Uncertain Structure and Fragility Ensemble (UNSAFE) framework for property-level flood risk estimation

UNSAFE is an open-source framework for estimating property-level flood risk that explicitly accounts for uncertainties in exposure and vulnerability.

Table of Contents

• Overview
• Statement of Need
• Installation
• Examples
• Documentation
• Contributions
• License
• Citation
• Acknowledgements

Overview

The Uncertain Structure and Fragility Ensemble (UNSAFE) framework enhances a property-level risk assessment framework common in academic research and practice (e.g., Federal Emergency Management Agency (FEMA) loss avoidance studies, United States Army Corps of Engineers (USACE) feasibility studies). At a high-level, UNSAFE:

1. Adds parametric uncertainty to the National Structure Inventory dataset (uncertainty in exposure)
2. Facilitates the use of multiple, potentially conflicting, expert-based Depth-Damage Functions (uncertainty in vulnerability)
3. Provides a consistent framework for estimating flood damages from any inundation model output

Statement of Need

Flooding is a frequent, widespread, and damaging natural hazard in the United States. Research and practice increasingly estimate economic flood damage at the property level to inform management practices and policies. Economic flood damage is often estimated as a function of:

• Hazard: The features of a flood over space and time
• Exposure: The assets that experience inundation from a flood
• Vulnerability: The susceptibility of exposed assets to damage for a set of flood feature

Property-level economic flood risk assessments often overlook uncertainty in these inputs. When uncertainty is incorporated, it is more common to account for uncertainty in flood hazard than in exposure or vulnerability. Although it is a common finding that flood risk estimates are most sensitive to uncertainty in flood hazard estimates, overlooking uncertainty in exposure and vulnerability can bias risk estimates.

UNSAFE aims to fill the need for a published, free, and open-source tool for representing exposure and vulnerability under uncertainty for flood-risk estimation in the U.S. We invite others to contribute to this project to help standardize best practices in the estimation of flood risk under uncertainty, improve reusability and efficiency, expand functionality for more use-cases, and maintain a state-of-the-art risk estimation codebase that is free and usable by any interested party.

Installation

There are two ways to install UNSAFE.

Option 1: For Users

If you just want to use UNSAFE, install with pip install git+https://github.com/abpoll/unsafe.

Option 2: For Developers

If you want to edit the source code and/or run examples:

1. Clone the repository into your project directory:

   git clone https://github.com/abpoll/unsafe.git
   cd unsafe

2. Create and activate the environment

   conda env create -f examples/env/environment.yml
   conda activate unsafe

3. Install UNSAFE in development mode: pip install -e .

Examples

We provide annotated, comprehensive examples to help get you started:

1. Partial Data Example: A tutorial with all the required data included in the repository.
   • Location: examples/philadelphia_frd/notebooks/partial_data_example.ipynb
2. Full Data Example: A more comprehensive example that requires an external data download
   • Location: examples/philadelphia_frd/notebooks/full_data_examples.ipynb

We recommend reading the README.md in the root of the examples/ directory before working through either example.

Documentation

• Technical Documentation: Available in the docs/ directory, currently v01.pdf
• API Reference: Coming soon! We're working on making the documentation more modern, including a comprehensive API documentation.

Contributions

We warmly welcome contributions from the community! If you're interested in contributing to UNSAFE, we'd love to have you involved. Feel free to engage with the development team on GitHub - we're excited to collaborate with you.

To get started, simply fork the repository and run pip install -e . from the project root to set up your local environment for testing and development.

We look forward to working with you to make UNSAFE even better!

License

This project is licensed under the BSD-2-Clause License. Please see the LICENSE file for details.

Citation

UNSAFE is currently under review at the Journal of Open Source Software (JOSS). If you use UNSAFE in your research, please cite the preprint:

Pollack, A., Doss-Gollin, J., Srikrishnan, V., & Keller, K. (2024, May 20). UNSAFE: An UNcertain Structure And Fragility Ensemble framework for property-level flood risk estimation. https://doi.org/10.31219/osf.io/jb9ta

We will update the citation when the review at JOSS is finished.

Acknowledgements

Contributions to the initial v0.1 of UNSAFE

• AP: conceptualization, software development, software testing, project management, JOSS paper original draft, JOSS paper review and editing
• JDG: conceptualization, software testing, methodology, JOSS paper review and editing
• VS: conceptualization, methodology, JOSS paper review and editing
• KK: conceptualization, methodology, JOSS paper review and editing