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1.
Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures. 相似文献
2.
Streamflow Depletion Modeling: Methods for an Adaptable and Conjunctive Water Management Decision Support Tool 下载免费PDF全文
Xander Huggins Tom Gleeson Hailey Eckstrand Ben Kerr 《Journal of the American Water Resources Association》2018,54(5):1024-1038
Groundwater pumping depletes streamflow, which can have significant ecological impacts depending on the magnitude of depletion relative to environmental flow needs. Streamflow depletion estimates from groundwater pumping have been quantified using both analytical and numerical methods, but are not routinely compared to environmental flow needs or used in practical water management tools. Decision support tools that incorporate groundwater dynamics are becoming increasingly necessary for water managers as groundwater regulations become more important in environmental policy, particularly concerning the preservation of environmental flow needs. We develop and apply methods for a web‐based decision support tool for conjunctive groundwater and surface water management, demonstrated using a case study watershed in British Columbia, Canada. Open‐source data are analyzed with a combination of spatial algorithms and previously developed analytical models, such that the tool can be applied to other regions. Streamflow depletion estimates are calculated in four regions in the largely undeveloped Bulkley Valley, British Columbia. Our transparent methodology has geographic and data input flexibility which is a significant improvement on currently existing water management tool methods. 相似文献
3.
Application of an Environmental Decision Support System to a Water Quality Trading Program Affected by Surface Water Diversions 总被引:3,自引:0,他引:3
Environmental decision support systems (EDSSs) are an emerging tool used to integrate the evaluation of highly complex and
interrelated physicochemical, biological, hydrological, social, and economic aspects of environmental problems. An EDSS approach
is developed to address hot-spot concerns for a water quality trading program intended to implement the total maximum daily
load (TMDL) for phosphorus in the Non-Tidal Passaic River Basin of New Jersey. Twenty-two wastewater treatment plants (WWTPs)
spread throughout the watershed are considered the major sources of phosphorus loading to the river system. Periodic surface
water diversions to a major reservoir from the confluence of two key tributaries alter the natural hydrology of the watershed
and must be considered in the development of a trading framework that ensures protection of water quality. An EDSS is applied
that enables the selection of a water quality trading framework that protects the watershed from phosphorus-induced hot spots.
The EDSS employs Simon’s (1960) three stages of the decision-making process: intelligence, design, and choice. The identification of two potential hot spots
and three diversion scenarios enables the delineation of three management areas for buying and selling of phosphorus credits
among WWTPs. The result shows that the most conservative option entails consideration of two possible diversion scenarios,
and trading between management areas is restricted accordingly. The method described here is believed to be the first application
of an EDSS to a water quality trading program that explicitly accounts for surface water diversions. 相似文献
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河流水质模型在双流县流域治理中的应用 总被引:1,自引:0,他引:1
研究利用现有的河流水质模型,构建了一个可实时模拟河流水环境质量变化状况的动态模型。模型采用一维稳态单组分水质模型对河流的CODCr、NH3-N的降解进行计算,采用多宾斯-坎普稳态模型对河流的BOD、DO变化情况进行计算。模型引入水文数据、水质监测数据、环境统计数据、社会统计公报数据,以Excel作为数据平台,可以反演出河流不同月份、不同区段的污染物降解系数。研究将该模型应用于双流县的流域治理,以在锦江双流段的应用为例进行了具体说明。根据2008年双流县河流的相关数据,研究使用该模型反演出了锦江双流段的污染物降解系数,并对其反映的流域污染状况进行了分析。随后,研究使用该模型已计算出的岷江中段河流的降解系数,模拟计算了4种情景下锦江双流段出境断面的可能水质变化,以验证拟定的双流县流域治理方案的预期效果。模型具有实用性和进一步扩展的功能。 相似文献
6.
Abstract: The sufficiency and usefulness of Effective Efficiency (EE) as a water resources index is shown through conceptual formulation of a generalized EE and practical applications. Two EE models are proposed: one is based on water quantity and the other on quantity and quality, with the possibility of considering water reuse (recycling) in both. These models were developed for two scales: the first is called Project EE and the second Basin EE. The latter gives the influence of the project on the water resources systems of the basin while the former does not make such connection to the whole basin. Such considerations give proper signals as to the adequacy of any intervention to increase efficiency. A crucial distinction is made between depletion and diversion water savings. Classical Efficiency (CE) models are analyzed and compared with the various EE models. CE results in values that are less than EE because of not considering water reuse and water quality in its calculation. Some authors, pointing to these problems – particularly the first problem – have advocated the use of hydrological “fractions” instead of efficiency concepts. This paper defends the use of a proper efficiency model such as EE and suggests putting an end to the use of the CE indicators. To test the models, they are applied to five cases of irrigation and city water use in the United States and Egypt. The analysis of the results demonstrates all the points mentioned above and the potential of the EE models to adequately describe the water resources efficiency and sustainability at a location. 相似文献
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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
9.
Stephen S. Warrner Robert U. Fischer Ann M. Holtrop Leon C. Hinz Jr. James M. Novak 《Environmental management》2010,46(5):761-770
Stream habitat assessments are conducted to evaluate biological potential, determine anthropogenic impacts, and guide restoration
projects. Utilizing these procedures, managers must first select a representative stream reach, which is typically selected
based on several criteria. To develop a consistent and unbiased procedure for choosing sampling locations, the Illinois Department
of Natural Resources and the Illinois Natural History Survey have proposed a technique by which watersheds are divided into
homogeneous stream segments called valley segments. Valley segments are determined by GIS parameters including surficial geology,
predicted flow, slope, and drainage area. To date, no research has been conducted to determine if the stream habitat within
a valley segment is homogeneous and if different valley segments have varying habitat variables. Two abutting valley segments
were randomly selected within 13 streams in the Embarras River watershed, located in east-central Illinois. One hundred meter
reaches were randomly selected within each valley segment, and a transect method was used to quantify habitat characteristics
of the stream channel. Habitat variables for each stream were combined through a principal components analysis (PCA) to measure
environmental variation between abutting valley segments. A multivariate analysis of variance (MANOVA) was performed on PCA
axes 1–3. The majority of abutting valley segments were significantly different from each other indicating that habitat variability
within each valley segment was less than variability between valley segments (5.37 ≤ F ≤ 245.13; P ≤ 0.002). This comparison supports the use of the valley segment model as an effective management tool for identifying representative
sampling locations and extrapolating reach-specific information. 相似文献
10.
水质报表是水环境监测领域内系统的重要组成部分,为加快水质报表的开发,增强水质报表的可维护性,设计独立于系统并且符合水质报表特性的报表工具。该报表工具分为报表设计器和报表服务器两部分,设计器提供可视化的报表编辑界面,允许用户自己设计报表函数,服务器负责报表的调用和解析并且采用缓存机制提高报表的运行效率,将该报表工具应用于水质环境监测及分析系统以验证其实用性,结果证明,该水质报表工具具有较高的灵活性和可扩展性。 相似文献
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Degradation Model: A Quantitative EIA Instrument,Acting as a Decision Support System (DSS) for Environmental Management 总被引:1,自引:0,他引:1
Makhdoum MF 《Environmental management》2002,30(1):151-156
Environmental assessment of alternative development plans, programs, and policies may bring conflict among decision-makers,
particularly when some quantitative measures for decision-making are needed and where cumulative impacts are neglected. Environmental
impact assessment (EIA) and environmental economics theories, despite their usefulness, are not capable of addressing those
issues and problems alone. In recent years, the decision support system (DSS) has provided some solutions, but mathematical
analysis of the system to show the internal structure of the problem is not always possible.
To addres the above shortcomings and ongoing problems of decision-making in Iran, a degradation model (DM) was introduced
as an instrument of EIA, to act as a DSS for managers. The model is a compromise between knowledge-based decision support
systems, detailed models, digested information models, and the basic theorem of environmental economics. In the present study
(1996–2000), the model was applied in three provinces of Iran, representing three of four biogeographical regions of Iran.
The study area was divided into a set of grids (100 km2). The degradation coefficient (H) was computed for all grids (1333), representing the degree of degradation in the grid. It is obvious that the higher the
coefficient the more area is degraded and less prone to further development, and vice versa. In order to provide decision-makers
with a set of quantitative measures to observe impacted areas (critical and noncritical) for resource allocation and further
development, the degradation coefficients of all grids were classified into categories and criteria, using a fuzzy set theoretic
approach. Accordingly, only 24% of study areas are prone to further development. The degradation model as a knowledge-based
decision support system has its strengths and weaknesses, but it has solved managers' ongoing problems in Iran and it could
be used elsewhere. 相似文献
13.
T. J. Foxon G. Mcilkenny D. Gilmour C. Oltean-Dumbrava N. Souter R. Ashley 《Journal of Environmental Planning and Management》2002,45(2):285-301
The incorporation of sustainability assessment into decision-making processes is a key task for water service providers in the UK and elsewhere. This paper describes the development and application of a set of sustainability criteria, which have been developed and tested with project partners in the UK and Romania. They will be used in a 'guidebook' that will set out a framework to facilitate the inclusion of sustainability in the decision-making process. This work is part of the Sustainable Water Industry Asset Resource Decisions project to develop a multi-criteria analysis decision support system to assist water service providers to assess the relative sustainability of water/wastewater system asset development decisions. 相似文献
14.
A weakness often found in conventional environmental management tools is that of treating the dynamics of environmental effects and the underlying dynamics of structural change as external factors, precluding their ability to capture the evolutionary behaviour which characterizes economic systems. This article suggests a spatial dynamic modelling framework which addresses explicitly complex sectorial linkages and their environmental effects. The economic dynamics of the model are given spatial reference by means of a set of sector-based suitabilities, which allows us to explore both local environmental degradation effects as they unfold, and how these impacts then affect the economic productivity of the system as a whole. The approach is illustrated by calibrating the model with 1971-1981 data for the island of Crete, and then running it to explore how the economic dynamics of the island might evolve to the year 2001. This article presents a means through which to endogenize the environment and its explicit linkages with sectorial economic dynamics which can be of considerable use to environmental management in all its dimensions. 相似文献
15.
《Journal of environmental management》1996,47(1):11-26
In this work on the management of water quality in a river basin by means of multiobjective programming, the programming model consists of three objectives that include simultaneously both economic and environmental factors. These objectives are the water quality of the rivers, the cost of wastewater treatment and the assimilative capacity of the rivers. In particular, this research is the first to take into account the last objective. For practical application, this paper proposes two methods of multiobjective programming, the constraint method and the step method. Furthermore, to illustrate the application of these techniques to water quality management problems, we use the basin of Tzeng-Wen River, Taiwan, as a case study. The results show that these methods work satisfactorily to improve the water quality, to ascertain the economic cost of wastewater treatment, and to allocate allowable loading in a manner of equality from non-inferior solutions. Alternatively, these methods provide important information for regulatory agencies to implement pollution control of river water. 相似文献
16.
This article presents the design of a fuzzy decision support system (DSS) for the assessment of alternative strategies proposed for the restoration of Lake Koronia, Greece. Fuzzy estimates for the critical characteristics of the possible strategies, such as feasibility, environmental impact, implementation time, and costs are evaluated and supplied to the fuzzy DSS. Different weighting factors are assigned to the critical characteristics and the proposed strategies are ordered with respect to the system responses. The best strategies are selected and their expected impact on the ecosystem is evaluated with the aid of a fuzzy model of the lake. Sensitivity analysis and simulation results have shown that the proposed fuzzy DSS can serve as a valuable tool for the selection and evaluation of appropriate management actions.
Note: This version was published online in June 2005 with the cover date of August 2004. 相似文献
17.
Xixi Wang Assefa M. Melesse Michael E. McClain Wanhong Yang 《Journal of the American Water Resources Association》2007,43(6):1383-1399
Abstract: Coalbed methane (CBM) development raises serious environmental concerns. In response, concerted efforts have been made to collect chemistry, salinity, and sodicity data on CBM produced water. However, little information on changes of stream water quality resulting from directly and/or indirectly received CBM produced water is available in the literature. The objective of this study was to examine changes instream water quality, particularly sodicity and salinity, due to CBM development in the Powder River watershed, which is located in the Rocky Mountain Region and traverses the states of Wyoming and Montana. To this end, a retrospective analysis of water quality trends and patterns was conducted using data collected from as early as 1946 up to and including 2002 at four U.S. Geological Survey gauging stations along the Powder River. Trend analysis was conducted using linear regression and Seasonal Kendall tests, whereas, Tukey’s test for multiple comparisons was used to detect changes in the spatial pattern. The results indicated that the CBM development adversely affected the water quality in the Powder River. First, the development elevated the stream sodicity, as indicated by a significant increase trend of the sodium adsorption ratio. Second, the development tended to shrink the water quality differences among the three downstream stations but to widen the differences between these stations and the farthest upstream station. In contrast, the development had only a minor influence on stream salinity, as indicated by that the stream electrical conductivity exhibited either no trend or a marginally significant positive trend. Hence, the CBM development is likely an important factor that can be managed to lower the stream sodicity. The management may need to take into account that the effects of the CBM development were different from one location to another along the Powder River. 相似文献
18.
根据2002~2008年合水水库及宁江兴南桥站位的实测资料,分析兴宁饮水源保护区及宁江的水质变化特点,并讨论影响富营养现象及锰等微量元素个别时间超标的原因;根据水质变化特点,提出保洁治理的方法,为梅州"以人为本"的和谐社会服务。 相似文献
19.
The decision-making environment in forest management (FM) has changed drastically during the last decades. Forest management
planning is facing increasing complexity due to a widening portfolio of forest goods and services, a societal demand for a
rational, transparent decision process and rising uncertainties concerning future environmental conditions (e.g., climate
change). Methodological responses to these challenges include an intensified use of ecosystem models to provide an enriched,
quantitative information base for FM planning. Furthermore, multi-criteria methods are increasingly used to amalgamate information,
preferences, expert judgments and value expressions, in support of the participatory and communicative dimensions of modern
forestry. Although the potential of combining these two approaches has been demonstrated in a number of studies, methodological
aspects in interfacing forest ecosystem models (FEM) and multi-criteria decision analysis (MCDA) are scarcely addressed explicitly.
In this contribution we review the state of the art in FEM and MCDA in the context of FM planning and highlight some of the
crucial issues when combining ecosystem and preference modeling. We discuss issues and requirements in selecting approaches
suitable for supporting FM planning problems from the growing body of FEM and MCDA concepts. We furthermore identify two major
challenges in a harmonized application of FEM-MCDA: (i) the design and implementation of an indicator-based analysis framework
capturing ecological and social aspects and their interactions relevant for the decision process, and (ii) holistic information
management that supports consistent use of different information sources, provides meta-information as well as information
on uncertainties throughout the planning process. 相似文献