self-reported collision involvement of the three age groups of adult drivers. The logistic regression model for the youngest group revealed that drivers who reported that driving was stressful at least some of the time, drank five or more drinks on an occasion, and drove after drinking had an increased risk of collision involvement. For the middle age group, those who reported using cannabis in the last 12 months had significantly increased odds of reporting collision involvement. None of the risk factor measures showed significant associations with collision risk for older drivers (aged 55+). Impact: The results suggest potential areas for intervention and new directions for future research.  相似文献   
128.
Models predicting species spatial distribution are increasingly applied to wildlife management issues, emphasising the need for reliable methods to evaluate the accuracy of their predictions. As many available datasets (e.g. museums, herbariums, atlas) do not provide reliable information about species absences, several presence-only based analyses have been developed. However, methods to evaluate the accuracy of their predictions are few and have never been validated. The aim of this paper is to compare existing and new presence-only evaluators to usual presence/absence measures.  相似文献   
129.
基于SWAT模型的阿什河流域非点源污染控制措施   总被引:3,自引:0,他引:3  
以阿什河流域为研究区,建立了SWAT模型,并通过情景模拟技术分别模拟了退耕还林.等高种植、化肥减量与植被过滤带等非点源污染控制措施及其综合效果.结果表明:通过坡耕地退耕还林,可减少1.03%~5.35%的非点源TN负荷与0.94%~8.09%的非点源TP负荷;通过等高耕作,可减少0.51%~2.77%的非点源TN负荷与0.49%~4.54%的非点源TP负荷;通过20%的化肥减量可减少0.65%~6.52%的非点源TN负荷与0.01%~2.95%的非点源TP负荷;20m的植被过滤带可减少42.62%~69.51%的非点源TN负荷与80.09%~86.27%的非点源TP负荷.通过综合管理措施,可减少34.90%~54.36%的TN负荷与35.32%~60.89%的TP负荷.为达到《地表水环境质量标准》(GB3838-2002)中Ⅳ类水体TN与TP的浓度标准,2006~2010年尚需削减45.87%~82.53%的点源TN负荷与35.58%~66.85%的点源TP负荷.  相似文献   
130.
Green electricity products are increasingly made available to consumers in many countries in order to address a number of environmental and social concerns. Most of the literature on this green electricity market focuses on consumers’ characteristics and product attributes that could affect participation. However, the contribution of this environmental consumerism to the overall environmental good does not depend on participation alone. The real impact relies on market participation for green consumers (the proportion of green consumers) combined with the level of green consumption intensity – the commitment levels, or proportion of consumption that is green. We design an online interface that closely mimics the real market decision environment for electricity consumers in Western Australia and use an error component model to analyze consumers’ choice of green electricity products and their commitment levels. We show that product attributes have limited impact on the choice of green products; however, there is still great potential for better participation by improving the design of green electricity programs. When green products are selected, most respondents select the minimum commitment possible, and this is insensitive to the premium being charged on green power, suggesting that we are largely observing a buy-in ‘warm glow’ for carbon mitigation.  相似文献   
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