The document describes a summer project analyzing distance-related variables at the block level in New York City. The project aims to calculate distances from city blocks to various points of interest, such as subway stations, parks, and other amenities, and analyze how these distances impact property values. The methodology uses GIS network analysis to calculate walking distances and Euclidean distances to measure externalities. Distances will be classified into groups for future hedonic modeling. The results can be used as variables to understand how proximity to amenities affects property values.
4. APPROACH
Exogeneity
The attributes may be price-independent.
Isolate the area-wide factors from property-dependent
factors.
Hedonic
Distances to certain facilities increase/decrease the value as
the level convenience of living increases/decreases
Distances as attributes
Distances to certain facilities contribute to the value of a block,
a lot, or a single property.
5. PLACE OF INTEREST (POI)
Facilities that impact on surrounding area.
POIs (in ArcGIS) present as points, lines, polygons, or raster.
We select some facilities as POIs to test if the impact of each
POI is significant.
We also summarize non-spatial factors as the zonal density of
noise as a POIs.
6. PROXIMITY(DISTANCE)
Proximity:
Attributes of each block
Test the sensitivity of block-level scale.
Measured as network distances
Accessibility of facilities-dependent of road
network, such as walking distances
Measured as Euclidean distances
Externality of the facilities-independent from
road network
Proximity to certain facilities may
positively/negatively impact on property values.
Impacts diminish at certain rates as distances
increase.
The diminishing rates may be non-linear.
https://en.wikibooks.org/wiki/Transportation_Geography_and_Network_Science/Circuity#/media/File:TGNS_NetworkDistance.png
https://en.wikibooks.org/wiki/Transportation_Geography_and_Network_Science/Circuity#/media/File:TGNS_EuclideanDistance.png
http://resources.arcgis.com/en/help/main/10.1/index.html#/Near/00080000001q000000/
8. Block shapefile of each borough
Use block suffix to identify
block of the same block
POI shapefile
Input
Network Analysis
Find closest facilities
Calculate Network Distance
Generate Near Table
Calculate Euclidean Distance
Rasterize non-spatial attributes
Calculate the number of
facilities within certain distance
of a block
Interim
Distance Table
Distance-Dummy Table
Zonal Attribute Table
Output
PROCESS
9. INPUT-POI PREPARATION
Name Selection Standard and Action Source Feature
SubwayStation
Copy and Paste DOITT points
Copy and Paste DOITT points
SelectedPark_5a Acreage>=217800 (5 acres) DOITT polygons
Rail_grd ROW_TYPE=Elevated, Surface, Open Cut Depression, Embankment,Viaduct DOITT polylines
Bridge_Tunnel RW_TYPE=Bridges (across shoreline), dissolve, DOITT polylines
PublicAccessibleWaterfront Merge PAWS.shp and NYC_Waterfront_Parks.shp BYTE of BIGAPPLE polygons
WasteManagement Copy and Paste BYTE of BIGAPPLE points
College_3K SubGroup Type=13, Capacity>=3000 BYTE of BIGAPPLE points
College_10K SubGroup Type=13, Capacity>=10000 BYTE of BIGAPPLE points
CulturalFacilities_Others FacType=1601, Capacity>0 BYTE of BIGAPPLE points
Library_300K FacType=1401 and 1402, Capacity>300000 BYTE of BIGAPPLE points
RailStation Copy and Paste DOITT points
Hospital FacType=3102,Capacity>0 BYTE of BIGAPPLE points
HistoricDistrict Status=Designated NYC OPEN DATA polygons
Noise_311 Complaint_Type Contains Noise,Display XY data NYC OPEN DATA points
Noise_Den_25 Point Density, cell size=25, mask=nybb NA raster
Pharmacy Selected by Location (nybb), Amenity=Pharmacy/Name=CVS, Duane Reade, WALGREENS, Rite Aid OpenStreetMap points
Shelter FacType=4401,4402,4411,4412,4414,Capacity>0 BYTE of BIGAPPLE points
10. INPUT-BLOCK PREPARATION
Identify each
Block
Newbase table
containing bbl and
block suffix
Select index lot from
each physical block
Sort by Boro, Block,
Block Suffix, Lot
Exclude lot of:
Pid <0
Land size=0
BC=T*, U*, R*
Select block
Digital Tax Map
containing tax lot
features
Table containing bbl
and block suffix
Join by lot BBL
Lot Feature
containing Boro,
Block, and Block
Suffix.
Blocks with
blksuf
Digital Tax Map tax
block feature
Spatial Join the lot
feature with block
feature (get attributes)
Dissolve to combine
the small block with
same block and suffix
number
Generate centroid for
each block
11. PROCESS METHODS
The accessibility of POI
relies on road network
Active Access
walking
Driving
Network
Analyst
The accessibility of POI
doesnt rely on road
network
Externality of
noise/pollution
Passive Access
Nearest
Distance
Summarize the non-
spatial variables
Create spatial
distribution surfaces
Point
Density
Subway
Station
Rail
Stations
Universi
ties
Museu
m
Hospital
Shelter
Library
Pharmacy
Publicly
Accessible
Waterfront
Railroad
on the
ground
Park
Bridge
and
Tunnel
Waste
Manage
ment
Brownfield
Historic
District
Noise
12. METHOD LOGIC
If the POI should be
actively accessed from
each block
Network Analyst
(5 nearest POIs)
Distance Table:
1st Nearest Distance
2nd Nearest Distance
3rd Nearest Distance
4th Nearest Distance
5th Nearest Distance
ArcGIS shapefile
If the POI should be
passively accessed
from each block
Make Near Table
Nearest Distance Table
ArcGIS shapefile
If the non-spatial
attributes can be
presented
geographically
Point Density/Raster/
Zonal Table
Zonal Table:
Non-spatial attributes
If the number of POIs
were to be
summarized at block
level
Multiple Buffers/Spatial
Join
Count Table:
Numbers of POIs of each
block at distance_1
Numbers of POIs of each
block at distance_2
ArcGIS shapefile
13. INTERIM-NETWORK ANALYST
Incidents
-Blocks
Block
centroid
shapefile
(OID)
By boro
Generate
IncidentID
Reasonable
Check
Facilities -
POIs
POI (Point
features only
Generate
FacilityID
From
incidents to
facilities
Use
Network
Road
Network
Generated
from CSCL
Centerline
(topology)
Solve
Use incidents,
facilities, and
network feature
layers
Find the Closest
Facility
Number of POIs
to find=5
Use trip length as
impedance
Save
results
Save route
feature
class
Save the 5
distance
values to
table
Transpose
by incident
Join
Distance
back to
Block
Distance
table with
IncidentID
Blocks with
IncidentsID
Blocks with
OID
15. Distance to the
1st nearest
Subway
Station
Distance to the
2nd nearest
Subway
Station
Distance to the
3rd nearest
Subway
Station
Distance to the
4th nearest
Subway
Station
Distance to the
5th nearest
Subway
Station
18. INTERIM-GENERATE NEAR TABLE
Input feature
-block
Block centroid
shapefile
Add OID to identify
each block
By boro
Near feature
-POIs
Polylines
Polygons
Points
Euclidean distance
Generate
Near Table
Join Distance
back to Block
Distance Table for
each block
22. INTERIM-
CAPTURE SPATIAL RELATED VARIABLES
Input feature
-block
Block centroid
shapefile
Add OID to identify
each block
By boro
Create Raster
-POIs
Polylines
Polygons
Points
Attributes: density
Create zonal
table to
summarize
the raster
attributes
into each
block
Sum
Area
Sum/Area
Join zonal
table back to
Block
Spatial attributes
for each block
25. INTERIM-
GIS PROCESS-GENERATE DUMMY VARS
Buffer
Block feature
Generate OID for
each block
Generate Multiple
Buffers for each
block
0.3-mile buffer
0.5-mile buffer
Calculate
numbers of
facilities within
buffers of each
block
Spatial Join with
the point POI
feature
Field summarize
the number of
facilities
Save the table
Generate
Dummy
Variables
If none of the facilities
fall in 0.3-mile buffer,
then dist_030_var0=1,
else=0
If 1 facility falls in 0.3-
mile buffer, then
dist_030_var1=1,
else=0
32. PROJECT DESCRIPTION
Takeaway
We create a pool of distance attributes for all blocks, and
distances will be classified into different groups based on future
modeling.
The data can be collected at block/lot/property level.
Reusable Python script tools enables distance calculation for
point/polyline/polygon POI feature classes.
The next step may be creating an index based on areal attributes,
such as distance-value index system.
The raw output as well as the index system can be input
variables for future models.
33. FILE SYSTEM-
ORIGINAL DATA RawInput
DCP DOITT OPENDATA OpenStreet Collected
workflow_d
ocumentati
on
NYC_PubliclyAccessibleWater
Front_2014
NYC_SelectedFacilities_
2015
TANK Borough_Bo
undaries
cscl_pub.gdb NYC_Planim
etrics_2010
Noise_311_
07012014_0
7012015
TANK remedsitebo
rders
new-
york_new-
york.osm-
point.shp
Potential
Materials
nyc_paws_2
014shp
nyc_waterfrontp
arks_2014shp
nyc_facilities2015_shp Potential
Materials
nybb_15b CSCL SubwayStati
on.shp
NYC_DOITT_
Planimetric_
Seamless_2
010.gdb
Potential
Materials
Remediatio
n_site_bord
ers
PAWS.shp NYC_Waterfront
_Parks.shp
Facilities - 01 -
Schools.lyr
nybb.shp Centerline.s
hp
RailStation.s
hp
NYCPlanime
tric
Remediation
_site_border
s.shp
Facilities - 02 -
Recreational & Cultural
Facilities.lyr
Rail.shp PARK.shp
Facilities - 04 - Nursing
Homes, Hospitals,
Hospices and
Ambulatory Services.lyr
Subway.shp
Facilities - 10 - Food
Programs & Residential
Facilities for Adults and
Families.lyr
Facilities - 12 - Waste
Management
Facilities.lyr
Table File
Shapefile or Layer File
Tools and Documentation
Folder or Geodatabase
35. FILE SYSTEM-
CREATE DUMMY VARIABLE (BETA)
DistanceAnalysis
POI_buffer_inpu
t
POI_buffer_ouput table_input_Python
table_interim_S
AS
table_output_SAS table_tablejoin Tools_Python Tools_SAS
SubwayStation SubwayStation SubwayStation
condosuff_Subw
ayStation_count
.dbf
SubwayStation
condosuff_Subw
ayStation_count
.dbf
blk_boro*_Sub
wayStation_720
15_dummy.dbf
7_number_coun
t.py
buffer_count.sa
s
cdsuff_xy.csv
boro*_SubwaySt
ation_72015.gd
b
scratch.gdb
boro*_SubwayS
tation_72015_b
fct.dbf
boro*_SubwayStati
on_bfct.dbf
8_count_join.py
boro*_SubwaySt
ation_72015.shp
boro*_SubwaySt
ation_72015_bf
ct.shp
blk_boro*_Subw
ayStation_72015
_dummy.shp
Table File
Shapefile or Layer File
Tools and Documentation
Folder or Geodatabase
36. *FUTURE ACTIONS-
ADD POI
Download original shapefiles in RawInput Folder
Sort by the source of the files (DCP, DOITT, OPENDATA,
OpenStreetMap, or SelfCollection)
Put POI shapefiles in POI_inputPOI.gdb
Select the Python Tools and SAS Tools to process
Need to change POIs manually in each script
37. *FUTURE ACTIONS-
TOOLS AND RESULT TABLES
Network Analysis-
Input
POI_inputPOI.gdb
POI_inputdtmblock.gdbblk(cent)
Point Features only
Tool_Python3_NA_NF.py
dist_mean_inputPOI*dbf
Tool_SASPOI_NetworkAnalystboro_macro
dist_mean_outputPOI*dbf
Tool_Python4_blkcent_dist_join
NA_block_meandistPOI*dbf
Generate Near Table-
Input
POI_inputPOI.gdb
POI_inputdtmblock.gdbblk(cent)
Point/Polyline/Polygon features
Tool_Python5_make_near_table.py
dist_mean_inputPOI*dbf
Tool_SASPOI_MakeNearTable boro_macro
dist_mean_outputPOI*dbf
Tool_Python 6_near_Blkcent_dist_join.py
NA_block_meandistPOI*dbf
38. *FUTURE ACTIONS-
SUMMARIZE THE RESULT
Summarize the result in the master table of each boro
Output_distDescriptiveboro*.xlsx
Sort the result based on the method of distance calculation
Near
Sorted by ORIG_FID
Network Analyst
Sorted by ORIG_FID
Mark the missing value with IncidentID
Raster (Beta)
Sorted by OID_12
Mark the missing value with IncidentID