Seamless3DEP: Topographic Maps retrieval from 3DEP

Features

Seamless3DEP is an open-source Python package that provides a simple and efficient way to retrieve topographic maps from the 3D Elevation Program (3DEP). This web service provides both dynamic and static elevation products. The static products are DEMs at three different resolutions (1/3 arc-second (10 m), 1 arc-second (30 m), and 2 arc-second (60 m)). The dynamic products are various elevation derivatives, such as hillshade, slope, aspect, and contours. Here's the full list of available products:

• DEM
• Hillshade Gray
• Aspect Degrees
• Aspect Map
• GreyHillshade Elevation Fill
• Hillshade Multidirectional
• Slope Degrees
• Slope Map
• Hillshade Elevation Tinted
• Height Ellipsoidal
• Contour 25
• Contour Smoothed 25

Seamless3DEP has four functions:

• get_dem: Retrieve DEM within a bounding box at any resolution. When the give resolution is 10, 30, or 60, the function will return the static DEM. This function, under the hood, decomposes the bounding box into smaller ones based on the maximum pixel size of 10 million. Then, saves the DEM tiles as GeoTIFF files and returns the file paths. The default resolution is 10.
• get_map: Retrieve any of the map products within a bounding box at any resolution. Similar to the get_dem function, this function returns the file paths of the downloaded GeoTIFF files. The default resolution is 10.
• decompose_bbox: Decompose a large bounding box into smaller based on maximum pixel size. Both get_dem and get_map functions use this function to decompose the bounding box into smaller ones with a default maximum pixel size of 10 million.
• build_vrt: Build a virtual raster file (VRT) from a list of raster files. This function can be used to build a VRT file from the downloaded GeoTIFF files. Note that GDAL must be installed to use this function which is an optional dependency.

Note that the input bounding box should be in the format of (west, south, east, north) in decimal degrees (WGS84).

Installation

You can install seamless-3dep using pip:

pip install seamless-3dep

Alternatively, seamless-3dep can be installed from the conda-forge repository using micromamba:

micromamba install -c conda-forge seamless-3dep

Quick start

Here's a quick example to retrieve a DEM within a bounding box:

from pathlib import Path
import seamless_3dep as sdem

bbox = (-105.7006276, 39.8472777, -104.869054, 40.298293)
data_dir = Path("data")
tiff_files = sdem.get_dem(bbox, data_dir)
if len(tiff_files) == 1:
    dem_file = tiff_files[0]
else:
    dem_file = data_dir / "dem.vrt"
    sdem.build_vrt(dem_file, tiff_files)
dem = rxr.open_rasterio(dem_file).squeeze(drop=True)

Now, let's get slope:

tiff_files = sdem.get_map("Slope Degrees", bbox, data_dir)
slope_dyn_vrt = data_dir / "slope_vrain_3dep_dynamic.vrt"
sdem.build_vrt(slope_dyn_vrt, slope_files)

Contributing

Contributions are appreciated and very welcomed. Please read CONTRIBUTING.md for instructions.