Land-use suitability analysis in the United States: historical development and promising technological achievements

Various methods of spatial analysis are commonly used in land-use plans and site selection studies. A historical overview and discussion of contemporary developments of land-use suitability analysis are presented. The paper begins with an exploration into the early 20th century with the infancy of documented applications of the technique. The article then travels through the 20th century, documenting significant milestones. Concluding with present explorations of advanced technologies such as neural computing and evolutionary programming, this work is meant to serve as a foundation for literature review and a premise for the exploration of new advancements as we enter into the 21st century.     

Exploratory visualization software for reporting environmental survey results

Environmental surveys yield three principal products: maps, a set of data tables, and a textual report. The relationships between these three elements, however, are often cumbersome to present, making full use of all the information in an integrated and systematic sense difficult. The published paper report is only a partial solution. Modern developments in computing, particularly in cartography, GIS, and hypertext, mean that it is increasingly possible to conceive of an easier and more interactive approach to the presentation of such survey results. Here, we present such an approach which links map and tabular datasets arising from a vegetation survey, allowing users ready access to a complex dataset using dynamic mapping techniques. Multimedia datasets equipped with software like this provide an exciting means of quick and easy visual data exploration and comparison. These techniques are gaining popularity across the sciences as scientists and decision-makers are presented with increasing amounts of diverse digital data. We believe that the software environment actively encourages users to make complex interrogations of the survey information, providing a new vehicle for the reader of an environmental survey report.     

Regulating water quantity and quality in irrigated agriculture

This paper largely applies the theoretical model formulated in an earlier paper by the authors, of an input based approach to control an agricultural non-point-source pollution. The empirical problem includes a groundwater aquifer being polluted by several agricultural producers. In order to prevent degradation of the quality and depletion of the quantity of the water in the aquifer, a regulatory agency must intervene. The regulatory agency does not have all the information needed for decision making. The producers» use of water from a surface supply is recorded and additional water is pumped from the ground aquifer, the amount of which is unknown to the agency. The agency also does not know the physical characteristics of the production process that is factored into the pollution process. The model evaluates two monitoring regimes (central and individual) and two regulatory tools (taxes and quotas) associated with each regime. Individual monitoring was found to be superior to central monitoring, both in terms of the physical characteristics of the problem (water quality and quantity) and in terms of regional income. For both the central and the individual monitoring regimes, the optimal paths of the state variables reach steady-state values relatively early, with values in the individual monitoring reaching the steady-state earlier than in the case of central monitoring. The optimal path of investment in monitoring equipment suggested investment in monitoring equipment as early as possible.1998 Academic Press     

Determinants of Spatial and Temporal Patterns in Compensatory Wetland Mitigation

Development projects that impact wetlands commonly require compensatory mitigation, usually through creation or restoration of wetlands on or off the project site. Over the last decade, federal support has increased for third-party off-site mitigation methods. At the same time, regulators have lowered the minimum impact size that triggers the requirement for compensatory mitigation. Few studies have examined the aggregate impact of individual wetland mitigation projects. No previous study has compared the choice of mitigation method by regulatory agency or development size. We analyze 1058 locally and federally permitted wetland mitigation transactions in the Chicago region between 1993 and 2004. We show that decreasing mitigation thresholds have had striking effects on the methods and spatial distribution of wetland mitigation. In particular, the observed increase in mitigation bank use is driven largely by the needs of the smallest impacts. Conversely, throughout the time period studied, large developments have rarely used mitigation banking, and have been relatively unaffected by changing regulatory focus and banking industry growth. We surmise that small developments lack the scale economies necessary for feasible permittee responsible mitigation. Finally, we compare the rates at which compensation required by both county and federal regulators is performed across major watershed boundaries. We show that local regulations prohibiting cross-county mitigation lead to higher levels of cross- watershed mitigation than federal regulations without cross-county prohibitions. Our data suggest that local control over wetland mitigation may prioritize administrative boundaries over hydrologic function in the matter of selecting compensation sites.     

Urbanization and Its Effect On Runoff in the Whiteoak Bayou Watershed,Texas1

Abstract: The capacity of a watershed to urbanize without changing its hydrologic response and the relationship between that response and the spatial configuration of the developed areas was studied. The study was conducted in the Whiteoak Bayou watershed (223 km²), located northwest of Houston, Texas, over an analysis period from 1949 to 2000. Annual development data were derived from parcel data collected by the Harris County Appraisal District. Using these data, measures of the spatial configuration of the watershed urban areas were calculated for each year. Based on regression models, it was determined that the annual runoff depths and annual peak flows depended on the annual precipitation depth, the developed area and the maximum 12‐h precipitation depth on the day and day before the peak flow took place. It was found that, since the early 1970s, when the watershed reached a 10% impervious area, annual runoff depths and peak flows have increased by 146% and 159%, respectively. However, urbanization is responsible for only 77% and 32% of the increase, respectively, while precipitation changes are responsible for the remaining 39% and 96%, respectively. Likewise, an analysis of the development data showed that, starting in the early 1970s, urbanization in the watershed consisted more of connecting already developed areas than of creating new ones, which increases the watershed’s conveyance capacity and explains the change in its response. Before generalizing conclusions, though, further research on other urban watersheds with different urbanization models appears to be necessary.     

Modeling Stream Channel Characteristics From Drainage‐Enforced DEMs in Puget Sound,Washington, USA1

Abstract: Mapping stream channels and their geomorphic attributes is an important step in many watershed research and management projects. Often insufficient field data exist to map hydromorphologic attributes across entire drainage basins, necessitating the application of hydrologic modeling tools to digital elevation models (DEMs) via a geographic information system (GIS). In this article, we demonstrate methods for deriving synthetic stream networks via GIS across large and diverse basins using drainage‐enforced DEMs, along with techniques for estimating channel widths and gradient on the reach scale. The two‐step drainage enforcement method we used produced synthetic stream networks that displayed a high degree of positional accuracy relative to the input streams. The accuracies of our estimated channel parameters were assessed with field data, and predictions of bankfull width, wetted width and gradient were strongly correlated with measured values (r² = 0.92, r² = 0.95, r² = 0.88, respectively). Classification accuracies of binned channel attributes were also high. Our methodology allows for the relatively rapid mapping of stream channels and associated morphological attributes across large geographic areas. Although initially developed to provide salmon recovery planners with important salmon habitat information, we suggest these methodologies are relevant to a variety of research and management questions.     

Impact of Urban Sprawl on Water Quality in Eastern Massachusetts,USA

A study of water quality, land use, and population variations over the past three decades was conducted in eastern Massachusetts to examine the impact of urban sprawl on water quality using geographic information system and statistical analyses. Since 1970, eastern Massachusetts has experienced pronounced urban sprawl, which has a substantial impact on water quality. High spatial correlations are found between water quality indicators (especially specific conductance, dissolved ions, including Ca, Mg, Na, and Cl, and dissolved solid) and urban sprawl indicators. Urbanized watersheds with high population density, high percentage of developed land use, and low per capita developed land use tended to have high concentrations of water pollutants. The impact of urban sprawl also shows clear spatial difference between suburban areas and central cities: The central cities experienced lower increases over time in specific conductance concentration, compared to suburban and rural areas. The impact of urban sprawl on water quality is attributed to the combined effects of population and land-use change. Per capita developed land use is a very important indicator for studying the impact of urban sprawl and improving land use and watershed management, because inclusion of this indicator can better explain the temporal and spatial variations of more water quality parameters than using individual land use or/and population density.     

Issues concerning the technology transfer of geographic information systems

Many state and local agencies have begun to adopt computer technology as a means of upgrading existing mapping and related practices. These agencies are faced with the dualism of wanting modern technology within a traditional setting and demanding technological independence at the same time. This article is an account of the art of technology transfers, with discussions about the necessary ingredients and constraints in the identification, adaptation, absorption, implementation, diffusion, and evaluation of new technologies. In general, a systematic approach towards the strengthening of endogenous capabilities with sufficient provision for operational and policy changes may be preferable to the idea of comprehensive planning.     

Geographic information systems within the national health service: the scope for implementation

The paper starts by assessing some of the needs for information management within the health service in Great Britain. Geographic Information Systems are introduced, and some of the functions such as database management, networking and overlying are described. Principally, it is argued that GIS can fill the role as a health information system, resource management system, and has the potential to assist in family practitioner monitoring and epidemiological studies.     

WATERSHED CONFIGURATION AND GEOGRAPHIC INFORMATION SYSTEM PARAMETERIZATION FOR SPUR MODEL HYDROLOGIC SIMULATIONS1

ABSTRACT: A grid cell geographic information system (GIS) is used to parameterize SPUR, a quasi-physically based surface runoff model in which a watershed is configured as a set of stream segments and contributing areas. GIS analysis techniques produce various watershed configurations by progressive simplification of a stream network delineated from digital elevation models (DEM). We used three watershed configurations: ≥ 2nd, ≥ 4th, and ≥ 13th Shreve order networks, where the watershed contains 28, 15, and 1 channel segments with 66, 37, and 3 contributing areas, respectively. Watershed configuration controls simulated daily and monthly sums of runoff volumes. For the climatic and topographic setting in southeastern Arizona the ≥ 4th order configuration of the stream network and contributing areas produces results that are typically as good as the ≥ 2nd order network. However both are consistently better than the ≥ 13th order configuration. Due to the degree of parameterization in SPUR, model simulations cannot be significantly improved by increasing watershed configuration beyond the ≥ 4th order network. However, a range of Soil Conservation Service curve numbers derived from rainfall/runoff data can affect model simulations. Higher curve numbers yield better results for the ≥ 2nd order network while lower curve numbers yield better results for the ≥ 4th order network.