Soil to leaf transfer factor for the radionuclides ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr at Kaiga region, India

Transfer factors are the most important parameters required for mathematical modeling used for environmental impact assessment of radioactive contamination in the environment. In this paper soil to leaf transfer factor for the radionuclides ⁴⁰K, ²²⁶Ra, ¹³⁷Cs and ⁹⁰Sr is estimated for Kaiga region in Karnataka state, India. Among the plants in which study is carried out, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr activity in leaves of herbaceous plants is higher than that of tree leaves. Soil to leaf transfer factor for ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr was found to be in the range of 0.03-0.65, 0.32-8.04, 0.05-3.03 and 0.42-2.67 respectively.     

Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water

Methyl tert-butyl ether (MTBE) groundwater remediation projects often require a combination of technologies resulting in increasing the project costs. A cost-effective in situ photocatalytic reactor design, Honeycomb II, is proposed and tested for its efficiency in MTBE degradation at various flows. This study is an intermediate phase of the research in developing an in situ photocatalytic reactor for groundwater remediation. It examines the effect of the operating variables: air and water flow and double passages through Honeycomb II, on the MTBE removal. MTBE vaporisation is affected by not only temperature, Henry’s law constant and air flow to volume ratio but also reactor geometry. The column reactor achieved more than 84% MTBE removal after 8 h at flows equivalent to horizontal groundwater velocities slower than 21.2 cm d⁻¹. Despite the contrasting properties between a photocatalytic indicator methylene blue and MTBE, the reactor efficiency in degrading both compounds showed similar responses towards flow (equivalent groundwater velocity and hydraulic residence time (HRT)). The critical HRT for both compounds was approximately 1 d, which corresponded to a velocity of 21.2 cm d⁻¹. A double pass through both new and used catalysts achieved more than 95% MTBE removal after two passes in 48 h. It also verified that the removal efficiency can be estimated via the sequential order of the removal efficiency of one pass obtained in the laboratory. This study reinforces the potential of this reactor design for in situ groundwater remediation.     

洞庭湖主要生态环境问题变化分析

通过对近几十年来洞庭湖水情、泥沙、污染和湿地生态等不同方面问题的回顾分析,认为在三峡工程建设、洞庭湖退田还湖和极端天气事件影响下,洞庭湖主要生态环境问题发生了一些变化。由于气候干旱化,加之三峡水库蓄水影响,导致洞庭湖入湖水量季节性减少,湖区水位下降,干旱期延长。模拟显示2006和2009年三峡秋季蓄水使洞庭湖出口水位平均下降2.03和2.11 m;由于三口来沙急剧减少,入湖泥沙打破了以淤积为主的模式,2006年洞庭湖第一次出现从拦蓄泥沙变成向长江净输出泥沙。低水位运行不仅对洲滩演进和湖泊水质带来影响,也加速了对湖滩的开发利用,外来物种的发展威胁了湖泊湿地生物多样性和动物栖息地的稳定。同时,湖区复合型水污染威胁加重,洞庭湖水质从2008年的Ⅳ类水下降为Ⅴ类水。洞庭湖在缺水与洪涝矛盾中,正从单一洪灾为主转向矛盾的两个方面共存。这些变化一方面与气候变化有关,也是流域生产由传统农业转向农、林、水、工的综合发展,以及湖泊与流域关系改变的结果。     

基于游客支付意愿的古树名木资源保护经济价值评估——以安徽省九华山风景区为例

运用条件价值评估法中支付卡式(PC)和二分式(DC)两种问卷,对九华山风景区游客保护古树名木的支付意愿进行研究,并分析了其影响因素。结果表明：838%的游客认为应该对古树名木进行保护,仅有302%对保护现状满意。支付卡式问卷调查结果为808元/(人·月),二分式问卷调查结果为954元/(人·月);按2010年游客接待量401万人次计算,2010年游客对九华山风景区古树名木保护的总支付意愿分别为1500×108元和4589×108元。影响支付卡式问卷支付意愿值的主要指标是年龄、个人年收入、文化程度和职业的相关性;影响二分式问卷支付意愿的主要指标是个人年收入。支付卡式问卷和二分式问卷支付意愿均与第一次调查结果无显著差异,PC1和PC2、DC1和DC2支付意愿值相差分别为062和173元,两次结果重现性良好,对本次研究结果的可靠性给予了保证     

Mountain substitutability and peak load pricing of high alpine peaks as a management tool to reduce environmental damage: A contingent valuation study

High alpine peaks throughout the world are under increasing environmental pressure from hikers, trekkers, and climbers. Colorado's “Fourteeners”, peaks with summits above 14,000 feet are no exception. Most of these peaks have no entrance fees, and reach ecological and social carrying capacity on weekends. This paper illustrates how a series of dichotomous choice contingent valuation questions can be used to evaluate substitutability between different alpine peaks and quantify the price responsiveness to an entrance fee. Using this approach, we find that peak load pricing would decrease use of popular Fourteeners in Colorado by 22%. This reduction is due almost entirely to substitution, rather than income effects. There is also price inelastic demand, as 60% of the hikers find no substitution for their specific Fourteener at the varying cost increases posed in the survey. The no substitute group has a mean net benefit of $294 per hiker, per trip, considerably higher than visitor net benefits in most recreational use studies.     

Interdependence with the environment: Commitment,interconnectedness, and environmental behavior

Do individuals’ perceptions of their interdependence with the natural environment affect their environmental behaviors? From the perspective of interdependence theory, we introduce a scale to measure commitment to the natural environment. In Study 1, higher levels of commitment to the environment and greater inclusion of nature in the self separately predicted higher levels of pro-environmental behavior, even when controlling for social desirability and ecological worldview. In Study 2, participants primed to experience high commitment to the environment reported greater levels of pro-environmental behavioral intentions as well as pro-environmental behavior relative to participants primed to experience low commitment to the environment. Commitment to the natural environment is a new theoretical construct that predicts environmental behavior.     

Rural Households’ Attitude and Economic Strategies Toward the Conversion of Cropland to Forest and Grassland Program (CCFG): A Case Study in Qira,China

The Conversion of Cropland to Forest and Grassland Program (CCFG), which was initiated by the Chinese government in 1999, is a cropland retirement program with integrated objectives for ecological preservation and local development. The purpose of this article was to study the influencing factors of attitude and economic strategies in rural households toward the CCFG. Rural households’ knowledge, attitude and economic strategies toward the CCFG were investigated through a questionnaire survey in Qira, China. Influencing factors of attitude and strategies of households were analyzed using a logit model technique. The analysis indicated that household’s income level, environmental knowledge of the program, and program implementation were significant influencing factors in a household’s attitude toward the CCFG, while major influencing factors of household strategies were their regional background and availability of income generation sources. Meaningful association was not found between attitude and strategy choices. Rich households had more strategy choices, while poor households were usually confined to low input strategies with uncertain income. To sustain their livelihood, the poor need extra assistances in marketing, loan granting, employment training, information, and technical services.     

Livelihood change and livelihood sustainability in the uplands of Lembang subwatershed, West Sumatra, Indonesia, in a changing natural resource management context

This paper analyzes livelihood change and livelihood sustainability of households in the upland part of the Lembang subwatershed, West Sumatra, in response to changes in the natural resource management context during the last decade. Using the sustainable livelihood framework (SLF), we measured livelihood changes at two separate points in time, 1996 and 2006, and assessed their environmental, economic, social, and institutional sustainability. We found that people with a low income had less access to capital assets than people from middle- and high-income groups. Our analysis revealed, however, that access to capital assets increased over time, and that poor households experienced economic improvement, indicating an overall increase in economic sustainability. Environmental sustainability, however, is threatened by intensive agricultural practices such as high agrochemical input and intensive soil tillage on steep slopes, leading to pollution and soil erosion. Social sustainability is also a matter of concern: while social exclusion has been reduced, income inequity has increased. Institutional sustainability is likely to remain uncertain, as local institutions for natural resource management are still weak, despite the fact that decentralization has been implemented during the last 8 years. External facilitation is needed to improve the livelihood of upland people while, at the same time, enhancing the sustainability of watershed management. Strengthening local institutions, conserving natural resources, and promoting environmentally sound agricultural practices are the three most important policies to be promoted within the watershed.     

湖南古村落的物质安全防御研究

基于湖南现存的一些古村落,从物质安全防御角度出发,对古村落在基地选址、整体布局、空间形态等方面所采用的安全防御进行研究。通过分析湖南当地居民的主要物质防御手段即利用山水作为村落的自然屏障、团结所有村民进行集群防御与在村落内部层层设防等方法,指出湖南古村落物质防御的有效性和科学性对当今社会安居工程建设具有借鉴意义。