Massachusetts Institute of Technology Department of Urban Studies & Planning Spatial Database Management and Advanced Geographic Information Systems Alternative strategies Allocate Residential Development on Commercial/Industrial Land Yi Zhu & Wanli Fang Thursday, May 15, 2008

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Flow Chart Review the result to get some implementation Evaluate the attractiveness in each grid cell Figure out the relative shortage on TAZ level Allocate development using different strategies

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Different strategies in algorithms Greedy Assignment Algorithm –Different land development types compete for the total amount of available land within the TAZ. –All demands are satisfied simultaneously, therefore some of the development may choose second even third best location instead of the most desirable ones. The result of this strategy –more likely to lead to a dispersed pattern of the same development type, and a mixed development within neighborhood.

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Different strategies in algorithms Neighborhood Emphasis Algorithm –Different measurement of attractiveness, not only consider the attractiveness of the grid itself, but also take into account the attractiveness in adjacent grids. –A linear process of allocation giving priority to denser development type rather than doing allocating in parallel. Result of this strategy –Deal with the preference on contiguity –More compact development patterns, with the same development type cluster together.

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Before Smoothing After Smoothing

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Technical Details of Implementation

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Convert Raster to Vector Spatial Join Model Builder for Batch Processing

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Low VMT Strategy Neighborhood Emphasis Strategy

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Low VMT Strategy Neighborhood Emphasis Strategy

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Low VMT Strategy Neighborhood Emphasis Strategy

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Low VMT Strategy Neighborhood Emphasis Strategy

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Problems we encountered Order of allocation –Give priority to the most dense type: is it feasible? Measures of attractiveness –Determine the weights for the local attractiveness and the average attractiveness of neighboring cells Grids on the borders –On the TAZ border: The allocated results need to be merged by grids, otherwise some of them will be erased when doing spatial joint. –On the Town border: allocation process will deal with demands from other towns which are not in question.

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Other Methods we tried Polygon based allocation –Allocate the development using the existing land use polygons (clipped by TAZ) as the fundamental units. Advantages –Consider the contiguity of development –Reflect the spatial distribution of land supply more precisely Disadvantages –An aggregated accessibility of the polygons may not reflect the reality as the area grows significantly larger than single grid cell. –Also, it adds to the complexity when reallocate the land further into each grid.

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Polygon-based allocation for HT_4B Polygon-based allocation for HT_7B

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning Conclusions Efficiency of the models –Different strategies of development can be captured by the adopting different algorithms. (Demand) –Good locations with higher accessibility can detected by the model and assign to development first. (Supply) Implementation for zoning –Cluster is a reasonable development in terms of land use efficiency. –However, to make it happen, we need zoning regulations to provide the desired access to public transportation and other facilities.

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning VMT Estimation Each cell in the grid has a value representative of the total meters traveled one-way for an “average” (non-work) trip for a single household. Non-Work VMT = Average Non work trip distance ( tripmerge) * No of households (hshlds_250m) * 4.18 trips/household

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning

Spatial Database Management and Advanced Geographic Information Systems Massachusetts Institute of Technology Department of Urban Studies & Planning