flood_mapping_intercomparison

NOTE: This repository is in active development. All notebooks here are subject to change and do not include full documentation.

Welcome to SERVIR's Flood Mapping Intercomparison Github! This code repository will introduce you to different flood mapping products and packages produced by researchers including ESA and NASA. These flood mapping products map surface water in near real time from Satellite Observations. The flood products considered for this study include the following

• VFM (VIIRS flood Map). Based on VIIRS (optical) satellite observations.
• GFM (Global Flood Monitor). Based on Sentinel-1 (SAR) satellite observations.
• MCDWD (MODIS Combined Water Detection Product). Based on MODIS (optical) satellite observations.
• DSWx-HLS (Dynamic Surface Water Extent - Harmonized Landsat Sentinel Product). Based on HLS (optical) observations.
• DSWx-S1 (Dynamic Surface Water Extent - Sentinel-1). Based on Sentinel-1 (SAR) observations.
• HYDRAFloods. Based on Sentinel-1 observations.
• HYDROSAR. Based on Sentinel-1 (SAR) observations.

This repository allows you to do the following for a given flood event of interest:

1. Determine if there was a Sentinel-1 and/or HLS overpass on your date of interest. If there are both, it will return the overlapping footprint of Sentinel-1 and HLS.
2. Quantify the cloud cover percentage in your area of interest for the various optical sensors. This will allow you to determine which optical product has the best view of ground conditions, as the optical products are acquired at different times of day.
3. Obtain up to 7 flood products (depending on temporal extent and resolution of products) for a given day during a flood event.
4. Distribute sampling points in order to evaluate the accuracy of the various flood products based on reference data obtained from high-resolution imagery.

The repository consists of both "scripts" and "modules". Both of these are .py files. The "modules" are designed to be reused by you. The "scripts" are code that we used in our research, but is not designed to be replicated. In order to run the modules, you will need a time period of interest, and a region of interest. for a flood event.You can run the modules sequentially (i.e module 1, module 2, module 3....) to replicate our workflow. Below you can find a description of what each script and module will do.

• Script 1: Data Availability. This script will determine the cloud-free flood events where all flood products were available.

• Script 2: Slope and Elevation Analysis. This script was used to determine the slope and elevation classes used in the sampling design

• Module 1: HydroSAR: This module will obtain the HydroSAR flood product for the region of interest during a single day of interest.

• Module 2: HydraFloods: This module will obtain the HYDRAFloods flood product for the region of interest during a single day of interest.

• Module 3: Product Access. This module will access the MCDWD, VFM, GFM, DSWx-HLS, and DSWX-S1 products (if they are available) for the region of interest during a single day of interest.

• Module 4: Harmonization & Validation. This module will harmonize all available products to a single classification schema.

  For a full overview of these products, including the products full names, documentation, spatial extent/resolution, temporal extent/resolution, latency, and more, please see the spreadsheet called "flood_product_info.csv" located in the main folder of this Github. The notebooks folder contains several Google Colaboratory notebooks that will allow you to replicate our workflow.