Mathematical models are utilized to approximate various highly complex environmental phenomena. Model parameters exerting the most influence on model results are identified through a "sensitivity analysis." A comprehensive review is presented of more than a dozen sensitivity analysis methods. (LZ)

In the research of environmental impact assessment (EIA), the problem of weight distribution for a set of parameters has not yet been properly solved. Presents an approach of objective weighting by using a procedure of Pij principal component-factor analysis (Pij PCFA), which suits specifically those parameters measured directly by physical…

In spite of rapid progress achieved in the methodological research underlying environmental impact assessment (EIA), the problem of weighting various parameters has not yet been solved. This paper presents a new approach, fuzzy clustering analysis, which is illustrated with an EIA case study on Baoshan-Wusong District in Shanghai, China. (Author)

Simplicity and efficiency in design and estimation are all important in deciding on sampling strategies. A simple model is given and illustrated for four practical situations to show how a good sampling strategy should be selected. (Author)

Describes methods of designing natural resource monitoring programs to provide indications of ecosystem health, define limits of normal variation, identify abnormal conditions, and suggest potential agent of abnormal change. (MDH)

In the direction-dependent approach to location modeling developed herein, the distance within which a point of demand can find service from a facility depends on direction of measurement. The utility of the approach is illustrated through an application to groundwater remediation. (Author/MDH)

Describes the Forest Science Data Bank that contains 2,400 data sets from over 350 existing ecological studies. Database features described include involvement of the scientific community; database documentation; data quality assurance; security; data access and retrieval; and data import/export flexibility. Appendices present the Quantitative…

Discusses the use of the human health risk assessment model as a basis for developing ecological risk assessment (ERA). For ERA, risk to individuals is less important than the survival of the population, with the exception of endangered species. Suggests that ERA take into account the relative reproductive value of the potentially impacted…

Examines the possibility of using expert system tools for environmental data management. Describes the domain-independent expert system shell SAK and Knowledge EXplorer, a system that learns rules from data. Demonstrates the functionality of Knowledge EXplorer on an example of water quality evaluation. (LZ)

Presents aids to assist the design and monitoring of natural resource systems. Defines and describes hypergeometric systems; discusses monitoriing objectives and classifies monitoring programs. (MDH)

Discusses a technique for estimating sample size that does not require an a priori definition of desired precision. Presents five modifications that make the method easier to use and reduce the probability of estimating a larger sample size than necessary. The technique can guide the design of environmental sampling programs. (Contains 31…

Provides a physical description of semivolatile organic compounds (SVOCs), both in terms of their characteristic nature in the atmosphere and the processes which control their deposition. Contains a summary of the requirements for a full assessment of atmospheric SVOCs and their deposition. (LZ)

Reviews how carrying capacity for different environmental problems is operationalized. Discusses whether it is possible to compare threats, using the exceeding of carrying capacity as a yardstick. Points out problems in comparative threat analysis using three case studies: threats to European groundwater resources, threats to ecosystems in Europe,…

Presents a general framework for designing sampling programs that ensure cost effectiveness, and managed errors kept within known and acceptable limits. (LZ)

Presents the objective and methodology chosen for the construction of a global emissions source database called EDGAR and the structural design of the database system. The database estimates on a regional and grid basis, 1990 annual emissions of greenhouse gases, and of ozone depleting compounds from all known sources. (LZ)