The spatiotemporal sequencing of everyday activities in the large-scale environment

Choices of where to carry out everyday activities in large-scale environments were conceptualized as a process of forming ‘travel plans’, and, to test a model of how such plans are formed, three experimental simulations of a planning task were performed in the laboratory. In Experiment 1, subjects (high school students) were found to choose a shortest route to travel between a number of actual, familiar locations in a town by first choosing the order between the locations that minimized straight-line (Euclidean) distances, then choosing the shortest paths between the locations in the constrained order. The order choices were, in Experiment 2, found to be made by minimizing distance locally rather than globally, except in some cases when ‘spatial configurations’ of the locations were discovered. Both the results of this experiment and of Experiment 3 suggested that such discoveries were facilitated by a simultaneous representation of the locations which was possible when they were positions on a display, committed to short-term memory or available for perceptual inspection, but to a less extent when they were actual locations.     

A MULTIVARIATE ANALYSIS OF SERIAL MURDERERS'' DISPOSAL SITE LOCATION CHOICE

The application of environmental psychology principles and findings to the work of criminal investigators is gaining ground. This paper presents one particular application of these principles to the study of those very rare criminals, serial killers. An environmental psychology perspective looks on the rational processes that may underlie these disturbing and highly emotive crimes. For, although the murders committed by serial killers may not be considered rational, but rather a consequence of heightened emotion and lack of impulse control, environmental psychology hypotheses predict that their choice of disposal site location may be guided by a recognisable rationality. Support for this rationality would be evident through their spatial patterns of disposal locations, but these spatial patterns themselves would vary depending on the range over which the offender was operating. It was therefore hypothesised that their spatial patterns would reflect the importance of a) the centrality of the home location for determining the disposal site locations, b) the relevance of maintaining distance between sequential disposal site locations themselves. Further, c) the nature of the influences of home and sequence would vary with the size of the area over which the offender disposed of his victims' bodies.The hypotheses were tested by examining three sub-sets of a sample of 120 American serial murderers, each sub-set travelling a different average distance from their homes to their crimes. The Multidimensional Scaling Procedure, Smallest Space Analysis (SSA-I) was used in order to examine the trends across the distances between each disposal site and every other and their distances from the offender's homes. A three dimensional space was used so that the ‘dimension’ of temporal sequence could be revealed as well as the two dimensions of geographical distances. All hypotheses were supported. Firstly, the home was central to the SSA disposal patterns for each of the three sub-sets. Secondly, the location of each subsequent disposal location tended to be in a different direction from that immediately prior to it. However, thirdly, this sequential process was strongest for the sub-set of 36 offenders who travelled on average less than 10 km and weakest for those 40 offenders who travelled on average greater than 30 km. The implications these results have for modelling offenders' geographical behaviour are discussed.     

A Comparison of Data Sets Varying in Spatial Accuracy Used to Predict the Occurrence of Wildlife-Vehicle Collisions

Wildlife-vehicle collisions (WVCs) pose a significant safety and conservation concern in areas where high-traffic roads are situated adjacent to wildlife habitat. Improving transportation safety, accurately planning highway mitigation, and identifying key habitat linkage areas may all depend on the quality of WVC data collection. Two common approaches to describe the location of WVCs are spatially accurate data derived from global positioning systems (GPS) or vehicle odometer measurements and less accurate road-marker data derived from reference points (e.g., mile-markers or landmarks) along the roadside. In addition, there are two common variable types used to predict WVC locations: (1) field-derived, site-specific measurements and (2) geographic information system (GIS)-derived information. It is unclear whether these different approaches produce similar results when attempting to identify and explain the location of WVCs. Our first objective was to determine and compare the spatial error found in road-marker data (in our case the closest mile-marker) and landmark-referenced data. Our second objective was to evaluate the performance of models explaining high- and low-probability WVC locations, using congruent, spatially accurate (<3-m) and road-marker (<800-m) response variables in combination with field- and GIS-derived explanatory variables. Our WVC data sets were comprised of ungulate collisions and were located along five major roads in the central Canadian Rocky Mountains. We found that spatial error (mean ± SD) was higher for WVC data referenced to nearby landmarks (516 ± 808 m) than for data referenced to the closest mile-marker data (401 ± 219 m). The top-performing model using the spatially accurate WVC locations contained all explanatory variable types, whereas GIS-derived variables were only influential in the best road-marker model and the spatially accurate reduced model. Our study showed that spatial error and sample size, using road-marker data for ungulate species, are important to consider for model output interpretation, which will impact the appropriate scale on which to apply modeling results. Using road-marker references <1.6 km or GPS-derived data locations may represent an optimal compromise between data acquisition costs and analytical performance. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Using Data From Seed-Dispersal Modelling to Manage Invasive Tree Species: The Example of Fraxinus pennsylvanica Marshall in Europe

Management strategies to control invasive species need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous tree species that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this tree species. The model predicts approximately 250,000 seeds for one F. pennsylvanica tree. These results were used to (2) calculate species-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the tree species, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive species.     

EFFECTS OF ADJACENT AGRICULTURAL ACTIVITIES AND WATERSHED CHARACTERISTICS ON STREAM MACROINVERTEBRATE COMMUNITIES1

Benthic macroinvertebrate communities in streams adjacent to cornfields, streams where cows had unrestricted access, and reference locations without agriculture were compared to examine the effects of local land use and land use/land cover in the watershed. At each local site, macroinvertebrates and a variety of habitat parameters were measured upstream, adjacent, downstream, and farther downstream of the local land use. A geographic information system (GIS) was used to calculate drainage basin area, land use/land cover percentages in each basin, and the distance from sample sites to the stream source. Three‐way analysis of covariance (ANCOVA) tests with date, site type, and sampling location as main effects were used to explore differences in macroinvertebrate metrics using median substrate size, percent hay/pasture area, and stream depth as covariates. The covariates significantly improved model fit and showed that multiple contributing factors influence community composition. Local impacts were greatest at sites where cows had access, probably because of sedimentation and embeddedness in the substrate. Differences between the upstream and the adjacent and downstream locations were not as great as expected, perhaps because upstream recolonization was reduced by agricultural impacts or because of differences in the intensity or proximity of agriculture to riparian areas in the watershed. The results underscore the importance of both local and watershed factors in controlling stream community composition.     

Assessing Spatial Scale Effects on Hydrometric Network Design Using Entropy and Multi‐objective Methods

In order to facilitate water resources decisions, it is important that accurate and informative hydrometric data are collected. Combining information theory with multi‐objective optimization has led to methods of optimizing the information content provided by hydrometric networks; however, there is no available study on the effects of spatial scale and data limitation on these methods. Herein, a dual entropy multi‐objective optimization (DEMO) and a transinformation (TI) analysis were done to recommend optimal locations for additional hydrometric stations in the Madawaska Watershed. This analysis was designed to be comparative to a similar study conducted on the Ottawa River Basin which encompasses the Madawaska Watershed to allow for an investigation of the spatial scale effects in this type of network design. This study concludes that TI analysis is not adversely affected by scaling; however, the DEMO analysis is sensitive to the placement of potential station locations and the size of the study area. This study also examines the benefit of including nearby stations when the area of interest does not have a sufficient number of existing hydrometric stations for analysis. It is shown that these stations can provide useful information because their inclusion in the analysis increased the average TI in the watershed. Recommendations were made as to the ideal locations of additional stations in the Madawaska Watershed hydrometric network.     

Effects of Impervious Cover at Multiple Spatial Scales on Coastal Watershed Streams1

Abstract: The spatial scale and location of land whose development has the strongest influence on aquatic ecosystems must be known to support land use decisions that protect water resources in urbanizing watersheds. We explored impacts of urbanization on streams in the West River watershed, New Haven, Connecticut, to identify the spatial scale of watershed imperviousness that was most strongly related to water chemistry, macroinvertebrates, and physical habitat. A multiparameter water quality index was used to characterize regional urban nonpoint source pollution levels. We identified a critical level of 5% impervious cover, above which stream health declined. Conditions declined with increasing imperviousness and leveled off in a constant state of impairment at 10%. Instream variables were most correlated (0.77 ≤ |r| ≤ 0.92, p < 0.0125) to total impervious area (TIA) in the 100‐m buffer of local contributing areas (～5‐km² drainage area immediately upstream of each study site). Water and habitat quality had a relatively consistent strong relationship with TIA across each of the spatial scales of investigation, whereas macroinvertebrate metrics produced noticeably weaker relationships at the larger scales. Our findings illustrate the need for multiscale watershed management of aquatic ecosystems in small streams flowing through the spatial hierarchies that comprise watersheds with forest‐urban land use gradients.     

Is elevation encoded in cognitive maps?

Two experiments examined whether differences in elevation of the terrain are encoded in cognitive maps of outdoor environments. In Experiment 1, two groups of subjects who had travelled a varying number of times between a set of locations made direct estimates in metres of the differences in elevation between the locations. The results showed that subjects in both groups had knowledge of elevation but those for whom the terrain was less familiar tended to exaggerate the differences. In Experiment 2, decision times were measured of responses to the question whether one location is below or above another one. Neither for subjects who were more, nor for subjects who were less familiar with the terrain, did the decision times vary with the distances between the locations, thus failing to support the hypothesis that differences in elevation are retrieved by a process of ‘mental travel’.     

Use of GIS in siting stabilization pond facilities for domestic wastewater treatment

Geographic information systems (GIS) use is presented in the problem of sitting areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected areas, mean minimum monthly temperatures and required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The required area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total required surface area of these systems was compared to the available surface area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new areas for construction of such systems.     

A geophysical perspective of value of information: examples of spatial decisions for groundwater sustainability

The value of information (VOI) can be used to determine what kind of spatial information maybe relevant and useful for groundwater sustainability decisions. In this paper, the unique challenges for applying VoI to spatial information from geophysical data are described. The uncertainty regarding the spatial structure or continuity of the subsurface properties can be described with geostatistical sample models. Using these models, one can quantify the prior value given our present state of uncertainty and a set of decision alternatives and outcomes. Because geophysical techniques are a type of remote-sensing data, assuming “perfect” information is not realistic since the techniques usually are indirectly sampling the aquifer properties. Therefore, the focus of this paper is describing how the data reliability (the measure of imperfectness) can be quantified. One of the foremost considerations is the non-unique relationship between geological parameters (which determine groundwater flow) and geophysical observables (what determines the response of the technique). Another is to have the information in a form such that it is useful for spatial decisions. This will often require inversion and interpretation of the geophysical data. Inversion reconstructs an image of the subsurface from the raw geophysical data. How closely the image reproduces the true subsurface structure or property of interest depends on the particular technique’s resolution, depth of investigation and sensor locations. Lastly, in some cases, interpretation of the geophysical data or inversion will be necessary to link the data to the variables that determine the outcome of the decision. Three examples are provided that illustrate different approaches and methods for addressing these challenges. In the examples, time-domain electromagnetic and electrical resistivity techniques are evaluated for their ability to assist in spatial decisions for aquifer management. The examples considered address these three situations: aquifer vulnerability to surface–borne contaminants, managed aquifer recharge and CO₂/brine leakage (related to CO₂ geologic sequestration activities). The methods presented here are transferable to other subsurface sciences and decisions that involve risk. Recent work has been applied to geothermal well-siting using electromagnetic techniques. These approaches can also be applied for oil and mining spatial decisions, and they offer advantages over previous VOI work done for oil applications: they explicitly include the geologic uncertainty modeling and simulate the physics of the considered geophysical technique.     

The use of an atmospheric dispersion model to determine influence regions in the Prince George,B.C. airshed from the burning of open wood waste piles

A means of determining air emission source regions adversely influencing the city of Prince George, British Columbia, Canada from potential burning of isolated piles of mountain pine beetle-killed lodge pole pine is presented. The analysis uses the CALPUFF atmospheric dispersion model to identify safe burning regions based on atmospheric stability and wind direction. Model results show that the location and extent of influence regions is sensitive to wind speed, wind direction, atmospheric stability and a threshold used to quantify excessive concentrations. A concentration threshold based on the Canada Wide PM_2.5 Standard is used to delineate the influence regions while Environment Canada's (EC) daily ventilation index (VI) is used to quantify local atmospheric stability. Results from the analysis, to be used by air quality meteorologists in assessing daily requests for burning permits, are presented as a series of maps delineating acceptable burning locations for sources placed at various distances from the city center and under different ventilation conditions. The results show that no burning should be allowed within 10 km of the city center; under poor ventilation conditions, no burning should be allowed within 20 km of the city center; under good ventilation conditions, burning can be allowed within 10–15 km of the city center; under good to fair ventilation conditions, burning can be allowed beyond 15 km of the city center; and if the wind direction can be reliably forecast, burning can be allowed between 5 and 10 km downwind of the city center under good ventilation conditions.     

Sociological edge effects: Spatial distribution of human impact in suburban forest fragments

Suburban forest fragments often experience heavy recreational and waste disposal use, with considerable damage to the vegetation. To suggest strategies for conservation of the forest flora, spatial distributions of human impact were described in 40 fragmentary stands in northern New Castle County, Delaware. The distribution of human impact showed a significant bias to the forest edge, with 95% of localized damage occurring in the first 82 m. Forms of impact related to lawn maintenance fell significantly closer to the edge than impacts related to recreation and showed the strongest edge orientation. Edge distances of campsites, vandalized trees, and firewood gathering were negatively correlated with distance to the nearest graded road, indicating the importance of road access. Several forms of impact were also clustered near footpaths, although distance to paths was independent of edge distance in all cases. In terms of penetration of the forest and severity of damage, human impact greatly exceeds natural edge effects reported for this community. These findings suggest that damage may be minimized by limiting road access and avoiding the creation of small forest fragments.     

Memory for the spatial layout of the everyday physical environment: Factors affecting rate of acquisition

That a memory representation of the spatial layout of a large-scale environment may be acquired very fast was shown in two experiments in which subjects (48 undergraduates and high-school students) were taken on tours through a residential area with which they were unfamiliar. Memory for the path traversed was almost perfect after the first trial, as indicated by almost perfect recall of the order in which a number of designated landmarks had been passed. Memory for the locations of the same landmarks appeared to reach an asymptotic level after the second of three trials. The memory representation of the locations were however not perfectly accurate, thus the asymptotic level might have been an acquisition plateau. The rate of acquisition was slightly faster for subjects driven in a car slowly through the area than for those who walked the same path. Men tended to improve slightly faster than women if they were driven by car but there were no other sex differences. Finally, the acquired memory representation appeared to be resistant to forgetting. Re-learning after a one-week retention interval was faster and rate of learning was not negatively affected whether the trials were massed or distributed with one week in between. The results are discussed in terms of hypotheses concerning the order in which different types of information about spatial layouts (landmarks, paths, and locations) are acquired. The bearing of the results on the question of why memory representations of the spatial layout are often found to be distorted is also discussed.     

Decision making under uncertainty using PEES–fuzzy AHP–fuzzy TOPSIS methodology for landfill location selection

The location selection for landfill municipal solid waste is an important issue in waste management. Selection of the optimal location requires consideration of multiple alternative solutions and evaluation factors because of system complexity. Further, ranking of the alternative locations and selection of the most optimal and efficient locations for landfill waste are an important multi-criteria decision-making problem. In this study, the candidate locations for landfill are determined based on Political, Economical, Environmental and Social factors are assessed through decision-makers’ opinion and by the methodology that incorporates fuzzy analytic hierarchy process (fuzzy AHP) and fuzzy technique for order preference by similarity to ideal solution (fuzzy TOPSIS). Specifically, the fuzzy AHP technique is applied to determine the weights of selected criteria impacting the location selection process, and the fuzzy AHP is adapted to model the linguistic vagueness and ambiguity, which can also be expressed as triangular fuzzy numbers. Furthermore, fuzzy TOPSIS technique is employed to rank the alternative locations. The applicability of this methodology is demonstrated by a case study of landfill waste location selection in the region of Casablanca, Morocco, and the results are compared with other techniques. Finally, to complete the treatment, a sensitivity analysis is performed to examine the impact of the preferences given by decision-makers to choose the best location.     

Assessment of surface water quality of selected estuaries of Malaysia: multivariate statistical techniques

Multivariate statistical techniques such as cluster analysis (CA), factor analysis (FA) were used for the evaluation of spatial variations and the interpretation of a large complex water quality data set of two selected estuaries of Malaysia. The two locations of interest with 10 sites in each location were Kuala Juru (Juru estuary) and Bukit Tambun (Jejawi estuary). Cluster analysis showed that some sites in both locations have similar sources of pollution from point or non-point sources whereas FA yielded four factors which are responsible for water quality variations explaining more than 80% of the total variance of the data set and allowed to group the selected water quality. Correlation analysis of the data showed that some parameters have strong association with other parameters and they share a common origin source. This study illustrates the usefulness of multivariate statistical analysis for evaluation and interpretation of complex data sets to get better information about the pollution sources/factors and understanding the behavior of the parameters in water quality for effective river water quality management.     

Effects of Riparian Areas,Stream Order,and Land Use Disturbance on Watershed‐Scale Habitat Potential: An Ecohydrologic Approach to Policy1

Abstract: Spatio‐temporal linkages between hydrologic and ecologic dimensions of watersheds play a critical role in conservation policies. Habitat potential is influenced by variation along longitudinal and lateral gradients and land use disturbance. An assessment of these influences provides critical information for protecting watershed ecosystems and in making spatially explicit, conservation decisions. We use an ecohydrologic approach that focuses on interface between hydrological and ecological processes. This study focuses on changes in watershed habitat potentials along lateral (riparian), and longitudinal (stream order) dimensions and disturbance (land use). The habitat potentials were evaluated for amphibians, reptiles, mammals, and birds in the Westfield River Watershed of Massachusetts using geographic information systems and multivariate analysis. We use a polynomial model to study nonlinear effects using robust regression. Various spatial policies were modeled and evaluated for influence on species diversity. All habitat potentials showed a strong influence along spatial dimensions and disturbance. The habitat potential for all vertebrate groups studied decreased as the distance from the riparian zone increased. Headwaters and lower order subwatersheds had higher levels of species diversity compared to higher order subwatersheds. It was observed that locations with the least disturbance also had higher habitat potential. The study identifies three policy criteria that could be used to identify critical areas within a watershed to conserve habitat suitable for various species through management and restoration activities. A spatially variable policy that is based on stream order, riparian distance, and land use can be used to maximize watershed ecological benefits. Wider riparian zones with variable widths, protection of headwaters and lower order subwatersheds, and minimizing disturbance in riparian and headwater areas can be used in watershed policy. These management objectives could be achieved using targeted economic incentives, best management practices, zoning laws, and educational programs using a watershed perspective.     

Temporal and spatial distributions of sediment total organic carbon in an estuary river

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.     

Sampling and Mapping a Soil Erosion Cover Factor by Integrating Stratification,Model Updating and Cokriging with Images

Cost-efficient sample designs for collection of ground data and accurate mapping of variables are required to monitor natural resources and environmental and ecological systems. In this study, a sample design and mapping method was developed by integrating stratification, model updating, and cokriging with Landsat Thematic Mapper (TM) imagery. This method is based on the spatial autocorrelation of variables and the spatial cross-correlation among them. It can lead to sample designs with variable grid spacing, where sampling distances between plots vary depending on spatial variability of the variables from location to location. This has potential cost-efficiencies in terms of sample design and mapping. This method is also applicable for mapping in the case in which no ground data can be collected in some parts of a study area because of the high cost. The method was validated in a case study in which a ground and vegetation cover factor was sampled and mapped for monitoring soil erosion. The results showed that when the sample obtained with three strata using the developed method was used for sampling and mapping the cover factor, the sampling cost was greatly decreased, although the error of the map was slightly increased compared to that without stratification; that is, the sample cost-efficiency quantified by the product of cost and error was greatly increased. The increase of cost-efficiency was more obvious when the cover factor values of the plots within the no-significant-change stratum were updated by a model developed using the previous observations instead of remeasuring them in the field.     

A Heuristic Method for Determining Changes of Source Loads to Comply with Water Quality Limits in Catchments

A common land and water management task is to determine where and by how much source loadings need to change to meet water quality limits in receiving environments. This paper addresses the problem of quantifying changes in loading when limits are specified in many locations in a large and spatially heterogeneous catchment, accounting for cumulative downstream impacts. Current approaches to this problem tend to use either scenario analysis or optimization, which suffer from difficulties of generating scenarios that meet the limits, or high complexity of optimization approaches. In contrast, we present a novel method in which simple catchment models, load limits, upstream/downstream spatial relationships and spatial allocation rules are combined to arrive at source load changes. The process iteratively establishes the critical location (river segment or lake) where the limits are most constraining, and then adjusts sources upstream of the critical location to meet the limit at that location. The method is demonstrated with application to New Zealand (268,000 km2) for nutrients and the microbial indicator E. coli, which was conducted to support policy development regarding water quality limits. The model provided useful insights, such as a source load excess (the need for source load reduction) even after mitigation measures are introduced in order to comply with E. coli limits. On the other hand, there was headroom (ability to increase source loading) for nutrients. The method enables assessment of the necessary source load reductions to achieve water quality limits over broad areas such as large catchments or whole regions.     

Geographic variability of Escherichia coli ribotypes from animals in Idaho and Georgia

Several genotypic methods have been developed for determining the host origin of fecal bacteria in contaminated waters. Some of these methods rely on a host origin database to identify environmental isolates. It is not well understood to what degree these host origin isolates are geographically variable (i.e., cosmopolitan or endemic). This is important because a geographically limited host origin database may or may not be universally applicable. The objective of our study was to use one genotypic method, ribotyping, to determine the geographic variability of the fecal bacterium, Escherichia coli, from one location in Idaho and three locations in Georgia for cattle (Bos taurus), horse (Equus caballus), swine (Sus scrofa), and chicken (Gallus gallus domesticus). A total of 568 fecal E. coli isolates from Kimberly, ID (125 isolates), Athens, GA (210 isolates), Brunswick, GA (102 isolates), and Tifton, GA (131 isolates), yielded 213 ribotypes. The percentage of ribotype sharing within an animal species increased with decreased distance between geographic locations for cattle and horses, but not for swine and chicken. When the E. coli ribotypes among the four host species were compared at one location, the percent of unshared ribotypes was 86, 89, 81, and 79% for Kimberly, Athens, Brunswick, and Tifton, respectively. These data suggest that there is good ribotype separation among host animal species at each location. The ability to match environmental isolates to a host origin database may depend on a large number of environmental and host origin isolates that ideally are not geographically separated.