get_nhd_subregion

A Raster* or Spatial* object to serve 
as a template for cropping.

template

A 4-character string indicating the HUC4 NHD subregion to download and crop.

area

A character string defining the resolution of the NHD to download.
Either "medium" (the default), or "high".

A character string indicating where raw downloaded files should be put.
The directory will be created if missing.

raw.dir


<code>get_nhd_subregion</code> returns a list of <code>SpatialPolygonsDataFrame</code>s of the layers of the HUC4 subregion,
 within the specified <code>template</code>. If template is not provided, returns the entire HUC4 subregion.


Functions to automate downloading geospatial data available from
several federated data sources (mainly sources maintained by the US Federal
government). Currently, the package allows for retrieval of five datasets:
The National Elevation Dataset digital elevation models (1 and 1/3 arc-second;
USGS); The National Hydrography Dataset (USGS); The Soil Survey Geographic
(SSURGO) database from the National Cooperative Soil Survey (NCSS), which is
led by the Natural Resources Conservation Service (NRCS) under the USDA; the
Global Historical Climatology Network (GHCN), coordinated by National Climatic
Data Center at NOAA; and the International Tree Ring Data Bank. Additional
data sources are in the works, including global DEM resources (ETOPO1, ETOPO5,
ETOPO30, SRTM), global soils (HWSD), MODIS satellite data products, the National
Atlas (US), Natural Earth, PRISM, and WorldClim.

get_nhd_subregion: Download and crop data from a zipped HUC4 subregion of the National Hydrography Dataset.

Description

Usage

Arguments

Value