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71.
华东森林及高山背景区域SO2、NOx、CO本底特征   总被引:2,自引:0,他引:2  
国家大气背景监测福建武夷山站是中国华东区域背景站点之一,可代表华东森林及高山区域背景状况。为了解该区域的大气背景状况,评估区域污染现状以及污染物输送在区域污染中的作用,选取福建武夷山背景站2011年3月至2012年2月主要气体污染物(SO2、NOx、CO)为期1年的监测数据,研究各污染物在不同时间尺度的浓度变化特征和相关关系,以及与气象因子的相关关系,并利用后向轨迹模式探讨区域输送对华东森林及高山背景区域各气体污染物质量浓度的影响。结果表明,武夷山背景点监测期间SO2、NOx、CO的平均质量浓度分别为3.9、5.1、409.8 μg/m3,且具有明显的季节变化特征,春、冬季明显高于夏、秋季;三者日变化幅度均很小,呈现出单谷型分布型态,说明武夷山背景点受人为活动的影响很小,主要受气象条件影响;相关性分析结果显示,SO2与NOx浓度相关性较好,与湿度有较好的负相关,与风速在冬季具有一定的正相关,NOx与CO浓度在秋季和冬季的相关性较好,且二者与温度的负相关性较好。后向轨迹分析结果表明,SO2全年最大浓度峰值主要来自北方采暖季燃煤排放的远距离输送影响,NOx、CO全年最大值则源于生物质燃烧的远距离输送影响。  相似文献   
72.
为查明华东某铀矿区稻米中放射性核素铀污染现状及健康风险问题,测定铀矿区和对照区共136件稻米样品中放射性核素U含量,采用单因子污染指数法评价放射性铀污染,并开展U元素健康风险评价。结果表明:(1)研究区稻米中U含量平均值为1.46 ng·g~(–1),各亚区稻米中U含量平均值从大到小顺序为:开采矿井区水冶场区含矿未采区废弃矿井区江西省背景值对照区;(2)稻米单因子污染指数为1.25,属于轻度污染。其中,开采矿井区和水冶厂区为轻度污染,废弃矿井区和对照区未受污染;(3)首次计算提出江西省大米U元素致癌风险最大斜率系数为1.04×10~3(d·kg)·mg~(–1)。各亚区稻米中成人和儿童致癌风险指数高低顺序均为:开采矿井区水冶厂区含矿未采区废弃矿井区对照区。儿童直接饮食稻米具有一定的致癌风险;开采矿井区和水冶厂区的成人存在一定致癌风险,含矿未采区和废弃矿井区以及对照区均无致癌风险。  相似文献   
73.
Historically, many watershed studies have been based on using the streamflow flux, typically from a single gauge at the basin's outlet, to support calibration. In this setting, there is great potential for equifinality of parameters during the optimization process, especially for parameters that are not directly related to streamflow. Therefore, some of the optimal parameter values achieved during the autocalibration process may be physically unrealistic. In recent decades a vast array of data from land surface models and remote sensing platforms can help to constrain hydrologic fluxes such as evapotranspiration (ET). While the spatial resolution of these ancillary datasets varies, the continuous spatial coverage of these gridded datasets provides flux measurements across the entire basin, in stark contrast to point‐based streamflow data. This study uses Global Land Evaporation: the Amsterdam Model data to constrain Soil and Water Assessment Tool parameter values associated with ET to a more physically realistic range. The study area is the Little Washita River Experimental Watershed, in southern Oklahoma. Traditional objective metrics such as the Nash‐Sutcliffe coefficients record no performance improvement after application of this method. However, there is a dramatic increase in the number of days with receding flow where simulations match observed streamflow.  相似文献   
74.
Anderson, SallyRose, Glenn Tootle, and Henri Grissino‐Mayer, 2012. Reconstructions of Soil Moisture for the Upper Colorado River Basin Using Tree‐Ring Chronologies. Journal of the American Water Resources Association (JAWRA) 48(4): 849‐858. DOI: 10.1111/j.1752‐1688.2012.00651.x Abstract: Soil moisture is an important factor in the global hydrologic cycle, but existing reconstructions of historic soil moisture are limited. We used tree‐ring chronologies to reconstruct annual soil moisture in the Upper Colorado River Basin (UCRB). Gridded soil moisture data were spatially regionalized using principal components analysis and k‐nearest neighbor techniques. We correlated moisture sensitive tree‐ring chronologies in and adjacent to the UCRB with regional soil moisture and tested the relationships for temporal stability. Chronologies that were positively correlated and stable for the calibration period were retained. We used stepwise linear regression to identify the best predictor combinations for each soil moisture region. The regressions explained 42‐78% of the variability in soil moisture data. We performed reconstructions for individual soil moisture grid cells to enhance understanding of the disparity in reconstructive skill across the regions. Reconstructions that used chronologies based on ponderosa pines (Pinus ponderosa) and pinyon pines (Pinus edulis) explained more variance in the datasets. Reconstructed soil moisture data was standardized and compared with standardized reconstructed streamflow and snow water equivalent data from the same region. Soil moisture and other hydrologic variables were highly correlated, indicating reconstructions of soil moisture in the UCRB using tree‐ring chronologies successfully represent hydrologic trends.  相似文献   
75.
以太湖15个入湖河流之一的社渎港为研究对象,利用社渎港流域的水环境质量监测数据、工业企业污染排放调查数据、环境统计数据及社会经济统计数据,对社渎港流域产业结构的合理性进行了诊断,并采用典型相关分析方法探讨了产业结构演变对水环境的影响。结果表明,研究区的工业污染总体上得到了较好控制,其中屺亭街道的工业污染排放最为严重;城乡生活污染和农业面源污染是研究区水环境质量恶化的主要原因,城乡生活污染对COD和氨氮入河量的贡献率较高,分别为46.59%和60.55%,农业面源污染对TN和TP入河量的贡献率突出,分别为64.05%和76.50%;研究区产业结构与钱纳里三次产业结构模式(产业结构合理程度的参照标准)的Hamming贴近度从2001年的0.83下降到2007年的0.77,产业结构不尽合理,且不合理程度逐渐加剧;研究区第一产业对TN和TP入河量的影响最为显著,第三产业对氨氮和COD入河量的影响最为明显;可通过优化产业结构来减轻研究区的水环境污染状况,产业结构调整的主要目标应为降低第二产业产值比例及增加第三产业产值比例。  相似文献   
76.
Zardari, Noor ul Hassan, Ian Cordery, and Ashish Sharma, 2010. An Objective Multiattribute Analysis Approach for Allocation of Scarce Irrigation Water Resources. Journal of the American Water Resources Association (JAWRA) 46(2):412-428. DOI: 10.1111/j.1752-1688.2009.00410.x Abstract: In this study, end user (farmer) and decision maker (water allocator) opinions were surveyed and a conjoint analysis (CA) based method was applied to the quantitative and qualitative data to assess the utility associated with each attribute that plays a role in forming the final thinking of the water users. The application of CA for estimating the utility for each attribute level is a novel approach, which helps provide a formal, objective basis for assigning relative scales for each attribute interval within a multiattribute decision-making model. The utilities (part-worths) obtained from the CA have a cardinal scale and were found to be comparable within and across the attributes. A farmers’ survey on five water allocation attributes was completed from 62 farmers and their opinions on the relative importance of attributes were elicited for a subarea of the Indus River Basin. The CA method was then applied to the survey data and the utilities for each attribute level were determined. This allowed, for instance, decisions to be made, which take account of the perceived value of the water and of the availability of local labor to work on the farm. Finally, these interval scales were used within the specification of the ELECTRE multiattribute decision-making method to provide a complete and objective ranking of nine irrigation districts so that the best decisions on water allocation could be made.  相似文献   
77.
River Nile is one of the longest transboundery rivers and it is shared and used by Burundi,Democratic Republic of Congo,Egypt,Ethiopia,Eritrea,Kenya,Rwanda,Sudan,Tanzania and Uganda.As of today,the Nile is a crucial resource for the economic development of the Nile Basin countries and a vital source of livelihood for 160 million inhabitants as well as 300 million people living in the 10 riparian countries.The Nile Basin Initiative(NBI) is one of the international cooperative river basin management program and regional partnership where all the Nile Basin countries except Eritrea unite to pursue long-term sustainable development,improved land use practices and management.This review therefore focused on the challenges not faced on NBI in terms of integrated use of the river and conducted analysis of strengths,weaknesses,opportunities and threats(SWOT) based on secondary data.The result of the review revealed that for decades,the Nile Basin people have been facing many complex environmental,social,economic and political challenges that have made it difficult for the proper management and sustainability of Nile water.The initiative provides training to develop skills in government ministries,non-governmental organizations and local communities in each country.It is also working to raise awareness of critical environmental issues by strengthening networks of environmental education practitioners;developing curriculum in the education sector.The challenges of NBI include the involvement and funding of World Bank,lack of sufficient staff,procedural and policies conflicts,lack of coordination and linkage with other regional institutions and lack of recognition as river basin organization.Considering the complex nature of the project,it is recommended that the NBI should come up with a strong multi-disciplinary monitoring and evaluation team to follow up all implemented projects.The NBI should carry out participatory land use planning in communities along the river basin.Moreover,livelihood analysis should be carried out especially in communities along the Nile to come up with poverty eradication projects which are socially acceptable,applicable,economically viable and affordable.  相似文献   
78.
太湖流域的稻麦两熟复种大约产生于东晋南朝时期(317~589年),此后这一种植制度长期存在,并不断有所发展。考察发现,此一区域的稻麦两熟在历史上的大多数时候并无突出的季节矛盾,只是有两个时期例外。这两个时期一是明末清初,一是19世纪。太湖流域历史上突出的季节矛盾不由人口、品种等社会原因引起,而由气候变化这一自然因素导致。明末清初和19世纪分别是历史上最为寒冷的时期,是气候变冷造成了这一区域稻麦两熟突出的季节矛盾  相似文献   
79.
基于MODIS的渍害田和正常农田遥感特性对比研究   总被引:1,自引:0,他引:1  
渍害田在我国南方地区分布广泛,严重影响农业生产。以四湖流域洪湖地区为实验区,基于渍害田的物理及生态特性来探讨渍害田遥感识别特性。利用2002~2011年MODIS产品,辅以土壤图、土地覆被数据,对比分析了正常农田及渍害田在反照率、增强型植被指数(EVI)、地表夜温、地表温差和表观热惯量的时相差异;并结合相关研究成果加以解释和验证。结果表明:一年中大部分时段,正常农田的反照率、EVI、地表温差都大于渍害田,而地表夜温、表观热惯量都低于渍害田;各指标的多年平均值也具有类似差别;渍害田的EVI在6、7月份比正常农田高, 可能是由于渍害田在雨、热、肥条件同时良好时比正常农田生长的更快。研究结果可为进一步准确识别渍害田空间分布及其动态变化  相似文献   
80.
通过界定水资源承载能力的概念和内涵,提出基于总量控制条件下人口 经济 水资源三者系统协调耦合的水资源承载能力分析计算方法,分别采用产业结构调整和水资源优化配置模型等措施,以赣江袁河流域水资源承载能力分析计算进行例证。研究结果表明:在用水总量控制、保障社会发展水平和人均GDP水平条件下,(1)优化后行业用水定额下降,流域需水总量减少,水资源利用效率提高,目标年2015年和2030年流域需水量调整后较调整前分别减少036亿m3、090亿m3,较调整前下降了23%和53%;(2)对于不同目标年,优化后用水区域可承载GDP和承载人口有所增加,2015年和2030年全流域可承载GDP分别增加2649亿元和15191亿元,全流域可承载人口分别增加773万人和1874万人  相似文献   
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