NYC Rodents

Geospatial Analytics Lab

 Location Intelligence & Maps

Christy Rupp artwork

Vanessa Mateus, NYC May 2018

NYC 311 Rodent Complaints – Geospatial Analysis

The NYC311 Rodent Complaints data was used to develop an interactive map representing locations across the NYC area where rodent related issues are chronically reported.

An investigation was also conducted on how the surrounding area looks like in terms of Urban Land Use in locations where rodent related complaints are highest. Additionally, the distance between a Rat sighting and a nearby NYC Urban Features was calculated. The selected features - residential buildings, food-related businesses, Subway system - are considered to provide an easy source of food and shelter. This proximity analysis allows a better understanding of the brown rat territory preferences.

 

MOTIVATION: Communities that live in rat-infested areas have their health, well-being, and property at risk. It has been studied that neighborhoods with an abundance of rats cause more stress to its residents than living in high crime areas. The city Sanitation / Waste Management has to join forces with Local Community to address this problem as efficiently as possible. This free interactive web map quantifies rat outbreak severity by location. It is intended to promote awareness and action in the effort to further control Rat proliferation in the NYC area.

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Exploring NYC311 Rodent data

The NYC311 Service Requests can be accessed through the NYC Open Data Portal.

The Rodent Complaint data used comprise data from January 2013 to April 2018 (63 months, 91,669 records with Lat/Long coordinates) and is subdivided into 4 classes:

"Rat sightings" (54%),"Mouse sightings" (15%) and "Signs of Rodents" ( 9%) and "Conditions attracting rodents" aka garbage (22%).

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1. Rodent complaints, by type.

 

2. NYC311 Rodent complaint, service usage trend.


3. Where are rodent-related complaints spotted?

NYC311 Rodent Complaint time-lapse (video)

Locations where Rodents were spotted and reported, from January 2013 to March 2018 (63 months). NYC Community Districts in yellow. Spatio-temporal trends and patterns.

Cumulative - points are aggregated over time (2013-18)

Complaits by Month (2013-18)

Data Source: NYC 311 Service Requests. Complaint Type: Rodent. Descriptor: Rat Sighting, Mouse Sighting and Signs of Rodents. Dates: Jan 2013 to Mar 2018 (63 months, all rodent records with Lat/Long).

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Identification of Rat-infested Neighborhoods

The Rodent Density Map divides the NYC area into Rodent Severity ranks (9 very high - 2 low), depending on the number and proximity of each complaint.

The density analysis was based on the Kernel algorithm; 63 months of data and 71,590 complaint points were included.

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Data: NYC311 Rodent Complaints from 2013 to April 2018 (63 months, N=71,590) includes "Rat sightings" (49,727), "Mouse sightings" (13,460) and "Signs of Rodents" (8,403). "Conditions attracting rodents" was excluded from the Kernel Density Analysis.

Instant Insights: Critical locations by Borough, Neighborhood and Street:

>Bronx:

Ranks 9 to 6 - Mott Haven, Melrose South: Willis Av, Courtland Avenue to Morris Av & East 144th St. to 152nd St. Most severe location in NYC

>Brooklyn:

Ranks 8 to 6 - Crown Heights, Clinton Hill, Bedford: Bedford Av. with Fulton St.

>Manhattan:

Rank 7 - Central Harlem South, Morningside Heights, Upper West Side: Malcolm X Boulevard to Amsterdam Av & 100th to 120th St.

Rank 7 – Yorkville. 1st to 2nd Av & East 82nd St. to east 89th St.

Rank 6 – East Harlem South, East Harlem North: Park Avenue to 2nd Av. & East 109th to 117th St.

Rank 6 - East Village: 1st Avenue to Av C & 10th St. to 20th St.

Rank 6 - Hamilton Heights.


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Understanding Rat Territory Preferences

How close are rats from possible food and shelter locations (urban features)?

Rat basic needs comprise food and shelter. The distance analysis is based on the relative distance between all reported Rat sightings and "target" locations, such as (public) Residential buildings, Food-related businesses, Open spaces and Parks, Parking lots, Education and Health-related buildings, the Subway system, heavy Commercial areas (business districts)

Table: Distance analysis between a reported rat (49.727 total) and a closest Urban Feature. The calculation is made for each urban feature at the time and it only accounts the closest feature from each rat point, followed by a rat count per distance band from each feature. These values reflect NYC as a whole. <0, 50, 100, 150, 200 meters>

Rat Territory Insights:

Rats can best be found in large quantities near: Food-related Businesses (66% within 330ft distance), Parks & Recreation areas, in NYC Business Districts (36%) Parking Lots (35%) and Open spaces (24%).

  • Parking Lots and nearby perimeter seem to be the most rat-infested feature - 35% of rats were seen within a 500feet distance from the lot centroid. And 31% of rats were seen within a 165feet / 50mt from Food-related Businesses.
  • Contrary to what people believe, rats are relatively less abundant and appear in larger quantities in areas farther from the Train System (75% are seen over a 650 feet / 200mt distance from the subway entrances). It appears to be a least favorite urban structure to live around. Only 2% of rats are seen near Entrances and 13% by Train Line - within a 165ft / 50 mt distance. This goes against the myth that there are “rat cities” in the subway system.
  • Buildings used for Public Housing and Health Services are surrounded by lowest rat concentration around their immediate area (up to 165feet) with only 8% of the total rat count. Education buildings have almost double, with 15%

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Analysis: LAND USE vs. Rodent Density

Investigate the association between high Rodent density and NYC Land Uses

An analysis was conducted to determine the relationship between higher and lower rat complaints and the 11 Land Use classes as well as building characteristics, provided by the NYC PLUTO* database.

Rodent Density vs. NYC Land Uses < click on the image to enlarge >

The Rodent Density map (ranked by severity, from 9 Very-high to 2 Lower complaint density) was intersected with the NYC PLUTO 11 Land Uses <by tax lot> to obtain the respective areas (%). ALL NYC AREA. *PLUTO - Primary Land Use Tax Lot Output 17v1.1

Insights:

Rodent Density  rank 9 - 8  > See Map Here

Areas defined by a higher number of buildings with a heavy human use: Office & Commercial, Public Facilities & Institutions, and buildings with both Residential and Commercial use. All of these building have a high human use, and possibly more waste is generated around these locations. The number of buildings exclusively residential is below the NYC average and there is a higher proportion of parking lots and vacant land (8-9% combined).

The density of Buildings with residential and commercial use (0.11-0.15), are older (built years 1719-1982 in average) and have the minimum land assessed tax value.

 

In less severe areas <rank 7-5>  Residential buildings compose most of the urban landscape, around 60% (multi-family walk-ups and with elevator, buildings with both residential and commercial use, and 1-2 family buildings). There is a significant number of Public Facilities and Institutions, ~12%.

These areas have higher residential-commercial building densities, with more floors, built in the early 1800's

 

In lower Rodent density areas <rank 4-2> There is less urban pressure with lower population and housing density. There is a larger proportion of 1-2 Family buildings and less Multi-family buildings with Elevator. There are more lots dedicated to Transport, Utility, Industrial and Manufacturing and a larger area dedicated to Open Space and Outdoor Recreation.

Building properties by Rodent Density severity rank

Very high Rodent densities may not always be a direct consequence of high population and housing units densities.

In the most notorious location for high Rat outspread - the southeastern Bronx, has fewer buildings with residential and commercial use, are older and have the lowest assessed tax value when compared to the rest of NYC.

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Study Note:

Rodent reporting is limited to action. It is unknown if the same rodent is reported more than once, and not all rodent sighting is reported.  It may not hold 100% of the times, but having an analytic-derived holistic view of any problem allows a better understanding of it.

Data Source:   NYC Open Data Portal

Fun Facts about Rats

- The Norway or brown rat -Rattus norvegicus is a pest of Asian origin that accepts human beings as a part of its environment.

- Brown rats are responsible for an estimated $19 billion of damage annually.

- In optimal conditions, a population of 2 can grow up to 15 000 in only one year, and they tend to breed until they have maxed out their food supply.

- The brown rat is nocturnal and has excellent swimming, climbing and digging skills.

- It prefers to live in burrow systems, drains, sewers and buildings.

- Rats have a 1-year lifespan and a foraging range of 150 feet (40-50 meters).

- They are omnivorous and need approx 1 ounce (20-30 gr.) per day of human food and feedstock.

- The Norway rat varies in color and size, depending on how old it is and where it lives. As a result, people call it different names (city rat, brown rat, sewer rat, wharf rat, river rat, alley rat, house rat), but it’s all one species.

- Some juvenile rats are mistaken by mice. It is known that rats prey mice so it is unlikely for these species to share the same territory.


In “Rats in Urban America” from James Clinton (1969), it can be read: In cities, rat-inflicted injuries are most common (a) under crowded conditions, (b) in substandard housing, (c) in areas with poor environmental sanitation, or (d) in neighborhoods where rat-infested property is being controlled.


Besides exacting a heavy economic toll through property and infrastructure damage, waste and contamination, the rat is a serious health hazard. Leptospirosis, a worldwide zoonosis, is commonly found in rats.


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Reads:

ON THE NEWS: On July 12 2017, Mayor Bill de Blasio announced a $32 million, multi-agency plan to reduce the city’s rat population that targets the three most infested parts of city.  “This investment is a multi-pronged attack to dramatically reduce the rat population in the City’s most infested areas and improve the quality of life for residents. (…) All New Yorkers deserve to live in clean and healthy neighborhoods.”


Vanessa Mateus, Geospatial Analyst

GeoBILab@gmail.com

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