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71.
Putu Liza Kusuma Mustika Riccardo Welters Gerard Edward Ryan Coralie D'Lima Patricia Sorongon-Yap Suwat Jutapruet 《Journal of Sustainable Tourism》2017,25(8):1138-1158
Dolphin-watching tourism is growing globally. In developing countries, the typically low environmental awareness of operators and poorly enforced or non-existent regulations exacerbate risks to wildlife. Ecological indicators like behavioural responses are useful to assess wildlife tourism, but obtaining such data is slow and expensive. We modified the Driver–Pressure–State–Impact–Response (DPSIR) framework to rapidly assess the risk of dolphin-watching tourism harming, displacing or causing local extinction to dolphin populations, using human dimension data to complement limited ecological data. We assessed industries at seven dolphin-watching sites in six countries in Asia: Cambodia, India, Indonesia, Malaysia, Thailand, and the Philippines. All sites have reached or almost reached financial saturation except Cambodia and Malaysia. We find high risk to dolphins at the sites in India and Indonesia and intermediate risk at the site in Cambodia. Pending more ecological data, the risk at Thailand, the Philippines, and Malaysian sites might be low. Our analysis also indicates site-specific conservation recommendations for Driver, Pressure and Response. We suggest that the DPSIR framework is useful to assess the risk of a wildlife watching industry, even when the impact is uncertain due to insufficient ecological data. 相似文献
72.
This paper proposes a procedure to analyze Moroccan hotels productivity, based on Luenberger productivity indicator to estimate and decompose productivity change into efficiency change and technological change. This paper enlarges the procedure and further decomposes technological change to study the sources of bias in technological change. Therefore, a clearer and more enlightening view of tourism productivity change emerges. Policy implications are developed. 相似文献
73.
根据马莲河流域地形地貌特点、水资源分布状况及社会经济、能源产业的发展情况,将流域系统概化为5个水资源分区,并依据2020和2030年的社会经济发展速度和水利工程建设速度、分为12个方案,采用指标分析法对12个方案进行供、需水量预测。结果表明:2020年最大概率方案为社会经济高速发展、水利工程低速建设方案,流域总需水量6.45亿m3,供水量4.67亿m3,缺水率27.56%。2030年的最优方案为2020年社会经济高速发展、2030年社会经济低速发展,水利工程高速建设方案,流域总需水量10.33亿m3,供水量8.72亿m3,缺水率15.62%。按照供需平衡方案进行水资源分配,可促使流域综合缺水率逐年减少,促使流域的水资源能够更好地为高速发展的社会经济服务,从而提高流域的供水、用水水平,为流域生产、生活安全提供强有力的保障和支撑。 相似文献
74.
Limnological features of Funil Reservoir (R.J., Brazil) and indicator properties of rotifers and cladocerans of the zooplankton community 总被引:3,自引:0,他引:3
Christina W. C. Branco Maria-Isabel A. Rocha Gláucia F. S. Pinto Gisele A. Gômara Rodrigo De Filippo 《Lakes & Reservoirs: Research and Management》2002,7(2):87-92
Funil Reservoir receives inflow from a highly industrialized region and acts as a natural sink to pollutants. Among the consequences of the uncontrolled nutrient loading is the constant presence and periodic heavy blooms of Microcystis aeruginosa . This study verified limnological features and zooplankton assemblage of the Funil Reservoir focusing on the environmental-indicator properties of rotifers and cladocerans. The summer bloom of M. aeruginosa caused reductions in water transparency, nitrate and orthophosphate concentrations and raises in chlorophyll a , pH, dissolved oxygen and chemical oxygen demand values. All zooplankton species presented spatial and temporal variations with the exception of the copepods, which were present in all samples. According to canonical correspondence analysis, ammonium was the variable most related to zooplankton variability and different Rotifera and Cladocera assemblages indicated distinct environment conditions. Rotifer taxa associated with increases of water temperature and chlorophyll a concentration were found with high densities during M. aeruginosa blooms. Species of rotifer and cladocerans are suggested as indicators that can be used to identify different physical and chemical gradients or eutrophic increases in Funil Reservoir. 相似文献
75.
Do Hydropeaking Flows Alter Juvenile Fish Growth Rates? A Test with Juvenile Humpback Chub in the Colorado River
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Riverine ecosystems have been altered in many large catchments by dam development to provide water, power, flood control and navigational benefits to humans. Conservation actions in these river ecosystems are commonly focused on minimum releases of water to downstream ecosystems. Increasingly minimum release approaches are being replaced with ‘experimental’ flows that mimic natural conditions in order to benefit riverine ecosystems. While these new policies are intuitive in their design, there is limited data of how riverine ecosystems actually respond to more natural flows. A test of more natural steady‐flow water release was compared with typical fluctuating hydropower flows in the adaptive management programme at Glen Canyon Dam, Arizona, during 2008–2011 to assess growth improvements of endangered juvenile humpback chub Gila cypha. Our results are counterintuitive and show that more natural steady flows reduced growth rates of juvenile humpback chub compared with fluctuating flows when both treatments occurred within the same year. Daily growth rates during steady flows of 2009 and 2010 were 0.05 and 0.07 mm day?1 slower, respectively, than fluctuating flows those same years, despite similar water temperatures. Juvenile humpback chub also grew more slowly during steady flows that occurred in the same season. During the summer, juvenile humpback chub grew 0.12 and 0.16 mm day?1 in fluctuating flow regimes in 2009 and 2010, respectively, and only 0.07 mm day?1 in the experimental steady flow regime in 2011, despite higher water temperatures. Our results suggest that optimal conservation management policies for endangered species in regulated rivers may not always be achieved with more natural flows. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
76.
上海市水环境生态安全评价 总被引:3,自引:0,他引:3
从“状态—压力—响应”指标框架体系出发,针对上海市水环境生态系统的现状特点,从时间变化和空间对比分析角度分别建立了上海市水环境生态安全评价指标体系;利用标准化和变异系数法确定各指标的标准化值和权重,采用综合指数评价法得到安全评价的综合指数值。在此基础上采用等级划分法,建立起综合指数值与生态安全评判的等级关系。各指标层的变化趋势揭示了上海市水环境生态安全的现状和发展趋势,即中心城区的水环境生态安全等级普遍低于郊区;在年际变化上,状态指标层评价值呈下降趋势,需要持续保护水环境生态系统;而压力和响应指标层评价值不断上升,保证了总体的良性发展趋势。 相似文献
77.
Patterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities; and (ii) islands and river margins disconnected from annual hydrogeomorphic disturbances and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for both vegetation types. However, significant differences in native and exotic species richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity were attained within the herbaceous vegetation type than within the woody type. These differences are most likely related to changes in local exposure to hydrogeomorphic disturbances driven by woody engineer plant species and to vegetation succession. A lower exotic species cover within the woody vegetation type than within the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation through landform construction resulted in a decrease of alpha (α) diversity at the patch scale but, in parallel, caused an increase in gamma (γ) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic acceptance of exotic species by native species at the local scale (generally <10 m2) within heterogeneous and disturbed environments. Furthermore, we suggest that in riparian contexts such as the River Tech exotic species trapp sediment at the same time as native species and thus contribute to the increase in ecosystem resistance during the biogeomorphic succession. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
78.
提出一种适用于配电系统架空线路的小电流接地故障区段定位新方法。该方法利用故障暂态电压、电流特征频段内分量计算无功功率,根据故障点前后暂态无功功率方向的不同确定故障区段。在故障信息不易获取的检测节点处,提出利用电磁场感应获取故障暂态信息的方法,通过测量架空线路下方垂直地面方向电场获取小电流接地故障暂态电压信息,测量水平方向磁场获取故障暂态电流信息,详细阐述了最佳检测点的计算思路,并以一典型10 kV架空线路为例验证了该方法的可行性。最后阐述了利用该方法实现故障区段定位需要解决的若干关键问题。 相似文献
79.
Southern African countries are increasingly dependent on natural beauty and wildlife for tourism. Conservation is essential for sustainable tourism, and is expensive, especially for threatened and endangered species. The current price of a species only takes into account its current usefulness, often leading to an underestimation of the value of wildlife. This paper contributes to debates on the value of endangered species by estimating current use and non-use values for the rhino, a species under extreme threat. Internationally, literature that values scarce and endangered species uses willingness-to-pay (WTP) to derive a value of the species. This paper uses WTP to determine the non-consumptive use value of the rhino based on three surveys, n = 1291, conducted in South Africa's Kruger National Park (KNP) and compare it to consumptive use values. Non-use and inter-temporal values are also estimated to provide a comprehensive valuation of the rhino. Non-consumptive use values per rhino in KNP are shown to exceed consumptive use values by a minimum of 50%. The threat of extinction is shown to be linked to institutional, market and policy failures. Policy implications include raising poaching fines, raising wildlife value awareness and incentivising the community benefits of wildlife conservation. 相似文献
80.
The impact of a large lowland temperate zone reservoir on chironomid and fish biodiversity was investigated in the same upstream (U) and downstream (D) sites on the same sampling occasions in spring and autumn of several post‐impoundment years. The true/Hill N1 diversity measure was used to construct diversity models of the impact, and partitioning of N1 to reveal the importance of ecological gradients. N1 is unique in being decomposable among multiple levels and easily comparable across ecosystems and animal groups. Chironomids were more diverse than fish in all community sets owing to their probably lower mobility, lower interspecific competition, opportunistic character and much shorter life spans than those of fish. Fish exerted consumption pressure on chironomids upstream by foraging mostly on benthic insects, but not downstream where they fed on microcrustaceans of reservoir origin or on epiphytic fauna (mainly Chironomidae). The reservoir impact on chironomids decreased their diversity in U and increased in D, while much the opposite was true in fish. In D in macroinvertebrates, the impact consisted in advancing over time intensification of seasonal development of submersed macrophytes, while in D in fish in a few species escaping from the reservoir after their populational explosions each year. Partitioning of diversity revealed that the spatial (upstream–downstream) gradient was the strongest factor of diversity change in chironomids as compared with season, and age of the impoundment. No gradient was dominant in fish. Comparisons of observed data with a null model testified to very strong intraspecific aggregation in both chironomids and fish. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献