ee-fastapi: Flood Detection System
A **ee-fastapi** is a simple [FastAPI](https://fastapi.tiangolo.com/) web application for performing flood detection using Google Earth Engine in the backend. The module [src/model.py](src/model.py) was adapted and translated to Python from [Radar-based Flood Mapping](https://www.un-spider.org/advisory-support/recommended-practices/recommended-practice-radar-based-flood-mapping). If you want to cite the methodology, takes a look at the bibliography available [here](https://www.un-spider.org/advisory-support/recommended-practices/recommended-practice-flood-mapping/in-detail).
### Installation
1. Install [Docker Compose](https://docs.docker.com/compose/install/)
2. Install the [EarthEngine Python API](https://developers.google.com/earth-engine/guides/python_install). You must have an active Earth Engine account (the credentials are copied to the app through [volumes](https://docs.docker.com/storage/volumes/))
3. Run the command
```
docker-compose up
```
and point your browser to
```
0.0.0.0:80
```
to start work
### Functionality
**ee-fastapi** use ready-to-use data freely available in the [Earth Engine Data Catalog](https://developers.google.com/earth-engine/datasets). **ee-fastapi** use the following public dataset:
- [**Sentinel-1 GRD: C-band Synthetic Aperture Radar**](https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S1_GRD): A composite after and before the flood. Main resource.
- [**MERIT DEM: Multi-Error-Removed Improved-Terrain DEM**](https://developers.google.com/earth-engine/datasets/catalog/MERIT_DEM_v1_0_3): To avoid areas with high slope.
- [**JRC Global Surface Water Metadata, v.1.2**](https://developers.google.com/earth-engine/datasets/catalog/JRC_GSW1_2_Metadata): To avoid water body areas.
Flood range dates, a hand-selected ROI, and the flood threshold are sent from the front-end to the back-end using [fetch](https://github.com/csaybar/ee-fastapi/blob/43f25d171a5bb17171d64de15af2d4170ca43c12/static/js/main.js#L158). The users control the response through two buttons: **display** and **download**. The display button will attach XYZ map tile resources with the results to the OpenLayer map. These tiles are obtained after running the model and the [ee.data.getMapId](https://developers.google.com/earth-engine/apidocs/ee-data-getmapid) method. On the other hand, the download button will download the flood area in a GeoPackage vector format.
### Design decisions
#### Why OpenLayer?
It was my first project using OpenLayer, and I can say that I did not miss Leaflet at all!. In my opinion, OpenLayers has much more advantages
over Leaflet. Here are some reasons from the point of view of a novice Web GIS user:
- OpenLayer counts with a complex API. There is no reason to load external plugins for simple tasks like in Leaflet.
- Great documentation and thousand of examples.
- Better map projection support
- I found the OpenLayer API more intuitive.
#### Why Google Earth Engine?
Google Earth Engine has everything: tons of publicly available datasets, a great well-documented API, and high-performance computing.
#### Why fetch?
Fetch API does not need to be installed as a dependency. It utilizes a modern JS syntax and is based on promise rather than callbacks.
### Student personal information
- **Name**: Cesar Luis Aybar Camacho
- **Program**: Copernicus Master in Digital Earth – CDE
- **Student ID**: s1078735
- **Course**: Geo-application Development