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1.
武汉市区第四系含水层地下水有机污染敏感性研究   总被引:14,自引:0,他引:14  
在详细调查武汉市水文地质条件和地下水污染现状的基础上,获得了高精度的武汉市水环境中微量有机污染物的组成数据。所检测出的有机组分达30余种,以苯及相关苯系物为主,污染程度较高的地下水主要分布在人口密集区和工业,商业区,应用改进的DRASTIC模型-地下水污染敏感性评价模型,在GIS平台上,编制了武汉市区地下水污染敏感性分区图。根据其评价结果,建议集中对那些敏感性相对较高的区域采取有效的环保措施,开发利用时应作出风险评价。  相似文献   

2.
Drought has an impact on many aspects of society. To help decision makers reduce the impacts of drought, it is important to improve our understanding of the characteristics and relationships of atmospheric and oceanic parameters that cause drought. In this study, the use of data mining techniques is introduced to find associations between drought and several oceanic and climatic indices that could help users in making knowledgeable decisions about drought responses before the drought actually occurs. Data mining techniques enable users to search for hidden patterns and find association rules for target data sets such as drought episodes. These techniques have been used for commercial applications, medical research, and telecommunications, but not for drought. In this study, two time-series data mining algorithms are used in Nebraska to illustrate the identification of the relationships between oceanic parameters and drought indices. The algorithms provide flexibility in time-series analyses and identify drought episodes separate from normal and wet conditions, and find relationships between drought and oceanic indices in a manner different from the traditional statistical associations. The drought episodes were determined based on the Standardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI). Associations were observed between drought episodes and oceanic and atmospheric indices that include the Southern Oscillation Index (SOI), the Multivariate ENSO Index (MEI), the Pacific/North American (PNA) index, the North Atlantic Oscillation (NAO) Index, and the Pacific Decadal Oscillation (PDO) Index. The experimental results showed that among these indices, the SOI, MEI, and PDO have relatively stronger relationships with drought episodes over selected stations in Nebraska. Moreover, the study suggests that data mining techniques can help us to monitor drought using oceanic indices as a precursor of drought.  相似文献   

3.
An Operational Agricultural Drought Risk Assessment Model for Nebraska, USA   总被引:4,自引:3,他引:4  
Drought is a common occurrence in Nebraska and agriculture is the primary economic sector affected. Because of repeated and widespread severe drought impacts, more emphasis on drought risk management is warranted. This study develops an agricultural drought risk assessment model using multivariate techniques. The model is specific to corn and soybeans and is able to assess real-time agricultural drought risk associated with crop yield losses at critical phenological stages prior to and during the growing season. The assessment results are presented in a Geographic Information System to provide a better visualization. This model provides information in a timely manner about potential agricultural drought risks on dryland crop yield to decision makers ranging from agricultural producers to policy makers from local to national levels.  相似文献   

4.
Drought has become a recurrent phenomenon in Turkey in the last few decades. Significant drought conditions were observed during years of late 1980s and the trend continued in the late 1990s. The countrys agricultural sector and water resources have been under severe constraints from the recurrent droughts. In this study, spatial and temporal dimensions of meteorological droughts in Turkey have been investigated from vulnerability concept. The Standardized Precipitation Index (SPI) method was used to detail geographical variations in the drought vulnerability based on frequency and severity of drought events at multiple time steps. Critical (threshold) rainfall values were derived for each station at multiple-time steps in varying drought categories to determine least amount of rainfall required to avoid from drought initiation. The study found that drought vulnerability portrays a very diverse but consistent picture with varying time steps. At regional scale, south-eastern and eastern Anatolia are characterized with moderate droughts at shorter time steps, while the occurrence of severe droughts at shorter time steps is observed at non-coastal parts of the country. A similar picture was observed with very severe droughts. The critical (threshold) values exhibited rising numbers during the growing season at 3-month step in the South-eastern Anatolia, which might have significant consequences considering presence of large irrigation projects under-development in the region. In general, rainfall amounts required for non-drought conditions decrease from the coastal parts toward the interiors with increasing time steps.  相似文献   

5.
房浩  何庆成  戚琦 《上海国土资源》2012,33(1):62-66,70
地下水环境脆弱性是当前地下水研究领域中的一个热点,其评价结果对于城市规划、垃圾堆放场址建设、地下水源选取与保护等具有非常重要的作用。本文是在MapGIS平台上,基于DRASTIC评价技术,选取地下水位埋深、含水层介质、地形坡度、含水层上覆地层、单井涌水量五个因子,利用DATUW模型,评价哈尔滨市区的地下水环境脆弱性。根据评价结果,将研究区的地下水环境划分为高、中、低三个脆弱性区,并就分区结果,提出了防护建议。  相似文献   

6.
The area of the Jizerské Mountains in the northern part of the Czech Republic is known to have suffered from heavy acid atmospheric deposition which has led to mass extinction of the forest cover in apical parts of the mountains and to degradation of groundwater quality. A methodology for construction of groundwater vulnerability maps, using a Geographical Information System (GIS), has been developed as a tool for protecting the groundwater resources. The maps were constructed by using four subsidiary layers, each of which reflects a particular parameter that governs acidification. The factors that determine vulnerability are: (1) elevation above sea level, (2) morphology of the terrain, (3) areal extent and type of vegetation cover, and (4) lithology of the aquifer. A step-wise analysis and application of the data in each of the layers was accomplished to compare changes in the quality of groundwaters, and to obtain the best weighting factors for the individual parameters. Changes in alkalinity of the groundwater during the last 30 years were used as a test criterion. The vulnerability map should be a valuable tool to identify and outline areas most vulnerable to acidification and also areas considered for reforestation. Electronic Publication  相似文献   

7.
地下水脆弱性研究进展   总被引:50,自引:0,他引:50  
姜桂华 《世界地质》2002,21(1):33-38
地下水脆弱性研究是合理开发利用和保护地下水的基础,近年来它已成为国际水文地质研究的热点问题。在详细阐述地下水脆弱性的概念及分类的基础上,对国内外有关脆弱性评价及编图的方法进行了分析评述。最后指出了目前地下水脆弱性研究中存在的一些问题,对有关方面的进一步研究提出了建议。  相似文献   

8.
区域地下水系统防污性能评价,面临影响因子多又复杂、评价指标难以客观性选定和权重不易确定等难题,以至严重影响评价结果的可信性。本文以鲁北平原为例,在以往地下水脆弱性评价常用的DRASTIC模型基础上,采用创新的迭置指数方法,改进为"DRITCS法",选择地下水位埋深、包气带综合岩性、地表2 m内单层厚度大于0.5 m的粘土层厚、含水砂层厚度及其渗透系数、和地下水净补给量等因子,组成区域地下水系统防污性能评价模型。合理地确定了区域地下水系统防污性能评价中关键指标——包气带粘性土层变化影响,并在鲁北平原示范性应用和通过以面源污染为主的三氮污染现状验证的结果表明:本文提出的方法能够客观地反映流域性相变造成的地下水系统防污性能空间差异性和区位分布特征,具有较强的实用性。  相似文献   

9.
岩溶地下水脆弱性评价研究   总被引:5,自引:1,他引:5  
王松  章程  裴建国 《地下水》2008,30(6):14-18
岩溶地下水脆弱性评价是基于保护岩溶含水层从而有效地管理和利用地下水提出的有效方法和手段。岩溶含水层的特殊性导致污染物极易进入地下含水层,并在岩溶管道中快速、远距离地运移。与其他基岩第四系含水层相比,岩溶含水层的保护面临更大的挑战。介绍了地下水脆弱性的概念;以及岩溶地下水脆弱性的相关问题,并讨论了岩溶区脆弱性评价应考虑的一些问题。  相似文献   

10.
应用模拟技术进行区域干旱分析   总被引:3,自引:0,他引:3       下载免费PDF全文
顾颖  刘培 《水科学进展》1998,9(3):269-274
根据历史资料,应用干旱模拟模型对旱作物进行了区域农业干旱时空分布规律研究,研究典型干旱年的发生、发展和缓解过程,并对旱情的实时监视、跟踪,可能的灾情评估作了初步探讨。  相似文献   

11.
皖北平原是安徽省地下水开发利用程度较高的地区。依据国际上运用较广泛的 DRASTIC 指标体系,结合安徽省皖北平原的实际情况,构建该区域浅层地下水脆弱性评价指标体系,利用 ArcGIS软件的空间分析功能评价该区域浅层地下水的脆弱性,绘制脆弱性分布图,评价结果可为该地区地下水资源保护和污染防治提供技术参考。  相似文献   

12.
开展农业干旱灾害风险评估,有利于定量认识农业旱灾和科学指导防旱抗旱工作。基于集对分析原理和模糊理论建立的模糊集对评价法,兼顾了信息的多尺度特征和评价等级的模糊性,概念清晰,计算简洁。构建了由旱灾危险性子系统、旱灾暴露性子系统、灾损敏感性子系统和抗旱能力子系统组成的干旱灾害风险评估体系和评价指标。将模糊集对评价法应用于2012年安徽省亳州市农业干旱灾害风险评估,研究结果表明,建议方法是可靠的,为农业干旱灾害风险评估提供了一种新途径。  相似文献   

13.
袁淑杰  王婷  王鹏 《冰川冻土》2013,35(4):1036-1043
水稻生育时期内水分亏缺, 是形成水稻气候干旱的首要条件. 利用四川省1960-2010年159个气象站逐日降水量、日平均气温资料和水稻生育时期资料, 以降水距平百分率、相对湿润度指数作为干旱指标, 分析四川省水稻分蘖期、拔节孕穗期和抽穗扬花期不同气候干旱等级发生概率, 构建水稻气候干旱灾害风险模型, 评估四川省水稻分蘖期、拔节孕穗期和抽穗扬花期以及整个生育时期的气候干旱风险. 结果表明:四川省水稻拔节孕穗期和抽穗扬花期气候干旱风险较高, 降水距平百分率和相对湿润度指数的风险区划结果并不完全相同, 但分布趋势相近. 水稻整个生育时期, 四川盆地和东北部部分地区干旱风险较高, 川南地区干旱风险相对较小.  相似文献   

14.
The growing appreciation of mitigation is highlighting theneed to develop a better understanding of what makes some people more vulnerable tothe impacts of a disaster. Health researchers have asked a similar question regarding thevarying vulnerability to illness within a population. This has lead to the identification of a setof social, physical and economic factors that are now referred to as the determinants of health.These factors are the same as those commonly associated with disaster vulnerability. Recognizingthat these same concepts are being applied in both the health and disaster management contextspresents an opportunity to also achieve a shared objective of reducing vulnerability withina population.  相似文献   

15.
We simulate a large-scale flooding in the province of South-Holland in the economic centre of the Netherlands. In traditional research, damage due to flooding is computed with a unit loss method coupling land use information to depth-damage functions. Normally only direct costs are incorporated as an estimate of damage to infrastructure, property and business disruption. We extend this damage concept with the indirect economic effects on the rest of the regional and national economy on basis of a bi-regional input output table.We broaden this damage estimation to the concept of vulnerability. Vulnerability is defined as a function of dependence, redundancy and susceptibility. Susceptibility is the probability and extent of flooding. Dependency is the degree to which an activity relates to other economic activities in the rest of the country. Input–output multipliers form representations of this dependency. Redundancy is the ability of an economic activity to respond to a disaster by deferring, using substitutes or relocating. We measure redundancy as the degree of centrality of an economic activity in a network. The more central an activity is, the less it encounters possibilities to transfer production and the more vulnerable it is for flooding. Vulnerability of economic activities is then visualized in a GIS. Kernel density estimation is applied to generalize point information on inundated firms to sectoral information in space. We apply spatial interpolation techniques for the whole of the province of South-Holland. Combining information of sectoral data on dependency and redundancy, we are able to create maps of economic hotspots. Our simulation of a flood in the centre of Holland reveals the vulnerability of a densely populated delta.  相似文献   

16.
西安市地下水污染广义/狭义脆弱性对比研究   总被引:4,自引:1,他引:4  
吴晓娟  孙根年 《地球学报》2007,28(5):475-481
从"污染源排放→包气带输送→地下水污染"的系统出发,提出了地下水污染广义和狭义脆弱性的概念,并构建了相应的指标体系和评价方法;在广泛污染源调查和水文地质调查的基础上,在GIS支持下完成了地下水污染脆弱性分析试验.结果显示:纯水文地质条件的狭义脆弱性,各河道、漫滩阶地、一级阶地和老城人工填土区最为脆弱;考虑土地利用和污染源分布的广义脆弱性评价,西安市建城区和北郊污灌区敏感最高.从而得出,狭义脆弱性适合人类活动差异较小的较大区域,而广义脆弱性适合人类活动差异较大的城市区域,两者有其适用的条件和范围.  相似文献   

17.
基于DRASTIC的地下水易污染性多目标模糊模式识别模型   总被引:24,自引:2,他引:24       下载免费PDF全文
介绍了目前国外广泛应用的含水层易污染性评价的DRASTIC模型,分析了该模型存在问题及产生原因,讨论了含水层易污染性及其评价中存在的模糊性,建立了多目标模糊模式识别模型,给出含水层易污染性评价大小的习惯性描述语言.分别用DRASTIC模型和多目标模糊模式识别模型对一个应用实例进行了研究,由评价结果的分析比较结果表明,多目标模糊模式识别模型比DRASTIC模型更真实地反映含水层易污染性.  相似文献   

18.
This article describes a generalframework for hazard mitigation-oriented planning assessments of mobile telecommunications lifelines. Geographic information systems (GIS) provide an integrated platform on which to operationalize this framework. Our view is that the creation and adoption of a mitigation-oriented assessment framework could provide the basis for better decision-making on the part of public officials and telecommunications carriers alike by providing a standard reference point for consultation and consensus-building. A standard point of consultation is a crucial first step toward a program of long-term risk reduction for emergency communications, contributing to more resilient communities across Canada.  相似文献   

19.
The public and the decision and policy makers who serve themtoo often have a view of community risks that is influenced and distorted significantlyby media exposure and common misconceptions. The regulators and managers, responsible forplanning and coordination of a community's mitigation, preparedness, response and recoveryefforts, are originated from a variety of disciplines and levels of education. Not only mustthese individuals deal with the misconceptions of their communities, but also frequently lacka basic methodology for the assessment of risks. The effective planning of mitigation andresponse are, however, directly dependent upon the understanding of the complexities, types,and nature of risks faced by the community, determining the susceptible areas, and conceptualizinghuman vulnerability.In this study, a review of the existing literature on both theconceptual underpinnings of risk and its assessment is attempted. A standardized framework is proposedfor use by all emergency managers, regardless of training or education. This frameworkconsists of the numerical ranking of the frequency of the event in the community, multiplied bya numerical ranking of the severity or magnitude of an event in a given community, based upon thepotential impact characteristics of a `worst-case' scenario. This figure is then multipliedby a numerical ranking indicating the Social Consequence; a combination of community perception ofrisk level and collective will to address the problem. The resulting score, which is notstrictly scientific, would permit emergency managers from a variety of backgrounds to comparelevels of community exposure to such disparate events as hazardous materials spills andtornadoes, and to set priorities for both mitigation efforts and for the acquisition of response needs,within the availability of community resources.  相似文献   

20.
刘丽红  刘启蒙  李娴 《水文》2013,33(3):34-37
岩溶泉流量时间序列蕴含大量岩溶含水系统水动力特征信息,可为岩溶地下水资源量的确定及水文干旱分析提供重要途径。本研究基于长系列泉流量时间序列,推求流量理论频率曲线,通过拟合的理论频率曲线获得后寨岩溶典型小流域在95%、80%、50%、20%保证率下的岩溶地下水流量为0.25m3/s、0.23m3/s、0.39m3/s、0.57m3/s。在概率为80%的流量截取水平下,获得岩溶含水系统1991~1997的中最严重干旱为1993年,干旱历时为195d,缺水量为2.9×106m3。泉流量时间序列的理论频率分析能很好的应用于岩溶含水系统地下水资源计算和干旱特征分析,为岩溶含水系统水资源的合理优化配置提供依据。  相似文献   

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