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681.
基于参与式社区评估法的泾河流域景观管理问题分析   总被引:3,自引:0,他引:3  
参与式社区评估法既兼顾了景观管理中的地理变量,同时还将社会经济因素纳入了考虑范畴,是深入进行问题分析客观有效的方法之一。本文采用参与式社区评估法,运用问题矩阵和问题树分析,对泾河流域景观管理中存在的问题和利益相关者的认知进行了分析。研究发现,绝大多数利益相关者认为土壤侵蚀已成为第一严重的问题,其次是土地生产力低下、自然灾害、植被破坏等。尽管当地公众已经认识到了土壤侵蚀的严重危害,但在安排土地利用方式时,却很少考虑土壤侵蚀带来的危害,仍然从事着自给自足的粮食生产活动。  相似文献   
682.
To reveal the effect of forest fires on the avifauna of the Northern Amur Region, bird assemblages of primary dark conifer-deciduous forests, wild rosemary larch forests, and secondary larch-birch forests have been studied in the Komsomol’skii and Norskii nature reserves. It has been shown that the replacement of primary dark conifer-deciduous forests by secondary forests is accompanied by a significant decrease in bird population density, with some species being lost and the composition of the dominant species group being changed. On the other hand, fires lead to increasing patchiness of the environment, which can sometimes provide for an increase in biological diversity.  相似文献   
683.
In the framework of dynamic morphology theory, the centers of gravity and geometric centers of projections have been determined for the bodies of more than 182 forms of invertebrates, and these data have been used to distinguish four types of dynamic body shapes. It has been demonstrated that specific dynamic types of body shape are characteristic of individual taxa. In addition, there are a group of “transformers,” which may assume any dynamic type of shape, and a group of invertebrates with one predominant dynamic type.  相似文献   
684.
685.
Coastal flooding affects physical and social place attachments. Values-based approaches to climate change adaptation examine how risks to place attachments are distributed within and among communities, with a view to informing equitable adaptation policies. In this nascent body of research, divergent theoretical frameworks and empirical approaches to measuring social values are evolving. While some studies explore the things people value about their everyday lives generally—the lived values approach, others locate specific social and cultural values in geographic space—the landscape values mapping approach. This study aims to compare the explanatory value of these two approaches for understanding the social risks of sea-level rise, and appraise whether either or both approaches are likely to meet local adaptation planning needs. It does this by examining the potential social impacts of sea-level rise in Kingston Beach, Australia, informed by a mail-out survey of the community. The lived values approach identified that the natural environment, scenery, relaxed lifestyle and safety are highly important to local residents, while the landscape values mapping approach revealed that Kingston Main Beach is the most highly valued of eight coastal landscape units. Incorporating the landscape values mapping into the lived values cluster analysis revealed that while Kingston Main Beach is highly important for its recreational value to some members of the community, for others manmade features such as community halls or sports ovals may be of higher importance because they facilitate social interactions. There is potential to further integrate these two approaches to better inform adaptation policy about how lived and landscape values are distributed among communities, where they are located in space and whether they change over time. A deeper understanding of such assigned values can lead to improved engagement with coastal residents to inform adaptation policy now and into the future.  相似文献   
686.
Abstract: A practical methodology is proposed to estimate the three‐dimensional variability of soil moisture based on a stochastic transfer function model, which is an approximation of the Richard’s equation. Satellite, radar and in situ observations are the major sources of information to develop a model that represents the dynamic water content in the soil. The soil‐moisture observations were collected from 17 stations located in Puerto Rico (PR), and a sequential quadratic programming algorithm was used to estimate the parameters of the transfer function (TF) at each station. Soil texture information, terrain elevation, vegetation index, surface temperature, and accumulated rainfall for every grid cell were input into a self‐organized artificial neural network to identify similarities on terrain spatial variability and to determine the TF that best resembles the properties of a particular grid point. Soil moisture observed at 20 cm depth, soil texture, and cumulative rainfall were also used to train a feedforward artificial neural network to estimate soil moisture at 5, 10, 50, and 100 cm depth. A validation procedure was implemented to measure the horizontal and vertical estimation accuracy of soil moisture. Validation results from spatial and temporal variation of volumetric water content (vwc) showed that the proposed algorithm estimated soil moisture with a root mean squared error (RMSE) of 2.31% vwc, and the vertical profile shows a RMSE of 2.50% vwc. The algorithm estimates soil moisture in an hourly basis at 1 km spatial resolution, and up to 1 m depth, and was successfully applied under PR climate conditions.  相似文献   
687.
本文对西部某老工业区土壤中As、Pb、Cr、Cd、Hg、Zn的含量、空间分布状况展开了研究,并依据《污染场地风险评估技术导则》对该老工业区的健康风险进行了评价。研究结果表明,该老工业区土壤重金属污染严重,6种元素与陕西土壤背景值相比超标100%,表明其不适宜作为居住用地开发。健康风险评价结果显示,As、Pb、Cr、Cd元素的非致癌风险值分别为3.83、1.7、1.94、1.09,均超过非致癌风险可接受值1,表明该老工业区对人们存在非致癌健康风险;对于致癌风险,As、Cr、Cd元素的致癌风险值远大于致癌风险边界值,分别超过致癌风险值的2个数量级(2.64×10-4)、4个数量级(1.94×10-2)、1个数量级(6.12×10-5),表示As和Cr已经达到了显著致癌风险的水平。  相似文献   
688.
铅锌冶炼厂周边农田土壤、苕子与荠菜的重金属污染特征   总被引:1,自引:0,他引:1  
在云南某铅锌矿冶炼厂周边农田,采集当地主要绿肥(苕子)与野菜(荠菜)的植株和根部土壤样品,测定重金属(Pb、Zn、Cu和Cd)的全量和DTPA提取的有效态质量比,并进行污染评价.结果表明:1)综合污染指数评价显示,铅锌冶炼厂周边农田土壤以重度和中度重金属污染为主,Cd质量比为GB 15618-1995《土壤环境质量标准》三级标准限值的1.94~8.30倍,污染程度最重,其次为Pb和Zn;2)荠菜植株Pb、Zn和Cd质量比的最大值、平均值均大于苕子;荠菜对Cd的富集系数大于1,对Pb、Zn和Cd的转移系数大于或接近1;3)苕子和荠菜地上部与土壤的Cd、Pb质量比,苕子地下部与土壤的Pb质量比,荠菜地上部与土壤的Zn质量比均呈显著或极显著正相关.研究表明:铅锌冶炼厂周边农田存在严重的重金属污染,Cd是主要污染因子;苕子和荠菜植株重金属质量比高,且荠菜对重金属的富集能力大于苕子.  相似文献   
689.
为了解河南省武陟县大田土壤重金属Cr、Cd、Pb、As、Cu、Se、Ni和Co的形态分布和生态风险情况,在该区域采集了12个表层土壤(0~20cm)样品,采用修正的BCR连续提取法进行形态分析,探讨其生物有效性,并采用Hakanson指数法评价了重金属的潜在生态风险.结果表明,土壤中不同重金属的形态分布差异很大,其中,Cr、As、Ni和Co均主要以残渣态存在,分别占其总量的66.6%、61.4%、50.7%和41.8%;Cu和Se主要以可氧化态存在,分别占其总量的43.8%和67.8%;Pb主要以可还原态存在,占总量的61.1%;Cd主要以酸提取态存在,占总量的53.3%.生物有效性分析表明,Cd的可利用态K1为0.933,生物有效性是最大的,对土壤生态系统的潜在危害性较大,其次是Pb和Co;Cu和Se在土壤环境发生变化时,很容易再次释放到外界环境中;Cr、As和Ni不易被外界生物利用.潜在生态风险评价结果显示,以国家土壤环境质量标准二级标准为参比值时,Cr、Cd、Pb、As、Cu和Ni的单项潜在生态风险程度均为轻微,综合潜在生态风险处于轻微等级.  相似文献   
690.
The Scottish Government is committed to carbon reduction targets which are the most ambitious across the devolved administrations of the UK. Whilst Scotland operates within broader international and UK policy contexts, it has developed particular programmes and approaches to engage communities in the transition towards low-carbon futures. Rural areas have a role in the transition to a low-carbon Scotland; however, beyond land use and agriculture contributions, little research has explored the “rural” dimension of “low-carbon” transitions. The paper presents a policy and literature review relating to the low-carbon agenda in Scotland. It reflects on Scottish low-carbon policy and governance, the positioning of “rural communities” within this, and the opportunities and challenges this might present. Based on this, we develop an understanding of how rural communities may contribute to a low-carbon Scotland and identify a future research agenda to explore in more detail the nature and relative effectiveness of diverse governance structures to support this.  相似文献   
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