MAPPING HYDROLOGIC UNITS FOR THE NATIONAL WATERSHED BOUNDARY DATASET1

ABSTRACT: In 2002, Wyoming became the first state to complete development of a statewide 1:24,000‐scale Watershed Boundary Dataset (WBD) under the new Federal Standards for Delineation of Hydrologic Unit Boundaries. The product was developed through the coordinated efforts of numerous state, federal, and local entities both within Wyoming and in neighboring states. Development of a comprehensive, standardized hydrologic unit boundary dataset in a “headwaters” state such as Wyoming poses a number of unique challenges. This paper details the WBD's development in Wyoming, highlighting technical methodology development and interagency coordination strategies. Evolution of the WBD standard is reviewed, addressing inconsistencies between definitions for hydro‐logic units and “true” watershed delineations. While automated methods are improving, manual and semi‐automated techniques continue to serve as valuable approaches to hydrologic unit boundary delineation given the quality of digital terrain models and the multijurisdictional nature of watershed based management. This case study provides insight on future development and maintenance of the WBD within and across other states and regions of the country and on opportunities for linking the WBD to related water resource geospatial data products like the National Hydrography Dataset.     

Modelling soil series data to facilitate targeted habitat restoration: a polytomous logistic regression approach

Habitat restoration at a landscape scale is becoming increasingly important in environmental management. In this context, geographical information systems are well suited as they can store and integrate many of the abiotic and biotic criteria used to assess the ecological worth of a site. However, this capacity can be limited by the availability or suitability of spatial data sets. A classic example of the latter case is the National Soil Map of England and Wales, which groups soils of a varied nature into associations. Consequently the national soil map has proved to be a poor predictor of habitat suitability. Using polytomous logistic regression we put forward a method for separating soil associations into their constituent soils within the Chilterns Natural Area. This approach used soil association, aspect, slope and relative height as variables for this analysis. Whilst the model's performance is likely to have been limited by the accuracy of the soil association data set, a predictive accuracy of between 47 and 65% is sufficient to facilitate better targeting of habitat restoration when combined with other abiotic factors such as climate and topography.     

Toxic risk of surface water pollution--six years of experience

Assessment of an ecological quality of surface water is necessary for effective protection, abatement and successive revitalisation of river ecosystems. This quality is primarily given by biological impact of surface water pollution. Substances contained in pollution are frequently toxic to aquatic organisms. Risk of chronic impact of surface water pollution is very often underestimated due to hidden long time action of pollutants. Proper estimation of the risk is not possible from results of chemical analyses and data of substances' toxicity. Chemical analyses are not able to detect all substances presented in water including the products of reactions between them. In addition, a simultaneous presence of substances can modify their final effect on aquatic organisms. Therefore, a complex method of assessment of toxic risk of surface water pollution based on ecotoxicological approach was developed. The toxic risk of surface water pollution is determined from results of evaluation of toxic risk of organic part and inorganic part of surface water pollution. Resultant degree of toxic risk of total pollution is given by the highest degree detected in any part of the water pollution. Presented method, which is routinely used for monitoring in the Czech part of the Odra river basin, was fully standardised and published in the form of the Czech branch technical norm of water management (TNV) in the year 2000.     

Importance of public relations in recycling strategies: principles and case studies

The separate collection of waste, and especially of recyclables with specific collection systems, would not be possible without the involvement of the users. Apart from the physical installations such as collection containers, collection points, etc., the motivation of the users is an essential component. Motivation can be reinforced through public relations work. In addition to the underlying technical considerations, this paper describes the difference between communication in general and public relations and specifically examines public involvement in recycling. Through the use of examples, we look at the targeted users and typical media employed. Furthermore, we analyzes the development of public involvement. The examples show that public relations for recycling strategies relies to a great extent on attitudes, habits, and access to the target group. Thus, standardized procedures cannot be developed. For these reasons, public relation activities must be planned carefully and professionally and include an analysis of the target group, choice of media, and verification of success.     

复合系统的协调与可持续发展

本文从“生态—社会—经济”复合系统协调的角度探讨可持续发展问题,提出了复合系统定义下可持续发展的系统观点及系统特征,建立了概念模型,根据协调理论,分析了可持续发展的系统协调原则及内容     

长江经济带建设的可持续发展研究

９０年代以来长江沿江地区经济发展速度明显加快,为实现其快速协调发展,须大力发展外向型经济。中快中上游开发开放促进区域经济合作,借鉴国外大河开发经验进行统一规划和建设。构筑上中下注重协调发展的农业支持系统,挖掘土地生产潜力,建设农业生产基地。     

Conceptual Design of a System for Selecting Appropriate Groundwater Models in Groundwater Protection Programs

/ An effective groundwater protection program requires understanding of water flow and contaminant transport processes in the subsurface. Although many mathematical models have been developed to simulate the processes, few actually are used in groundwater protection programs due to the difficulties in data collection, model selection, and model implementation. This study presents a conceptual design of a GIS-supported model selection system that evaluates available data and mathematical models to facilitate groundwater protection programs. Steady-state groundwater and contaminant transport models applied in isotropic aquifers are placed into four classes to simulate conservative or nonconservative contaminant transports in simple or complex geohydrological conditions. After analyzing specific study objectives, available data, and model requirements, the proposed system selects a class of models that can be used in simulation and recommends any need for additional data collection. This study initiates an effort to integrate GIS, mathematical models, and expert knowledge in one system to promote the application of appropriate groundwater models. The new technology of GIS and digital data-base management makes it possible to develop such a system in practice.KEY WORDS: Groundwater models; Geographic information systems     

WATERSHEDSS: A DECISION SUPPORT SYSTEM FOR WATERSHED-SCALE NONPOINT SOURCE WATER QUALITY PROBLEMS1

ABSTRACT: A significant portion of all pollutants entering surface waters (streams, lakes, estuaries, and wetlands) derives from non-point source (NPS) pollution and, in particular, agricultural activities. The first step in restoring a water resource is to focus on the primary water quality problem in the watershed. The most appropriate NPS control measures, which include best management practices (BMPs) and landscape features, such as wetlands and riparian areas, can then be selected and positioned to minimize or mitigate the identified pollutant(s). A computer-based decision sup. port and educational software system, WATERSHEDSS (WATER, Soil, and Hydro-Environmental Decision Support System), has been developed to aid managers in defining their water quality problems and selecting appropriate NPS control measures. The three primary objectives of WATERSHEDSS are (1) to transfer water quality and land treatment information to watershed managers in order to assist them with appropriate land management/land treatment decisions; (2) to assess NPS pollution in a watershed based on user-supplied information and decisions; and (3) to evaluate, through geographical information systems-assisted modeling, the water quality effects of alternative land treatment scenarios. WATERSHEDSS is available on the World Wide Web (Web) at http://h2osparc.wq.ncsu.edu .     

Effects of forest clearcutting in New England on stream macroinvertebrates and periphyton

Clearcutting may alter stream biota by changing light, temperature, nutrients, sediment particle size, or food in the stream. We sampled macroinvertebrates during late summer of 1979 in first and second order headwater streams draining both two- and three-year-old clearcuts and nearby uncut reference areas in northern New England, USA. Periphyton were sampled throughout the summer by placing microscope slides in these streams for 13–37 days. Periphyton cell densities on these slides following incubation were about six times higher in cutover than in reference streams. Green algae (Chlorophyceae) accounted for a higher proportion of total cell numbers in cutover than in reference streams, whereas diatoms (Bacillariophyceae) dominated the reference streams. The macroinvertebrate density in cutover streams was 2–4 times greater than that in the reference streams, but the number of taxa collected was similar in both cutover and reference streams. Higher numbers of mayflies (Ephemeroptera) and/or true flies (Diptera) in the cutover streams accounted for the differences. Because nutrient concentrations in the cutover streams were nearly the same as those in the reference streams, these differences in macroinvertebrate and periphyton densities were apparently caused by higher light levels and temperature in the streams in the clearcuts. Leaving buffer strips along streams will reduce changes in stream biology associated with clearcutting.Contribution from the Northeastern Forest Experiment Station, USDA Forest Service, Durham, New Hampshire 03824, USA.     

Acid-forming emissions in Alberta,Canada

The sulphur dioxide and nitrogen oxides emissions from all sources in Alberta, Canada, during 1982 amounted to 488,297 and 353,511 tonnes, respectively. During this year deposition of wet sulphate from all stations in the province, 8 kg ha^–1 yr^–1, compares well with the five-year average (1978–1982) value of 10 kg ha^–1 yr^–1. These measurements are about one-half of the wet sulphate deposition criteria of 20 kg ha^–1 yr^–1 established for protecting the moderately sensitive aquatic ecosystem in eastern Canada. Due to dry, cold, continental climate conditions of Alberta, dry sulphate or sulphur deposition is equally or more important than wet deposition. No effects of the long-range transport of atmospheric pollutants (LRTAP) on the ecosystems in Alberta have been observed to date. Atmospheric deposition target loadings of SO₄ ^–2, NO₃ ^–, and H⁺ for Alberta and western Canadian environmental conditions should be developed to protect the highly sensitive ecosystems. Some future research and monitoring priorities for Alberta and western Canada are outlined.