Geography

Sustainable urban form has been recognized as one of the major concerns of the planning practice. Current land use pattern trends with low-density, single-use, leapfrog urban growth on city outskirts call for a more efficient land use development strategies balancing economy, environmental protection, and social equity. In this paper, we present a new multiobjective spatial optimization model, which minimizes the conflicting objectives of open space development, infill and redevelopment, land use neighborhood compatibility, and cost distance to already urbanized areas. Land use allocation is restrained by a density based design constraint. Based on a hypothetical problem of 400 raster cells, we generate multiple exact compromise solutions with varying importance of allocation objectives. We discuss further model refinements and propose evaluating the prescribed patterns with multi agent geosimulation.

Suburbia and exurbia have an undeniable appeal to many urban dwellers. At the same time, they are characterized by an ineffective and fragmented residential patchwork of developed and undeveloped tracts. This research addresses a question of whether other arrangements of land, ameliorating the negative effects of current growth in the suburban fringe, are feasible from the perspectives of planning agencies and property developers. In order to answer this research question, the study employs two loosely coupled land use models: multiobjective land use allocation (MOLA) and an exploratory agent-based modeling (ABM) of residential development. The aligned modeling methodology has a number of advantages. Firstly, it combines top-down and bottom-up modeling. Such an approach is an attempt to represent society from two standpoints: institutions on one side (like zoning regulations of local planning agencies) and individual agents on the other (like developers). Secondly, the framework combines both static form (MOLA) and dynamic process (ABM). The MOLA model is equipped with mechanisms that encourage both compact and alternative residential land use arrangements. The outcomes of this model are used as zoning regulations in the ABM to examine the impact of regional-scale top-down urban growth plans on agent disutility which reflects the competitiveness of the local property market. Selected MOLA plans are further relaxed using different distance buffers. The findings point to a complex disutility-fragmentation relationship. Under the simulated planning situation, a potentially acceptable solution for planners and developers involves a relatively high compactness of development, which could satisfy agents' overall disutility.

This paper presents a new approach to deriving preferences assigned to evaluation criteria in geographical multicriteria decision analysis. In this approach, the preferences, expressed by numeric weights, are adjusted by distance measures derived from the explicit consideration of a locational structure. The structure is given by locations of decision options and high importance reference objects. The approach is demonstrated on the example of a house selection case study in San Diego, California. The results show that proximity-adjusted preferences for the evaluation criteria can alter significantly the rank order of decision options. Consequently, the explicit modeling of spatial preference variability may be needed in order to better account for decision-maker's preferences.

We report on the first year results of a four-year (2003-2007) research project called ���participatory geographic information systems for transportation���(PGIST). This project investigates the development and evaluation of geospatial information technologies for decision support of a complex decision making situation called transportation improvement programming.

Large quantity water withdrawals (> 70 gallons per minute���GPM) in Michigan are regulated by the state's Department of Environmental Quality (DEQ). The goal of this regulation is to protect fish sensitive to reductions in stream baseflow. Applicants for well or surface water pump permits must demonstrate that their proposed withdrawals will not have an adverse resource impact on fish in nearby streams. To that end, the state developed an on-line Water Withdrawal Assessment Tool (www. miwwat. org)(Hamilton et al.

Multiple criteria land suitability evaluation is perhaps the best known application domain of spatial multiple criteria analysis���S-MCA (Malczewski 2006). It involves a set of quantifiable spatial criteria, their standardization functions, techniques for expressing preferences regarding the relative importance of the criteria, and aggregation procedures combining the quantitative representations of the preferences with standardized criterion values into an overall suitability score.

Changes in climate and land management practices in the San Pedro River basin have altered the vegetation patterns and dynamics. Therefore, there is a need to map the spatial and temporal distribution of the vegetation community in order to understand how climate and human activities affect the ecosystem in the arid and semi-arid region. Remote sensing provides a means to derive vegetation properties such as fractional green vegetation cover (fc) and green leaf area index (GLAI). However, to map such vegetation properties using multitemporal remote sensing imagery requires ancillary data for atmospheric corrections that are often not available. In this study, we developed a new approach to circumvent atmospheric effects in deriving spatial and temporal distributions of fc and GLAI. The proposed approach employed a concept, analogous to the pseudo invariant object method that uses objects void of vegetation as a baseline to adjust multitemporal images. Imagery acquired with Landsat TM, SPOT 4 VEGETATION, and aircraft based sensors was used in this study to map the spatial and temporal distribution of fractional green vegetation cover and green leaf area index of the San Pedro River riparian corridor and southwest United States. The results suggest that remote sensing imagery can provide a reasonable estimate of vegetation dynamics using multitemporal remote sensing imagery without atmospheric corrections.

In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is closely coupled to atmospheric processes and is typically known with little certainty is seasonal riparian evapotranspiration (ET). This quantity can often be a significant factor in the basin water balance in semi-arid regions yet is very difficult to estimate over a large area. Better understanding and quantification of seasonal, large-area riparian ET is a primary objective of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. To address this objective, a series of interdisciplinary experimental campaigns were conducted in 1997 in the San Pedro Basin in southeastern Arizona. The riparian system in this basin is primarily made up of three vegetation communities: mesquite (Prosopis velutina), sacaton grasses (Sporobolus wrightii), and a cottonwood (Populus fremontii)/willow (Salix goodingii) forest gallery. Micrometeorological measurement techniques were used to estimate ET from the mesquite and grasses. These techniques could not be utilized to estimate fluxes from the cottonwood/willow (C/W) forest gallery due to the height (20-30 m) and non-uniform linear nature of the forest gallery. Short-term (2-4 days) sap flux measurements were made to estimate canopy transpiration over several periods of the riparian growing season. Simultaneous remote sensing measurements were used to spatially extrapolate tree and stand measurements. Scaled C/W stand level sap flux estimates were utilized to calibrate a Penman-Monteith model to enable temporal extrapolation between synoptic measurement periods. With this model and set of measurements, seasonal riparian vegetation water use estimates for the riparian corridor were obtained. To validate these models, a 90-day pre-monsoon water balance over a 10 km section of the river was carried out. All components of the water balance, including riparian ET, were