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 15 毫秒
1.
This study quantifies and spatially characterizes land use and land cover changes in the Segara Anakan lagoon (SAL), Java, Indonesia, from 1987–2006. Classification of four satellite (SPOT) images from the years 1987, 1995, 2004 and 2006 and field ground truth data from 2004 and 2005 were used for map generation. The results show major changes in the western area of the SAL, with large area increases of rice fields, dry land agriculture, aquaculture and rural areas, and decreases in mangrove cover, mud flat and lagoon area. In the eastern area, minor decreases in mangrove area and increase in aquaculture, rural and industrial areas were also observed. Changes are due to the filling of the lagoon with riverine sediments derived from the hinterland and to mangrove conversion and resources exploitation. The results of this study provide basic information which is required for developing measures towards a sustainable management and conservation of the SAL.  相似文献   

2.
Segara Anakan is a mangrove-fringed lagoon in Java, Indonesia, which is affected by human activities in the lagoon and its hinterland. Nutrient and sediment input from the Citanduy River which drains an agriculture-dominated hinterland is thought to be an important factor for ecosystem degradation. From dry and rainy season investigations of dissolved inorganic nutrients between May 2004 and August 2006 we infer that the nutrient inventory of Segara Anakan is controlled by a complex mixture of anthropogenic and natural sources and processes. Maximum inputs into the western lagoon were supplied by the Citanduy during the rainy season while tidal exchange with the Indian Ocean dominated in the eastern lagoon with little freshwater input. During the dry season recycling in mangroves appeared to be an additional source of nutrients to the lagoon. Despite an extremely high population density and intensive agriculture in the hinterland nutrient pollution and eutrophication in the lagoon were low to moderate on a global scale. It is probably due to the short residence time of water in the shallow lagoon which indicates that major part of the land-derived nutrient input is rapidly exported to the sea. Although Segara Anakan is a highly perturbed system for decades, it appears that still natural processes exert major control on the nutrient inventory of the lagoon.  相似文献   

3.
A hydrodynamic field study of the Segara Anakan lagoon combined with a reconstruction of the recorded data using a three-dimensional numerical model provides insights into the processes driving the hydrodynamics of the lagoon. This includes bathymetry, quantification of water volume fluxes with ADCP measurements, sea level recordings, salinity measurements, water budget and numerical model results for the periods of the field studies. Salinity measurements at the Klaces village show a complete flushing of the western lagoon during neap tide in the rainy season, which is assumed to increase the sedimentation. Mean salinities of the western part are in the order of 10 and 21 g/kg, while the eastern part has a larger mean salinity of 27 and 32 g/kg for the rainy and dry season, respectively. A numerical sensitivity study shows a relationship between the Citanduy discharge and the nett water volume transport between the eastern and western part of Segara Anakan. A nett transport to the west, which differs from neap to spring tides, turns to zero when Citanduy discharges are between 300 and 400 m3/s. The flushing time of the lagoon depends on the monsoon season and is about 1–3 days at the western outlet and increases to 12 days in the central parts.  相似文献   

4.
Inefficient feeding practices for producing fish in captivity create environmental problems. Therefore, the feed input should be reduced to a level that does not result in negative impacts of fish production. Reducing feed input can be done by periodic feed deprivation which does not necessarily decrease the fish production. This study was designed to investigate the effect of repeated unfed–fed cycles on the growth and feed utilization of the orange-spotted grouper Epinephelus coioides raised in floating net cages in estuarine ponds. The trial was conducted in the north east of Segara Anakan, Java, Indonesia. The fish were purchased from local fishermen and mean fish body weight was 53.2 g. After acclimation in the cages for 2 weeks, 500 fish were randomly assigned to four feeding groups. The groups included: fish fed daily as a control (C); fish not fed every Monday and Thursday and fed on Tuesday and Wednesday, then on Friday, Saturday and Sunday (T1); fish unfed every Sunday, Monday and Thursday and fed on Tuesday and Wednesday, then on Friday and Saturday (T2). The experiment ran for 10 weeks. The results showed that reducing feed input by repeating unfed–fed cycles induced compensatory growth of the fish. Application of this feeding regime provides flexibility in feeding management and may reduce organic discharge into the environment. Reduction of organic pollution should help the sustainable use and conservation of the Segara Anakan ecosystem.  相似文献   

5.
In the Segara Anakan lagoon, Java, 21 tree species and 5 understorey genera have been identified. Average tree density is 0.80 ± 0.99 Ind./m2 with 48.71% seedlings and an average basal area of 9.86 ± 10.54 cm2/m2. Tree density and diversity are high in the eastern part of the lagoon, located near the city of Cilacap. There, the dominant tree species are Aegiceras corniculatum, Nypa fruticans and Rhizophora apiculata, of which the two latter are characteristic for mature forests. By contrast, understorey species and the pioneer species (Avicennia alba, Aegiceras corniculatum and Sonneratia caseolaris) dominate the central lagoon where several rivers discharge. Compared to former studies, seedling density and tree diameter in the central lagoon has declined considerably and tree species dominance has changed. The high sedimentation rates and deforestation are likely to prevent the formation of a mature forest there. Tree communities are more equilibrated in the eastern lagoon which points to a more stable and less disturbed mangrove forest.  相似文献   

6.

Watershed processes and their effects on coasts are shaped by numerous interacting natural and societal factors. The knowledge of these factors and processes is often limited. This makes the field prone to politicisations with debates, research, and interventions being confined to a few selected factors. Debates on the causes of high river sediment loads and coastal sedimentation in Java have focussed on rainfed agriculture on peasants’ private lands, while other drivers have been neglected. This has undermined the effectiveness of watershed management. This paper links the sedimentation of the Segara Anakan lagoon on Java’s south coast with landscape characteristics and transformations in its catchment. Three-fourths of the lagoon have silted up since 1857/60. This is the result of a much broader range of drivers than commonly assumed to date. In addition to rainfed agriculture on peasants’ private lands, these drivers include coffee cultivation, timber extraction, plantation development, and in-migration in the late nineteenth and early twentieth century; erosion on contested state forest and plantation lands; state forest management practices; slope cuts to enlarge agricultural fields; agriculture in riparian zones; erosion from roads, trails, and settlements; river channel and floodplain modifications; and volcanic eruptions. The choice and expectations of societal responses aimed at reducing river sediment loads and coastal sedimentation hence need to be reconsidered, and related debates and research agendas must be broadened.

  相似文献   

7.
Human security is linked to people’s access to natural resources and vulnerabilities to environmental change. In the case study of Chilika lagoon, the findings reveal that insecurity linked to natural resources is largely embedded in the historical process of resource allocation among stakeholders, rather than on the presence of resource stocks. The insecurities are strongly tied not only to allocation changes, but also to multiple factors (environmental, technological, and demographic factors). Based on the Chilika lagoon experience, this article develops a pathway toward a clear understanding of the linkage between human security and natural resources in a local context.  相似文献   

8.
9.
The benthic macrofauna of the Segara Anakan lagoon, Java, Indonesia and its fringing mangroves were investigated between May 2004 and August 2006. This lagoon has been affected by various human activities for decades, in particular fishing, effluents from agriculture and industry, and illegal deforestation. In total, 163 taxa were identified, including 127 species occurring in the mangrove forest and 59 species in the subtidal. Mean density of macrobenthos was 2.5-fold higher in the central (881.8 ± 1,151.3 ind. m?2) than in the eastern mangrove site (356.3 ± 218.8 ind. m?2). Community structures differed significantly between these sites and showed a serial shift during the investigation period. Gastropods dominated the community in the central mangrove location, whereas sipunculids, polychaetes and gastropods had similar densities in the eastern site. Differences in community composition were best explained by three sediment properties: pore water salinity, δ13Corg, and Corg/N. It is suggested that small-scale heterogeneity of food availability and quality is a main factor determining the small-scale variability of the community composition. Compared to other Indo-West Pacific mangroves, species richness and densities are high. However, the dominance of specific taxa, especially of opportunistic species and the comparably low species richness in the subtidal of the lagoon may be attributed to the high sediment input by rivers in the central part and to the large-scale cutting of mangroves. Continuous tree logging will probably lead to a further spread of two fast growing understorey plants and thus to an increase of uniform swamp sites and a decrease of micro-habitats for benthic macrofauna. To our knowledge, this is the first detailed study on the spatio-temporal variation of benthic macrofauna in mangroves of Indonesia.  相似文献   

10.
Biodiversity is acknowledged as one of the most important resources that helps to sustain life’s processes. Additionally, it is also one of the most important sources of livelihood for different kinds of stakeholders at various levels of resource markets—local, domestic, or international. With globalization and increasing sophistication in the methods of commercial trade in biological resources, various issues arise related to the sustenance of resources, of ecological balances, and equity in transactions. All of these are concerns to be addressed to achieve a state of ‘sustainability.’ This paper prescribes to the definition of ‘sustainability’ as the capacity to maintain a certain process or state for “improving the quality of human life while living within the carrying capacity of supporting eco-systems” (IUCN/UNEP/WWF, in Caring for the Earth: a strategy for sustainable living. Gland, Switzerland, 1991). This goes beyond ensuring inter- and intragenerational equity in access to resources and includes several other parameters, including equity among stakeholders to returns from biological resources, related knowledge, trade-offs, and ethical business practices related to these resources. Through the prism of an examination of a simplistic supply route(s) and value addition chain of biodiversity resources for commercial use, this paper reviews and highlights issues related to ‘sustainability’ at each stage. Evidence points to shortcomings in the sustainable use of biological resources at each stage of value addition, calling for focused and specific measures to address them.  相似文献   

11.
This article focuses on the problems of water governance at a river basin level, and on the role of institutional coordination, participation and partnerships between multiple stakeholders towards sustainable water management. Its approach presupposes that institutional capacity building, strengthening coordination between government institutions (vertical and horizontal), on the one hand, and broadening participation and consolidating partnerships between public, private and civil society actors, on the other hand, is among effective tools in integrated water resource management in river basins. It explores environmental challenges, problems, emerging trends and recent institutional innovations in the Volga basin in Russia—the largest river basin in Europe. Transfer and adaptation of good practices in good water governance between the EU and Russia are discussed. This article presents some research findings and lessons learned from practice by the EC international project ‘CABRI—Cooperation along a big river: Institutional coordination among stakeholders for environmental risk management in the Volga basin’, which is assessed as one of the selected success stories of the European research.’  相似文献   

12.
Analyzing different pathways by which social–ecological systems can loose resilience and enter trajectories of collapse constitutes an important aspect of our quest towards understanding resource sustainability. This paper’s goal was to better understand the effect of a particular class of disturbance—the accumulative effects of routine stressors—in the context of marine social–ecological systems. To that effect, we built a system dynamics model using empirically collected institutional and biological field data of an artisanal fishery in the Gulf of California, Mexico. Among our findings, we identified different scenarios under which even very small endogenous changes in the relationship between ecological and institutional variables can send a seemingly resilient system into a trajectory of collapse. We discuss why these types of disturbances are so difficult to prevent and be identified by the users of the resource, as well as potential strategies to address these challenges.  相似文献   

13.
Issues and complexities arising when the fisheries and marine tourism sectors have stakes in an institution governing the coral reefs ecosystem called awig-awig are discussed, awig-awig is a colloquialism meaning ‘a local rule’. The community-based management system is commonly recognized as a better approach to governing resources, however, the success of awig-awig in the study area is questionable. Awig-awig fails to deal with the conflict of interest among stakeholders in coastal resource appropriation, despite the community being relatively culturally homogenous. The benefits of awig-awig are biased in favor of the tourism as opposed to fisheries, leading to the fishers’ resistance of awig-awig. There are critical factors to this weakness: a crisis of legitimacy within community, socio-economic inequality among actors involved in such system, high intervention from external agencies, and the institutional conflict over conservation policy. In addition, awig-awig reduces community spirit as it is perceived as not being attached to any customary law or traditional norms. Group cohesion is challenged and there is no common understanding of the problem or alternatives strategies.  相似文献   

14.
Using institutional appraisal focused groups (FG) and participatory appraisals with Dillman Total Design Method (TDM), this study examines community interaction with and utilization of wetland resources in Xinhui, Guangdong Province, China. Field results show high commercial activities and corresponding impacts on coastal environment. Other interacting factors identified include: legislation and ecosystem management, stakeholders’ participation, international guidelines criteria, and utilization of mangrove resources in the region. Sensitivity index and community-based natural resources management collaboration comparison percentile showed significant differences between cumulative distributions of respondents (D = 0.2568, P = 0.078). Likert statement of 11 sensitivity optional indexes in EMS of K–S test at 0.05 level of P = 0.078 also show significant differences in interaction between respondent groups and sensitivity factors. This indicates a dysfunction between regional environmental management systems and CBNRM in Xinhui coastal district. Considering the high tourism potential and economic quest of the region, there is the need for coordinated community enlightenment and further studies on the social, ecological and economic value of wetland resources. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

15.
China’s economic growth has a serious impact on the environment and resources. How much real cost did China pay for its economic growth? This paper estimates the monetary costs of resource depletion, environmental pollution, and ecological degradation. The paper examines the geographic distribution of resource and environmental losses across 31 provinces. The findings allow us to reach the following conclusions. First, the national cost of resource depletion, environmental pollution, and ecological degradation in 2005 was 2.5 trillion RMB. It accounted for 13.5% of China’s gross domestic product (GDP). Secondly, the cost of resource depletion, ecological degradation, and environmental pollution has a different spatial distribution. The cost of resources depletion mainly distributes in the central area, the cost of environmental pollution is in the eastern area, and the cost of ecological degradation lies in the western area. Thirdly, the cost of natural resources depletion is 1,672.5 billion RMB, accounting for 67.8% of the total cost of resource and environment. It indicates that economic development has a high cost of resource depletion.  相似文献   

16.
This paper presents the technical aspects of a new methodology for assessing the susceptibility of society to drought. The methodology consists of a combination of inference modelling and fuzzy logic applications. Four steps are followed: (1) model input variables are selected—these variables reflect the main factors influencing susceptibility in a social group, population or region, (2) fuzzification—the uncertainties of the input variables are made explicit by representing them as ‘fuzzy membership functions’, (3) inference modelling—the input variables are used to construct a model made up of linguistic rules, and (4) defuzzification—results from the model in linguistic form are translated into numerical form, also through the use of fuzzy membership functions. The disadvantages and advantages of this methodology became apparent when it was applied to the assessment of susceptibility from three disciplinary perspectives: Disadvantages include the difficulty in validating results and the subjectivity involved with specifying fuzzy membership functions and the rules of the inference model. Advantages of the methodology are its transparency, because all model assumptions have to be made explicit in the form of inference rules; its flexibility, in that informal and expert knowledge can be incorporated through ‘fuzzy membership functions’ and through the rules in the inference model; and its versatility, since numerical data can be converted to linguistic statements and vice versa through the procedures of ‘fuzzification’ and ‘defuzzification’.  相似文献   

17.
Abstract

The natural supply of land resources is limited, but the economic supply may change along with social and economic development, and its size is decided bye nature and social and economic body conditions. When the supplying ability of land resources threatens the development of society and the conflict between people and land becomes tense, it forced people to improve land utilization and to increase the effective supply of land resources. The paper made an overall consideration on the characteristics of the irrigated farming and the frail ecological environment in Fuhai County, Altay Area, Xinjiang Uigur Autonomous Region and explored land arrangement planning as well as water resource planning and environmental protection. The paper evaluated natural resources, land utilization and water resource of the case study areas and focused on the spatio-temporal balance between the utilization of water and land resources. In the end the paper a feasible plan was made out for the land arrangement project.  相似文献   

18.
The need for environmental and urban planning reached a critical point in the year 2007, when one-half of the world's population could be defined as living in cities. Urbanisation in India is also increasing at a fast rate. Urban chaos in India, emanating from the continuous ignorance of fragile ecosystems, calls for the reshaping of existing cities as ‘eco-cities’. The ‘eco-city’—a well-known concept in the western world—is new to the Indian context. While western connotations of eco-cities should not be discarded outright in the context of India, core concerns vary significantly for obvious reasons. Recognising two facts—firstly, eco-city development is altogether a fresh approach to human settlement development in India, and, secondly, the manifold increase in the vulnerability of cities—this paper discusses documented good practice, reinforcing evolution towards the eco-city vision. Lessons drawn from the examples cited are further deconstructed in the light of their contribution to urban risk reduction, which provides direction to appreciating the ‘disaster-resilient eco-community’ concept in Puri, a coastal city in India. Further, this paper attempts to unravel existing community-based practices in Puri, which are boon to the local environment and invariably reduce disaster risk. These seemingly modest neighbourhood initiatives symbolise immense societal wealth, which can be calibrated appropriately for reducing urban environmental risk as well. This paper also illustrates how a ‘disaster resilient eco-community’ approach is inevitable in the present and future contexts not only to preserve sustainable development gains but also to secure human well-being.  相似文献   

19.
In Bolivia, recent decentralisation policies have broadened the participation of local actors in development processes. However, development is far from sustainable, and poverty and natural resources degradation still increase. The challenge is to develop strategies that achieve the genuine participation of poor farmers in natural resources management and sustainable development. The logical strategy, which was developed and validated in five Bolivian mountain villages, is an example. In this strategy, first a solid foundation for sustainable development is laid, with activities focussing on five basic conditions for sustainable development in rural villages: leadership and organisation, responsible participation, effective collaboration, mutual trust and environmental awareness. The results show that the existence of a solid foundation is crucial for the success of other development activities, such as soil and water conservation activities. However, given that 2 years after the project’s withdrawal the firmness of the foundation had slightly weakened, it was concluded that a better integration of these villages in local development processes is essential to profit from the new dynamics. This is especially true for soil and water conservation. To achieve this integration, municipalities—with the support of international development agencies—must be encouraged to invest in laying this solid foundation in rural villages and in facilitating follow-up activities to keep the dynamic process going. This study shows that such investments result in better organised villages, more equality, and the genuine participation of more people in sustainable village development. Effective collaboration and accountability at institutional level are, however, required.  相似文献   

20.
各类资源是生态城市建设的基础条件,也是塑造城市特色的重要依据之一。基于生态城市建设的资源可持续利用,不仅要重视资源的数量问题,更需要着眼全局,综合分析城市社会、经济、环境发展的现状、目标与资源之间的矛盾,制定资源可持续利用的保障对策。基于生态城市的深刻内涵,资源可持续利用的研究视野亟待拓展,不仅要关注自然资源、生物资源的可持续利用问题,同时还必须重视对城市人文禀赋与历史文脉的传承和保护,实现古代、近代、现代和当代“四代文明”可持续发展。以常州市为例,基于生态城市建设,对其土地资源、水资源、生物资源与人文资源的可持续利用进行了系统研究,并作了概念性规划。  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