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1.
ABSTRACT: Making decisions for environmental management is a complex task due to the multiplicity and diversity of technological choices. Furthermore, the exploitation of natural resources and the preservation of the natural environment imply objectives that are often in conflict within a sustainable development paradigm. Managers and other decision makers require techniques to assist them in understanding strategic decision making. This paper illustrates the use of a multiple‐objective decision‐making methodology and an integrative geographical information system‐based decision‐making tool developed to help watershed councils prioritize and evaluate restoration activities at the watershed level. Both were developed through a multidisciplinary approach. The decision‐making tool is being applied in two watersheds of Oregon's Willamette River Basin. The results suggest that multiple‐objective methods can provide a valuable tool in analyzing complex watershed management issues.  相似文献   

2.
In conjunction with socioeconomic development in watersheds, increasingly challenging problems, such as scarcity of water resources and environmental deterioration, have arisen. Watershed management is a useful tool for dealing with these issues and maintaining sustainable development at the watershed scale. The complex and uncertain characteristics of watershed systems have a great impact on decisions about countermeasures and other techniques that will be applied in the future. An optimization method based on scenario analysis is proposed in this paper as a means of handling watershed management under uncertainty. This method integrates system analysis, forecast methods, and scenario analysis, as well as the contributions of stakeholders and experts, into a comprehensive framework. The proposed method comprises four steps: system analyses, a listing of potential engineering techniques and countermeasures, scenario analyses, and the optimal selection of countermeasures and engineering techniques. The proposed method was applied to the case of the Lake Qionghai watershed in southwestern China, and the results are reported in this paper. This case study demonstrates that the proposed method can be used to deal efficiently with uncertainties at the watershed level. Moreover, this method takes into consideration the interests of different groups, which is crucial for successful watershed management. In particular, social, economic, environmental, and resource systems are all considered in order to improve the applicability of the method. In short, the optimization method based on scenario analysis proposed here is a valuable tool for watershed management.  相似文献   

3.
以日本琵琶湖流域东北部净化中心为例,介绍了日本琵琶湖流域市政污水处理概况,重点阐述了以投加絮凝剂的多段硝化脱氮法为核心生物工艺的"超深度"处理技术和以"焚烧—熔融"为核心工艺的污泥资源化处置技术,为我国市政污水的深度处理和污泥处置提供了技术和发展借鉴。  相似文献   

4.
A watershed management framework for mountain areas is based on lessons learned from watershed management experience, social and institutional learning, and the use of a watershed management program evaluation in Nepal. The lessons led to the adoption of a subwatershed-based ecosystem approach based on local participation at the subwatershed level. An integrated watershed management framework (IWMF) consisting of eight steps with three checklists was developed focusing on improvement-oriented adaptive management. The eight steps lead to the preparation of a watershed management plan. In the process three checklists are used. While the first checklist has general questions pertaining to watershed analysis, the second allows participation analysis of stakeholders in terms of their strengths, weaknesses, opportunities and threats and opens up new prospects for further reinforcing or building new user group institutions based on consensus. The final checklist consists of hierarchical watershed management objectives, including goals, results and activities leading to a program planning matrix. The framework was applied to watershed planning in the Chure Region to compare the framework-based planning with conventional planning procedures. A significant difference in quality and substance of the output, with and without the use of the framework, suggests that an integrated framework is a useful tool for an ecosystem-based approach to natural resource management and socio-technical conservation.  相似文献   

5.
Abstract: Information on the nature and relative contribution of different watershed sediment sources is recognized as a key requirement in the design and implementation of targeted management strategies for sediment control. A direct method of assessing sediment sources in a watershed that has attracted attention in recent years is sediment fingerprinting. The aim of this article is to describe the development of sediment fingerprinting as a research tool and to consider how the method might be transformed from a research tool to a management tool within a regulatory framework, with special reference to the United States total maximum daily load (TMDL) program. When compared with the current source assessment tools in developing sediment TMDLs, sediment fingerprinting offers considerable improvement as a tool for quantifying sources of sediment in terms of source type (e.g., channel vs. hillslope) as well as spatial location (subwatershed). While developing a conceptual framework for sediment TMDLs, we recognize sediment fingerprinting along with sediment budgeting and modeling as valuable tools in the TMDL process for developing justifiable sediment TMDLs. The discussions presented in this article may be considered as a first step toward streamlining the sediment fingerprinting approach for its wider application in a regulatory framework.  相似文献   

6.
ABSTRACT: Significant land cover changes have occurred in the watersheds that contribute runoff to the upper San Pedro River in Sonora, Mexico, and southeast Arizona. These changes, observed using a series of remotely sensed images taken in the 1970s, 1980s, and 1990s, have been implicated in the alteration of the basin hydrologic response. The Cannonsville subwatershed, located in the Catskill/Delaware watershed complex that delivers water to New York City, provides a contrast in land cover change. In this region, the Cannonsville watershed condition has improved over a comparable time period. A landscape assessment tool using a geographic information system (GIS) has been developed that automates the parameterization of the Soil and Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS) hydrologic models. The Automated Geospatial Watershed Assessment (AGWA) tool was used to prepare parameter input files for the Upper San Pedro Basin, a subwatershed within the San Pedro undergoing significant changes, and the Cannonsville watershed using historical land cover data. Runoff and sediment yield were simulated using these models. In the Cannonsville watershed, land cover change had a beneficial impact on modeled watershed response due to the transition from agriculture to forest land cover. Simulation results for the San Pedro indicate that increasing urban and agricultural areas and the simultaneous invasion of woody plants and decline of grasslands resulted in increased annual and event runoff volumes, flashier flood response, and decreased water quality due to sediment loading. These results demonstrate the usefulness of integrating remote sensing and distributed hydrologic models through the use of GIS for assessing watershed condition and the relative impacts of land cover transitions on hydrologic response.  相似文献   

7.
Conceptual modeling is a useful tool for identifying pathways between drivers, stressors, Valued Ecosystem Components (VECs), and services that are central to understanding how an ecosystem operates. The St. Jones River watershed, DE is a complex ecosystem, and because management decisions must include ecological, social, political, and economic considerations, a conceptual model is a good tool for accommodating the full range of inputs. In 2002, a Four-Component, Level 1 conceptual model was formed for the key habitats of the St. Jones River watershed, but since the habitat level of resolution is too fine for some important watershed-scale issues we developed a functional watershed-scale model using the existing narrowed habitat-scale models. The narrowed habitat-scale conceptual models and associated matrices developed by Reiter et al. (2006) were combined with data from the 2002 land use/land cover (LULC) GIS-based maps of Kent County in Delaware to assemble a diagrammatic and numerical watershed-scale conceptual model incorporating the calculated weight of each habitat within the watershed. The numerical component of the assembled watershed model was subsequently subjected to the same Monte Carlo narrowing methodology used for the habitat versions to refine the diagrammatic component of the watershed-scale model. The narrowed numerical representation of the model was used to generate forecasts for changes in the parameters “Agriculture” and “Forest”, showing that land use changes in these habitats propagated through the results of the model by the weighting factor. Also, the narrowed watershed-scale conceptual model identified some key parameters upon which to focus research attention and management decisions at the watershed scale. The forecast and simulation results seemed to indicate that the watershed-scale conceptual model does lead to different conclusions than the habitat-scale conceptual models for some issues at the larger watershed scale.  相似文献   

8.
9.
Abstract: The main objective of the study is to examine the accuracy of and differences among simulated streamflows driven by rainfall estimates from a network of 22 rain gauges spread over a 2,170 km2 watershed, NEXRAD Stage III radar data, and Tropical Rainfall Measuring Mission (TRMM) 3B42 satellite data. The Gridded Surface Subsurface Hydrologic Analysis (GSSHA), a physically based, distributed parameter, grid‐structured, hydrologic model, was used to simulate the June‐2002 flooding event in the Upper Guadalupe River watershed in south central Texas. There were significant differences between the rainfall fields estimated by the three types of measurement technologies. These differences resulted in even larger differences in the simulated hydrologic response of the watershed. In general, simulations driven by radar rainfall yielded better results than those driven by satellite or rain‐gauge estimates. This study also presents an overview of effects of land cover changes on runoff and stream discharge. The results demonstrate that, for major rainfall events similar to the 2002 event, the effect of urbanization on the watershed in the past two decades would not have made any significant effect on the hydrologic response. The effect of urbanization on the hydrologic response increases as the size of the rainfall event decreases.  相似文献   

10.
In the recent past, the Sepetiba Bay watershed, located in the Rio de Janeiro State, Brazil has experienced rapid industrial development and population growth, as well as an increase in water pollution and environmental degradation. To analyze the complex interrelationships among the agents affecting the Sepetibza Bay environment, a system dynamics model was developed. The model builds on extensive studies conducted for the watershed, and simulates different hypotheses of economic growth and of demographic expansion. Thus, it can be used as a decision support tool for the identification of investment priorities and policy analyses under various scenarios. In order to provide a comprehensive approach to the environmental management of the Sepetiba Bay watershed, the model had to consider only the most relevant aspects of the behavior and the key interactions among agents operating in the watershed. In this article, the model’s structure is presented together with some of its main results.  相似文献   

11.
ABSTRACT: The objective of water quality/watershed management is attainment of water quality goals specified by the Clean Water Act. The Total Maximal Daily Load (TMDL) planning process is a tool to set up watershed management. However, TMDL methodologies and concepts have several problems, including determination of Loading Capacity for only low flow critical periods that preclude consideration of wet weather sources in water quality management. Research is needed to develop watershed pollutant loading and receiving waters Loading Capacity models that will link wet and dry weather pollution loads to the probability of the exceedence of water quality standards. The long term impact of traditional Best Management Practices as well as ponds and wetlands, must be reassessed to consider long term accumulation of conservative toxic compounds. Socioeconomic research should focus on providing information on economic and social feasibility of implementation of additional controls in water quality limited watersheds.  相似文献   

12.
Watershed analysis and watershed management are developing as tools of integrated ecological and economic study. They also assist decision-making at the regional scale. The new technology and thinking offered by the advent of the Internet and the World Wide Web is highly complementary to some of the goals of watershed analysis. Services delivered by the Web are open, interactive, fast, spatially distributed, hierarchical and flexible. The Web offers the ability to display information creatively, to interact with that information and to change and modify it remotely. In this way the Internet provides a much-needed opportunity to deliver scientific findings and information to stakeholders and to link stakeholders together providing for collective decision-making. The benefits fall into two major categories: methodological and educational. Methodologically the approach furthers the watershed management concept, offering an avenue for practical implementation of watershed management principles. For educational purposes the Web is a source of data and insight serving a variety of needs at all levels. We use the Patuxent River case study to illustrate the web-based approach to watershed management. A watershed scale simulation model is built for the Patuxent area and it serves as a core for watershed management design based on web applications. It integrates the knowledge available for the Patuxent area in a comprehensive and systematic format, and provides a conceptual basis for understanding the performance of the watershed as a system. Moreover, the extensive data collection and conceptualisation required within the framework of the modeling effort stimulates close contact with the environmental management community. This is further enhanced by offering access to the modeling results and the data sets over the Web. Additional web applications and links are provided to increase awareness and involvement of stakeholders in the watershed management process. We argue that it is not the amount and quality of information that is crucial for the success of watershed management, but how well the information is disseminated, shared and used by the stakeholders. In this respect the Web offers a wealth of opportunities for the decision-making process, but still to be answered are the questions at what scale and how widely will the Web be accepted as a management tool, and how can watershed management benefit from web applications.  相似文献   

13.
ABSTRACT: The Stream Corridor Assessment survey has been developed by the Maryland Department of Natural Resources as a watershed management tool to identify environmental problems and to help prioritize restoration opportunities on a watershed basis. Potential environmental problems commonly identified during the survey include: stream channel alterations, excessive bank erosion, exposed pipes, inadequate stream buffers, fish migration blockages, trash dumping sites, near stream construction, pipe outfalls, and unusual conditions. In addition, the survey records information on the location of potential wetlands creation sites and collects data on the general condition of instream and riparian habitats. Over the past several years, in collaboration with the Maryland Conservation Corps, watershed associations, and local governments, more than 3,293 km (2,046 miles) of Maryland streams have been surveyed. Overall, the survey has proven to be a cost effective starting point for many watershed restoration efforts.  相似文献   

14.
ABSTRACT: Geographic Information Systems (GIS) are being used increasingly as a method of preparing, analyzing, and displaying data for watershed analysis and modeling. Although GIS technology is a powerful tool for integrating and analyzing watershed characteristics, the initial preparation of the necessary database is often a time consuming and costly endeavor. This demonstration project assesses the viability of creating a cost-effective spatial database for urban stormwater modeling from existing digital and hard-copy data sources. The GIS was used to provide input parameters to the Source Loading and Management Model (SLANM), an empirical urban stormwater quality model. Land use characteristics, drainage boundaries, and soils information were geocoded and referenced to a base data layer consisting of transportation features. GIS overlay and data manipulation capabilities were utilized to preprocess the input data for the model. Model output was analyzed through postprocessing by GIS, and results were compared to a similar recent modeling study of the same watershed. The project, undertaken for a small urban watershed located in Plymouth, Minnesota, successfully demonstrates that the use of GIS in stormwater management can allow even small communities to reap the benefits of stormwater quality modeling.  相似文献   

15.
ABSTRACT: SWMHMS is a conceptual computer modeling program developed to simulate monthly runoff from a small nonurban watershed. The input needed to run model simulations include daily precipitation, monthly data for evapotranspiration determination (average temperature, crop consumptive coefficients, and percent daylight hours), and six watershed parameter values. Evapotranspiration was calculated with the Blaney-Criddle equation while surface runoff was determined using the Soil Conservation Service curve number procedure. For watershed parameter evaluation, SWMHMS provides options for both optimization and sensitivity analysis. Observed runoff data are required along with the model input previously mentioned in order to conduct parameter optimization. SWMEIMS was tested with data from six watersheds located in different regions of the United States. Model accuracy was generally found to be very good except on watersheds having substantial snowfall accumulation. In having only six watershed parameters, SWMHMS is less complex to use than many other computer programs that calculate monthly runoff. Consequently, SWMHMS may find its greatest application as an educational tool for students learning principles of hydrologic modeling, such as parameter evaluation procedures and the impacts of input data uncertainty on model results.  相似文献   

16.
Abstract: The U.S. Environmental Protection Agency is charged with establishing standards and criteria for assessing lake water quality. It is, however, increasingly evident that a single set of national water quality standards that do not take into account regional hydrogeologic and ecological differences will not be viable as lakes clearly have different inherent capacities to meet such standards. We demonstrate a GIS‐based watershed classification strategy for identifying groups of Nebraska reservoirs that have similar potential capacity to attain a certain level of water quality standard. A preliminary cluster analysis of 78 reservoirs was performed to determine the potential number of Nebraska reservoir groups. Subsequently, a Classification Trees method was used to refine number of classes, describe the structure of reservoir watershed classes, and to develop a predictive model that relates watershed conditions to reservoir classes. Results suggest that Nebraska reservoirs can be represented by nine classes and that soil organic matter content in the watershed is the most important single variable for segregating the reservoirs. The cross‐validation prediction error rate of the Classification Tree model was 26.3%. Because all geospatial data used in this work are available nationally, the method could be adopted throughout the U.S. Hence, this GIS‐based watershed classification approach could provide water resources managers an effective decision‐support tool in managing reservoir water quality.  相似文献   

17.
ABSTRACT. In urban hydrologic studies, it is often necessary to determine the effect of changes in urban land use patterns on such runoff characteristics as flood peaks and flow volumes. Nonparametric statistical methods have certain properties that make them a valuable tool for detecting hydrologic change caused by a treatment, such as urbanization, that changes watershed over a period of time. As many hydrologists do not have a working familiarity with nonparametric methods, a number of them are used for illustrative purposes to analyze the effect of urbanization on 24 years of annual flood peaks for a Louisville, Kentucky, watershed. In the example, urbanization was found to increase the central tendency, but not the dispersion of the peaks. Peak flows modeled by holding watershed parameters constant were also found to be increasing because of an upward trend in precipitation. By following the numerical examples in the paper and looking up test statistics in referenced sources, the reader can easily apply these methods to other situations.  相似文献   

18.
In this study, we used public participation geographic information systems methods to collect spatial data identifying places that stakeholders in Mobile Bay, Alabama think are important providers of watershed services. These methods allowed us to spatially analyze participatory data from general public respondents and directly compare them with other scientific data in a geographic information systems database. This study identified which places in the region participants believe are important providers of specific watershed services, including fish nurseries, storm protection, flood protection, and water quality protection, which would likely have public support for conservation. Additionally, we assessed the accuracy of participant watershed service identification using land cover data to identify inconsistencies and participant knowledge gaps. This information can be used to target outreach education efforts. We found that the accuracy with which participants correctly identified places with the necessary land cover to provide each service varied considerably. We believe this to be a useful tool for managers to elicit stakeholder input and to identify knowledge gaps regarding the provisioning of watershed services.  相似文献   

19.
20.
ABSTRACT: Pollutants entering a water system can be very destructive to the health of that system. Best Management Practices (BMPs) are used to reduce these pollutants, but understanding the most effective practices is very difficult. Watershed models are an effective tool to aid in the decision‐making process of selecting the BMPs that are most effective in reducing the pollutant loading and are also the most cost effective. The Annualized Agricultural Nonpoint Source Pollution model (AnnAGNPS 2.0) is a technological tool that can be used to estimate watershed response to agricultural management practices. The main purpose of this paper is to test the performance of AnnAGNPS 2.0 on nitrogen loading using comparisons with measurements from the Deep Hollow watershed of the Mississippi Delta Management Systems Evaluation Area (MDMSEA) project. Previous work has demonstrated the capability of the model to simulate runoff and sediment. From sensitivity analyses in this study, initial nitrogen concentration in the soil and crop nitrogen uptake had the most impact on the nitrogen loadings. AnnAGNPS simulations of monthly nitrogen loadings are poor. However, statistical test (t‐test) showed that the predicted nitrogen loading is not significantly different from observed nitrogen loading at the 95 percent level of confidence.  相似文献   

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