Using fuzzy set theory to address the uncertainty of susceptibility to drought

This paper presents the technical aspects of a new methodology for assessing the susceptibility of society to drought. The methodology consists of a combination of inference modelling and fuzzy logic applications. Four steps are followed: (1) model input variables are selected—these variables reflect the main factors influencing susceptibility in a social group, population or region, (2) fuzzification—the uncertainties of the input variables are made explicit by representing them as ‘fuzzy membership functions’, (3) inference modelling—the input variables are used to construct a model made up of linguistic rules, and (4) defuzzification—results from the model in linguistic form are translated into numerical form, also through the use of fuzzy membership functions. The disadvantages and advantages of this methodology became apparent when it was applied to the assessment of susceptibility from three disciplinary perspectives: Disadvantages include the difficulty in validating results and the subjectivity involved with specifying fuzzy membership functions and the rules of the inference model. Advantages of the methodology are its transparency, because all model assumptions have to be made explicit in the form of inference rules; its flexibility, in that informal and expert knowledge can be incorporated through ‘fuzzy membership functions’ and through the rules in the inference model; and its versatility, since numerical data can be converted to linguistic statements and vice versa through the procedures of ‘fuzzification’ and ‘defuzzification’.     

Susceptibility indexing method for irrigation water management planning: applications to K. Menderes river basin, Turkey

A susceptibility indexing method was developed based on vulnerability and quality indices. The contamination susceptibility index (SI) at a given location was calculated by taking the product of the vulnerability index (VI) and the quality index (QI): SI = VI × QI. This method incorporates both hydrogeological and hydrochemical data for a comprehensive index mapping. The DRASTIC index methodology was used for the hydrogeological data evaluations. The quality index calculation procedure based on a water quality classification scheme was introduced to evaluate hydrochemical data. The suggested susceptibility indexing method was applied to the Küçük Menderes river basin located in western Turkey. The susceptibility index map shows both hydrogeological and hydrochemical data related to the contamination problem including areas that should be taken into consideration during water management planning. The index map indicates that the most susceptible groundwater is located along the river channel between Kiraz and Tire towns, in the Selçuk area and along the Fertek stream channel to the north of Torbal? town. The results indicate that the incorporation of both hydrogeological and hydrochemical datasets enables more realistic evaluations than those of an individual dataset to estimate the groundwater contamination susceptibility of an aquifer. The numerical procedure applied could be extended further by including other parameters such as retardation, potential contaminant sources, etc. that affect the water quality in a given basin.     

电器防雷滤波技术探讨

我国是雷电多发地区,在我们日常生活中电器经常会被雷电击坏或不能正常工作。本文就产品设计中我们常采用的一种既防雷又解决滤波的防雷滤波技术讨论,并加以验证。     

基于信息熵与KPSO聚类法滑坡敏感性分析

选取南京地区滑坡为研究对象。基于DEM及遥感影像数据,选取样本,提取滑坡影响因素,计算影响因素熵值。利用K折粒子群优化(K PSO)方法,在GIS环境下针对地质资料缺乏情况,生成一个可靠的南京地区滑坡敏感图。自组织特征映射网络(SOM)法用作一个并行研究,结果作为K PSO法结果对比。结果表明,K PSO法聚类准确率为85%,自组织映射(S OM)法聚类结果准确率为80%,由此说明K PSO聚类法在地质资料不足前提下形成滑坡敏感区是一种行之有效的方法。     

A new approach to quantifying and comparing vulnerability to drought

In this study we develop an “inference modeling” approach to compare and analyze how different disciplines (economics, political science, and behavioral science/environmental psychology) estimate vulnerability to drought. It is thought that a better understanding of these differences can lead to a synthesis of insights from the different disciplines and eventually to more comprehensive assessments of vulnerability. The new methodology consists of (1) developing inference models whose variables and assertions incorporate qualitative knowledge about vulnerability, (2) converting qualitative model variables into quantitative indicators by using fuzzy set theory, (3) collecting data on the values of the indicators from case study regions, (4) inputting the regional data to the models and computing quantitative values for susceptibility. The methodology was applied to three case study regions (in India, Portugal and Russia) having a range of socio-economic and water stress conditions. In some cases the estimates of susceptibility were surprisingly similar, in others not, depending on the factors included in the disciplinary models and their relative weights. A new approach was also taken to testing vulnerability parameters by comparing estimated water stress against a data set of drought occurrences based on media analysis. The new methodologies developed in this paper provide a consistent basis for comparing differences between disciplinary perspectives, and for identifying the importance of the differences.

Who is susceptible and why? An agent-based approach to assessing vulnerability to drought

In this paper, we specify susceptibility to drought from a psychology-based bottom-up perspective. On the basis of the protection motivation theory (Rippetoe and Rogers in J Pers Soc Psychol 52(3):596–604, 1987), we developed the protection-capacity model (Krömker and Mosler in Global environmental change in Alpine regions: impact, recognition, adaptation, and mitigation. Edward Elgar, Cheltenham, pp 93–112, 2002) to analyse the susceptibility with respect to the protection capacity of agents. The protection capacity is determined by the agents’ subjective assessment of the situation, which consists of the appraisal of threat, on the one hand, and the coping appraisal, on the other hand. Additionally, the protection-capacity model specifies several factors which influence the two central appraisal processes. Empirical data were collected in interviews with experts and with a total of 65 exemplarily selected households which are typical for the respective case study regions (Andhra Pradesh, India; Algarve and Alentejo, Portugal; Volgograd and Saratov, Russia). The data were analysed with the help of fuzzy set methodology. Results show that the households of the Indian region are the most susceptible when compared to those of the Russian region with ‘low’ and to households of the Portuguese region with a ‘very low’ degree of susceptibility. Moreover, we identified subgroups within the regions which are characterized by different degrees of susceptibility and a different profile of factors influencing susceptibility. Altogether, the agent-based perspective allows identifying relevant factors that need to be addressed to minimize susceptibility of the population and special subgroups. However, the results are not representative for the case study regions because of the small database. Additionally, more effort is needed to validate the findings.     

Application of fuzzy models to assess susceptibility to droughts from a socio-economic perspective

By combining the concepts of environmental stress, state susceptibility and environmental crisis, “Security Diagram” (SD) provides a quantitative approach to assessing environmental change and human security. The SD is a tool that clearly presents in a diagram the security situation of a population or region affected by a particular environmental crisis. Its underlying concept emphasises that the higher the level of environmental stress and socio-economic susceptibility, the higher the probability of the occurrence of crisis. Focusing on drought, this study analyses the susceptibility of case study regions in India, Portugal, and Russia from a socio-economic perspective. A conceptual framework of socio-economic susceptibility is developed based on the economic development theories of modernisation and dependency. Fuzzy set theory is used to generate susceptibility indices from a range of national and sub-national indicators, including financial resources, agricultural dependency and infrastructure development (for economic susceptibility), and health condition, educational attainment and gender inequality (for social susceptibility). Results indicate that socio-economic susceptibility over the period 1980–1995 was highest in India, followed by Russia and (since 1989) lowest in Portugal. Globalisation is likely to contribute to changes in the level of socio-economic susceptibility over time. Moreover, specific social and economic structures unique in each country (e.g., the role of women in society in India, the socialist legacy in Russia) may explain differences in susceptibility between the case study regions.

The challenge of validating vulnerability estimates: the option of media content analysis for identifying drought-related crises

For an integrated assessment of the vulnerability of societies to drought it is necessary to set the benchmark at a level where the impacts of droughts lead to a state of affairs that departs from normal conditions, i.e. a crisis event. This article aims to improve the understanding of drought-related crisis events on the basis of a twofold media content analysis. This approach enables us to test when increased vulnerability in fact leads to a crisis situation and offers an improved understanding of the intensity and the extent of crisis events. To this end, we first outline our perspective on crisis and give an overview on existing approaches to identify crisis events. We then outline our two-step approach of media content analysis aimed at developing a crisis data set for the case study regions Andhra Pradesh (India), Southern Portugal and the Volga region (Russia). Using the Factiva news database and information by regional newspapers, a crisis data set is generated enabling us to define the occurrence and extent of drought-related crisis events in the case study regions. Moreover, based on attributes of drought impacts reported by news sources, we categorize the extensiveness of a specific drought. As a key result, our findings suggest that Southern Portugal, the case study region which is expected to be less susceptible to drought events than the other case study regions, faced the most extended crisis events.     

Assessing the susceptibility of societies to droughts: a political science perspective

In this article we develop a concept for the assessment of state’s susceptibility to drought based on a political science perspective. Different sources of capacities and sensitivities need to be taken into account to assess the overall susceptibility of states as political systems. We argue that the overall susceptibility of a society depends on an interplay of state capacity and readiness as main elements of political susceptibility, wealth and economic sensitivity as elements of economic susceptibility and the degree of social integration. To transform the conceptual model into a susceptibility assessment we developed an inference model in order to generate quantitative indices. For this purpose we apply fuzzy set theory using data from our case study regions, namely Andhra Pradesh (India), the Volga region (Russia) and (Southern) Portugal. The resulting computed trends for Portugal suggest that the society will be able to deal even with severe natural conditions due to existing political, economic, and social conditions. The assessment results for the Indian and Russian case study regions, in contrast, give reason for precaution since the occurrence of drought-induced crisis events seems much more likely in the light of more crucial, overall conditions, namely lower degrees of state capacity and readiness as well as, in the case of India, a high economic susceptibility. However, further improvements are possible given the improved availability of data and the integration of more qualitative information. Additionally, the expansion to further case study regions could help validate the overall concept.     

Antimicrobial susceptibility of Escherichia coli isolated from shrimp (Litopenaeus vannamei) and pond environment in northeastern Brazil

This study aimed to test the susceptibility of Escherichia coli strains isolated from the water, bottom sediments and individuals cultivated in shrimp farm ponds, to antibiotics belonging to different families, namely B-Lactams: Imipenem (IPM; 10 μ g), Ampicillin (AMP; 10 μ g), Cephalothin (CEP; 30 μ g), Cefoxitin (FOX; 30 μ g), Ceftriaxone (CRO; 30 μ g); Tetracycline: Tetracycline (TCY; 30 μ g); Aminoglycosides: Gentamicin (GEN; 10 μ g), Amikacin (AMK; 30 μ g); Chloramphenicol: Chloramphenicol (CHO; 30 μ g); Fluoroquinolones: Ciprofloxacin (CIP; 5 μ g); Nitrofurans: Nitrofurantoin (NIT; 300 μ g); Sulfonamides: Trimethoprim-Sulfamethoxazole (SXT; 30 μ g); Quilononas: Nalidixic Acid (NAL; 30 μ g). In the laboratory, the method of dissemination (Test Kirby-Bauer) was performed in order to fulfill the antibiogram tests. The results showed high indices of resistance to Imipenem, Cephalothin and Ampicillin. Chloramphenicol, Nitrofurantoin, Cefoxitin, Ceftiaxone and Ciprofloxacin have displayed the highest index of sensitive strains. The antibiotic resistance index (ARI) and the multiple resistance index (MAR) varied within the ranges of 0.068–0.077 and 0.15–0.39, respectively. More than 90.5% of strains of Escherichia coli showed a variety of resistance profiles to the tested antibiotics. The high indices of resistance may be a consequence of indiscriminate use of antibiotics, but also the transfer of resistance through mobile genetic elements found in shrimp farms.