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1.
Shrimp farming in mangrove areas has grown dramatically in Asia and Latin America over the past decade. As a result, demand for resources required for farming, such as feed, seed, and clean water, has increased substantially. This study focuses on semiintensive shrimp culture as practiced on the Caribbean coast of Colombia. We estimated the spatial ecosystem support that is required to produce the food inputs, nursery areas, and clean water to the shrimp farms, as well as to process wastes. We also made an estimate of the natural and human-made resources necessary to run a typical semiintensive shrimp farm. The results show that a semiintensive shrimp farm needs a spatial ecosystem support—the ecological footprint—that is 35–190 times larger than the surface area of the farm. A typical such shrimp farm appropriates about 295 J of ecological work for each joule of edible shrimp protein produced. The corresponding figure for industrial energy is 40:1. More than 80% of the ecological primary production required to feed the shrimps is derived from external ecosystems. In 1990 an area of 874–2300 km2 of mangrove was required to supply shrimp postlarvae to the farms in Colombia, corresponding to a total area equivalent to about 20–50% of the country’s total mangrove area. The results were compared with similar estimates for other food production systems, particularly aquacultural ones. The comparison indicates that shrimp farming ranks as one of the most resource-intensive food production systems, characterizing it as an ecologically unsustainable throughput system. Based on the results, we discuss local, national, and regional appropriation of ecological support by the semiintensive shrimp farms. Suggestions are made for how shrimp farming could be transformed into a food production system that is less environmentally degrading and less dependent on external support areas.  相似文献   

2.
Situations of water scarcity challenge sustainability and threaten small users' access to water. In response to this problem, there has been a search for a method of hydrological analysis that can better represent the needs of small water users. While this search is rooted in the debate favouring a more participatory and inclusive allocation of the resource, it also requires a new focus on smallholder hydrology that can confront the gaps and biases found in current hydrological practices in many countries. This article looks at past hydrological practices and also at results of recent studies, highlighting the perspective of smallholder irrigators in surface water planning in Zimbabwe, and groundwater planning in India. These case studies show that wider social forces, not always best science, drive hydrological practices. However, new frameworks focusing on the water user can emerge for more equitable and sustainable water management.  相似文献   

3.
Decision-making in spatial planning is often based only on administrative regulations and procedures. This approach does not guarantee an efficient allocation of scarce financial resources. Consequently, the present paper discusses the practical relevance of an approach to incorporate results of economic valuation into strategic spatial planning for the example of green infrastructure. For this, a contingent valuation was conducted at a reference site in Esslingen, Germany. Here, participants of the survey stated their willingness to pay for different green infrastructure investment categories. Build on the survey results, the possible future foci of regional green infrastructure planning are derived and impacts on regional green infrastructure policy for the case of the Neckar region are investigated.  相似文献   

4.
Large scale rainwater harvesting (LSRWH) is a promising alternative to address security and flood issues in urban areas. The development and planning of a LSRWH for an eco-community involves comprehensive site-planning, systems planning and design, which includes the rainwater source collection (roof) to the storage tank, the distribution and allocation system. This paper describes a new technique for designing a LSRWH for a community of 200 houses with an average of 4 persons per house and an average total daily water demand of 160 m3. It was found that the optimal size storage tank for a 20,000 m2 roof area is 160 m3 with a 60% reliability. The application of this model to the case study revealed a significant water saving up to 58% .The total cost for this system is 443,861 USD over a life-span of 25 years.  相似文献   

5.
6.
A planning and decision-making framework for ecological restoration   总被引:2,自引:0,他引:2  
A broad and objective perspective of ecological and socioenomic knowledge is required to underlie a scientific approach to the problems of terrestrial restoration ecology. Uncertainty associated with limited scientific knowledge highlights the crucial importance of the interaction between science and policy in weighing ecological restoration alternatives in relation to other management options. In this paper, we provide a pragmatic definition for restoration ecology that is suitable for extensive terrestrial applications and present a decision framework to help organize and clarify different phases of the decision process as it is related to ecological restoration. We argue that restoration planning should include a wider spectrum of participants and decisions than have traditionally been employed.  相似文献   

7.
Water and related resources planning and decision-making have developed to the state of multiple objective and/or multiple criteria analysis using complicated systems analysis. The objective of this paper is to indicate the major components of information needed to facilitate the planning process for resource utilization, and to provide desirable outputs from management schemes. The process could best be described as the proper development of Management Information Systems (MIS) or Decision Support Systems (DDS). Data and information systems are never completed and must be continually updated and modified. The exact composition of any system depends also upon the general type of decision techniques being used. A brief outline of the decision process is given with the remainder of the paper dealing with the types of information needed to support the decision system.  相似文献   

8.
The growing use of computers in environmental management is profoundly changing data collection procedures, analytic processes, and even the decision-making environment itself. The emerging technology of geographic information systems (GIS) is expanding this revolution to integrate spatial information fully into research, planning, and management of land. In one sense, this technology is similar to conventional map processing involving traditional maps and drafting aids, such as pens, rub-on shading, rulers, planimeters, dot grids, and acetate sheets for light-table overlays. In another sense, these systems provide advanced analytic capabilities, enabling managers to address complex issues in entirely new ways. This report discusses a fundamental approach to computer-assisted map analysis that treats entire maps as variables. The set of analytic procedures for processing mapped data forms a mathematical structure analogous to traditional statistics and algebra. All of the procedures discussed are available for personal computer environments.  相似文献   

9.
Life cycle inventory (LCI) is becoming more widely used as a tool to evaluate the resource and energy use and the environmental releases associated with various products. The methodology for handling different recycling scenarios is also becoming increasingly important. Several different methods exist for handling recycling in an LCI. The method described in this paper uses mathematical models to show that the same basic equations can be used to handle a variety of recycling options for multi-product systems.  相似文献   

10.
Environment Systems and Decisions - For mission critical (MC) applications such as bushfire emergency management systems (EMS), understanding the current situation as a disaster unfolds is critical...  相似文献   

11.
ABSTRACT

The energy consumed around the world and especially in Morocco is dominated by oil products. The latter; whether in the global or the national context; are mainly due to diesel, whose climate impacts are well established, suggesting the search for a greener alternative. Despite its virtues, biodiesel is struggling to impose itself for purely economic reasons. Thus, in order to offer a sustainable solution, while keeping in mind the unpredictable fluctuations (price, demand …). This work proposes a generalization of fuzzy goal programming into fully fuzzy goal programming and a relative application, where the aim is to have a final product at a competitive price.  相似文献   

12.
This paper describes a fuzzy hierarchical analytic approach to determine the weighting of subjective judgments. In addition, it presents a nonadditive fuzzy integral technique to evaluate a green engineering industry case as a fuzzy multicriteria decision-making (FMCDM) problem. When the investment strategies are evaluated from various aspects, such as economic effectiveness, technical feasibility, and environmental regulation, it can be regarded as an FMCDM problem. Since stakeholders cannot clearly estimate each considered criterion in terms of numerical values for the anticipated alternatives/strategies, fuzziness is considered to be applicable. Consequently, this paper uses triangular fuzzy numbers to establish weights and anticipated achievement values. By ranking fuzzy weights and fuzzy synthetic utility values, we can determine the relative importance of criteria and decide the best strategies. This paper applies what is called a λ fuzzy measure and nonadditive fuzzy integral technique to evaluate the synthetic performance of green engineering strategies for aquatic products processors in Taiwan. In addition, we demonstrate that the nonadditive fuzzy integral is an effective evaluation and appears to be appropriate, especially when the criteria are not independent.  相似文献   

13.
The use of organic farming technologies has certain advantages in some situations and for certain crops such as maize; however, with other crops such as vegetables and fruits, yields under organic production may be substantially reduced compared with conventional production. In most cases, the use of organic technologies requires higher labor inputs than conventional technologies. Some major advantages of organic production are the conservation of soil and water resources and the effective recycling of livestock wastes when they are available.  相似文献   

14.
Cooperatives are increasingly advocated as a means to improve incomes, livelihoods and the sustainability of smallholder farmers. This study analyzes the impact of commercial vegetable cooperative membership on smallholder agricultural performance in Cambodia. Institutional heterogeneities are considered across cooperatives and various econometric techniques are used to control for potential selection bias. The impacts of horticulture on agricultural outcomes are also analyzed. The results indicate that membership of commercial vegetable cooperatives has so far had no effect on agricultural incomes or the value or amounts of agricultural inputs. However, results indicate that membership has affected technology choice, access to credit services and information transmission through technological training. Additionally, there is evidence that horticulture, as a component of overall agricultural diversification, can augment farm income. The results suggest that much of the benefit of cooperative membership stems from the cooperative's provision of services, which might not be easily inferred from measures of member incomes.  相似文献   

15.
Group decision-making for leakage management strategy of water network   总被引:2,自引:0,他引:2  
The problem of leakage is complex and requires actions drawn from different aspects of water network management. Inadequate maintenance has serious consequences, both financial and environmental. This paper proposes a group decision-making model based on PROMETHEE V method to aim a leakage management strategy, which takes into account the points of view of four stakeholders, selecting feasible options, and considering the available budget as constraint. Thus, this strategy is the combination of options that will efficiently meet technical, socio-economic and environmental criteria to achieve sustainable development.  相似文献   

16.
This article describes a process of developing socio-cultural indicators to support local and regional decision-making for eco-efficiency. Although eco-efficiency is calculated using environmental and economic variables, decisions on local and regional levels cannot ignore the socio-cultural impacts. The indicators were developed by a participatory process that was based on involvement and empowerment of local actors. The process ensured policy relevance and meaningful indicators and advanced their future use in the decision-making.  相似文献   

17.
This article describes a multiobjective programming (MOP) framework for integrating timber and wildlife management. The framework allows for the simultaneous consideration of timber and wildlife objectives. Management strategies are defined in terms of management regimes consisting of a time-identified and site-specific schedule of activities. A MOP model is described and demonstrated using an integrated planning example involving a forest managed for timber production and a variety of wildlife species.  相似文献   

18.
A mathematical model for a hybrid anaerobic reactor (HAR), which uses self-immobilized anaerobic bacterial granules under completely fluidized condition, has been developed. Stoichiometry of glucose fermentation into methane has been considered in this model. The model includes: (1) a biofilm model which describes substrate conversion kinetics within a single granule; (2) a bed fluidization model which describes the distribution of biogranules within the fluidized bed and (3) a reactor model which links the above two to predict the substrate and products concentration profile along the reactor height. Product and pH inhibition for each group of bacteria has been considered in the kinetic model. The spatial distribution of each group of anaerobic bacteria within granules has been found to play a vital role in bringing about the conversion. Experiments were conducted in the reactor using a synthetic effluent containing glucose as the carbon source to study the treatment efficiency. The model was simulated first assuming a 3-layered distribution [MacLeod, F.A., Guiot, S.R., Costerton, J.W., 1990. Layered structure of bacterial aggregates produced in an upflow anaerobic sludge bed and filter reactor. Applied and Environmental Microbiology 56, 1598-1607.] of anaerobic bacteria within granules and then homogeneous distribution [Grotenhuis, J.T.C., Smit, M., Plugge, C.M., Yuansheng, X., van Lammeren, A.A.M., Stams, A.J.M., Zehnder, A.J.B., 1991. Bacterial composition and structure of granular sludge adapted to different substrates. Applied and Environmental Microbiology 57, 1942-1949.] of anaerobic bacteria. The predictions of model simulation with the assumption of layered structure closely represented the experimental data.  相似文献   

19.
Abstract

This article describes a process of developing socio-cultural indicators to support local and regional decision-making for eco-efficiency. Although eco-efficiency is calculated using environmental and economic variables, decisions on local and regional levels cannot ignore the socio-cultural impacts. The indicators were developed by a participatory process that was based on involvement and empowerment of local actors. The process ensured policy relevance and meaningful indicators and advanced their future use in the decision-making.  相似文献   

20.
The conservation of biodiversity is an important issue world wide and in Australia the maintenance of native biodiversity on farms makes an important contribution to overall conservation objectives. This paper seeks to explain Australian farmers' rationale for maintaining biodiversity on their farms for personal as opposed to business reasons by developing a decision-systems theory from in-depth interviews. This difference has implications for policy development. The decision-systems theory is divided into two main sections. The first section contains five parts. (1) A hierarchy of motivation stories, (2) the concept of suitability and availability of opportunities, (3) a hierarchy of three decision-systems, (4) the concept of personal career paths, (5) the concept of Lenses. The second section contains one part, a policy classification system called 'boxes of influence' that suggests how policy developers can use the information in the first section to develop new biodiversity conservation policy. The paper suggests that decision-systems theory could be used to shed new light on current trends in agriculture and become an important investigative tool for policy development concerning the conservation of biodiversity on farms.  相似文献   

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