首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
延河流域水供给服务供需平衡与服务流研究   总被引:4,自引:0,他引:4  
水供给服务的供需定量评估与空间制图是当前研究的核心与前沿议题,然而耦合人类需求与自然过程进行供需时空关联分析和服务流模拟仍需进一步加强。以延河流域为研究区,基于GIS手段和SWAT模型,融合多源数据构建了水供给服务供需平衡与空间流动模型,从子流域尺度探究了延河流域水供给服务的供需空间匹配特征与流动规律,明确流域供给区和受益区的空间范围与流量。研究结果表明:1)2005—2015年延河流域水供给量先增多后减少,水需求量则逐年增多,供需平衡状况在逐年恶化。到2015年,流域的水资源安全指数(Freshwater Security Index,FSI)仅为0.095。2)延河流域水供给服务的供给与需求在空间分布上呈现显著的不匹配特征,尤其是位于延河中游的延安市区及周边地区,水资源供需矛盾突出。3)在水供给服务流研究的框架下,本文明确了流域内4个主要受益区的空间范围及其接受的相应上游子流域(供给区)提供的服务流量,分别为安塞城区、延安市区、青化砭镇、延长县城区及其附近城镇。本评估模型与研究结果不仅可以为实现延河流域水资源的合理配置和保障流域用水安全提供科学依据,也可以为其他流域的水资源管理提供参考。  相似文献   

2.
Based on large-scale human mobility data collected in San Francisco and Boston, the morning peak urban rail transit (URT) ODs (origin-destination matrix) were estimated and the most vulnerable URT segments, those capable of causing the largest service interruptions, were identified. In both URT networks, a few highly vulnerable segments were observed. For this small group of vital segments, the impact of failure must be carefully evaluated. A bipartite URT usage network was developed and used to determine the inherent connections between urban rail transits and their passengers'' travel demands. Although passengers'' origins and destinations were easy to locate for a large number of URT segments, a few show very complicated spatial distributions. Based on the bipartite URT usage network, a new layer of the understanding of a URT segment''s vulnerability can be achieved by taking the difficulty of addressing the failure of a given segment into account. Two proof-of-concept cases are described here: Possible transfer of passenger flow to the road network is here predicted in the cases of failures of two representative URT segments in San Francisco.  相似文献   

3.
徐彩瑶  崔铭烨  王宁  孔凡斌 《生态学报》2024,44(8):3223-3240
生态保护修复是维持和提升生态系统稳定性和可持续性的重要举措。识别生态保护修复优先区并进行有规划的生态保护修复能够达到抑制生态环境退化的目的。以浙江省为研究对象,运用生态系统服务价值计算模型、神经网络自组织映射(SOM)聚类分析法、空间统计、Spearman非参数相关性分析等方法,识别生态系统服务簇,分析生态系统服务簇演化和人类活动强度变化特征,识别生态保护修复优先区,探讨不同生态系统服务价值的权衡/协同关系,提出生态保护修复优先区规划策略。结果表明:(1)2000-2021年浙江省生态系统服务空间分布逐渐趋于均衡,生态系统服务价值总量由7279.73亿元降低至6980.28亿元;(2)2000-2021年浙江省人类活动强度显著增加,呈现由西到东、由南到北的递增趋势;(3)2000-2021年浙江省生态系统服务与人类活动强度变化Moran''s I指数呈现显著负相关性,说明人类活动强度与生态服务价值两者空间上处于相互制约状态;(4)2000-2021年浙江省 90 县(区)可划分为4类生态系统服务簇,包括:城市中心簇、农业生产簇、核心生态簇和生态保育簇;(5)基于2021年双变量Moran''s I指数聚类结果将研究区划分的5种类型分区作为生态保护修复一级分区,以区域内主导生态系统服务簇作为生态保护修复二级分区划分依据。浙江省生态保护修复优先区划分为4个类型,即面积占比14.83%的生态预防治理区、面积占比19.94%的生态调控建设区、面积占比50.23%的核心生态保护区和面积占比15.00%的生态综合提升区。据此,提出不同类型优先分区实施生态保护修复的规划策略。  相似文献   

4.
In recent years, there has been an increasing interest in the study of the spatial link between service providing areas (SPA) and service benefiting areas (SBA). Understanding the spatial link between SPAs and SBAs is essential when studying the ecosystem service delivery and the fulfilment of ecosystem service demand. However, far too little attention has been paid to the user movement related ecosystem services and where people should be geographically situated in order to benefit from these services. In the movement related services, benefiting areas are equal to providing areas and the spatial link from residential area to SPA is important. The spatial link is addressed through the concept of accessibility which determines the opportunity to move from the area where beneficiaries are located to areas where ecosystem services are produced.This study presents an accessibility approach to the ecosystem services research. Accessibility analyses offer an opportunity to identify the gap between the ecosystems’ potential to produce services and the actual usage possibilities of such services. We demonstrate the suitability of the method by using outdoor recreation and cultural heritage as examples of cultural ecosystem services that people actively want to reach. Accessibility was calculated using a geographical information system-based least-cost path analysis, which measures travel time by car between residential location and the nearest SPA via road network.The examples highlight that accessibility varies according to the ecosystem service and depends mostly on population distribution and travel possibilities. Our results demonstrate that the density of the analysed ecosystem service opportunities is higher near urban areas than elsewhere. The accessibility of different ecosystem services also depends on how much time people are willing to spend for reaching these services. Our study emphasised that, from a population perspective, accessibility analyses provide a powerful tool for illustrating the utilisation possibilities of spatially distributed ecosystem services. The accessibility approach offers great potential to assess the potential use of SPAs and respond to the need to develop a practical tool for ecosystem service research. It effectively shows, for example, the areas where the risk of overuse of ecosystem services is increased. Knowing about the regional differences in ecosystem service usage also gives background information for the decision-makers for drawing conclusions about how much and where it is sensible to invest in the maintenance of ecosystem services.  相似文献   

5.
邴振华  高峻 《生态学报》2016,36(14):4298-4306
九寨沟作为国家级自然保护区、风景名胜区和世界自然遗产地,面临在有效保护自然资源的同时最大化地满足人类游憩服务需求的挑战。学者已经采用CVM、TCM等不同方法的测算九寨沟游憩价值,并针对测算结果的有效性和信度进行探讨,但以往的研究方法无法测算不同旅游资源的游憩价值贡献。以景观服务为视角,通过景观游憩服务识别的方法,进行不同旅游资源价值评估。同类旅游资源因位置不同、个人偏好不同也会产生不同的价值贡献,以参与式制图的方法进行不同游憩服务点的感知评价,实现游憩价值的空间分异研究。采用参与式制图与条件价值法(CVM)相结合的方法,实现游客对游憩服务点的感知评价和位置制图,并完成游客对游憩服务的支付意愿调研,实现价值空间分异研究,共调研730人,有效样本614。分析发现,2012年九寨沟游憩支付意愿率为72.95%,取旅游者意愿支付平均值354.98元,测算九寨沟自然保护区2012年的游憩价值为9.4亿元,其中价值最高是高山湖泊、瀑布、滩流等观赏水体,为2.9亿元,最低的是观赏植物,为0.47亿元。从空间位置来看,单位价值高的游憩服务点主要集中在几条沟谷两侧,特别是已开发的树正沟、日则沟和则查洼沟。游憩价值的空间分异研究注重不同位置旅游资源价值贡献的强弱对比,以期为九寨沟自然保护区的具体监控管理提供依据。  相似文献   

6.
Landscape scale, heterogeneity, and the viability of Serengeti grazers   总被引:1,自引:1,他引:1  
Species persistence can be threatened by substantial temporal variation in food resources over time. On the other hand, spatial heterogeneity in resources at the landscape scale might allow mobile consumers to compensate for temporal variability in resource availability at the local scale. We evaluated this hypothesis, using an extensive data set on foraging, grass growth, and movement by Thomson's gazelles living on the Serengeti Plains. Here we show that modelled populations of Thomson's gazelles can only persist under Serengeti conditions in the face of observed levels of rainfall stochasticity by making adaptive movements to take advantage of ephemeral spatial distributions of food resources. More importantly, our models suggest that Thomson's gazelles in Serengeti require unrestricted access to relatively large areas of grassland (> 1600 km2) to guarantee long‐term persistence, particularly when there is positive spatial autocorrelation in resource abundance, as is the case in Serengeti. If this proves to be true for other species and/or other systems, then understanding of complex behavioural responses to spatially and temporally heterogeneous food supplies may be essential to successful conservation of grazing herbivores.  相似文献   

7.
Prey depletion is a major threat to the conservation of large carnivore species globally. However, at the policy‐relevant scale of protected areas, we know little about how the spatial distribution of prey depletion affects carnivore space use and population persistence. We developed a spatially explicit, agent‐based model to investigate the effects of different human‐induced prey depletion experiments on the globally endangered tiger (Panthera tigris) in isolated protected areas—a situation that prevails throughout the tiger's range. Specifically, we generated 120 experiments that varied the spatial extent and intensity of prey depletion across a stylized (circle) landscape (1,000 km2) and Nepal's Chitwan National Park (~1,239 km2). Experiments that created more spatially homogenous prey distributions (i.e., less prey removed per cell but over larger areas) resulted in larger tiger territories and smaller population sizes over time. Counterintuitively, we found that depleting prey along the edge of Chitwan National Park, while decreasing tiger numbers overall, also decreased female competition for those areas, leading to lower rates of female starvation. Overall our results suggest that subtle differences in the spatial distributions of prey densities created by various human activities, such as natural resource‐use patterns, urban growth and infrastructure development, or conservation spatial zoning might have unintended, detrimental effects on carnivore populations. Our model is a useful planning tool as it incorporates information on animal behavioral ecology, resource spatial distribution, and the drivers of change to those resources, such as human activities.  相似文献   

8.
Balancing trade-offs between foraging and risk factors is a fundamental behavior that structures the spatial distribution of species. For African elephants Loxodonta africana, human pressures from poaching and conflict are primary drivers of species decline, but little is known about how elephants structure their spatial behavior in the face of human occupancy and predation. We seek to understand how elephants balance trade-offs between resource access, human presence and human predatory risk factors (poaching and conflict killing) in an unfenced, dynamic ecosystem where elephants persist primarily outside protected areas in community rangelands. We used tracking data from 101 elephants collected between 2001 and 2016. We investigated elephant behavior in response to landcover, topography, productivity, water, human features and human predation risk using third-order resource selection functions. We extended this analysis by employing a mixed-effects multinomial regression to identify temporal shifts in habitat use, and evaluated temporal shifts in movement patterns by estimating mean squared displacement across different productivity periods. Across periods, elephants displayed strong selection for productive areas and areas near water. Temporal shifts in habitat use showed that, during the dry period, elephants were clustered around permanent water sources where humans also congregated. At the onset of the wet period, a shift occurred where elephants moved away from permanent water and from permanent settlements towards seasonal water sources and seasonal settlements. Our findings indicate that foraging and water access are important limiting factors affecting elephants that potentially restrain their spatial responses to humans at the scale of our analysis. Given that pastoralists and elephants rely on the same resources, increasing human and livestock populations enhance pressure on shared resources and space in Africa's drylands. The long-term conservation of elephants will require approaches that reduce poaching as well as landscape level planning to prevent negative impacts from increasing competition for preferred resources.  相似文献   

9.
吴晓  周忠学 《生态学报》2019,39(24):9211-9221
城市绿色基础设施(Urban Green Infrastructure,UGI)是城市自然景观和生态环境的主要营造者,为居民提供关键的生态系统服务。探讨UGI生态系统服务供给及其需求之间的空间关系,对城市生态建设和绿地系统规划具有重要科学意义。本文运用生态系统服务测算的方法基于人口、GDP以及土地利用数据构建需求测算模型,对西安市建成区UGI的生态系统服务供给与需求的空间格局进行研究,并分析了城市各功能区内UGI生态系统服务供给与需求的空间关系。结果表明:西安市建成区UGI生态系统服务供给总价值为4.23亿元;生态系统服务供给从研究区边缘向中心区逐渐减少,而生态系统服务需求表现出相反的格局,在空间上明显不一致,并且在城市各功能区内差别显著;西安市建成区UGI生态系统服务供给与城市对生态系统服务需求在空间分布上不相匹配。因此为了实现城市的生态环境与经济社会的可持续发展,迫切需要通过合理的UGI建设使生态系统服务供需趋于协调。  相似文献   

10.
Integrating cultural dimensions into the ecosystem service framework is essential for appraising non-material benefits stemming from different human–environment interactions. This study investigates how the actual provision of cultural services is distributed across the landscape according to spatially varying relationships. The final aim was to analyse how landscape settings are associated to people's preferences and perceptions related to cultural ecosystem services in mountain landscapes. We demonstrated a spatially explicit method based on geo-tagged images from popular social media to assess revealed preferences. A spatially weighted regression showed that specific variables correspond to prominent drivers of cultural ecosystem services at the local scale. The results of this explanatory approach can be used to integrate the cultural service dimension into land planning by taking into account specific benefiting areas and by setting priorities on the ecosystems and landscape characteristics which affect the service supply. We finally concluded that the use of crowdsourced data allows identifying spatial patterns of cultural ecosystem service preferences and their association with landscape settings.  相似文献   

11.
基于道路廊道的辽宁省旅游景区(点)空间格局分析   总被引:5,自引:1,他引:4  
在分析辽宁省内旅游景(区)点和人口分布的空间格局的基础上,以双休日出游游程为服务距离,基于公路交通网络创建各主要城市的旅游区域和各旅游景区(点)的服务区域,揭示辽宁省内旅游景区(点)和人口之间的空间关系。结果表明,旅游景区(点)空间格局以一个旅游重点发展区域和一条滨海廊道热线为特征,重点发展“金三角区”由沈阳、大连、丹东3个重要城市节点和贯穿9个主要城市的3条旅游黄金廊道构成;辽西旅游廊道热线由盘锦和葫芦岛为主体的滨海廊道构成;辽宁省的14个地级市市区,特别是中部城市群成为省内旅游客源的主体;城市旅游域内景区(点)较多的城市也集中于金三角廊道;人口分布和旅游景区(点)的空间分布重心基本吻合。省内9个国家级风景名胜区的200 km的服务区总面积占全省总面积的92.5%,各服务区面积1.00×106~7.00×106hm2,其中4处可为千万以上人口服务。各服务区所覆盖的城市数、总人口数和城市人口数,与该风景区在道路网络中的位置及其与周围城市的空间分布密切相关,省内各景区(点)的服务范围及服务人口数量均已达一定规模。  相似文献   

12.
The advantages of group living are not shared equally among all group members and these advantages may depend on the spatial position occupied by a forager within the group. For instance, it is thought that socially dominant individuals prefer the predator-safe central position of groups forcing subordinates to the periphery. Uneven spread of benefits among group members can occur when some animals (the scroungers) parasitically exploit the food findings of other foragers (the producers). Here we focus on how playing producer or scrounger affects an individual''s spatial position within a group. We model the movement of foraging animals playing scrounger or producer using a spatially explicit simulation and use a genetic algorithm to establish movement rules. We find that groups containing producers and scroungers are more compact compared to an equivalent group of producers only. Furthermore, the position occupied by strategies varies: scroungers are mainly found in central positions, while producers in the periphery, suggesting that the best position for strategies differs. Dominants, therefore, should prefer movement rules which lead to central positions because of the positional benefits provided to the scrounger strategy they use. Moreover, position within a group will introduce an asymmetry among otherwise phenotypically symmetric individuals.  相似文献   

13.
At the interface of Indonesia and Malaysia, border-crossing maritime trade appears to elude attempts to conserve marine resources. In Berau district (East Kalimantan) attempts to protect coastal waters from illegal fishing and trade fail to correspond with mobile trade networks. In this article, I describe how a female Bajau trader acts out her (illegal) trade network in practice. The article draws on 18 months of ethnographic research, during which I joined the trader along her travels through the coastal zone of northeastern Kalimantan. Using a performative network approach, I explore the trader's network as a continuously generated effect of practice and movement. Following her trading practices, I show that the performance of her network requires the ceaseless movement of people and things, in travelling (mobility) as well as in the reshaping of relations (fluidity). The trader's network is enmeshed in historically grown relations of kinship, ethnicity, and patron–client associations across the sea. These socially and spatially mobile associations are at odds with conservationists’ preoccupation with a spatial fixation of people, places, and borders. By showing how relations of loyalty, debt, and affiliation systematically transgress these borders, I demonstrate the significance of a relational approach to marine conservation that takes into account the mobility and interdependency of maritime networks. Such an approach may help to redress the hegemony of place-based approaches in marine conservation.  相似文献   

14.
The distribution of Aedes aegypti (L) (Diptera: Culicidae) oviposition in Buenos Aires City is spatially heterogeneous. Oviposition activity was monitored for a year with a grid of 279 traps at 850-m intervals that were serviced weekly. Geostatistics were used for the spatial analysis and generalized linear regression to model oviposition as a function of demographic and environmental variables. The proportion of weeks infested and the total number of eggs showed spatial continuity and were higher in areas that had higher densities of houses and were closer to industrial sites; they were lower in areas with higher human populations or higher densities of flats. When all sites were considered, the spatial structure showed a strong trend, but after regression, the residuals presented lower spatial dependence. When only infested sites were considered, the oviposition variables were spatially autocorrelated and the regression residuals showed little or no spatial dependence. The spatial pattern of Ae. aegypti oviposition in a highly urbanized city such as Buenos Aires seems to be related to the urbanization gradient. These urban environments might present different resource availability or continuity between patches of resources.  相似文献   

15.
This study integrated accessibility and location-allocation models in geographic information systems as a proposed strategy to improve the spatial planning of public health services. To estimate the spatial accessibility, we modified the two-step floating catchment area (2SFCA) model with a different impedance function, a Gaussian weight for competition among service sites, a friction coefficient, distances along a street network based on the Dijkstra’s algorithm and by performing a vectorial analysis. To check the accuracy of the strategy, we used the data from the public sterilization program for the dogs and cats of Bogot´a, Colombia. Since the proposed strategy is independent of the service, it could also be applied to any other public intervention when the capacity of the service is known. The results of the accessibility model were consistent with the sterilization program data, revealing that the western, central and northern zones are the most isolated areas under the sterilization program. Spatial accessibility improvement was sought by relocating the sterilization sites using the maximum coverage with finite demand and the p-median models. The relocation proposed by the maximum coverage model more effectively maximized the spatial accessibility to the sterilization service given the non-uniform distribution of the populations of dogs and cats throughout the city. The implementation of the proposed strategy would provide direct benefits by improving the effectiveness of different public health interventions and the use of financial and human resources.  相似文献   

16.
The analysis of animal movement within different landscapes may increase our understanding of how landscape features affect the perceptual range of animals. Perceptual range is linked to movement probability of an animal via a dispersal kernel, the latter being generally considered as spatially invariant but could be spatially affected. We hypothesize that spatial plasticity of an animal''s dispersal kernel could greatly modify its distribution in time and space. After radio tracking the movements of walking insects (Cosmopolites sordidus) in banana plantations, we considered the movements of individuals as states of a Markov chain whose transition probabilities depended on the habitat characteristics of current and target locations. Combining a likelihood procedure and pattern-oriented modelling, we tested the hypothesis that dispersal kernel depended on habitat features. Our results were consistent with the concept that animal dispersal kernel depends on habitat features. Recognizing the plasticity of animal movement probabilities will provide insight into landscape-level ecological processes.  相似文献   

17.
Members of social groups face a trade-off between investing selfish effort for themselves and investing cooperative effort to produce a shared group resource. Many group resources are shared equitably: they may be intrinsically non-excludable public goods, such as vigilance against predators, or so large that there is little cost to sharing, such as cooperatively hunted big game. However, group members'' personal resources, such as food hunted individually, may be monopolizable. In such cases, an individual may benefit by investing effort in taking others'' personal resources, and in defending one''s own resources against others. We use a game theoretic “tug-of-war” model to predict that when such competition over personal resources is possible, players will contribute more towards a group resource, and also obtain higher payoffs from doing so. We test and find support for these predictions in two laboratory economic games with humans, comparing people''s investment decisions in games with and without the options to compete over personal resources or invest in a group resource. Our results help explain why people cooperatively contribute to group resources, suggest how a tragedy of the commons may be avoided, and highlight unifying features in the evolution of cooperation and competition in human and non-human societies.  相似文献   

18.
The posterior parietal cortex has long been considered an ''association'' area that combines information from different sensory modalities to form a cognitive representation of space. However, until recently little has been known about the neural mechanisms responsible for this important cognitive process. Recent experiments from the author''s laboratory indicate that visual, somatosensory, auditory and vestibular signals are combined in areas LIP and 7a of the posterior parietal cortex. The integration of these signals can represent the locations of stimuli with respect to the observer and within the environment. Area MSTd combines visual motion signals, similar to those generated during an observer''s movement through the environment, with eye-movement and vestibular signals. This integration appears to play a role in specifying the path on which the observer is moving. All three cortical areas combine different modalities into common spatial frames by using a gain-field mechanism. The spatial representations in areas LIP and 7a appear to be important for specifying the locations of targets for actions such as eye movements or reaching; the spatial representation within area MSTd appears to be important for navigation and the perceptual stability of motion signals.  相似文献   

19.
李佳鸣  冯长春 《生态学报》2019,39(13):4741-4750
以内蒙古自治区为例,基于土地利用与生态系统服务价值(ESV)的关系,提出将生态改善效果纳入生态服务功能综合评价的分级方法,并分析生态服务功能的空间分布格局,揭示生态改善与生态系统服务价值的对应关系。结果表明:(1)2015年研究区ESV为1.87万亿元,区域整体生态环境质量水平提升;(2)研究区的生态改善具有空间分异特征,高ESV改善区仅集中于大兴安岭等高生态价值区,其余地区生态改善不明显,甚至呈恶化趋势,造成地区间差距不断扩大;(3)生态系统服务的提供程度与生态改善效果具有高关联性,依据各功能和生态改善水平可将研究区划分为北部大兴安岭核心区、中部高覆盖草原区两类高值区,以及西部沙地区、南部沿黄河地区和东部科尔沁地区三类低值区。生态管控措施应综合生态服务功能与生态改善效果的匹配程度,以达到减小区域ESV差距、促进生态环境协调发展的目的。  相似文献   

20.
phylin is a package for the r programming environment which offers different methods to spatially interpolate genetic information from phylogeographic data. These interpolations can be used to predict the spatial occurrence of different lineages within a phylogeny using a modified method of kriging, which allows the usage of a genetic distance matrix to derive a model of spatial dependence. phylin improves the available methods to generate interpolated surfaces from a phylogenetic trees by assessing the autocorrelation structure of the genetic information, interpolating the genetic data based on a statistical model, estimating the uncertainty of the predictions and identifying lineage occurrence and contact zones probability without projection of pairwise genetic distances into mid‐points between sample locations. The package also includes methods to plot interpolation surfaces and provide summary tables from the generated data and models. We provide an example of the usefulness of this tool by inferring the spatial occurrence of distinct historical evolutionary lineages of the Lataste's viper (Vipera latastei Boscá, 1878) in the Iberian Peninsula and identifying potential contact areas. The maps of phylogenetic patterns obtained with these methods provide a spatial context to test hypotheses related to processes underlying the geographic distribution of genetic diversity and to inform conservation planning.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号