Rapid Watershed Delineation
using an Automatic Outlet Relocation Algorithm

Delineating a large number of watersheds for hydrological simulations in the big data era 🔥

demo.mp4

🚀  Usage

Start

• First, download Watershed.zip from the release page
• Next, unzip and open Watershed.exe, click start to execute an example
• A detailed guide is attached to the Supporting Information of the paper

Inputs

1. Flow direction: a file path or a folder path of tiff (see example_flowdir.tif for example)
2. The given coordinates of watershed outlets: a excel sheet contains longitudes and latitudes in the WGS84 projection. Watershed area is optional as auxiliary information to improve the delineation accuracy (see example_station.xlsx for example)

Outputs

1. Shapefile: watershed boundaries stored as vector data
2. Info.xlsx: delineated watershed areas, containing areas of confluence, mainstream, and tributray relocations.
3. Map.html: a visual map of watershed boundaries with satellite images as the background

⚡  Best Practices

Use flow directions of HydroSHEDS and MERIT Hydro

• HydroSHEDS and MERIT Hydro are 90m-resolution flow directions, and have been proven effective in watershed delineation. It is recommended to divide the flow directions into several parts to reduce memory usage.

Rerun the algorithm with watershed area as auxiliary information

• Assuming that the algorithm incorrectly relocates an outlet to the tributray, and the correct relocation should be on the mainstream. Since the algoirthm also returns the watershed area of mainstream relocation, we can quickly fix this incorrection by reruning the algorithm with the watershed area as auxiliary information.

📌  Publications

It is highly appreciated for citing the following paper:

• Xie, J., Liu, X., Bai, P., & Liu, C. (2022). Rapid Watershed Delineation Using an Automatic Outlet Relocation Algorithm. Water Resources Research, 58(3), e2021WR031129. https://doi.org/10.1029/2021WR031129