We compared different sources of land use/land cover data using the percentages of forest, agriculture, urban, and mined lands in approximately 400 watersheds of the U.S. Mid-Atlantic region. The primary data sources were digital Land Use/Land Cover maps (LULQ from the U.S. Geological Survey (USGS) and data derived from Landsat Thematic Mapper (TM) imagery obtained by the Multi-Resolution Land Characteristics (MRLQ Consortium and interpreted at the Earth Resources Observation Systems (EROS) Data Center (version 2). The latter is referred to as MRLC-TM. We also used aerial photographs (AP), topographic maps, field comments, and qualitative watershed assessments as ancillary information. The LULC and MRLC-TM data differed in age, source material, classifications, format (vector vs. raster), and resolution. However, Pearson correlation coefficients between LULC and MRLC-TM were high for broad (composite) forest, agriculture, and urban categories (0.95, 0.96, and 0.92, respectively). Correspondence varied by forest type and by percentage. Where deciduous forests comprised less than 50% of the watershed, MRLCTM data depicted greater amounts than did LULC, while the reverse was true where deciduous forests were dominant Agriculture and forest percentages were inversely related in all cases. Urban land percentages were consistently lower for MRLC-TM than LULC. Relatively few watersheds contained strip mines, quarries, or gravel pits and the MRLC-TM vs. LULC relationship was weak (correlation coefficient = 0.41). Detection of reclaimed mines seemed problematic for LULC and MRLC-TM, but these were readily discerned on AP. A single “snapshot” of land cover data will inadequately characterize a watershed if rapid landscape changes occur (e.g., forest clearcuts). Each data type has strengths and weaknesses, depending on a study's objectives, but individual limitations may be alleviated by using multiple data sources.

Freshwater in the United Kingdom constitutes a typical example of a supposedly abundant resource for which no system of sustainable use and management has been planned in the past Indeed, as H. Cook (The Protection and Conservation of Water Resources: A British Perspective, 1998) has shown, it has been a neglected area of concern compared with other areas of public policy. Recent droughts, problems of water pollution caused by excessive levels of nitrate and pesticides in groundwater, and acidification and pollution by heavy metals, as well as freshwater wildlife at risk, constitute important environmental problems. The management of water needs guidance, and this guidance needs to be very strongly ecologically based. However, this ecological information must also be integrated at the economic-policy level if water resources, which are fundamental for the survival of ecosystems, economies, and humans, are to be managed in a sustainable way in the long run. This paper presents a policy framework that is based on the reform of national accounts heavily relied on by policy makers, that uses “indicators of sustainability” (more and more viewed as the practical solution to operationalize the concept of sustainability), and that is oriented towards the pursuit of economic goals while respecting ecological constraints (“sustainability standards”). It is hoped that the construction of such a framework, based on the review of existing literature, can be a useful contribution to the sustainable management of water resources.

Leaking underground storage tanks present threats to groundwater, aquatic resources, and drinking water quality. Beyond that, however, migrating contaminants present a range of threats to residential, commercial, and industrial structures as vapors move through soils and accumulate indoors. The most severe vapor impact threats are explosion and fire. A less dramatic effect is diminished health due to reduced air quality. This study is a preliminary analysis of the geophysical site characteristics that contribute to vapor impacts in Texas. Bivariate analysis is used to evaluate the strength of prediction of vapor impacts using soil characteristics, groundwater depth, distances to impacted structures, presence of free products, and rainfall amounts. Analysis indicates that tanks leaking gasoline products that phase separate in clayey soils with shallow water tables and that are near structures are more likely to generate vapor impacts after a heavy rain.

In our modern society, waste has become a necessary evil. And like sewage treatment, waste removal costs money. Fortunately, some waste materials are recycled. This paper identifies the economic value of removing and recycling waste materials. A statelevel model was developed, using Michigan data for the demonstration case. Specific volumes of some 14 major components of the waste stream as well as nine separate high-value recycled commodities were identified. Monetary values were derived for total waste removal and the high-value recycled materials. Michigan's waste stream was found to have an economic value of $1.73 billion per year, which equals $180/person/year. Of this total, municipal waste collection accounted for $1.07 billion per year and the high-value recycled materials accounted for the other $0.65 billion.