成都市土壤中天然放射性核素含量调查研究

本文报告1986至1987年成都市土壤中天然放射性核素含量的调查方法和结果。全市共采集19个土壤样品,样品采集与分析按国家环保局《环境天然放射性水平调查规定》进行。结果表明,成都市土壤中放射性核素含量各测点平均值与面积加权平均值相吻合,其中总β为786.5Bq/Kg;1 m高处空气中的γ吸收剂量率为5.78×10-8Gy/h;238U,29.5Bq/Kg;232Th,45.7Bq/Kg;226Ra,36.0 Bq/Kg;40K,525.2Bq/Kg;137Cs,14.2Bq/Kg。成都市土壤中天然放射性核素含量比四川省和全国略低,但总体上处于同一水平。     

新疆某铁矿冶炼企业天然放射性水平调查与评价

为了解新疆某铁矿冶炼企业的铁矿石、冶炼初级产品及冶炼尾矿中的放射性水平状况,对尾矿渣的资源化利用所致辐射影响进行分析。通过对该企业进行现场监测与取样,并对采集样本进行天然放射性核素含量分析,评估冶炼尾矿资源化利用的可行性。结果表明:铁矿冶炼企业污染源项表面1 m处的γ辐射剂量率的测量值范围处于新疆天然贯穿辐射所致空气吸收剂量率(室外)的波动范围之内。样品中放射性核素含量低于国家标准中天然放射性核素免管限值。在没有掺杂的情况下,尾矿废物进行资源化利用时,部分尾矿砂可以作为A类装饰装修材料,其生产、销售及使用不加限制,一小部分尾矿砂只能作为B类装饰装修材料及建筑的外饰面使用。在资源化利用过程中,当地生态环境部门应加强对企业的辐射环境安全监管工作。     

吐鲁番市环境放射性水平

本文报道了对吐鲁番市环境放射性的调查结果。调查表明,吐鲁番市的外照射贯穿辐射剂量率、贯穿辐射致居民人均年有效剂量当量、土壤和水体中的天然放射性核素含量均比较低,属于世界正常本底辐射水平。     

四川主要煤矿原煤天然放射性核素测定分析

本文介绍用Ce(Li)低本底r谱仪测量原煤中放射性核素的结果。用60Kevr射线质量减弱系数法配制标准源样品。从而确定四川范围内二十七个煤矿原煤样品中天然放射性核素的含量。     

准东煤矿开采区土壤中天然放射性水平环境调查及评价

以高纯锗伽马能谱分析仪测量了准东煤矿开采区土壤中放射性核素~(238)U、~(232)Th、~(226)Ra和~(40)K的比活度,测量值分别为24.53(13.82~36.71)Bq/kg、33.29(20.34~47.76)Bq/kg、48.7(27.98~72.64)Bq/kg和700.31(560.29~866.95)Bq/kg。将其同新疆及昌吉州的平均放射比活度进行了比较,并计算了距地面1 m高处空气中γ辐射吸收剂量率和年有效剂量率,最后对γ辐射外照射水平进行了评价。评价结果表明,准东煤矿开采区土壤中天然放射性水平处于正常范围内。     

四川凉山州稀土矿采选冶炼中~(138)La活度浓度分布调查

采用γ能谱分析方法,分析四川凉山州轻稀土矿采选冶炼物料和产品中的138La活度浓度。研究采选冶炼工艺与138La放射性水平的关系,它们的138La主要集中在镧金属及其化合物产品中,镧金属产品可达771Bq/kg。我国虽然将稀土行业纳入《矿产资源开发利用辐射环境监督管理名录(第一批)》,但未建立TENORM中138La技术标准和法规,轻稀土中138La核素既不属于排除又不属于豁免范围。     

日本福岛核事故后四川省部分生态系统和食物链的γ核素放射性水平调查

本文调查和掌握了四川省部分生态系统中放射性水平,分析了日本福岛核泄漏事故中放射性核素对四川省主要环境介质的影响和放射性核素的迁移和富集情况,了解此次事故对部分食物链和生态系统的影响程度。对气溶胶、沉降物、土壤、植物、动物、人类食物这一链条样品中的238U、232Th、226Ra、40K、137Cs、131I 6种放射性核素进行检测,结果表明,天然放射性核素238U、232Th、226Ra、40K的检测结果均属于环境正常水平,人工放射性核素137Cs、131I低于仪器检出限。所有样品的检测结果均符合相关国家标准,与环境背景值相当,日本福岛核事故在短时间内,未对四川省生态环境和食物链造成放射性影响。     

四川省嘉陵江及其部分支流水体放射性水平调查

通过2013年、2014年对嘉陵江、白龙江和涪江水体的放射性水平调查,得到了天然核素U、Th、~(226)Ra、~(40)K和人工核素~(90)Sr、~(137)Cs以及~3H的放射性水平数据,发现嘉陵江、白龙江和涪江等江河水体中天然放射性核素浓度,并未因流域内经济活动的发展而出现明显的上升。此调查对四川省核应急工作以及科研工作提供了宝贵的基础性数据。     

2018～2021年广元市饮用水源地总放射性水平及健康风险评价

为了解广元市集中饮用水源地的放射性水平，对居民通过饮水途径摄入放射性物质导致的健康风险进行评估。调查了广元市四县三区的集中饮用水源地2018年～2021年期间的总α、总β放射性水平，使用克鲁斯卡尔-沃利斯检验对检测数据进行了组间比较和分析；根据不用年龄段公众饮水的情况计算饮水途径导致的辐射吸收剂量，再应用健康风险模型评估导致的居民健康风险。调查结果显示总α放射性浓度范围为0.0045～0.1610Bq/L,总β放射性浓度范围为：0.0103～0.1560Bq/L;不同年度、不同水源地、不同水源地类型的总α、总β放射性水平间比较，差异均无统计学意义(P>0.05);不同水期的总α、总β放射性水平间比较，差异有统计学意义(P<0.05)。各年龄组通过饮水途径摄入总α、总β放射性所导致的年均总待积有效剂量均低于0.1mSv,总α和总β放射性对各年龄段居民所致的总致癌风险处于1.80×10^-8～3.74×10^-7,低于WHO和ICRP发布的最严格控制限值。广元市四县三区的集中饮用水源地的总α和总β放射性水平均符合《生活饮用水卫生标准》(G...     

新疆大学校园辐射环境水平初步调查

为了了解新疆大学本部校园内辐射环境水平状况,对校园环境γ辐射剂量率、氡浓度水平、土壤中核素含量及红湖水样等采用国家规定的技术规范和方法进行现场测量、采样与实验室分析工作。结果表明,新疆大学本部校园内辐射环境水平处于乌鲁木齐市本底值范围之内,未见放射性异常。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

Surface applied water treatment residuals affect bioavailable phosphorus losses in Florida sands

Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.     

Animal Consciousness and Ethics in Asia and the Pacific

The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. This revised version was published online in July 2006 with corrections to the Cover Date.     

Rehabilitation and Flood Management Planning in a Steep,Boulder-Bedded Stream

This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects.     

AN INDEX FOR MEASURING THE PERFORMANCE OF IRRIGATION MANAGEMENT SYSTEMS WITH AN APPLICATION1

ABSTRACT: This paper presents a statistically valid index for measuring the performance of irrigation systems. The index is applied to a sample of 39 farms on a watercourse under the warabandi system of irrigation management in India. It is found that while the farmers in fact irrigated almost exactly the total amount of irrigated area as designed, inter-farm variations were considerable. The index shows that the degree of error of managerial effectiveness of irrigation on this watercourse is 20 percent. Therefore it is concluded that the system is performing at 80 percent effectiveness.     

WATER LOSS EQUATIONS AND COEFFICIENTS TO ESTIMATE RUNOFF FROM RAINFALL1

Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found.     

Vegetation dynamics in impounded marshes along the Indian River Lagoon,Florida, USA

Data are presented on the vegetation dynamics of two impounded marshes along the Indian River Lagoon, in east-central Florida, USA. Vegetation in one of the marshes (IRC 12) was totally eliminated by overflooding and by hypersaline conditions (salinities over 100 ppt) that developed there in 1979 after the culvert connecting the marsh with the lagoon was closed. Over 20% recovery of the herbaceous halophytesSalicornia virginica, S. bigelovii, andBatis maritima was observed at that site after the culvert was reopened in 1982, but total cover in the marsh remains well below the original 75%. No recovery of mangroves was observed at this site. The second site (SLC 24), while remaining isolated from the lagoon during much of the study, did not suffer the complete elimination of vegetation experienced at the first site. At this location, mangroves increased in cover and frequency with a concomitant decrease in herbaceous halophytes. Considerable damage to the vegetation was evident at IRC 12 when the impoundment was closed and flooded for mosquito control in 1986. Although the damage was temporary, its occurrence emphasizes the need of planning and constant monitoring and adjustment of management details as conditions within particular marshes change. Storms and hurricanes may be important in promoting a replacement of black mangroves by red mangroves in closed impoundments because the former cannot tolerate pneumatophore submergence for long periods of time. University of Florida-IFAS Journal Series R-00521.