Uncovering Community Debris Disposal Behaviors During Post-Disaster Recovery

Thu, 17 Sep 2026 00:00:00 +0000

Research explainer

Debris does not move through a community by logistics alone.

After a hurricane, every pile of debris sits at the end of a chain of human decisions: what residents know, how they prepare, what help they can find, and which disposal options they can actually reach.

1,600Hurricane Ian respondents

13impacted Florida counties

3linked decision stages

7debris streams examined

📰 In press

Please note that the paper has been accepted and is currently in press.

Post-disaster debris management is often treated as an engineering problem: estimate the volume, locate temporary sites, schedule collection, and route trucks. Yet cleanup outcomes also depend on thousands of household-level decisions made under urgency, uncertainty, and uneven access to services.

Our research, “Uncovering Community Debris Disposal Behaviors During Post-Disaster Recovery: A Case Study of Illegal Dumping After Hurricane Ian,” reframes those decisions as a staged behavioral process. It combines a Knowledge–Attitudes–Practices (KAP) framework, survey evidence from communities affected by Hurricane Ian, and a county-level Illegal Debris Disposal Tendency Index (IDDTI) for planning and screening.

The behavioral journey

One outcome, three decision environments

Select a stage to see how behavior develops before debris reaches its final destination.

Decision question

Figure 1. Preparedness, on-property handling, and final disposal are analytically distinct but behaviorally connected. Some roadside or curbside placements remain context-dependent because emergency authorization can vary locally.

From survey response to behavioral evidence

The survey mapped nine constructs across the three stages: knowledge, attitudes or constraints, and practices. Outcome-specific models were then matched to the data: Poisson models for counts and logistic models for binary legality, placement, and material-handling outcomes. False-discovery-rate correction was applied within each outcome family.

This design matters because “illegal dumping” is not one undifferentiated act. The study distinguishes designated sites and authorized collection, locally contingent roadside placements, and clearly unauthorized locations such as highways, parks, and other cities.

The central result

Knowledge changes compliance. Access still shapes possibility.

Switch the outcome to compare standardized total associations at the final disposal stage.

Knowledge · direct

Knowledge · via access

Disposal knowledge

Access

Prior preparation

← fewer reported instances more reported instances →

Figure 2. Standardized total associations from the staged path models. Bootstrap 95% intervals excluded zero for Stage-C knowledge and access, but not for Stage-B preparation. These cross-sectional relationships are associations, not causal effects.

At the count level, a one-unit increase in standardized Stage-C knowledge was associated with a 24% increase in expected reported legal behaviors (IRR = 1.24) and an 11% decrease in expected reported illegal behaviors (IRR = 0.89). Knowledge was more strongly associated with expanding legal practice than eliminating illegal placement—a signal that information alone cannot remove physical and institutional barriers.

Evidence explorer

The answer changes with the question

Explore the reported associations for behavior counts, placement locations, and correct material handling.

Lower association1.0 · no differenceHigher association

Figure 3. IRRs are shown for count models and odds ratios for binary outcomes. Values above 1 indicate a positive association and values below 1 a negative association, holding other modeled constructs constant.

The material-specific results make the knowledge signal especially visible. Higher Stage-C knowledge was associated with correct handling of white goods (OR = 3.67), wrecked vehicles (3.34), hazardous debris (3.24), construction and demolition waste (2.58), soil (1.99), and vegetative debris (1.61).

Placement tells a different story. Concern and help-seeking were positively associated with both ambiguous and illegal off-site locations, while correct Stage-B preparation was associated with designated-site use. More knowledgeable respondents were not consistently less likely to place debris off-site. The practical interpretation is not that knowledge fails, but that knowing the right action and being able to take it are different problems.

From households to counties

What changes when hazard exposure enters the index?

Choose a validation target to compare the socioeconomic-only IDDTI-A with IDDTI-B, which adds Hurricane Ian wind exposure.

IncomeAgeHomeownershipEducationEmploymentEstablishment size

Wind exposure IDDTI-B only

Figure 4. IDDTI values rank relative screening priority; they do not predict individual behavior. Validation was internal, county samples were uneven, and performance depends on the chosen target.

Against the survey-derived county ranking, adding hazard exposure improved Spearman correlation from 0.15 to 0.26 and pairwise accuracy from 0.54 to 0.60. Against the observed illegal-disposal ratio, however, IDDTI-A and IDDTI-B were close, and the hazard-enhanced version did not lead on every metric. That target dependence is a feature worth seeing, not hiding: the indices are screening tools for prioritization, not deterministic risk scores.

Translating evidence into action

Barrier

Intervention

Evaluate with

The evidence argues for a paired strategy. Use clear, debris-specific education where correct handling is technically demanding. At the same time, reduce the friction of compliance through closer temporary debris-management sites, mobile hazardous-waste drop-offs, real-time wait information, and coordinated collection support. Enforcement messaging is most credible when residents also have a practical legal option.

Use for outreach and planning—not enforcement targeting. The survey is cross-sectional, recall-based, self-reported, and geographically imbalanced. The online panel over-represents higher-income homeowners, reported illegal behavior is not measured prevalence, and the index lacks external validation against independent complaint or cleanup records. The framework and construction procedure are transferable; the Hurricane Ian coefficients and weights are not.

The broader contribution

This research shows why post-disaster disposal should not be reduced to a single cleanup choice. Earlier preparedness and handling conditions matter, but their associations with final behavior are largely mediated. At the moment of disposal, knowledge is linked to compliance quality, while access, convenience, concern, and available support shape where debris can end up.

That distinction gives emergency managers a more useful question than “Why did residents dump debris illegally?” It asks: At which stage did the path toward compliant disposal break down—and was the missing piece knowledge, access, support, or credible alternatives?

Behavior sandbox

Watch a neighborhood respond

Change the conditions and watch the residents redistribute among authorized disposal, curbside or locally contingent placement, and clearly unauthorized off-site placement.

Disposal knowledge 65% Access to authorized options 55% Collection delay 7 days

Figure 5. This is a qualitative teaching game, not a fitted agent-based model or forecast. It translates the study’s supported directional relationships into an illustrative neighborhood scene; the character counts are not estimated population shares.

Knowledge Attitudes Practices on Mohammad Movahedi