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1.
An Interval-Parameter Waste-Load-Allocation Model for River Water Quality Management Under Uncertainty 总被引:1,自引:0,他引:1
A simulation-based interval quadratic waste load allocation (IQWLA) model was developed for supporting river water quality
management. A multi-segment simulation model was developed to generate water-quality transformation matrices and vectors under
steady-state river flow conditions. The established matrices and vectors were then used to establish the water-quality constraints
that were included in a water quality management model. Uncertainties associated with water quality parameters, cost functions,
and environmental guidelines were described as intervals. The cost functions of wastewater treatment units were expressed
in quadratic forms. A water-quality planning problem in the Changsha section of Xiangjiang River in China was used as a study
case to demonstrate applicability of the proposed method. The study results demonstrated that IQWLA model could effectively
communicate the interval-format uncertainties into optimization process, and generate inexact solutions that contain a spectrum
of potential wastewater treatment options. Decision alternatives can be generated by adjusting different combinations of the
decision variables within their solution intervals. The results are valuable for supporting local decision makers in generating
cost-effective water quality management strategies. 相似文献
2.
3.
Role of Adaptive Management for Watershed Councils 总被引:1,自引:0,他引:1
Habron G 《Environmental management》2003,31(1):0029-0041
Recent findings in the Umpqua River Basin in southwestern Oregon illustrate a tension in the rise of both community-based
and watershed-based approaches to aquatic resource management. While community-based institutions such as watershed councils
offer relief from the government control landowners dislike, community-based approaches impinge on landowners' strong belief
in independence and private property rights. Watershed councils do offer the local control landowners advocate; however, institutional
success hinges on watershed councils' ability to reduce bureaucracy, foster productive discussion and understanding among
stakeholders, and provide financial, technical, and coordination support. Yet, to accomplish these tasks current watershed
councils rely on the fiscal and technical capital of the very governmental entities that landowners distrust. Adaptive management
provides a basis for addressing the apparent tension by incorporating landowners' belief in environmental resilience and acceptance
of experimentation that rejects “one size fits all solutions.” Therefore community-based adaptive watershed management provides
watershed councils a framework that balances landowners' independence and fear of government intrusion, acknowledges the benefits
of community cooperation through watershed councils, and enables ecological assessment of landowner-preferred practices. Community-based
adaptive management integrates social and ecological suitability to achieve conservation outcomes by providing landowners
the flexibility to use a diverse set of conservation practices to achieve desired ecological outcomes, instead of imposing
regulations or specific practices. 相似文献
4.
Serveiss VB 《Environmental management》2002,29(2):145-154
Considerable progress in addressing point source (end of pipe) pollution problems has been made, but it is now recognized
that further substantial environmental improvements depend on controlling nonpoint source pollution. A watershed approach
is being used more frequently to address these problems because traditional regulatory approaches do not focus on nonpoint
sources. The watershed approach is organized around the guiding principles of partnerships, geographic focus, and management
based on sound science and data. This helps to focus efforts on the highest priority problems within hydrologically-defined
geographic areas. Ecological risk assessment is a process to collect, organize, analyze, and present scientific information
to improve decision making. The U.S. Environmental Protection Agency (EPA) sponsored three watershed assessments and found
that integrating the watershed approach with ecological risk assessment increases the use of environmental monitoring and
assessment data in decision making. This paper describes the basics of the watershed approach, the ecological risk assessment
process, and how these two frameworks can be integrated. The three major principles of watershed ecological risk assessment
found to be most useful for increasing the use of science in decision making are (1) using assessment endpoints and conceptual
models, (2) holding regular interactions between scientists and managers, and (3) developing a focus for multiple stressor
analysis. Examples are provided illustrating how these principles were implemented in these assessments. 相似文献
5.
ICCLP: An Inexact Chance-Constrained Linear Programming Model for Land-Use Management of Lake Areas in Urban Fringes 总被引:3,自引:1,他引:2
Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development
and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming
(ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use
suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use
allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different
probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental
requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was
performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use
suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use
allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development.
Sixteen constraints were set for the optimal model. The model results indicated that NEB was between $1.48 × 109 and $8.76 × 109 or between $3.98 × 109 and $16.7 × 109, depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use
structure were analyzed under different probabilities (q
i
) of TEC. Changes in q
i
resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed
by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop
optimal land-use management strategies that better balance urban expansion and grassland conservation. 相似文献
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Eugene Z. Stakhiv 《Journal of the American Water Resources Association》2011,47(6):1183-1196
Stakhiv, Eugene Z., 2011. Pragmatic Approaches for Water Management Under Climate Change Uncertainty. Journal of the American Water Resources Association (JAWRA) 47(6):1183–1196. DOI: 10.1111/j.1752‐1688.2011.00589.x Abstract: Water resources management is in a difficult transition phase, trying to accommodate large uncertainties associated with climate change while struggling to implement a difficult set of principles and institutional changes associated with integrated water resources management. Water management is the principal medium through which projected impacts of global warming will be felt and ameliorated. Many standard hydrological practices, based on assumptions of a stationary climate, can be extended to accommodate numerous aspects of climate uncertainty. Classical engineering risk and reliability strategies developed by the water management profession to cope with contemporary climate uncertainties can also be effectively employed during this transition period, while a new family of hydrological tools and better climate change models are developed. An expansion of the concept of “robust decision making,” coupled with existing analytical tools and techniques, is the basis for a new approach advocated for planning and designing water resources infrastructure under climate uncertainty. Ultimately, it is not the tools and methods that need to be revamped as much as the suite of decision rules and evaluation principles used for project justification. They need to be aligned to be more compatible with the implications of a highly uncertain future climate trajectory, so that the hydrologic effects of that uncertainty are correctly reflected in the design of water infrastructure. 相似文献
8.
TUGAI: An Integrated Simulation Tool for Ecological Assessment of Alternative Water Management Strategies in a Degraded River Delta 总被引:1,自引:0,他引:1
Schlüter M Rüger N Savitsky AG Novikova NM Matthies M Lieth H 《Environmental management》2006,38(4):638-653
The development of ecologically sound water allocation strategies that account for the needs of riverine ecosystems is a pressing
issue, especially in semiarid river basins. In the Aral Sea Basin, a search for strategies to mitigate ecological and socioeconomic
deterioration has been in process since the early 1990s. The Geographic Information System–based simulation tool TUGAI has
been developed to support the policy determination process by providing a simple, problem-oriented method to assess ecological
effects of alternative water management strategies for the Amudarya River. It combines a multiobjective water allocation model
with simple, spatially explicit statistical and rule-based models of landscape dynamics. Changes in environmental conditions
are evaluated by a fuzzy habitat suitability index for Populus euphratica, which is the dominant species of the characteristic riverine Tugai forests. Water management scenarios can be developed
by altering spatiotemporal water distribution in the delta area or the amount of water inflow into the delta. Outcomes of
scenario analysis are qualitative comparisons of the ecological effects of different options for a time period of up to 28
years. The given approach utilizes different types of knowledge, from quantitative hydrological data to qualitative local
expert knowledge. The main purpose of the tool is to integrate the knowledge in a comprehensive way to make it available for
discussions on alternative policies in moderated workshops with stakeholders. In this article, the modules of the tool, their
integration, and three hypothetical scenarios are presented. Based on the experience gained when developing the TUGAI tool,
we propose that the general framework can be transferred to other areas where tradeoffs in water allocation between the environment
and other water users are of major concern. The potential for a simulation tool to structure and inform a complex resource
management situation by involving local experts and stakeholders in the development of possible future scenarios will become
increasingly valuable for transparent and participatory resource management. 相似文献
9.
Recent attention has focused on resource management initiatives at the watershed scale with emphasis on collaborative, locally driven, and decentralized institutional arrangements. Existing literature on limited selections of well-established watershed-based organizations has provided valuable insights. The current research extends this focus by including a broad survey of watershed organizations from across the United States as a means to estimate a national portrait. Organizational characteristics include year of formation, membership size and composition, budget, guiding principles, and mechanisms of decision-making. These characteristics and the issue concerns of organizations are expected to vary with respect to location. Because this research focuses on organizations that are place based and stakeholder driven, the forces driving them are expected to differ across regions of the country. On this basis of location, we suggest basic elements for a regional assessment of watershed organizations to channel future research and to better approximate the organizational dynamics, issue concerns, and information needs unique to organizations across the country. At the broadest level, the identification of regional patterns or organizational similarities may facilitate the linkage among organizations to coordinate their actions at the much broader river basin or ecosystem scale. 相似文献
10.
This article provides an overview of the use of risk-based analysis (RBA) in flood damage assessment, and it illustrates the
use of Geographic Information Systems (GIS) in identifying flood-prone areas, which can aid in flood-mitigation planning assistance.
We use RBA to calculate expected annual flood damages in an urban watershed in the state of Rhode Island, USA. The method
accounts for the uncertainty in the three primary relationships used in computing flood damage: (1) the probability that a
given flood will produce a given amount of floodwater, (2) the probability that a given amount of floodwater will reach a
certain stage or height, and (3) the probability that a certain stage of floodwater will produce a given amount of damage.
A greater than 50% increase in expected annual flood damage is estimated for the future if previous development patterns continue
and flood-mitigation measures are not taken. GIS is then used to create a map that shows where and how often floods might
occur in the future, which can help (1) identify priority areas for flood-mitigation planning assistance and (2) disseminate
information to public officials and other decision-makers. 相似文献
11.
Watershed management requires integration of social and ecological understanding. Participatory approaches to planning and management incorporate stakeholder knowledge and understanding. An action research strategy using focus groups with Michigan State University operations units helped generate a soft systems model of watershed impacts of organizational decision-making regarding road de-icing. The results reveal tensions and inconsistencies between the mission and operation of the institution. These tensions are exacerbated by inadequate communication among various elements of the campus watershed management system. The action research approach facilitated the researchers understanding of the complex institutional system and helped identify possible areas for making improvements. Specifically, the researchers were able to facilitate improvement in some linkages between scientists developing campus watershed models and the operations staff responsible for handling many of the inputs being modeled. 相似文献
12.
Bruce L. Rhoads David Wilson Michael Urban Edwin E. Herricks 《Environmental management》1999,24(3):297-308
The authors' personal experience in watershed planning and decision making in the agricultural Midwest is described to illustrate
how: (1) formalization of the process of community-based management is not sufficient to guarantee that local people will
meaningfully consider scientific information and opinion when making decisions about watersheds, and (2) genuine social interaction
between scientists and nonscientists requires a considerable investment of time and energy on the part of the scientist to
develop personal relationships with nonscientists based on trust and mutual exchange of information. This experience provides
the basis for developing a general conceptual model of the interaction between scientists and nonscientists in community-based
watershed management in the agricultural Midwest.
An important aspect of integrating science effectively into community-based decision making is the need to revise existing
concepts to accommodate place-based contexts. Stream naturalization is introduced as an alternative to stream restoration
and rehabilitation, which are viewed as inappropriate management strategies in human-dominated environments. Stream naturalization
seeks to establish sustainable, morphologically and hydraulically varied, yet dynamically stable fluvial systems that are
capable of supporting healthy, biologically diverse aquatic ecosystems. This general goal is consistent with the types of
stream-management practices emerging from community-based decision making in human-dominated, agricultural landscapes. Further
research on the linkages between geomorphological and ecological dynamics of human-modified agricultural streams over multiple
spatial and temporal scales is needed to provide a sound scientific framework for stream naturalization. 相似文献
13.
In this study, an interval-based regret-analysis (IBRA) model is developed for supporting long-term planning of municipal solid waste (MSW) management activities in the City of Changchun, the capital of Jilin Province, China. The developed IBRA model incorporates approaches of interval–parameter programming (IPP) and minimax–regret (MMR) analysis within an integer programming framework, such that uncertainties expressed as both interval values and random variables can be reflected. The IBRA can account for economic consequences under all possible scenarios associated with different system costs and risk levels without making assumptions on probabilistic distributions for random variables. A regret matrix with interval elements is generated based on a matrix of interval system costs, such that desired decision alternatives can be identified according to the interval minimax regret (IMMR) criterion. The results indicate that reasonable solutions have been generated. They can help decision makers identify the desired alternatives regarding long-term MSW management with a compromise between minimized system cost and minimized system-failure risk. 相似文献
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15.
Parametric (propagation for normal error estimates) and nonparametric methods (bootstrap and enumeration of combinations)
to assess the uncertainty in calculated rates of nitrogen loading were compared, based on the propagation of uncertainty observed
in the variables used in the calculation. In addition, since such calculations are often based on literature surveys rather
than random replicate measurements for the site in question, error propagation was also compared using the uncertainty of
the sampled population (e.g., standard deviation) as well as the uncertainty of the mean (e.g., standard error of the mean).
Calculations for the predicted nitrogen loading to a shallow estuary (Waquoit Bay, MA) were used as an example. The previously
estimated mean loading from the watershed (5,400 ha) to Waquoit Bay (600 ha) was 23,000 kg N yr−1. The mode of a nonparametric estimate of the probability distribution differed dramatically, equaling only 70% of this mean.
Repeated observations were available for only 8 of the 16 variables used in our calculation. We estimated uncertainty in model
predictions by treating these as sample replicates. Parametric and nonparametric estimates of the standard error of the mean
loading rate were 12–14%. However, since the available data include site-to-site variability, as is often the case, standard
error may be an inappropriate measure of confidence. The standard deviations were around 38% of the loading rate. Further,
95% confidence intervals differed between the nonparametric and parametric methods, with those of the nonparametric method
arranged asymmetrically around the predicted loading rate. The disparity in magnitude and symmetry of calculated confidence
limits argue for careful consideration of the nature of the uncertainty of variables used in chained calculations. This analysis
also suggests that a nonparametric method of calculating loading rates using most frequently observed values for variables
used in loading calculations may be more appropriate than using mean values. These findings reinforce the importance of including
assessment of uncertainty when evaluating nutrient loading rates in research and planning. Risk assessment, which may need
to consider relative probability of extreme events in worst-case scenarios, will be in serious error using normal estimates,
or even the nonparametric bootstrap. A method such as our enumeration of combinations produces a more reliable distribution
of risk. 相似文献
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17.
Michaels S 《Environmental management》2001,27(1):27-35
Initiatives in the Neponset, Ipswich, and Sudbury-Assabet-Concord watersheds highlight how watershed-scale innovation in engaging
nongovernment participants is influenced, but not dominated, by the statewide program, the Massachusetts Watershed Initiative.
The presence or absence of three elements—external support, process, and issue—and the order in which they occur, shape the
viability of collaborative watershed-scale management initiatives. External support includes providing personnel or funding
from outside an initiative. Process is the interaction among individuals undertaking watershed-wide policy development and/or
implementation. An issue is an attention-requiring concern, vital to a watershed, that can most effectively be addressed by
a coordinated strategy among different parties. A process generated by an issue is sustainable and amenable to enhancement
through external support. The contribution of external support is most apparent when outside assistance is provided after
an issue has crystallized into clear problem needs that can be addressed through specific research projects or implementation
activities. Process is central in shaping issues, utilizing external support, and generating management results. The outcomes
of voluntary processes in the three watershed initiatives highlight how the evolution of the Massachusetts Watershed Initiative
leads to, and depends upon, the development of watershed-scale initiatives. 相似文献
18.
/ Geographic information systems (GIS) allow users to explore possible spatial relations that may exist within their data. At the Missouri Department of Conservation (MDC), GIS data is being used to help make management decisions. Thirteen geographic data layers of the Meramec River Basin, Missouri, were used to help demonstrate the usefulness of GIS for making fisheries management decisions. The data were used to help identify potential acquisition areas within the Meramec River Basin. The basin was separated into 22 strata based on ecoregion boundaries, watershed boundaries, and stream order. Suitability for acquisition was determined for each stratum based on species richness, habitat characteristics, percent of public land, and number of human impacts, such as gravel and ore mining. Eleven strata scored high enough to be recommended as potential acquisition areas. After further evaluation of the 11 strata, three were chosen as areas where available land and willing sellers should be considered. Four strata needed more sampling before land within them should be considered for acquisition. The final four were considered low priority because there was already a considerable amount of public land present in the strata. The analysis was helpful in allowing managers to focus in on a smaller area for acquisition consideration; 91% of the area was eliminated from the analysis. Instead of having to survey every parcel of land that becomes available, parcels that don't fall within the recommended strata can be eliminated without further investigation. 相似文献
19.
Employing in-depth, elite interviews, this empirical research contributes to understanding the dynamics among policy windows,
policy change, and organizational learning. First, although much of the research on agenda setting—how issues attract enough
attention that action is taken to address them—has been conducted at the national scale, this work explores the subnational,
regional scale. With decentralization, regional-scale environmental decision-making has become increasingly important. Second,
this research highlights the role of policy windows and instances of related organizational learning identified by natural
resources managers. Having practitioners identify focusing events contrasts with the more typical approach of the researcher
identifying a particular focusing event or events to investigate. A focusing event is a sudden, exceptional experience that,
because of how it leads to harm or exposes the prospect for great devastation, is perceived as the impetus for policy change. 相似文献
20.
Grassroots watershed associations have formed as an avenue to facilitate public involvement in protecting watersheds. Growth in the number of watershed associations has created a need to evaluate whether their existence enhances environmental protection by local communities. In this research, environmental protection was measured by the number of watershed protection activities conducted and amount of funding directed towards protecting surface waters by non-profit, volunteer organizations. Regression models were utilized to examine the influence of population demographic and watershed characteristics variables to explain the formation of watershed associations along with watershed protection activities and funding. Regression results showed that the presence of watershed associations had positive impacts on both the number of activities and financial resources acquired. The results confirm that watershed associations enhance the ability of communities to obtain funding and to implement watershed protection actions. Thus, watershed associations serve as an effective institution for promoting environmental protection. 相似文献