A first step toward micro-scale spatial analysis:
New methods for analyzing network events with a free ArcGIS plug-in toolbox,
SANET
In the real world, there are numerous and various network events that occur on and alongside networks, including the occurrence of traffic accidents on highways, the incidence of crime on streets, infection of disease through streets or corridors, the contamination along rivers, and importantly, the location of almost all kinds of facilities alongside streets. It is proved that the application of the
conventional spatial analysis assuming a plane with Euclidean distance is likely to lead to false conclusions.
An alternative new approach is spatial analysis assuming a network embedded in a plane with the shortest-path distance, termed network (-constrained) spatial analysis. A GIS-based toolbox, SANET, provides user-friendly tools. This tutorial instructs how to use this toolbox, together with underlying statistical and computational theories.
Typical questions analyzed by SANET are:
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Q1: How can we obtain the catchment areas of parking lots in a downtown area including one-way streets, assuming that drivers access their nearest parking lot?
How to place nearest WC sign boards in a department store considering up/down escalators (see the above figure)? -
Q2:Do street burglaries tend to take place near railway stations?
Does infection by MDRP tend to take place near shower rooms in a hospital?
Do falls of aged persons tend to take place on sloped streets? -
Q3:Does street walkability in neighborhoods affect the distribution of obesity persons?
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Q4: How can we estimate the density of traffic accidents and street crimes incidence?
How can we identify locations where the densities of those occurrences are high, referred to as black spots and hot spots (see the above figure)? -
Q5:How can we spatially interpolate an unknown NOx (nitrogen oxides) density at a point on a road using known NOx densities at observation points in a high-rise building district, such as Midtown Manhattan?