NASA DEVELOP Spring 2019
WET Link: https://code.earthengine.google.com/c028d40c9d6d8de09af17fad5aa9bcc9
The Wetland Extent Tool (WET) was developed by the Great Lakes Water Resources Team to increase the efficiency of wetland mapping in Minnesota. WET is an automated tool hosted on Google Earth Engine (GEE) that maps wetland change and extent using Sentinel-1 C-SAR backscatter ratios, Landsat 8 (OLI) indices, and a LiDAR derived Topographic Wetness Index (TWI).
WET was created for use within Google Earth Engine, an open source cloud computing platform, and was scripted in JavaScript. The GEE API can be accesed on the homepage, where users can sign up and request approval. Resources for getting started and navigating the platform can be found in the GEE user guide.
| Dataset | Source | Parameter | Resolution |
|---|---|---|---|
| Landsat 8 (OLI) | GEE | TCWGD, MNDWI | 30m |
| Sentinel-1 C-SAR | GEE | VV, VH | 10m |
| DEM (LiDAR) | Steve Kloiber | TWI | 3m |
| Field Data | Steve Kloiber |
Classified maps can be inspected using GEE's inspector tool on the right panel. The Classified Clusters layer will return an indexed number indicating which landcover class the pixel belongs to.
| Level-1 Classification Code Key | Code Key | Description |
|---|---|---|
| Upland | 1 | Dry land |
| Open Water | 2 | Includes rivers, lakes, ponds |
| Wetland | 3 | Inundated Area |
By default, the variable Classfied Clusters will contain the classified map for the date range that is specified, which by default is the growing season of 2017. Users can alter the date range in lines 11 and 12 of the code to create other classification outputs. We recommend only selecting dates within Northern Minnesota's growing season of 05/21 to 09/26, to avoid using imagery with snow.
If the region of interest is too large, the computation may time out on Google Earth Engine. To avoid this issue, users may instead export the output to their Google Drive. A function for doing this can be found in lines 981 to 988.
- Erica O'Connor - Team Lead
- Melissa Ferriter
- Alice Lin
- Christopher Notto
- Name: Alice Lin
- Email: alin14@g.ucla.edu
- Erika Higa and Nega Kasraee
- Bruce Chapman and Benjamin Holt
- Our project partners at the US Fish and Wildlife Service, Minnesota Department of Natural Resources, Environmental Protection Agency, Ducks Unlimited, National Oceanic and Atmospheric Administration Office for Coastal Management, and the University of Montana