ALBERT

Notes: : Existing legal regimes for the management of water resources are already stressed by changing technologies and growing populations. There is little reason for doubt that today the planet is undergoing significant and even alarming climate change. In the past such global climatic changes had dramatic effects on water resource availability with disastrous consequences for many human communities. Today's climate changes can be managed without such disastrous consequences for present day communities only if there are major reforms to existing water law regimes at the local, national, and international levels. In particular, at the local and national levels, water resources must be treated as public property rather than as common or private property. At the international level, water must be managed at the drainage basin level rather than according to national boundaries that largely ignore rational water management criteria. At all levels, care must be given to decentralizing decision making and to use economic incentives insofar as possible, without, however, mistaking economic incentives for markets. The public nature of water resources precludes true markets as a significant management tool.

Notes: : Understanding the effects of climate change on water resources requires coupling atmospheric and hydrologic models. With the wide array of hydrologic models, from simple empirical to complex physically based, it is not clear which is preferable to simulate hydrologic variations over long time scales. To address this issue, a black-box artificial neural network (ANN) model was compared to a distributed parameter conceptual Geographic Information System based Hydrologic Modeling System (GIS-HMS). Both models computed daily direct surface runoff in four sub-basins of the West Branch of the Susquehanna River Basin, Pennsylvania and were evaluated with five objective functions. Overall, results were comparable between models. However, the ANN was favored in the larger sub-basins, while GIS-HMS was more accurate in the smaller catchments. Both models were impaired by the poor spatial and temporal resolution of precipitation data and the simplified representation of antecedent soil-moisture conditions. In the context of climate change, where simulations are limited by computing power, results suggest that both models are appropriate. When detailed simulations are essential, GIS-HMS is a preferable model to use. On the other hand, the ANN model is more suitable when multiple scenarios require immediate analysis and the distributed qualities of runoff are not required.

Notes: : We review published analyses of the effects of climate change on goods and services provided by freshwater ecosystems in the United States. Climate-induced changes must be assessed in the context of massive anthropogenic changes in water quantity and quality resulting from altered patterns of land use, water withdrawal, and species invasions; these may dwarf or exacerbate climate-induced changes. Water to meet instream needs is competing with other uses of water, and that competition is likely to be increased by climate change. We review recent predictions of the impacts of climate change on aquatic ecosystems in eight regions of North America. Impacts include warmer temperatures that alter lake mixing regimes and availability of fish habitat; changed magnitude and seasonality of runoff regimes that alter nutrient loading and limit habitat availability at low flow; and loss of prairie pothole wetlands that reduces waterfowl populations. Many of the predicted changes in aquatic ecosystems are a consequence of climatic effects on terrestrial ecosystems; shifts in riparian vegetation and hydrology are particularly critical. We review models that could be used to explore potential effects of climate change on freshwater ecosystems; these include models of instream flow, bioenergetics models, nutrient spiraling models, and models relating riverine food webs to hydrologic regime. We discuss potential ecological risks, benefits, and costs of climate change and identify information needs and model improvements that are required to improve our ability to predict and identify climate change impacts and to evaluate management options.

Notes: : This research examines the sensitivity and vulnerability of community water systems (CWSs) to weather and climate in the Pennsylvania portion of the Susquehanna River Basin. Three key findings emerge from a survey of 506 CWS managers. First, CWSs are sensitive to extreme weather and climate, but that sensitivity is determined more by type of system than system size. CWSs that rely partly or wholly on surface water face more disruptions than do groundwater systems. Larger systems have more problems with flooding, and size is not a significant determinant of outages from storms or disruptions from droughts. Second, CWS managers are unsure about global warming. Few managers dismiss global warming; most think global warming could be a problem but are unwilling to consider it in their planning activities until greater scientific certainty exists. Third, the nature of the CWS, its sensitivity to weather and climate, and projected risks from weather and climate are insignificant determinants of how managers plan. Experienced, full-time managers are more likely to consider future weather and climate scenarios in their planning, while inexperienced and part-time managers are less likely to do so. Implications of these findings include support for efforts to move away from surface water, for clear communication of climate change information, and for the hiring and retention of full-time professional CWS managers.

Notes: : To fully take advantage of regional climate forecast information for agricultural applications, the relationship between divisional and station scale precipitation characteristics must be quantified. The spatial variability of monthly precipitation is assumed to consist of two components: a systematic and a random component. The systematic component is defined by differences in long-term mean precipitation between stations within a climate division, and the random component by differences between station and divisional standardized values. For the Central Climate Division of Oklahoma, the systematic component has a positive precipitation gradient from west to east with a slope ranging between 3 to 16 mm of precipitation per 100 km depending on the month of the year. On the other hand, the random component ranges between 27 to 48 percent of the mean temporal variation of the monthly precipitation. This significant random spatial variability leads to large localized departures from divisional values, and clearly demonstrates the critical influence of the random component in the utilization of divisional climate forecasts for local agricultural applications. The results of this study also provide an uncertainty range for local monthly precipitation projections that are derived from divisional climate information.

Notes: : April 1 snowpack accumulations measured at 311 snow courses in the western United States (U.S.) are grouped using a correlation-based cluster analysis. A conceptual snow accumulation and melt model and monthly temperature and precipitation for each cluster are used to estimate cluster-average April 1 snowpack. The conceptual snow model is subsequently used to estimate future snowpack by using changes in monthly temperature and precipitation simulated by the Canadian Centre for Climate Modeling and Analysis (CCC) and the Hadley Centre for Climate Prediction and Research (HADLEY) general circulation models (GCMs). Results for the CCC model indicate that although winter precipitation is estimated to increase in the future, increases in temperatures will result in large decreases in April 1 snowpack for the entire western U.S. Results for the HADLEY model also indicate large decreases in April 1 snowpack for most of the western US, but the decreases are not as severe as those estimated using the CCC simulations. Although snowpack conditions are estimated to decrease for most areas of the western US, both GCMs estimate a general increase in winter precipitation toward the latter half of the next century. Thus, water quantity may be increased in the western US; however, the timing of runoff will be altered because precipitation will more frequently occur as rain rather than as snow.

Notes: : Downscaling coarse resolution climate data to scales that are useful for impact assessment studies is receiving increased attention. Basin-scale hydrologic processes and other local climate impacts related to water resources such as reservoir management, crop and forest productivity, and ecosystem response require climate information at scales that are much finer than current and future GCM resolutions. The Regional Climate System Model (RCSM) is a dynamic downscaling system that has been used since 1994 for short-term precipitation and streamflow predictions and seasonal hindcast analysis with good skill. During the 1997–1998 winter, experimental seasonal forecasts were made in collaboration with the NOAA Climate Prediction Center and UCLA with promising results. Preliminary studies of a control and 2°CO2 perturbation for the southwestern U.S. have been performed.

Notes: : Climate change has the potential to have dramatic effects on the agricultural sector nationally and internationally as documented in many research papers. This paper reports on research that was focused on a specific crop growing area to demonstrate how farm managers might respond to climate-induced yield changes and the implications of these responses for agricultural water use. The Hadley model was used to generate climate scenarios for important agricultural areas of Georgia in 2030 and 2090. Linked crop response models indicated generally positive yield changes, as increased temperatures were associated with increased precipitation and CO2. Using a farm management model, differences in climate-induced yield impacts among crops led to changes in crop mix and associated water use; non-irrigated cropland received greater benefit since irrigated land was already receiving adequate moisture. Model results suggest that farm managers will increase cropping intensity by decreasing fallowing and increasing double cropping; corn acreage decreased dramatically, peanuts decreased moderately and cotton and winter wheat increased. Water use on currently irrigated cropland fell. The potential for increased water use through conversion of agriculturally important, but currently non-irrigated, growing areas is substantial.

Notes: : We apply a physically based lake model to assess the response of North American lakes to future climate conditions as portrayed by the transient trace-gas simulations conducted with the Max Planck Institute (ECHAM4) and the Canadian Climate Center (CGCM1) atmosphere-ocean general circulation models (A/OGCMs). To quantify spatial patterns of lake responses (temperature, mixing, ice cover, evaporation) we ran the lake model for theoretical lakes of specified area, depth, and transparency over a uniformly spaced (50 km) grid. The simulations were conducted for two 10-year periods that represent present climatic conditions and those around the time of CO2 doubling. Although the climate model output produces simulated lake responses that differ in specific regional details, there is broad agreement with regard to the direction and area of change. In particular, lake temperatures are generally warmer in the future as a result of warmer climatic conditions and a substantial loss (〉 100 days/yr) of winter ice cover. Simulated summer lake temperatures are higher than 30°C over the Midwest and south, suggesting the potential for future disturbance of existing aquatic ecosystems. Overall increases in lake evaporation combine with disparate changes in A/OGCM precipitation to produce future changes in net moisture (precipitation minus evaporation) that are of less fidelity than those of lake temperature.

Notes: Manures and fertilizers are applied to agricultural lands in excess of recommended amounts, resulting in widespread pollution of surface and ground water and contributing a substantial source of greenhouse gases associated with global warming. By developing policies that exploit the value of farm produced nutrients, input costs can be minimized. Better accounting for or crediting of farm produced nutrients is leading to economically beneficial conservation of fertilizer. In addition, hog producers who own enough land may benefit from properly managing manure nutrients. Poultry litter is valuable as fertilizer and can be marketed by independent dealers to farmers in nutrient deficit areas, with very modest assistance from the government. Dairy producers may modify their past income support programs to finance central compost facilities. Although nutrient problems were neglected in the past, recent Federal initiatives and joint initiatives with states exploit many of these and other opportunities to avoid excessive application of nutrients to the land.

Notes: This paper details a case study of economic and natural system responses to alternative water management policies in the Cache La Poudre River basin, Colorado, 1980–1994. The case study is presented to highlight the value and application of a conceptual integration of economic, salmonid population, physical habitat, and water allocation models. Five alternative regimes, all intended to increase low winter flows, were investigated. Habitat enhancements created by alternative regimes were translated to population responses and economic benefits. Analysis concluded that instream flows cannot compete on the northern Colorado water rental market; cooperative agreements offer an economically feasible way to enhance instream flows; and establishing an instream flow program on the Cache La Poudre River mainstem is a potentially profitable opportunity. The alliance of models is a dynamic multidisciplinary tool for use in professional settings and offers valuable insight for decision-making processes involved in water management.

Notes: A user-friendly decision support system (DSS) for long-term reservoir operation has been introduced with an eye to practical use. The system can assist reservoir managers to work out applicable rules for real-time reservoir operation. The DSS model has already been applied experimentally to the main reservoirs in Taiwan with success. In this study, Tsengwen Reservoir, the largest reservoir in Taiwan, was chosen to test the applicability of the model. The simulation results show that the DSS is not only well suited to long-term reservoir operation, but also very easily applied. A handy DSS was designed for user-friendly computer interaction with Microsoft Excel in the Windows system. Users can survey on-line reservoir operation with a browser on the World Wide Web (WWW). The uniform resource locator of the DSS is . So users may easily access the DSS via the Internet.

Notes: Sensible (H) and latent (LE) heat fluxes, soil moisture (SM) and surface temperatures (Ts) were analyzed from seven sites at FIFE to evaluate relationships among the spatial variability of evaporative fraction, EF, SM, and the diurnal surface temperature range (Tdr). Intersite correlations between EF and Tdr were significantly negative for regional average soil moisture SMr 〈 20 percent, insignificant for 20 〈 SMr 〈 27 percent, and slightly positive for SMr 〉 27 percent. Statistical analysis of the pooled correlation coefficient between EF and Tdr for SMr 〈 20 percent indicates that it is less than zero at a very high level of significance, while the pooled correlation coefficient for regional SMr 〉 27 percent is greater than zero at the 10 percent level. The positive EF:Tdr correlations are attributed to increased surface vapor pressure at warmer sites under nearly potential conditions. These results suggest that to characterize the spatial variability of the energy budget partitioning, a variable representing the thermal response of the site should be included. An important application of these findings relates to modeling the subgrid variability of a region by subdividing the region into a few classes within which surface variables and parameters are assumed invariant. The thermal response of the surface should be included as a variable in defining these classes.

Notes: The storage function model is a nonlinear rainfall-runoff model that has been developed for and applied to flood runoff analysis in Japan. This paper extends the model applicability by developing practical equations for estimating model parameters which are appropriate on a regional basis, i.e., so-called regional equations. Previously, the parameters were computed from historical data for a specific basin or from relationships that do not account for land use and topography.To develop the regionalized equations, model parameters were identified for 91 flood events from 22 watersheds in Japan by applying a mathematical optimization technique. Results from 39 of these events were statistically compared and regional relationships were determined as a function of land use, basin area and rainfall intensity. The utility of the estimated equations were tested by computing runoff hydrographs for lumped basins. The estimated parameters were also applied in a distributed watershed model formulation. Both applications showed acceptable results that validate the use of the regionalized relationships.

Notes: We used a closed-ended viewer box in the measurement of Secchi depth and compared the results with simultaneous naked-eye measurements. We have shown that use of such a viewer box increases Secchi depth measurement by removing the interfering effects of water surface glare and glitter. A viewer box also increases between-observer precision. Measurements made both with and without the viewer box are slightly greater on the shady side of the boat than on the sunny side; the latter is the preferred side if Secchi data are to be related to other optical properties. As expected, the difference between viewer box and naked eye measurements increases with increasing wave height but not with increasing illuminance. Because of the lack of uniformity in the way Secchi depth is estimated, and the inherent optical problems with current Secchi depth procedures, an appeal is made for production of a standardized protocol for Secchi observations, including the use of a closed-ended viewer box on the sunny side of the boat.

Notes: : In two workshops, we evaluated decision analysis methods for comparing Lake Erie levels management alternatives under climate change uncertainty. In particular, we wanted to see how acceptable and effective those methods could be in a public planning setting. The methods evaluated included simulation modeling, scenario analysis, decision trees and structured group discussions. We evaluated the methods by interviewing the workshop participants before and after the workshops. The participants, who were experienced Great Lakes water resources managers, concluded that simulation modeling is user-friendly enough to enable scenario analysis even in workshop settings for large public planning studies. They felt that simulation modeling can improve not only understanding of the system, but also of the options for managing it. Scenario analysis revealed that the decision for the case study, Lake Erie water level regulation, could be altered by the likelihood of climate change. The participants also recommended that structured group discussions be used in public planning settings to elicit ideas and opinions. On the other hand, the participants were less optimistic about decision trees because they felt that the public might view subjective probabilities as difficult to understand and subject to manipulation.

Notes: : Global climate change due to the buildup of greenhouse gases in the atmosphere has serious potential impacts on water resources in the Pacific Northwest. Climate scenarios produced by general circulation models (GCMs) do not provide enough spatial specificity for studying water resources in mountain watersheds. This study uses dynamical downscaling with a regional climate model (RCM) driven by a GCM to simulate climate change scenarios. The RCM uses a subgrid parameterization of orographic precipitation and land surface cover to simulate surface climate at the spatial scale suitable for the representation of topographic effects over mountainous regions. Numerical experiments have been performed to simulate the present-day climatology and the climate conditions corresponding to a doubling of atmospheric CO2 concentration. The RCM results indicate an average warming of about 2.5°C, and precipitation generally increases over the Pacific Northwest and decreases over California. These simulations were used to drive a distributed hydrology model of two snow dominated watersheds, the American River and Middle Fork Flathead, in the Pacific Northwest to obtain more detailed estimates of the sensitivity of water resources to climate change. Results show that as more precipitation falls as rain rather than snow in the warmer climate, there is a 60 percent reduction in snowpack and a significant shift in the seasonal pattern of streamflow in the American River. Much less drastic changes are found in the Middle Fork Flathead where snowpack is only reduced by 18 percent and the seasonal pattern of streamflow remains intact. This study shows that the impacts of climate change on water resources are highly region specific. Furthermore, under the specific climate change scenario, the impacts are largely driven by the warming trend rather than the precipitation trend, which is small.

Notes: : This paper considers the distribution of flood flows in the Upper Mississippi, Lower Missouri, and Illinois Rivers and their relationship to climatic indices. Global climate patterns including El Niño/Southern Oscillation, the Pacific Decadal Oscillation, and the North Atlantic Oscillation explained very little of the variations in flow peaks. However, large and statistically significant upward trends were found in many gauge records along the Upper Mississippi and Missouri Rivers: at Hermann on the Missouri River above the confluence with the Mississippi (p = 2 percent), at Hannibal on the Mississippi River (p 〈 0.1 percent), at Meredosia on the Illinois River (p = 0.7 percent), and at St. Louis on the Mississippi below the confluence of all three rivers (p = 1 percent). This challenges the traditional assumption that flood series are independent and identically distributed random variables and suggests that flood risk changes over time.

Notes: : An assessment of current and future water quality conditions in the southeastern United States has been conducted using the EPA BASINS GIS/database system. The analysis has been conducted for dissolved oxygen, total nitrate nitrogen and pH. Future streamflow conditions have been predicted for the region based on the United Kingdom Hadley Center climate model. Thus far, the analyses have been conducted at a fairly coarse spatial scale due to time and resource limitations. Two hydrologic modeling techniques have been employed in future streamflow prediction: a regional stochastic approach and the application of a physically based soil moisture model. The regional model has been applied to the entire area while the physically based model is being used at selected locations to enhance and support the stochastic model. The results of the study reveal that few basins in the southeast exhibit dissolved oxygen problems, but that several watersheds exhibit high nitrogen levels. These basins are located in regions of intense agricultural activity or in proximity to the gulf coast. In many of these areas, streamflow is projected to decline over the next 30–50 years, thus exacerbating these water quality problems.

Notes: : As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.

Notes: : This paper reports on new methods of linking climate change scenarios with hydrologic, agricultural an water planning models to study future water availability for agriculture, an essential element of sustainability. The study is based on the integration of models of water supply and demand, and of crop growth and irrigation management. Consistent modeling assumptions, available databases, and scenario simulations are used to capture a range of possible future conditions. The linked models include WATBAL for water supply; CERES, SOYGRO, and CROPWAT for crop and irrigation modeling; and WEAP for water demand forecasting, planning and evaluation. These models are applied to the U.S. Cornbelt using forecasts of climate change, agricultural production, population and GDP growth.Results suggest that, at least in the near term, the relative abundance of water for agriculture can be maintained under climate change conditions. However, increased water demands from urban growth, increases in reservoir evaporation and increases in crop consumptive use must be accommodated by timely improvements in crop, irrigation and drainage technology, water management, and institutions. These improvements are likely to require substantial resources and expertise. In the highly irrigated basins of the region, irrigation demand greatly exceeds industrial and municipal demands. When improvements in irrigation efficiency are tested, these basins respond by reducing demand and lessening environmental stress with an improvement in system reliability, effects particularly evident under a high technology scenario. Rain-fed lands in the Cornbelt are not forced to invest in irrigation, but there is some concern about increased water-logging during the spring and consequent required increased investment in agricultural drainage. One major water region in the Cornbelt also provides a useful caveat: change will not necessarily be continuous and monotonic. Under one GCM scenario for the 2010s, the region shows a significant decrease in system reliability, while the scenario for the 2020s shows an increase.

Notes: Watershed planning groups and action agencies seek to understand how lake water quality responds to changes in watershed management. This study developed and demonstrated the applicability of an integrated modeling approach for providing this information. An integrated model linking watershed conditions to water-quality of the receiving lake incorporated the following components: (1) an event-based AGNPS model to estimate watershed pollutant losses; (2) annualization of AGNPS results to produce annual lake pollutant loadings; (3) a base flow separation package, SAM, to estimate base flow; (4) estimates of nutrients in base flow and point sources; and (5) linkage of watershed loadings directly to EUTROMOD lake water quality algorithms. Results are presented for Melvern Lake, a 28-km2 multipurpose reservoir with a 900-km2 agricultural watershed in east central Kansas. Reasonable estimates of current lake quality were attained using an average phosphorus availability factor of 31 percent to calibrate model results to measured in-lake phosphorus. Comparison of a range of possible scenarios, including all cropland changed to no-till (best case) and all CRP and good-condition grasslands changed to cropland (worst case), indicated only a (4 percent change for in-lake phosphorus and a (2 percent change for chlorophyll a. These results indicated that this watershed is not sensitive to projected changes in land use and management.

Notes: Data from seven Management Systems Evaluation Areas (MSEA) were used to test the sensitivity of a leaching model, Pesticide Root Zone Model-2, to a variety of hydrologic settings in the Midwest. Atrazine leaching was simulated because it was prevalent in the MSEA studies and is frequently detected in the region's groundwater. Short-term simulations used site specific soil and chemical parameters. Generalized simulations used data avail. able from regional soil databases and standardized variables. Accurate short-term simulations were precluded by lack of antecedent atrazine concentrations in the soil profile and water, suggesting that simulations using data for less than five years underestimate atrazine leaching. The seven sites were ranked in order of atrazine detection frequency (concentration 〉 0.2 μg L-1) in soil water at 2 m depth in simulations. The rank order of the sites based on long-term simulations were similar to the ranks of sites based on atrazine detection frequency from groundwater monitoring. Simulations with Map Unit Use File (MUUF) soils data were more highly correlated with ranks of observed atrazine detection frequencies than were short-term simulations using site-specific soil data. Simulations using the MIJUIF data for soil parameters were sufficiently similarity to observed atrazine detection to allow the credible use of regional soils data for simulating leaching with PRZM-2 in a variety of Midwest soil and hydrologic conditions. This is encouraging for regional modeling efforts because soil parameters are among the most critical for operating PRZM-2 and many other leaching models.

Notes: Common carp (Cyprinus carpio) collected from four sites in the Red River of the North in 1994 were analyzed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), selenium (So), and zinc (Zn). Concentrations differed among liver, muscle, and whole body. Generally, trace element concentrations were the greatest in livers while concentrations in whole bodies were greater than those in muscle for Cd, Cu, Ni, Pb, and Zn, and concentrations in muscle were similar to whole body for As and Se. Concentrations of Cr were lower in liver than either muscle or whole body. Correlations between liver and whole body concentrations were stronger than those between liver and muscle concentrations, but the strongest correlations were between muscle and whole body concentrations. Examination of tissue concentrations by collection sites suggested that, for a general survey, the whole body may be the most effective matrix to analyze.

Notes: Road-related erosion was estimated by measuring 100 randomly located plots on a 180 km road network in the middle reach of R'dwood Creek in northwestern California. The estimated erosion ratn of 177 m3 km-1 was contrasted with two earlier studies in nearby parts of the same watershed. A sizable proportion of the great reduction in erosion from that reported in the earlier studies is attributed to changes in forest practice rules. Those changes have resulted in better placement and sizing of culverts and, especially, to less reliance on culverts to handle runoff from logging roads.

Notes: Several published BOD data sets are examined to show that approximately half of them are described best in the least squares sense by treating the BOD equation as being of the three-halves order instead of first order. A dissolved oxygen (DO) sag equation for a stream is developed in which the BOD is described as a three-halves order reaction. The time when the minimum DO concentration occurs is calculated numerically. The DO sag model applied to example problems shows that an increase in the BOD reaction rate constant results in a smaller minimum DO concentration and a decrease in the time to reach the minimum DO.

Notes: Hydrologic modeling of urban watersheds for designs and analyses of stormwater conveyance facilities can be performed in either an event-based or continuous fashion. Continuou simulation requires, among other things, the use of a time series of rainfall amounts. However, for urban drainage basins, which are typically small, the temporal resolution of the rainfall time series must be quite fine, and often on the order of 5 to 15 minutes. This poses a significant challenge because rainfall-gauging records are usually kept only for hourly or longer time steps. The time step sizes in stochastic rainfall generators are usually also too large for application to urban runoff modeling situations. Thus, there is a need for methods by which hourly rainfall amounts can be disaggregated to shorter time intervals. This paper presents and compares a number of approaches to this problem, which are based on the use of polynomial approximating functions. Results of these evaluations indicate that a desegregation method presented by Ormsbee (1989) is a relatively good performer when storm durations are short (2 hours), and that a quadratic spline-based approach is a good choice for longer-duration storms. Based on these results, the Ormsbee technique is recommended because it provides good performance, and can be applied easily to long time series of precipitation records. The quadratic spline-based approach is recommended as a close second choice because it performed the best most consistently, but remains more difficult to apply than the Ormsbee technique. Results of this study also indicate that, on average, all of the disaggregation methods evaluated introduce a severe negative bias into maximum rainfall intensities. This is cause for some well-justified concern, as the characteristics of runoff hydrographs are quite sensitive to maximum storm intensities. Thus, there is a need to continue the search for simple yet effective hourly rainfall disaggregation methods.

Notes: We develop and compare three regression models for estimating flood quantiles at ungaged stream reaches in New Hampshire and Vermont. These models emerge from systematic analysis and validation of relations between flood magnitude and six candidate predictors reflecting basin size, topography, and climate and channel size at 36 gaging stations with record lengths exceeding 20 years. Of the candidate predictors, bank full width is most highly correlated with flood magnitude and the best prediction equation is based on width. Thus channel geometry is closely related to the current hydrologic regime in spite of geologically recent glaciation and apparently non-alluvial bank materials. We also develop models that use information obtainable from maps or GIS. The best of these uses drainage area and drainage-basin elevation as predictors, but it is substantially less precise than the width-based relation. A third relation using only drainage area as a predictor is even less precise but may be useful for some purposes. No other single predictors or combinations yielded useful predictions, although some had been included in previously-established models for the region. Model comparison included examination of residuals generated by regression using one-at-a-time suppression of data points and comparison with precision obtainable with gaging records of varying lengths.

Notes: This study systematically evaluates residential consumer responses to a utility conservation initiative based on an econometric analysis of a sample of 510 households served by Artesian Water Company, Inc. (New Castle County of Delaware). Using a panel study approach covering the period from 1992 to 1997, this study shows that Artesian's water conservation program has had statistically significant and persistent impacts on residential water consumption.

Notes: The City of Cedar Rapids obtains its municipal water supply from four well fields in an alluvial aquifer along the Cedar River in east-central Iowa. Since 1992, the City and the U.S. Geological Survey have cooperatively studied the groundwater-flow system and water chemistry near the well fields. The geochemistry in the alluvial aquifer near the Seminole Well Field was assessed to identify potentially reactive minerals and possible chemical reactions that produce observed changes in water chemistry. Calcite, dolomite, ferrihydrite, quartz, rhodochrosite, and siderite were identified as potentially reactive minerals by calculating saturation indexes. Aluminosiicate minerals including albite, Ca-montmorillonite, gibbsite, illite, K-feldspar, and kaolinite were identified as potentially reactive minerals using hypothetical saturation indexes calculated with an assumed dissolved aluminum concentration of 1 microgram per liter. Balanced chemical equations derived from inverse-modeling techniques were used to assess chemical reactions as precipitation percolates to the water table. Calcite dissolution was predominate, but aluminosilicate weathering, cation exchange, and redox reactions also likely occurred. Microbial-catalyzed redox reactions altered the chemical composition of water infiltrating from the Cedar River into the alluvial aquifer by consuming dissolved oxygen, reducing nitrate, and increasing dissolved iron and manganese concentrations. Nitrate reduction only occurred in relatively shallow (3 to 7 meters below land surface) groundwater near the Cedar River and did not occur in water infiltrating to deeper zones of the alluvial aquifer.

Notes: : Water is, and most likely will continue to be, one of the main concerns and potential causes of instability in the Middle East (ME). The contribution of the existing renewable water resources is limited and can not fulfill the long-term projected gap between water supply and demand for most of the countries in the ME. An integrated regional approach for fulfilling this gap was preferred. A regional institutional framework was proposed for the implementation of this integrated regional approach and consists of a regional water board operating through three units for technical, implementation, and management aspects of project and activities. An analysis of the regional water supply and demand development, the design and policy making of the proposed institution, technology and water markets, cooperation, actors and beneficiaries, finances, and expected obstacles and constraints to the establishment and sustainable operation of the proposed institution are included.

Notes: : A selenium budget for Lake Powell, Utah-Arizona was determined based on selenium loads at the principal stream input sites to and the output site from the lake. Based on data collected during 1985-1994, 83 percent of the selenium entering Lake Powell is accounted for at the output site. The rest of the selenium may be incorporated by lake sediment or used by the biota. Considerably more selenium per unit area is produced from the Colorado River Basin above the Colorado River-Green River confluence than from the Green River Basin and the San Juan River Basin combined. The Gunnison River Basin and the Grand Valley in Colorado produce an estimated 31 and 30 percent of the selenium that reaches Lake Powell, respectively. Irrigation-related activities are thought to be responsible for mobilizing 71 percent of the selenium that reaches Lake Powell. Selenium concentrations in water at Imperial Dam on the Colorado River upstream of the United States-Mexico international border are similar to those at the output site of Lake Powell. Therefore, most selenium observed in downstream areas of the Colorado River therefore probably is derived mostly from the Colorado River Basin above Lake Powell.

Notes: : The Caloosahatchee River has two major sources of freshwater one from its watershed and the other via an artificial connection to Lake Okeechobee. The contribution of each source to the freshwater discharge reaching the downstream estuary varies and either may dominate. Routine monitoring data were analyzed to determine the effects of total river discharge and source of discharge (river basin, lake) on water quality in the downstream estuary. Parameters examined were: color, total suspended solids, light attenuation, chlorophyll a, and total and dissolved inorganic nitrogen and phosphorus. In general, the concentrations of color, and total and dissolved inorganic nitrogen increased, and total suspended solids decreased, as total discharge increased. When the river basin was the major source, the concentrations of nutrients (excepting ammonia) and color in the estuary were relatively higher than when the lake was the major source. Light attenuation was greater when the river basin dominated freshwater discharge to the estuary. The analysis indicates that water quality in the downstream estuary changes as a function of both total discharge and source of discharge. Relative to discharge from the river basin, releases from Lake Okeechobee do not detectably increase concentrations of nutrients, color, or TSS in the estuary.

Notes: : Predicting stream eutrophication potential from non-point source nutrient loading across large temporal and spatial scales is a significant problem. In this paper we describe how two physiological indicators of P stress of stream bioflims, alkaline phosphatase activity (APA) and stored (surplus) P relate to two predictors of P loading: annual P loading predicted by the watershed model SIMPLE, and stream concentrations of soluble reactive P (SRP) in eight subbasins in the illinois River basin in Oklahoma. Data for APA, surplus P, nutrients and water chemistry were obtained at watershed outlets once during the cold season and twice during the warm season. There was a negative curvilinear relationship between APA and both predictors. Best fit was achieved by APA vs. annual predicted P loading. Both SRP and P. load are potentially useful to identify subbasins requiring no pollution abatement and to establish a regional target for P-load reduction. Surplus P is not as useful as APA in establishing these thresholds.

Notes: : An experimental one-year fieldwork has been conducted in the vicinity of the Chernobyl NPP, within an agricultural watershed, to study the transfer of radionuclides brought into the environment by the disaster of 1986. Presented are results of observation of the washout of 137Cs from the runoff plot both in natural conditions and under artificial rainfalls. Beside traditional hydro-logical methods, new techniques were used allowing to consider microtopographical peculiarities of the runoff plot and their role in the redistribution of radionuclides. The estimate of the annual mass balance for the soil and the radionuclides within the runoff plot has shown that, regardless of significant areal variation of their concentration, the 137Cs washout with the solid runoff resulted from artificial rainfalls amounts to some 1 percent of its reserves in the uppermost 5 cm of the topsoil. The same parameter for the natural runoff is lower by an order of magnitude. Both these factors of self-purification are about two times less than natural radioactive decay of 137Cs.

Notes: : Typically, infrastructure agencies build massive water projects to serve expanding populations in emerging country cities, but collect and treat only a fraction of the resulting wastewater. This effluent often overwhelms existing sewerage systems and fouls waterways. Cleaning urban waterways requires large investments over long terms and the political will to make and sustain them. This challenge - difficult in advanced countries - becomes daunting with the scarce resources and weak institutions typical of emerging countries. This paper presents a framework to structure such a strategy, and applies it to Madras, India. It consists of three parts: (1) setting a vision through a participatory process; (2) macro investments mainly in wastewater treatment that use least-cost methods; and (3) micro investments in small projects that involve local people and galvanize public support. The macro investment, $350 million for Madras, appears very large, but averages out to $66 per capita, far below the $1,000-$2,000 typical of advanced country cities. Micro projects to be undertaken by Non-Governmental Organizations (NGOs) included an independent wastewater monitoring program, sanitary upgrading of slums along waterways banks, a cattle waste demonstration project, and an industrial pollution survey. Together, a macro/micro strategy promises the funding and political will to achieve a balanced vision of waterways quality.

Notes: : Integrated watershed management in the Lower Mississippi Alluvial Plain (Delta) requires blending federal, state, and local authority. The federal government has preeminent authority over interstate navigable waters. Conversely, state and local governments have authority vital for comprehensive watershed management. In the Delta, integrating three broad legal and administrative regimes: (1) flood control, (2) agricultural watershed management, and (3) natural resources and environmental management, is vital for comprehensive intrastate watershed, and interstate river basin management. Federal Mississippi River flood control projects incorporated previous state and local efforts. Similarly, federal agricultural programs in the River's tributary headwaters adopted watershed management and were integrated into flood control efforts. These legal and administrative regimes implement national policy largely in cooperation with and through technical and financial assistance to local agencies such as levee commissions and soil and water conservation districts. This administrative infrastructure could address new national concerns such as nonpoint source pollution which require a watershed scale management approach. However, the natural resources and environmental management regime lacks a local administrative infrastructure. Many governmental and non governmental coordinating organizations have recently formed to address this shortcoming in the Delta. With federal and state leadership and support, these organizations could provide mechanisms to better integrate natural resources and environmental issues into the Delta's existing local administrative infrastructure.

Notes: : Australia's ‘Landcare’ program is a community-based participatory program established by government to tackle the problem of land degradation. Landcare involves thousands of Australians working together in locally based groups, tackling problems of common concern. Government and community are now looking to ‘scale up’ the Landcare idea to a regional level. State and territory governments have moved to create regional (often watershed-based) frameworks for land management planning and resource conservation, in accordance with the concept of integrated watershed management. Growing out of the success of community involvement in Landcare, many of these approaches involve the community. However scaling up of the Landcare idea introduces problems of both time and space. There have been a number of problems experienced in the implementation of Landcare and integrated watershed management. These problems include the equitable delineation of membership on decision-making bodies; the raising of sufficient funds for program implementation; and the coordination of a diversity of governmental layers, planning processes and management programs. This paper reviews how the State of Victoria has responded to these challenges and suggests what challenges remain.

Notes: : Social scientists were included in the planning and design for an integrated, trans-basin water resource project. Within this complex project, a socioeconomic impact assessment (SIA) concentrated on identifying the social, political, and economic issues and potential impacts inherent in developing a city's water rights. Before the SIA began, some of the development alternatives had already generated widespread hostility and organized opposition from communities within the watershed. The SIA involved residents of affected communities in the study design and project planning. The study found a number of components that constituted the concerns, beliefs, and expectations about perceived, potential impacts that might result from the different alternatives. In most cases these issues constituted threats to valued environmental resources, valued community resources, the social environment, the economic base, and a secure future. The social science component was a key factor in the ultimate decision to pursue a particular alternative which was sensitive to the social and political issues, minimized environmental and socioeconomic impacts, and ultimately had support among the communities potentially affected. The experience from this case study suggests that the approach used can be applied successfully in the planning of other water development projects and result in cooperation from the wide range of interest groups that often present costly obstacles to such projects.

Notes: : Water providers nationwide are implementing nonprice conservation measures such as education, public information, appliance retrofit and ordinances, with the expectation that these programs will reduce residential water demand. However, little empirical information exists on the effectiveness of nonprice conservation programs in reducing water demand. Previous econometric studies indicate these programs have had minimal impact. We examine the types and number of major nonprice conservation programs that have been implemented during an 11-year period in seven cities in the southwestern United States. A cross sectional, monthly time series residential water demand model, with parameters to control for variation in prices, temperature, precipitation and other factors, was used to empirically investigate the effectiveness of nonprice conservation programs in reducing water demand. We found significant reductions in use ranging between 1.1 percent and 4.0 percent per program. Because of the lack of information, we were unable to distinguish the effectiveness of individual or specific types of programs. Beyond finding that nonprice programs can be effective in reducing demand, questions regarding the efficiency and benefits to be achieved by conservation remain. As a step towards separating and evaluating the effects of individual programs, program benefits and efficiency, we recommend that utilities maintain more detailed and consistent information regarding the implementation of their nonprice programs.

Notes: : Policy and management plans can be enhanced through effective communication between researchers and decision makers. Differences in understanding can come from differences in professional cultures. Scientists deal with facts, proof and incremental progress whereas the decision makers are often faced with perceptions, emotions and deadlines. A case study is presented illustrating the interaction between the political system and science on a water management issue. Irrigation projects in the western San Joaquin Valley of California lead to a situation requiring subsurface drainage and disposal of the drainage water. The original plan was to discharge the drainage water in the Suisun Bay east of the San Francisco Bay. Severe damage to birds associated with selenium in the water led to a reevaluation of irrigation and drainage management options. Federal and state agencies cooperated to establish a San Joaquin Valley Drainage Program (SJVDP) which was to develop plans for solving the problem. Discharge to the Bay was politically eliminated as an option for evaluation, an action criticized by a National Research Council Committee as not being scientifically based. The SJVDP published a Management Plan in 1990 which contained proposals viewed by the scientific community as not necessarily incorrect but not completely justified based on the scientific knowledge at the time. A segment of the Citizens Advisory Committee that was part of the SJVDP consisting of representatives from the interest groups viewed the Management Plan as a negotiated agreement between the environmental and agricultural interests. Presently, an Activity Plan exists, consisting of technical committees to evaluate the current technical and economic evaluation of the management options proposed in the Management Plan. This case study illustrates that factors other than scientific facts have bearing on decisions. Successful management plans must be technically sound, economically viable and socially acceptable. The scientific community needs to evaluate its role in the policy making arena and to focus research on questions of greatest value to decision makers, as well as to scientific peers.

Notes: : To better understand the flow processes, solute-trans. port processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimensional flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) ground-water recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.

Notes: : The objectives of this paper were to test the ability of various design storm distributions to simulate the actual rainfall pattern and to compare the runoff rates used in the design of stormwater management devices in the State of Florida using continuous simulation approach. The analyses were performed for four gaged stations to evaluate the applicability of design storm distributions in different parts of the State of Florida.The approach used in this study compared the peak runoff rates from design storms based on the various distributions to those that would result from actual rainfall events. A series of continuous runoff rates were developed through the use of actual fifteen-minute recorded rainfall data, Horton type infiltration decay and recovery rate, and a continuous simulation model. The runoff rates were analyzed using frequency distributions to obtain peak runoff rates associated with different return periods based on the assumption that the continuous simulation approach closely predicts the actual runoff rates from the gaged stations. The results show that the behavior of the design storm distributions varies for different watershed characteristics in different parts of the state. The study also suggests that in general the Florida Department of Transportation and the Suwanne River Water Management (FDOT/ SRWMD) distributions appeared to agree with the continuous simulation results.

Notes: This paper briefly examines the current position in absolute and exterior orientation and highlights some of the limitations of existing techniques. An alternative system for performing absolute orientation and, potentially, exterior orientation is introduced. Some preliminary tests have given encouraging results.

Notes: The aim of this study is to assess the impact of sensor size and resolution of different digital camera sensors upon the accuracy and precision of three dimensional data derived by photogrammetry. Kodak DC40, DCS420 and DCS460 digital cameras were used to produce digital images of retroreflective targets in a 4 m three dimensional test field. The image locations of the targeted points were automatically measured using an off the shelf image processing software package. Two different sub-pixel measurement approaches were examined: centre of gravity and weighted mean. From the automated sub-pixel measurement of the targeted points, results indicate that the high resolution DCS460 camera produces optimum results using either the weighted mean or centre of gravity approaches. Although this was perhaps expected, the far lower resolution DC40 camera performed better than was originally anticipated, suggesting potential for the cheaper DC40 for many applications.

Notes: This paper describes initial work carried out to advance the use of vision metrology and three dimensional visualization techniques in structural testing and monitoring. A description is given of a methodology for semi-automatically generating dynamic three dimensional computer graphics models, which is employed to provide a three dimensional spatial framework for conventional engineering instrumentation. The use of techniques developed for two structural measurement applications is explained and opportunities for current and future research are reported.

Notes: This paper investigates possible solutions to the problem of urban orthophotography. Extensive work has been carried out to attain the best possible results, using all the existing software in the Department of Geomatic Engineering, University College London. Two of the most promising methods, which yield the best results, are analysed further. New routines were written in C language, as additions to the existing software, to allow for the special problems that arise in urban areas. The final results overcome the problem of double mapping (or occlusions) and will potentially enable even greater success to be achieved. A simple accuracy assessment of the results has been made. Difficulties and current limitations are analysed and presented.

Notes: This paper describes the use of photogrammetry to measure and quantify ice accretion on an aerofoil section. A series of stereoscopic photographs was taken during the ice accretion on the section in an icing tunnel. From measurements made on these photographs with a Kern (Leica) DSR 14 analytical photogrammetric plotter, a series of three dimensional models of the ice surfaces was constructed. The results of the project are discussed and possible improvements in the methodology are suggested.

Notes: A theoretical model for describing a direct image to ground relationship for slant range images extracted from synthetic aperture radar imaging satellites (for instance ERS-1 and ERS-2) is formulated. The rigorous orbital model is based on orbital parameters. Transformations and equations describing the relationship are derived.

Notes: For in excess of 100 years, photogrammetry has played a significant role in documenting the cultural heritage of nations and peoples. Many recent advances in the technique have enhanced the use of photogrammetry as a recording tool, enabling more complex representations of objects and moving access to the procedure from the expert to the interested user. Some of these recent developments include low cost digital photogrammetric systems, image sequence analysis, bundle adjustment and camera calibration procedures, and three dimensional laser scanning. An overview of some of these developments is given in this paper.The University of Melbourne, in conjunction with Chulalongkorn University in Bangkok, has been working on a project to create a computer visualization of the ancient Thai city of Ayutthaya. This project has blended three dimensional CAD models of the architectural features of Ayutthaya with historical research and artistic rendering to build a realistic representation of this city as it may have existed in the past.The model of the city has been built up from historical “maps”, aerial photographs, field survey and the use of photogrammetry to derive models of individual wat, chedi, prang (see GLOSSARY) and statuary. The historical research conducted in Thailand has provided the basis for the determination of the most likely location and appearance of the missing structures. The CAD models created from the photogrammetry have been visualized by the addition of surface textures and materials and rendered in as realistic a manner as possible. The virtual city has also been augmented by the incorporation of live actors in the computer reconstruction.When completed, the end product will be capable of producing an experience of daily life in Ayutthaya, with the potential for giving the user a level of interaction. The reconstruction will also be used as the basis of a variety of educational products to be produced in Thailand on a number of different media, including a bilingual CD-ROM already developed to “proof-of-concept” stage.

Notes: The feasibility of applying commercial digital photogrammetric software to the measurement of small objects photographed through an optical microscope has been examined. The objects, about 20 mm across, were photographed using a 35 mm film camera (at the lowest magnification setting of the Olympus microscope) giving photographs at a scale of 2:1. The photographs were then scanned before processing with the VirtuoZo digital photogrammetric system. Various problems needed to be overcome, some due to the limited options available with the highly automated digital system which was not designed for such measurement tasks. The unusual image scales, the uncommon pixel sizes and the unconventional and uncertain imaging geometry, all impeded immediate photogrammetric implementation. Photographic problems with the microscope were also faced, as with all microscope photogrammetry. Creating control points and independently assessing the accuracy of results at these scales were also difficult operations, but an analytical plotter was utilized for both these purposes and to verify the imaging geometry. Once such problems were overcome, image matching proceeded well and an accurate DTM could be created successfully, provided that a suitably textured object was chosen.

Notes: This paper discusses the role of Ordnance Survey International as a division within Ordnance Survey and outlines the work currently being carried out world-wide. It identifies the commercial structure of the business and justifies the reasons for participation in overseas markets. The key business activities of Adviser to the United Kingdom Department for International Development, international relations, library services, training and consultancy are all described. In addition, three case studies are included to support the main text.

Notes: Some exciting developments have been made recently, in the field of digital image rectification, which are of interest to both the photogrammetric specialist and non-specialist. This paper outlines the technical processes involved in generating digitally rectified images, as well as raising some of the issues that are becoming apparent when applying this modern technology to archaeological and architectural presentation.

Notes: The number of people involved in the actual process of airborne data collection has always been relatively small in comparison with the large number of end users of the product. As with many aspects of photogrammetry, the techniques and equipment used in aerial imagery acquisition have changed rapidly over recent years. Other outside influences are having an effect on how aerial operations are carried out and this paper examines how these factors will affect air survey as we approach the millennium.

Notes: Book review in this ArticlePHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING. Edited by G. Guyot and T. Phulpin. A. A. Balkema, Rotterdam, 1997. ISBN 90 5410 917 3. Two volumes, each 172.254 mm. Volume 1: xiii + 390 pages; volume 2: x + 411 pages. Price NLG 225.MANUAL OF REMOTE SENSING, THIRD EDITION, VOLUME 2. PRINCIPLES AND APPLICATIONS OF IMAGING RADAR. Edited by F. M. Henderson and A. J. Lewis. John Wiley & Sons, Inc., New York, in co-operation with the American Society for Photogrammetry and Remote Sensing, 1998. ISBN 0 471 29406 3. 221.287 mm. xxv + 899 pages. 76 colour plates. Price US$198 hardback.GEOGRAPHICAL INFORMATION SYSTEMS. PRINCIPLES, TECHNIQUES, APPLICATIONS AND MANAGEMENT. Second edition. Edited by P. A. Longley, M. F. Goodchild, D. J. Maguire and D. W. Rhind. John Wiley & Sons, Chichester, 1999. ISBN 0471 32182 6 hardback. Boxed set of two volumes. 200.270 mm. Volume 1: xcv + 580 pages, with 40 colour plates. Volume 2: xciii + 521 pages, with 66 colour plates. Price £195.FUTURE TRENDS IN REMOTE SENSING. Edited by P. GUDMANDSEN. A. A. Balkema, Rotterdam, 1998. ISBN 90 5410 933 5. 180.254mm. xii + 496 pages, including 18 pages of colour plates. Price NLG 205.INTERPRETATION OF AIRPHOTOS AND REMOTELY SENSED IMAGERY. By R. H. Arnold. Prentice-Hall, Inc., New Jersey, USA, 1997. ISBN 0 02 303924 8. 225.274 mm. xiv + 250 pages. 189 figures, including 17 in colour. Price £21.95 spiral bound.GEOCOMPUTATION: A PRIMER. Edited by P. A. Longley, S. M. Brooks, R. McDonnell and W. MacMillan. John Wiley & Sons Ltd., Chichester, 1998. ISBN 0 471 98575 9 clothbound, 0 471 98576 7 paperback. 168.244 mm. xii + 278 pages, plus 8 pages of colour plates. Price £22.50 paperback.DIRECTORY OF AERIAL PHOTOGRAPHIC COLLECTIONS IN THE UNITED KINGDOM. Second edition. National Association of Aerial Photographic Libraries (NAPLIB), Dereham, 1999. ISBN 0 9530436 1 4. 210.297 mm. 132 pages. 8 plates and 3 figures. Price £40 (£20 to new members of NAPLIB and to members of the Photogrammetric Society).DIGITAL LANDSCAPE MODEL FOR EUROPE (DLME). By E. Blau, F. Boochs and B.-S. Schulz, with editorial assistance of P. R. T. Newby. OEEPE Official Publication No. 34. Institut für Angewandte Geodäsie, Frankfurt am Main, 1997. ISSN 0257 0505. 175.245 mm. 108 pages. 21 figures, 9 tables, 4 diagrams and 15 appendices. Price DM 40.THE AGI SOURCE BOOK FOR GEOGRAPHIC INFORMATION SYSTEMS 1998/99. Edited by C. Corbin. Association for Geographic Information, London, 1998. ISBN 1 847059 314. 210.297 mm. 396 pages. 43 trade directories and 21 reference tables. Price £39.50 paperback.

Notes: This paper discusses the application of two fixed base non-metric camera systems. The first is a helicopter supported 5m boom carrying two 70 mm Hasselblad cameras, fired simultaneously. The 1;850 scale stereomodels, each covering about 40 ×45 m, were used to measure individual tree characteristics, such as crown closure and size. The second system is a portable camera platform designed for microtopography, which used sequential Minolta 35mm photography (1;80 scale) for generating DEMs and computing volume of soil erosion. In both cases, an analytical plotter was used to collect measurements without ground control. With the helicopter boom system, distances and heights were measured to within 5 per cent of true dimensions. With the portable platform system, volume estimates were within 1 per cent of field measurement values. Particular attention is given to the orientation and scaling of stereopairs. Because the air base is used to scale the model, errors in scale due to non-parallel lines of sight are avoided. Advantages and disadvantages of both systems are discussed.

Notes: Stereoscopic softcopy photogrammetric systems were originally as expensive as analytical stereoplotters, which prohibited their use in most small production firms. At the lower end of the cost spectrum, the functioning of these systems has previously been somewhat limited. Advances in computing technology and software architecture have now made an economic replacement of analogue stereoplotters a reality. A reasonably priced, high performance, off the shelf production solution is now possible on standard PC hardware. This paper provides a comparison of analogue and digital photogrammetry for a production work flow, commencing after scanning the films and progressing through project set up, orientations, stereodisplay and feature collection, DTM collection and editing, finally ending prior to orthophotography production. The underlying breakthrough software architecture making an effective digital system possible at moderate cost is described in detail and the benefits of such a system compared with analogue plotters are highlighted.

Notes: For the construction of the new Athens International Airport, it was imperative that a hill, obstructing air traffic, be lowered by approximately 40 m. Unfortunately, a fortified prehistoric settlement was situated on top of that hill. In order to carry out this task, it was required: (a) to produce a model of the site at a scale of 1;50; and (b) to monitor and document every single stone during the dismantling of the most important parts of the site, so that its rebuilding elsewhere and at a later time would be possible.The Laboratory of Photogrammetry, National Technical University of Athens, undertook to provide the necessary metric data. By using low altitude aerial photographs from a helicopter, a specialized tripod and terrestrial photogrammetric techniques, the following products were created, all at a scale of 1;50: contour lines and DTM of the site; digital orthophotograph of the site; graphic drawing of the development of the exterior of the surrounding wall; and graphic drawings of the upper (initial) and the lower (last) levels of the parts to be removed. In this paper, both the fieldwork and the final products are presented and evaluated.

Notes: The Department of Geomatics and the Regional Centre for Innovation in Engineering Design in the University of Newcastle upon Tyne collaborated in a project to produce precise measurements for use in the fabrication of the body of the “Angel of the North” sculpture. This 20 m high edifice, by the sculptor Antony Gormley, is located adjacent to the A1(M) in Gateshead, Tyne and Wear.This paper reviews the photogrammetric reverse engineering work carried out on a 1:10 scale plaster maquette of the “Angel of the North”, which is a life-size model of the sculptor's body without any arms. The three dimensional measurements of the maquette, made by analytical photogrammetric techniques, were then processed to produce a fully functional three dimensional CAD model from which the dimensions needed by the fabricating company, Hartlepool Steel Fabrications Ltd., could be extracted. Additionally, the VirtuoZo digital photogrammetric software package was used to investigate the potential of automated measurement for this type of work and the results were compared with those obtained analytically.

Notes: Although well established, digital photogrammetry continues to change. More sources offer imagery which can be treated photogrammetrically. Users need improved scanner performance as they attempt to offset costs by feeding clusters of workstations or establishing bureau services; increased speed, variable pixel size, use of roll film and “on the fly” dodging are desirable scanner characteristics. On the workstation side, the demand for the Windows NT platform has been irresistible. New applications and the quest for higher productivity have resulted in demands including output of orientation data to analytical plotters, processing of data from airborne GPS and inertial measurement unit (IMU), triangulated irregular network (TIN) DTMs, automated radiometric balancing in mosaicking, smoother operation within feature collection and batch processes. Moreover, the market place itself changes, with suppliers, their customers and the end users all competing for position.

Notes: The use of circular object targets is very common in spatial photogrammetric object reconstruction. An object circle is projected on to the image plane as an ellipse if the object plane and the image plane are not parallel to each other. The image co-ordinates of the centre of the ellipse are usually determined automatically by means of digital image processing. These co-ordinates are then used as observations for a subsequent reconstruction of the three dimensional object point. The image co-ordinates of the centre of the ellipse and the true co-ordinates of the projected centre of the circular object target are not identical; thus eccentricity is caused, resulting in systematic geometric image measurement errors. This paper describes the functional context of this eccentricity for a typical target/camera set-up. The possible solutions for a correction of this systematic eccentricity error are derived. Guidelines for the correct combination of object target sizes and exposure distances, guaranteeing reliable image point measurements and accurate object point determination, are proposed.

Notes: Dolphins are agile animals and are very difficult to measure at sea. However, for the conservation of threatened or endangered species, measurement may be vital because it allows a demographic analysis of the population. Hector's dolphin (Cephalorhynchus hectori) is a rare species living only in coastal waters around New Zealand where it is studied from small boats. This paper describes a stereophotogrammetric technique developed to measure body length accurately at sea without having to capture the individual. Constant calibration with the use of a control frame allowed accurate body length measurements of dolphins to be made with this low cost system, with a measurement error of 4 per cent to 6 per cent of actual length.

Notes: The users of many digital photogrammetric systems are allowed a degree of control over the automated digital elevation model (DEM) generation software with a set of strategy parameters. These parameters control the search and quality control characteristics of the algorithm; hence the wrong choice of parameters can have a significant detrimental effect on the accuracy of the DEM. This paper describes the strategy parameters used in the Erdas Imagine OrthoMAX digital photogrammetric system and a set of tests used to define the optimum set of parameters for a project. The algorithm employs an area correlator and a hierarchical approach in the matching process. The results show that a 35 per cent increase in accuracy can be achieved through the process of parameter optimization. They also demonstrate that changes to the strategy parameters have a similar effect on the results for all areas of a set of imagery used in the test, which is of particular note because the imagery contains a diverse range of landcover types. The paper additionally provides a description of a system currently being developed which will automatically prescribe the correct set of parameters for a project.

Notes: Book review in this ArticlePHOTOGRAMMETRY. Volume 2 Advanced methods and applications. By K. Kraus with contributions by J. Jensa and H. Kager. Fourth edition, translated into English by P. Stewardson.Dümmler Verlag, Bonn, 1997. ISBN 3 427 78694 3. 240 x164 mm. 466 pages. lllustrated. Price DM 88.ERROR PROPAGATION IN ENVIRONMENTAL MODELLING WITH GIS. By G. B. M. Heuvelink.Taylor & Francis, London, 1998. ISBN 0 7484 0743 X (hardback), 0 7484 0744 8 (paperback). 233 × 156 mm. xviii + 127 pages. Price £24.95 paperback.GOVERNMENTS AND GEOGRAPHIC INFORMATION. By I. Masser.Taylor & Francis Ltd., London, 1998. ISBN 07484 0789 8 (cased), ISBN 07484 0706 5 (paperback). 246 × 170 mm. xi + 120 pages. 10 figures, 6 colour plates and 10 tables. Price £19.95 paperback.AN INTRODUCTION TO GEOGRAPHICAL INFORMATION SYSTEMS. By I. Heywood, S. Cornelius and S. Carver.Addison Wesley Longman Ltd., Harlow, 1998. ISBN 0 582 08940 9. 245 × 187 mm. xiv + 279 pages. Black and white illustrations and colour plates. Price £18.99paperback.EUROPEAN GEOGRAPHIC INFORMATION INFRASTRUCTURES: OPPORTUNITIES AND PITFALLS. GISData series V. Edited by P. A. Burrough and I. Masser.European Science Foundation/Taylor & Francis Ltd., London, 1998. ISBN 0 7484 0755 3 (hardbac ISBN 0 7484 0756 1 (paperback). 252 × 173 mm. xv + 172 pages. 4 colour plates. Price £55–95 hardback, £26.95 paperback.INNOVATIONS IN GIS. Selected Papers from the Fifth National Conference on GIS Research UK (GISRUK). Edited by S. Carver.Taylor & Francis Ltd., London, 1998. ISBN 0 7484 0810 X. 252 × 174 mm. xxii + 246 pages. Numerous illustrations, including four colour plates. Price £69.95.SCALE IN REMOTE SENSING AND GIS. Edited by D. A. Quattrochi and M. F. Goodchild.Lewis Publishers, New York, 1997. ISBN 1 56670 104 X. 235 × 165 mm. 406 pages, 21 colour plates, including bibliographical references, index, many diagrams and illustrations. Price £48.00 hardback.PRACTICAL GEODESY: USING COMPUTERS. By M. Hooijberg.Springer-Verlag, Heidelberg, 1997. ISBN 3 540 61826 0. 273 x198 mm. xi + 308 pages. 69 figures and 21 tables. Price £49.00 hardback.GIS ONLINE: INFORMATION RETRIEVAL, MAPPING, AND THE INTERNET. By B. Plewe.OnWord Press, Santa Fe, New Mexico, 1997. ISBN 1 56690 137 5. 179 × 228 mm. xv + 311 pages. 99 figures. World Wide Web site containing supporting material and update information: Price £29.95 paperback.ANALYSIS OF SAR DATA OF THE POLAR OCEANS: RECENT ADVANCES. Edited by C. Tsatsoulis. and R. Kwok. Springer-Verlag, Berlin, 1998. ISBN 3 540 62802 9. 241 × 160 mm. vi + 290 pages. 125 figures, including 26 in colour, and 18 tables. Price £95.50 hardback.IMAGES OF THE EARTH: A GUIDE TO REMOTE SENSING. Second edition. By S. A. Drury.Oxford University Press, Oxford, 1998. ISBN 0 19 854997 0. 276 × 220 mm. viii + 203 pages. 201 illustrations, 2 tables. Price £25.00 paperback.EXPLORING GEOGRAPHIC INFORMATION SYSTEMS. By N. R. Chrisman.John Wiley & Sons, Inc., New York, 1997. ISBN 0 471 10842 1. 230 × 190 mm. xvi + 298 pages. 103 figures and 27 tables. Price £24.95 paperback.

Notes: Abstract In laboratory experiments, we investigated two task/ambient conditioning systems with air supplied from desk-mounted air outlets to efficiently ventilate the breathing zone of heated manikins seated at desks. In most experiments, the task conditioning systems provided outside air while a conventional ventilation system provided additional space cooling but no outside air. Air change effectiveness (i.e., exhaust air age divided by age of air at the manikin's face) was measured with a tracer gas step-up procedure. Other tracer gases simulated the release of pollutants from nearby occupants and from the floor covering, and the associated pollutant removal efficiencies (i.e., exhaust air concentrations divided by concentrations at manikin's face) were calculated. High values of air change effectiveness (∼1.3 to 1.9) and high values of pollutant removal efficiency (∼1.2 to 1.6) were measured when these task conditioning systems supplied 100% outdoor air at a flow rate of 7 to 9 L s-1 per occupant. Air change effectiveness was reasonably well correlated with the pollutant removal efficiency. Overall, the experimental data suggest that these task/ambient conditioning systems can be used to improve ventilation and air quality or to save energy while maintaining a typical level of IAQ at the breathing zone.

Notes: Abstract Sixteen flights had been investigated for indoor air quality (IAQ) on Cathay Pacific aircraft from June 1996 to August 1997. In general, the air quality on Cathay Pacific aircraft was within relevant air quality standards because the average age of aircraft was less than 2 years. Carbon dioxide (CO2) levels on all flights measured were below the Federal Aviation Administration (FAA) standard (30,000 ppm). The CO2 level was substantially higher during boarding and de-boarding than cruise due to low fresh air supply. Humidity on the aircraft was low, especially for long-haul flights. Minimum humidity during cruise was below the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) minimum humidity standard (20%). The average temperature was within a comfortable temperature range of 23±2°C. The vertical temperature profile on aircraft was uniform and below the International Standard Organization (ISO) standard. Carbon monoxide levels were below the FAA standard (50 ppm). Trace amount of ozone detected ranged from undetectable to 90 ppb, which was below the FAA standard. Particulate level was low for most non-smoking flights, but peaks were observed during boarding and de-boarding. The average particulate level in smoking flights (138 (ig/m3) was higher than non-smoking flights (7.6 μg/m3). The impact on IAQ by switching from low-mode to high-mode ventilation showed a reduction in CO2 levels, temperature, and relative humidity.

Notes: Abstract The chemical and sensory emissions from five building materials (carpet, polyvinyl chloride (PVC) flooring, sealant, floor varnish and wall paint) were tested under different combinations of temperature and relative humidity in the ranges 18–28°C and 30–70% relative humidity (RH). The experiment was performed in a climate chamber where a specially designed test system was built to study emissions from the five materials. The test system could provide different temperatures and humidities of air around the materials, while the air, after being polluted by the emissions from the materials, could be reconditioned to 23°C and 50% RH for sensory assessments. The experiment was designed to separate the direct impact of temperature and humidity on perception from the impact on sensory emission. The study found little influence of temperature on the emissions from the five materials whether expressed in chemical or sensory terms. The effect of humidity was found to be significant only for the waterborne materials – floor varnish and wall paint. Compared with the direct impact of temperature and humidity on the perception of air quality, the impact of temperature and humidity on sensory emissions from the building materials has a secondary influence on perceived air quality.

Notes: Abstract Volatile organic emissions from particleboard, medium density fibreboard (MDF) and office furniture have been measured in dynamic environmental chambers, both small and room-sized. Characterisation of product emission properties in small chambers was possible when inter- and intra-sheet variations were considered. Formaldehyde emission factors for all products were approximately double European low-emission specifications and did not decay to the latter for several months. Long-term emission behaviour could not be predicted from short-term measurements. Volatile organic compounds (VOC) emissions were low for the MDF product, higher for particleboard, and highest for laminated office furniture. The compounds emitted differed from those reported in other countries. VOC emissions from the sheet products decreased more quickly than formaldehyde, reaching low levels within two weeks, except for MDF which was found to become a low-level source of hexanal after several months.

Notes: Abstract Birch and grass pollen grains as well as pollen-derived small particles appear as potent allergens in the outdoor air during spring and summer. The occurrence of pollen allergens in indoor air, however, has not been studied in depth due to lack of suitable sampling and analytical methods. Herein, a recently reported “direct on sampling filter estimation” (DOSAFE) technique (Acevedo et al., 1998) has been validated for quantification of pollen allergens in indoor air using two school rooms and two office rooms as experimental models. Using DOSAFE and polyclonal antibodies against water extracts of pollen from Betula pendula and Phleum pratense L, we found that indoor air of school and office rooms carried substantial amounts of pollen allergens, expressed as SQ units, predominantly occurring as particles with smaller diameters than the pollen grains. In one school room the indoor air birch pollen allergen concentrations increased from 242 to 403 SQ units/m3 over the sampling period although the corresponding outdoor air concentrations decreased from 350 to 90 SQ units/m3. Electrostatic air cleaning in one office room reduced its grass pollen allergen concentrations by more than 95% to 0.02–0.34 SQ units/m3 as compared to the control room.

Notes: Abstract Polyurethane products were subjected to chamber testing to determine their emission rates of 2,4- and 2,6-toluene diisocyanate (TDI). The polyurethane (PU) products included carpet padding, furniture cushions, sheet foam, varnishes, and sealants, as well as a commercially-applied water sealant product for concrete that contained up to 4 percent TDI by weight. The PU products were screened in a 9-L glass chamber, under elevated temperature and chamber loading conditions, using both a time-integrated sampling and analysis method specific for TDI and a continuous but non-specific real-time monitor for isocyanates. None of the products normally found in residences showed a positive response in the screening tests, indicating that TDI emissions and consequently toxic effects from such products are negligible. However, the commercially-applied water sealant gave a positive response in the screening test. Further testing of that product at realistic temperatures showed initial TDI emission rates of about 300,000 μg/m2/hr, with emissions lasting only one hour or less. At 21 and 27°C, about 1 percent and 5 percent, respectively, of the TDI content of the product was released to the air. The emitted TDI was predominantly the 2,6-isomer, although the TDI originally present in the product was predominantly the 2,4-isomer.

Notes: Abstract A simple test chamber method to quantify adsorption and desorption of organic compounds on material surfaces is described. Important environmental parameters such as temperature, relative humidity and air velocity were varied and controlled independently around typical indoor values. Experiments were performed with α-pinene and toluene in concentrations of 160-300 μg/m3. The measurements show adsorption on and desorption from wool carpet, nylon carpet, polyvinyl chloride (PVC) floor coverings, cotton curtain material and the empty chamber. The ranking of the materials, with respect to their sorption capacity, is as mentioned above. The adsorption of α-pinene was higher than the adsorption of toluene for all the materials. Air velocity was not found to influence the sorption of α-pinene and toluene on wool carpet, tested with air velocities at 0, 10 and 20 cm/s. The experiments were carried out during both the adsorption and the desorption phase. The uncertainty of the experiments was lowest during the desorption phase. Based on the results obtained, it can be recommended that sorption experiments should be performed as desorption phase experiments. A one-sink model, based on the Langmuir adsorption isotherm, appears adequate to describe the results.

Notes: Abstract Walk through questionnaires may be feasible tools to obtain data on the indoor environment in community studies. However, limited information is available regarding the reproducibility of the data obtained through these questionnaires. In this pilot study, two construction engineering students inspected ten dwellings twice by means of a standardized walk through questionnaire. The two engineering students inspected the dwellings independent of each other within two months. Time between the two visits varied between 14 and 40 days. The variables presented were based on information from the residents and inspection. The continuous variables recorded included number of rooms in the dwellings, room volume, length of filled shelves and textile area. The inter- and intra-observed variabilities were poorer for number of rooms and shelf factor than for the other variables. For the 3 of the 9 categorical variables based on inspection, the inter-observer comparison showed complete agreement with a kappa statistics of 1.0, these variables being condition of the window frames and construction of outside walls and roof. One of the categorical variables showed a kappa statistics of 〈0.5, these variables being presence of basement and presence of condensation at windows. This study indicates a wide variation in observer variability between various items of a walk through questionnaire. Clear definitions of all the parts of the questionnaire are needed, as well as thorough training of observers.

Notes: Abstract Data of chemical emissions from flooring materials have been collected and investigated in a database known as METS. The emission tests are performed using the Field and Laboratory Emission Cell (FLEC). The emission rates of total volatile organic compounds (TVOC) in the boiling point range of hexane to octa-decane varies from around 4,000 μg/(m2· h) to less than 10 μg/ (m2· h). Results obtained 1994/95 are presented and compared with the results obtained in 1992 for similar materials. The tests are performed 4 weeks and 26 weeks after the manufacturing of the material. The emission rates of TVOC decrease on the average approximately 60% from 4 to 26 weeks. The differences and trends in emission rates of individual chemicals and their use are discussed. For many VOCs emission rates decrease rapidly and become near to or below 2 μg/(m2· h) (the detection limit) after 26 weeks. For a small number of individual compounds the emission rate decrease little over 26 weeks. A small number of chemicals are singled out for particular interest in a health and comfort evaluation based on the emission results.

Notes: Abstract Various studies on indoor and outdoor particulate matter in the urban environment in the vicinity of busy arterial roads in the centre of the subtropical city of Brisbane have indicated that the revised United States Environmental Protection Agency National Ambient Air Quality Standards (US EPA NAAQS) for Particulate matter PM2.5 could be exceeded not only outdoors but also indoors. The aim of this work was to investigate outdoor exposure to submicrometer particles and their relationship with indoor exposure in a hypothetical office building located in the vicinity of a busy arterial road. The outdoor exposure values and trends were measured in terms of particle number in the submicrometer size range and were then recalculated to represent mass concentration trends. The results of this study indicate that exposure to PM0.7 particles in ambient air close to a busy road often exceeds the levels of the annual and 24-hour US EPA NAAQS PM2.5 standards. It is likely that exposure to PM2.5 is even higher, and may significantly exceed these standards.

Notes: Abstract Eighteen laboratories from 10 European countries participated in a comparison organized as part of the VOCEM project, a 2.5-year research collaboration among 4 research institutes and 4 industrial companies. The scope of the project was to improve the procedure used to measure volatile organic compounds (VOC) emitted from building materials and products in small test chambers. The interlaboratory comparison included the GC-MS determination of 5 target compounds from carpet, 8 from polyvinyl chloride (PVC) cushion vinyl and 2 from paint; for the first time, chamber recovery (sinks), homogeneity of solid materials and possible contamination during transport were tested. The results show that the intralaboratory variance (random errors) is much smaller than the interlaboratory variance (systematic errors). Causes of the largest interlaboratory discrepancies were: (i) analytical errors; (ii) losses of the heaviest compounds due to sorption on the chamber walls; and (iii) non homogeneity of the materials. The output of this work concerns both the objective of labelling materials with regard to their VOC emissions and the pre-standard drafted by the European Commitee for Standardization (CEN) for this type of determination.

Notes: Abstract To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s−1 to 9.7 cm s−1. There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s−1 to 35.5 cm s−1 with turbulence intensities from 33% to 108%.

Notes: Abstract The age of the air in a room is normally determined either from a pulse response or from a step change response (up or down). There are a certain number of problems involved in applying these two theoretical models, especially those associated with the duration of the injection, which must either be infinitely short or infinitely long. A hybrid method that consists of injecting a known quantity of tracer for a given time offers the advantages of both methods. The equation for calculating age is exact, regardless of the type of flow considered, and is derived from the expressions already established for a pulse response to which a correction is included to account for the tracer generation function. If a rectangular pulse is used for the injection, the solution is particularly simple.

Notes: Abstract The aim of the study was to describe how allergies and non-allergies perceive the same environment. All high school students in a town in southern Sweden were invited to answer a questionnaire concerning allergy, subjective symptoms, annoyance reactions and perception of the environment (response rate: 81%). The results show that only 45% of the students were non-allergic (n = 1,715). Since the symptom frequency among non-allergic students was normal, the schools were classified as healthy. However, compared to the non-allergic students, a higher percentage among the allergies suffered from symptoms every week, a lower percentage was satisfied with the air quality and the cleaning, and a higher percentage was bothered every week by temperature, stuffy/stale air, bad odor, passive smoke, bad lighting, noise, dust and dirt (ANOVA, P 〈 0.05). The findings could indicate that allergies note discomfort earlier than non-allergies by being more critical in general and especially critical to factors that could effect their health. The findings could also indicate that awareness of ones own sensitivity could lead to attention to different risk factors, which in turn could lead to stress/anxiety, which could make symptoms worse. The conclusion is that it is important to take allergy into consideration when the environment is assessed.

Notes: Abstract Five classrooms, air-conditioned or naturally ventilated, at five different schools were chosen for comparison of indoor and outdoor air quality. Temperature, relative humidity (RH), carbon dioxide (CO2), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), particulate matter with diameter less than 10 mm (PM10), formaldehyde (HCHO), and total bacteria counts were monitored at indoor and outdoor locations simultaneously. Respirable particulate matter was found to be the worst among parameters measured in this study. The indoor and outdoor average PM10 concentrations exceeded the Hong Kong standards, and the maximum indoor PM10 level was even at 472 μ;g/m3. Air cleaners could be used in classrooms to reduce the high PM10 concentration. Indoor CO2 concentrations often exceeded 1,000 μl/l indicating inadequate ventilation. Lowering the occupancy and increasing breaks between classes could alleviate the high CO2 concentrations. Though the maximum indoor CO2 level reached 5,900 μl/l during class at one of the sites, CO2 concentrations were still at levels that pose no health threats.