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401.
Engaging communities in managing multiple hazards: Reflections from small islands in North Sulawesi,Indonesia
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Mercy M.F. Rampengan Lisa Law J.C. Gaillard Agni Klintuni Boedhihartono Jeffrey Sayer 《Singapore journal of tropical geography》2016,37(2):249-267
Participatory methods are a common approach for giving voice to local communities in hazard and disaster research. Drawing on a study that trialled and modified a range of participatory methods in North Sulawesi, eastern Indonesia, this paper reflects on how such methods help document the capacities of small island communities. We assessed capacity from a sustainable livelihoods perspective, identifying the assets that enable villagers to cope with hazards. This overall approach promoted a discourse of strengths and resourcefulness, contrasting with vulnerability and needs‐assessment approaches common to government and non‐governmental organizations, which tend to focus on weaknesses and can sometimes fuel undeliverable expectations of funding. We provide a critical reflection on participatory methods and their significance for researchers, policy makers and funding agencies working with communities in hazard‐prone regions. 相似文献
402.
Mountain regions are characterized by complex biophysical and marginal socio-economic conditions that contribute to the vulnerability of agricultural communities. Owing to the extremely heterogeneous conditions in mountains, it becomes imperative to understand the spatial distribution of vulnerability at fine-scale. This study assesses the inherent vulnerability of agricultural communities at village level for the entire state of Uttarakhand. Inherent vulnerability, conceptualized as an internal property of agriculture dependent communities, is measured as a function of sensitivity and adaptive capacity. Data on 36 indicators, reflecting the social and ecological dimensions of sensitivity and adaptive capacity, was collected from secondary sources for 15,285 villages. Each indicator was weighed according to its importance in determining vulnerability using Analytical Hierarchical Process (AHP) and finally aggregated to map the spatial distribution of inherent vulnerability under five classes. To enable more effective adaptation planning, identification of vulnerability hotspots was done using local Moran's I. Our analysis reveals that majority of the villages have very low (36.1%) and low (19.6%) adaptive capacity characterized by the poor developmental and high agricultural constraints. Overall the state observes high vulnerability (0.66 ± 0.15), with about 23.6% and 24.7% villages classified under very high and high vulnerability class respectively. The spatial pattern of inherent vulnerability shows significant altitudinal gradient with most of the vulnerability hotspots villages located in middle altitudinal zone. The outcomes of the study assist the policy interventions in prioritizing allocation of resources to enhance the capacities of agricultural communities inhabiting the identified inherent vulnerability hotspots. 相似文献
403.
Metazoan/microbial biostalactites from present‐day submarine caves in the Mediterranean Sea
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Rossana Sanfilippo Antonietta Rosso Adriano Guido Adelaide Mastandrea Franco Russo Robert Riding Emma Taddei Ruggiero 《Marine Ecology》2015,36(4):1277-1293
Biostalactites formed by metazoan–microbialite associations from three submerged marine caves in the Plemmirio Peninsula (south of Syracuse, Ionian Sea) are randomly distributed and show different sizes and morphologies, as well as variations in surface roughness/smoothness. The biostalactites consist of crusts a few centimeters thick of small serpulids and other metazoans, associated with fine‐grained carbonate; the larger ones often include a nucleus of serpulid tubes (Protula). The metazoans include mainly serpuloideans, sponges, bryozoans and foraminifers but microbial carbonates are also significant components. The composition of both the living communities and thanatocoenoses on the outer surfaces, as well as the composition and fabric of the internal framework, were analysed and used to reconstruct the history of the caves. All of the identified sessile faunas mainly consist of cryptic and sciaphilic dwellers that reflect cave conditions and their variations through time. The distribution pattern, composition and abundance of the present‐day dwellers largely depend on the degree of roughness of the biostalactite surfaces and their positions within the caves. It has been suggested that the Protula specimens in the nuclei represent pioneer populations that formed aggregates during the early cave colonization phase, in response to relatively high food supply from seawater inflow and intruding continental waters. By contrast, the outer metazoan–microbialite carbonates reflect more confined conditions in the caves caused by Holocene sea‐level rises. Hypotheses are proposed for biostalactite growth, taking into account information about the growth rates of some constituents, and evidence of dissolution effects. Similarities and differences between these biostalactites and other Holocene deposits previously described from submarine caves in the Mediterranean Sea and in tropical reefs are discussed. 相似文献
404.
Agricultural expansion remains the most important proximate cause of tropical deforestation, while interactions between socio-economic, technological and institutional factors represent the fundamental drivers. Projected population increases could further raise the pressure on the remaining forests, unless agricultural intensification allows raising agricultural output without expanding agricultural areas. The purpose of this article is to understand the role of institutional factors in governing the intensification process towards the goal of preserving forests from agricultural pressures, with a focus on Indigenous Peoples’ and local communities’ rights to forests (as embedded in the various tenure regimes). In this paper we adopt an international dimension and analyse the process of agricultural expansion across eleven Latin American countries over the period 1990–2010 to assess whether, in a context of agricultural intensification, different land tenure regimes impact differently on the realization of land-sparing or Jevons paradox. The results, based on a number of multivariate statistical models that controls for socio-economic factors, strongly suggest that the formal recognition of Indigenous Peoples and local communities’ forest rights has played an important role in promoting land sparing or attenuating Jevons paradox. 相似文献
405.
At high latitudes, the albedo and energy budget of shrub‐tundra landscapes is determined by the relationship between the fractional snow cover and the fraction of vegetation protruding above the snowpack. The exposed vegetation fraction is affected by the bending and/or burial of shrubs in winter and their spring‐up during melt. Little is known about the meteorological conditions and snowpack and shrub properties required to cause bending, and few quantitative measurements of bending processes exist. Here, a model combining the few, mostly qualitative, observations available with a biomechanical model representing branches as cantilevers is proposed to provide a first approximation of bending mechanisms. The exposed vegetation fraction is then calculated using structural parameters of shrubs measured at two sites in Canada: the Granger Basin in the Yukon Territory and Trail Valley Creek in the Northwest Territories. The exposed vegetation fraction is in turn used to calculate albedo, which is evaluated against measurements at the two sites. The model considerably improves modelled albedo compared to a model which only buries but does not bend shrubs at TVC, where shrubs become completely buried. However, the model overestimates albedo at GB where only a few shrubs get buried. The bending model is then used to calculate a compression factor for use in a simple parameterization of the exposed vegetation fraction proposed by previous investigators. The parameterization, which is simpler and computationally less expensive than the full model, is evaluated and found to perform well. Despite the need for further developments, the model provides a first approximation of bending processes and contributes to the identification of measurements that are needed in order to improve the model and our understanding of the bending of shrubs. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
406.
Charles K. Paull William R. Normark William Ussler III David W. Caress Rendy Keaten 《Marine Geology》2008,250(3-4):258-275
Seafloor blister-like mounds, methane migration and gas hydrate formation were investigated through detailed seafloor surveys in Santa Monica Basin, offshore of Los Angeles, California. Two distinct deep-water (≥ 800 m water depth) topographic mounds were surveyed using an autonomous underwater vehicle (carrying a multibeam sonar and a chirp sub-bottom profiler) and one of these was explored with the remotely operated vehicle Tiburon. The mounds are > 10 m high and > 100 m wide dome-shaped bathymetric features. These mounds protrude from crests of broad anticlines (~ 20 m high and 1 to 3 km long) formed within latest Quaternary-aged seafloor sediment associated with compression between lateral offsets in regional faults. No allochthonous sediments were observed on the mounds, except slumped material off the steep slopes of the mounds. Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds. 相似文献
407.
北京城市老年贫困人口识别与空间分布 总被引:2,自引:1,他引:1
随着中国老龄化程度加深和城镇化水平的提高,城市地区的老年贫困问题日渐突出。由于缺乏明确的界定和统一的标准,老年贫困人口识别的准确性不足,不同研究的结论存在很大分歧。特别是教育、健康、家庭和社会支持等因素与老年贫困的关联被忽视、贫困线的设定较为主观等问题,对厘定城市老年贫困的空间格局和制定相关政策造成很大困扰。本文通过北京市典型居住社区的实证研究对上述问题进行了探讨,首先基于老年人属性变量的因子分析构建了城市老年贫困的综合判别指标;然后通过贫困线的优化分析,估计不同类型居住社区的老年贫困比例;再以市域范围内的街道和中心城区周边的地区办事处为空间单元,对北京市城市老年贫困的空间格局进行了分析。研究结论为:① 资源、健康、独立性和性别是老年人属性差异的决定因子,其中资源因子得分综合反映了城市老年人的贫困程度。② 不同类型居住社区的城市老年贫困比例存在显著差异,根据居住社区的分布,测得北京城市老年人口的贫困比例为9.55%。③ 城市内部老年贫困的空间格局分析表明:城市老年贫困人口比例从首都功能核心区、城市功能拓展区、城乡结合部地区到外围城区顺次增加;城市老年贫困人口密度则以外围城区与首都功能核心区最高,城市功能拓展区居中,城乡结合部地区最低。这些结果为进一步制定不同地区的老年贫困对策提供了参考依据。 相似文献
408.
409.
Mohammad Belal Hossain 《国际泥沙研究》2019,34(1):48-57
The trophic structure of a community is used to infer ecosystem functioning(e.g. energy transfer and nutrient cycling). Here the trophic structure of the benthic infaunal and epifaunal communities in the Brunei Estuary are characterized, and their distribution along an estuarine pH gradient is analyzed using univariate and multivariate techniques. This analysis revealed that surface deposit feeders(e.g., polychaetes) were numerically dominant within the infaunal communities whereas in the epifaunal communities filter feeders(e.g., bivalves) were highly abundant. Species richness for almost all trophic groups increased toward the lower estuary, except for omnivores in the epifaunal communities, which decreased markedly. Both Analysis of Variance(ANOVA) and Analysis of Similarities(ANOSIM) detected significant differences in the density of respective trophic groups among stations. Within infaunal communities, both Biological and Environmental procedure(BIO-ENV) and Canonical Correspondence Analysis(CCA) showed that trophic shifts were associated with environmental gradients. Surface-deposit feeders and omnivores were the most abundant macrobenthos of the upper estuary characterized by low salinity, low pH, and a higher percentage of mud particles. The proportion of filter feeders and carnivores increased with salinity/pH and sand. A more uniform distribution of trophic structure was found in the lower estuary, with high salinity and pH over sandy habitat. In contrast, within epifaunal trophic groups,the percentage of surface deposit feeders and omnivores declined, but filter feeders remarkably increased toward the sea. The proportion of carnivores remained similar at all stations. Non-Metric Multidimensional Scaling(nMDS) ordination for epifaunal trophic groups clearly demarcated higher salinity/pH stations from lower salinity/pH stations, suggesting different trophic compositions along the estuarine pH gradient. 相似文献
410.
喀斯特地区地质化学、气候和人类活动强烈影响植物群落组成、植物元素含量和化学计量特征。本文以云南省蒙自市断陷盆地区天然林、灌丛和草地群落植物为对象,研究了植物叶片12种元素含量和生态化学计量特征。结果显示:研究区内植物元素含量存在较大差异,各元素含量从高到低的顺序依次是C>Ca>N>K>Mg>P>Fe>Al>Zn>Mn>Na>Cu,三种群落植物N、K、Ca、Mg、Al、Cu、Zn、Mn含量存在显著差异。天然林与灌丛群落植物生长受到P含量的限制,而草地群落植物生长受到N与P单独或共同的影响。草地群落植物C:N、C:Ca、C:Mg显著高于天然林与灌丛植物,N:P则呈现相反格局。三种群落间植物C:Ca比例显著不同,表现为草地>天然林>灌丛。在研究区内,有27对元素含量呈现显著相关,占总元素对的40.9%。这些结果表明,云南喀斯特断陷盆地植物为适应环境,形成了独特的化学计量特征和适应策略。 相似文献