Illegal Border Crossers andWildfires in AZ

Geoffrey KrassyGEOG 594A Prof Todd Bacastow

The Question… Are the occurrence, rates and/or severity of

wildfires in southern Arizona affected by the frequency of smuggling operations which occur.

Soldier Basin fire seen from Nogalas Intl Airport, AZ (Images from KVOA.com)

The problem of wildfires Illegal immigration and smuggling is an endemic

problem along the US-Mexico border. The flow of contraband (both human and other)

through the Tucson sector in Arizona varies dependent on numerous factors within the United States and Mexico.

The desert Southwest is also highly susceptible to brush and wildfires.

It has been shown that some of these fires have been deliberately set in order to draw attention away from another portion sector.

Study area Red outline is the study area. It is the lower half

of the Office of Border Patrol’s Tucson Sector.

Datasets Primary

CBP Apprehension Data Group size, location and time Aggregate by year (2009-2013) Clipped to study area Datum: WGS84

MODIS Thermal Anomalies & Fires Aggregate by year

Datum: NAD1983 Monitoring Trends in Burn Severity (MTBS), National MTBS Burned Area Boundaries Dataset

Datum: NAD 1983 Background

CBP Administrative Borders, V10 BaseMap – ESRI World Topo

Software

Software Version Developer Website

ArcGIS 10.2 ESRI http://www.esri.com/software/arcgis

Pre-processing: ArcGIS

Optimized Hot Spot Analysis

Set for 50% Transparency

Set Symbology GiBin for 3 ClassesRed indicates 95% + confidence that

the clustering is significant

ArcGIS

Repeat

for

each

data

-set

GoTo Visual Comparison

CBP Apprehension Data

MODIS-Thermal Anomalies & Fire Overview

MTBS (Monitoring Trends in Burn Severity) Overview

Apprehensions

Seems like a (mostly) random distribution. Need something to find the trends.

Optimized Hot Spot Analysis “Given incident points, creates a map of statistically

significant hot and cold spots using the Getis-Ord Gi* statistic. It evaluates the characteristics of the input feature class to produce optimal results.” (ArcGIS 10.2 Help)

Analysis, in this case, is based on apprehended group size, in addition to geographic location.

It identifies the “non-random” elements.

Non-random implies a regular route.

Note: these are the groups apprehended, not necessarily the ones who started fires.

Sample Results 2011

A closer look…

And closer….

Conclusions

Visual correlation performed for every fire noted from 2009-20012

Every notable fire within 25 NM of the border was within 1 NM of an Apprehension HotSpot.

Considering that National Park Service claims 90% of wildfires are of human origin, and that the fire locations are functionally depopulated…

It is likely that most of the wildfires in southern Arizona are caused by illegal border crossers.

Questions?