Environment, Population, and Health [Working Papers]

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Now showing 1 - 8 of 8
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    Household cooking fuel use in rural and peri-urban Viet Nam : a multilevel longitudinal analysis of supply side factors
    (Honolulu, HI : East-West Center, 2017-05) Saksena, Sumeet ; Tran, Chinh Cong ; Fox, Jefferson
    2006 and 2011 agriculture census data of approximately 9500 communes was analyzed to examine the role of supply and demand side factors in the choice of main cooking fuel. The use of fuel wood was found to be significantly associated with all forest types -- whether they were natural or plantations; whether they were owned by households or other entities. We have provided evidence that officially designated rural places are not homogenous in terms of fuel use. There is a distinct difference between traditional rural communes and the more modern rural communes. The latter we term as peri-urban communes. In peri-urban communes wood usage decreased over the years. In rural communes wood use however increased. This may partly be due to a natural transition of moving up the energy ladder from crop residues to wood. We find some evidence that given Viet Nam's highly successful and well documented small-holder plantation programs that have led to significant reforestation there may be rural pockets in the country where movement up the energy ladder from wood to cleaner fuels has slowed down considerably. Peri-urban areas have a greater fraction of gas users and also have a greater diversity of fuel use patterns. In the future household factors and behaviors are likely to continue being the dominant drivers of fuel switching. However, our study indicates that external interventions aimed at improving community conditions such as access to markets, roads and highways can also facilitate households moving up the energy ladder. These factors may affect modern fuel access directly or may also work at modernizing communes to create a broader wealth effect over a period of time. Our findings are of much relevance to the newly proposed policy paradigm of ‘making the clean available’ as opposed to ‘making the available clean’ (Smith 2015). Promoting and marketing top of the ladder clean fuels would require satisfactory marketing and transportation networks, which our study has shown to be associated with fuel use. Our community level analysis is also relevant to those agencies that wish to transform an entire community at a time rather than targeting only a few households within it.
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    Age structure and trade openness : an empirical investigation
    (Honolulu, HI : East-West Center, 2015-06) Fukumoto, Yukio ; Kinugasa, Tomoko
    This research focuses attention on the relationship between age structure and trade openness. We hypothesized that a higher working-age population share of a total population raises trade openness because dependent population tend to spend more than working-age population for non-tradable goods such as education and medical services. We estimated the effects of age structure on trade openness empirically using panel data of 85 countries from 1991 to 2010, and we simulated trade openness based on changes in age structure from 1991 to 2100. The estimation results show that an increase in the share of working-age (dependent) population in a total population has a positive (negative) effect on trade openness. According to the simulation results, an increase in the share of the working-age population will increase trade openness until the beginning of the 21st century. However, the turnover of the share of the working-age population and more rapid increase in the share of the old-dependent population will decrease trade openness after that.
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    Role of Urbanization, Land-Use Diversity, and Livestock Intensification in Zoonotic Emerging Infectious Diseases
    (Honolulu, HI: East-West Center, 2014-10) Saksena, Sumeet ; Fox, Jefferson ; Epprecht, Michael ; Tran, Chinh C. ; Castrence, Miguel ; Nong, Duong ; Spencer, James ; Nguyen, Lam ; Finucane, Melissa ; Vien, Tran Duc ; Wilcox, Bruce
    Emerging infectious diseases (EIDs) continue to significantly threaten human and animal health. While there has been some progress in identifying underlying proximal driving forces and causal mechanisms of disease emergence, the role of distal factors is most poorly understood. This article focuses on analyzing the statistical association between highly pathogenic avian influenza (HPAI) H5N1 and urbanization, land-use diversity and poultry intensification. A special form of the urban transition--peri-urbanization--was hypothesized as being associated with 'hot-spots' of disease emergence. Novel metrics were used to characterize these distal risk factors. Our models, which combined these newly proposed risk factors with previously known natural and human risk factors, had a far higher predictive performance compared to published models for the first two epidemiological waves in Viet Nam. We found that when relevant risk factors are taken into account, urbanization is generally not a significant independent risk factor. However, urbanization spatially combines other risk factors leading to peri-urban places being the most likely 'hot-spots'. The work highlights that peri-urban areas have highest levels of chicken density, duck and geese flock size diversity, fraction of land under rice, fraction of land under aquaculture compared to rural and urban areas. Land-use diversity, which has previously never been studied in the context of HPAI H5N1, was found to be a significant risk factor. Places where intensive and extensive forms of poultry production are collocated were found to be at greater risk.
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    Perceived Risk of Avian Influenza in Poultry Varies with Urbanization in Vietnam
    (Honolulu, HI: East-West Center, 2014-10) Finucane, Melissa L. ; Nghiem, Tuyen ; Saksena, Sumeet ; Spencer, James ; Fox, Jefferson ; Nguyen, Lam ; Trinh, Dinh Thau ; Vien, Tran Duc ; Lewis, Nancy Davis
    Highly pathogenic avian influenza (HPAI) is an important public health concern because of its potential to cause widespread morbidity and mortality in humans and poultry and associated devastating economic losses. In this study we examined how perceptions of and response to the risk of HPAI in poultry vary across communes/wards in the north of Vietnam at different levels of urbanization (rural, transitional, urban). We conducted a quantitative household survey with 1073 respondents. Results suggested that the perceived risk of HPAI in poultry was highest in transitional and rural settings. Respondents in these settings were more likely than respondents in urban settings to agree that the process of change (in urbanization, agricultural practices, or natural habitat) increased the likelihood of an outbreak of HPAI in poultry. Compared with others, respondents in transitional areas reported that they do less planning and perceive vaccines to be more effective, while respondents in rural areas reported less perceived ability to separate infected poultry from others. We also found that the inability to respond is not necessarily because of an inability to perceive change but because, rapid and extensive change poses different challenges for poultry management as communes move from rural to transitional to urban settings. Our results suggest that public and animal health campaigns could be tailored in a way that recognizes the needs of poultry raisers in different settings.
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    Policy implications for prevention of highly pathogenic avian influenza subtype H5N1 in conjunction with risk factors in the Red River Delta, Vietnam
    (Honolulu, HI: East-West Center, 2014-10) Tran, Chinh C. ; Yanagida, John F. ; Saksena, Sumeet ; Fox, Jefferson
    The challenge is to develop the vaccination program that is more successful in containing and preventing the Highly Pathogenic Avian Influenza subtype H5N1 from recurrence in the Red River Delta, Vietnam and reducing vaccination costs. This study addresses the tradeoff between the current policy which implements an annual two-round vaccination for the entire geographical area of the Delta and an alternative policy which involves more frequent vaccination in higher probability areas for the disease occurrence within the Delta. The ex-ante analysis framework is used to identify the location of higher probability areas for the alternative policy and evaluate the accuracy of the analysis. The efficacy and cost analysis of vaccination programs are then implemented for the tradeoff between the current and the alternative policies. The ex-ante analysis suggests that the focus areas for the alternative vaccination program include 1137 communes, corresponding to 50.6% of total communes in the Delta and mostly located in the coastal areas to the east and south of Hanoi. The efficacy and cost analyses suggests that the alternative policy would be more successful in reducing the rate of disease occurrence and the costs of vaccination as compared to the current policy.
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    Economic analysis of duck production household farm level in the context of highly pathogenic avian influenza subtype H5N1 in the Red River Delta, Vietnam
    (Honolulu, HI: East-West Center, 2014-10) Tran, Chinh C. ; Yanagida, John F.
    Occurrence of the Highly Pathogenic Avian Influenza subtype H5N1 usually results in the complete loss of the producer's entire flock due to high mortality rate and stamping out conducted to contain the virus. This study explores the expected economic impacts of HPAI H5N1 on smallholder duck producers in the Red River Delta of Vietnam. A conceptual model is developed to describe how a producer responds at each week of duck production to maximize profit and evaluate expected profits/losses of the producer in light of HPAI H5N1. The results suggests that in the case of no disease occurrence, the optimal time to sell ducks is at week 10 of the production cycle when ducks reach the age of 8 weeks. Maximum profit gained is US$805 for a producer with an average flock size of 794 ducks. However, the producer would suffer serious losses once the disease occurs. The expected investment loss is far higher than the maximum profit received at each production cycle and is estimated to be 3 times higher (US$2665.19 expected loss vs. US$805 maximum profit).
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    Quantify spatiotemporal patterns of urban growth in Hanoi using time series spatial metrics and urbanization gradient approach
    (Honolulu, HI: East-West Center, 2014-10) Nong, Duong ; Lepczyk, Christopher ; Miura, Tomoaki ; Fox, Jefferson ; Spencer, James ; Chen, Qi
    This paper combined multi-temporal remotely sensed data with landscape indices to investigate urban growth patterns of the Hanoi capital city of Vietnam from 1993 to 2010. Furthermore, the quantitative composition and distribution of the growth types were analyzed during the different periods. Afterwards, the distance effect on urban growth pattern from the center and fringe of urban patches was studied using buffering analysis. Our objectives were to quantify the speed, growth modes, and resultant changes in landscape pattern of urbanization and to examine the diffusion-coalescence and the landscape structural homogenization processes in Hanoi capital city. Cities in Vietnam have been experiencing major urban transition since the country adopted the economic reform in 1986 which introduce liberal market mechanisms, encouraging private-sector initiatives, while retaining the government's role as the nation's strategic planner and enforcer. Hanoi, one of the two largest economic centers, has been experiencing a progressive urbanization during the 17 years between 1993 and 2010. Using gradient approach, our study has shown that the rate of urban growth was higher in between 10 to 35 km buffer zones. The growth modes and landscape structure changes of urbanization were also comprehensively captured and described using the landscape expansion index and selected landscape metrics. The process of urbanization was characterized by relative dominance of infilling, edge expansion, and spontaneous growth modes across the landscape. Our observation of the Hanoi urbanization in 17 year period could support the diffusion and coalescence phase dynamics. In addition, periodicity in the growing process, and the regularities of the shift of growth hot-zone revealed in this paper could be important implications for urban modeling and prediction. Through our landscape pattern analysis and comparison with other cities, it revealed that the urbanization of Hanoi is limited by its infrastructure systems which make the urban growth not evenly distributed, limiting their competitive advantage, disproportionately high transport costs, growing congestion and land market distortions. Therefore, strategic urbanization plan for future should consider improving urban transport and infrastructure systems, as well as strengthening its competitiveness in the region.
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    Built-up area change analysis in Hanoi using support vector machine classification of Landsat multi-temporal image stacks
    (Honolulu, HI: East-West Center, 2014-10) Nong, Duong ; Castrence, Miguel ; Miura, Tomoaki ; Fox, Jefferson ; Spencer, James ; Chen, Qi
    Vietnam is experiencing one of the greatest urban transitions over the last two decades after the embankment of "Doi Moi" policy in 1986. The urban transition is vividly manifested in social, economic and physical aspects. While the urbanization can boost the industrialization and modernization goals of the country, it can cause adverse impact on natural environment as well as society and economy. To support a sound urban development plan, it is important that data and analysis on urban built-up areas are accurate and timely available. In this study, the Support Vector Machine Classification Algorithm (SVM) was applied to the multi-temporal image stacks of Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) from 1993 to 2010 to quantify the changes of built-up areas over three time periods, 1993-2001, 2001-2006, and 2006-2010 and across twelve buffer zones. Our SVM classification algorithm has produced a highly accurate map of land use/land cover change with the overall accuracy of 95%. The study showed that most of the urban expansion occurred in the periods 2001-2006 and 2006-2010. The analysis was strengthened by the analysis of population census and other socio-economic figures. Through out this study, an implicit correlation between the urban growth, the trend of spatial expansion and other relevant geographic and socio-economic factors can be proposed. Result of this study would allow urban planners and decision makers to timely evaluate and adjust accordingly the urban growth and be aware of the sustainable usage of the invaluable natural lands and other environmental, social and economical problems.
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