pygridmet 0.17.1

Description:

pygridmet 0.17.1

Package
Description
Status



PyNHD
Navigate and subset NHDPlus (MR and HR) using web services


Py3DEP
Access topographic data through National Map’s 3DEP web service


PyGeoHydro
Access NWIS, NID, WQP, eHydro, NLCD, CAMELS, and SSEBop databases


PyDaymet
Access daily, monthly, and annual climate data via Daymet


PyGridMET
Access daily climate data via GridMET


PyNLDAS2
Access hourly NLDAS-2 data via web services


HydroSignatures
A collection of tools for computing hydrological signatures


AsyncRetriever
High-level API for asynchronous requests with persistent caching


PyGeoOGC
Send queries to any ArcGIS RESTful-, WMS-, and WFS-based services


PyGeoUtils
Utilities for manipulating geospatial, (Geo)JSON, and (Geo)TIFF data





PyGridMET: Daily climate data through GridMET



































Features
PyGridMET is a part of HyRiver software stack that
is designed to aid in hydroclimate analysis through web services. This package provides
access to daily climate data over contermonious US (CONUS) from
GridMET database using NetCDF
Subset Service (NCSS). Both single pixel (using get_bycoords function) and gridded data (using
get_bygeom) are supported which are returned as
pandas.DataFrame and xarray.Dataset, respectively.
You can find some example notebooks here.
Moreover, under the hood, PyGridMET uses
PyGeoOGC and
AsyncRetriever packages
for making requests in parallel and storing responses in chunks. This improves the
reliability and speed of data retrieval significantly.
You can control the request/response caching behavior and verbosity of the package
by setting the following environment variables:

HYRIVER_CACHE_NAME: Path to the caching SQLite database for asynchronous HTTP
requests. It defaults to ./cache/aiohttp_cache.sqlite
HYRIVER_CACHE_NAME_HTTP: Path to the caching SQLite database for HTTP requests.
It defaults to ./cache/http_cache.sqlite
HYRIVER_CACHE_EXPIRE: Expiration time for cached requests in seconds. It defaults to
one week.
HYRIVER_CACHE_DISABLE: Disable reading/writing from/to the cache. The default is false.
HYRIVER_SSL_CERT: Path to a SSL certificate file.

For example, in your code before making any requests you can do:
import os

os.environ["HYRIVER_CACHE_NAME"] = "path/to/aiohttp_cache.sqlite"
os.environ["HYRIVER_CACHE_NAME_HTTP"] = "path/to/http_cache.sqlite"
os.environ["HYRIVER_CACHE_EXPIRE"] = "3600"
os.environ["HYRIVER_CACHE_DISABLE"] = "true"
os.environ["HYRIVER_SSL_CERT"] = "path/to/cert.pem"
You can also try using PyGridMET without installing
it on your system by clicking on the binder badge. A Jupyter Lab
instance with the HyRiver stack pre-installed will be launched in your web browser, and you
can start coding!
Moreover, requests for additional functionalities can be submitted via
issue tracker.


Citation
If you use any of HyRiver packages in your research, we appreciate citations:
@article{Chegini_2021,
author = {Chegini, Taher and Li, Hong-Yi and Leung, L. Ruby},
doi = {10.21105/joss.03175},
journal = {Journal of Open Source Software},
month = {10},
number = {66},
pages = {1--3},
title = {{HyRiver: Hydroclimate Data Retriever}},
volume = {6},
year = {2021}
}


Installation
You can install PyGridMET using pip as follows:
$ pip install pygridmet
Alternatively, PyGridMET can be installed from the conda-forge repository
using Conda:
$ conda install -c conda-forge pygridmet


Quick start
You can use PyGridMET using command-line or as a Python library. The commanda-line
provides access to two functionality:

Getting gridded climate data: You must create a geopandas.GeoDataFrame that contains
the geometries of the target locations. This dataframe must have four columns:
id, start, end, geometry. The id column is used as
filenames for saving the obtained climate data to a NetCDF (.nc) file. The start
and end columns are starting and ending dates of the target period. Then,
you must save the dataframe as a shapefile (.shp) or geopackage (.gpkg) with
CRS attribute.
Getting single pixel climate data: You must create a CSV file that
contains coordinates of the target locations. This file must have at four columns:
id, start, end, lon, and lat. The id column is used as filenames
for saving the obtained climate data to a CSV (.csv) file. The start and end
columns are the same as the geometry command. The lon and lat columns are
the longitude and latitude coordinates of the target locations.

$ pygridmet -h
Usage: pygridmet [OPTIONS] COMMAND [ARGS]...

Command-line interface for PyGridMET.

Options:
-h, --help Show this message and exit.

Commands:
coords Retrieve climate data for a list of coordinates.
geometry Retrieve climate data for a dataframe of geometries.
The coords sub-command is as follows:
$ pygridmet coords -h
Usage: pygridmet coords [OPTIONS] FPATH

Retrieve climate data for a list of coordinates.

FPATH: Path to a csv file with four columns:
- ``id``: Feature identifiers that gridmet uses as the output netcdf filenames.
- ``start``: Start time.
- ``end``: End time.
- ``lon``: Longitude of the points of interest.
- ``lat``: Latitude of the points of interest.
- ``snow``: (optional) Separate snowfall from precipitation, default is ``False``.

Examples:
$ cat coords.csv
id,lon,lat,start,end
california,-122.2493328,37.8122894,2012-01-01,2014-12-31
$ pygridmet coords coords.csv -v pr -v tmmn

Options:
-v, --variables TEXT Target variables. You can pass this flag multiple
times for multiple variables.
-s, --save_dir PATH Path to a directory to save the requested files.
Extension for the outputs is .nc for geometry and .csv
for coords.
--disable_ssl Pass to disable SSL certification verification.
-h, --help Show this message and exit.
And, the geometry sub-command is as follows:
$ pygridmet geometry -h
Usage: pygridmet geometry [OPTIONS] FPATH

Retrieve climate data for a dataframe of geometries.

FPATH: Path to a shapefile (.shp) or geopackage (.gpkg) file.
This file must have four columns and contain a ``crs`` attribute:
- ``id``: Feature identifiers that gridmet uses as the output netcdf filenames.
- ``start``: Start time.
- ``end``: End time.
- ``geometry``: Target geometries.
- ``snow``: (optional) Separate snowfall from precipitation, default is ``False``.

Examples:
$ pygridmet geometry geo.gpkg -v pr -v tmmn

Options:
-v, --variables TEXT Target variables. You can pass this flag multiple
times for multiple variables.
-s, --save_dir PATH Path to a directory to save the requested files.
Extension for the outputs is .nc for geometry and .csv
for coords.
--disable_ssl Pass to disable SSL certification verification.
-h, --help Show this message and exit.
Now, let’s see how we can use PyGridMET as a library.
PyGridMET offers two functions for getting climate data; get_bycoords and get_bygeom.
The arguments of these functions are identical except the first argument where the latter
should be polygon and the former should be a coordinate (a tuple of length two as in (x, y)).
The input geometry or coordinate can be in any valid CRS (defaults to EPSG:4326). The
dates argument can be either a tuple of length two like (start_str, end_str) or a list of
years like [2000, 2005]. It is noted that both functions have a snow flag for separating
snow from precipitation using
Martinez and Gupta (2010) method.
We can get a dataframe of available variables and their info by calling
GridMET().gridmet_table:


Variable
Abbr
Unit



Precipitation
pr
mm

Maximum Relative Humidity
rmax
%

Minimum Relative Humidity
rmin
%

Specific Humidity
sph
kg/kg

Surface Radiation
srad
W/m2

Wind Direction
th
Degrees Clockwise from north

Minimum Air Temperature
tmmn
K

Maximum Air Temperature
tmmx
K

Wind Speed
vs
m/s

Burning Index
bi
Dimensionless

Fuel Moisture (100-hr)
fm100
%

Fuel Moisture (1000-hr)
fm1000
%

Energy Release Component
erc
Dimensionless

Reference Evapotranspiration (Alfalfa)
etr
mm

Reference Evapotranspiration (Grass)
pet
mm

Vapor Pressure Deficit
vpd
kPa



from pynhd import NLDI
import pygridmet as gridmet

geometry = NLDI().get_basins("01031500").geometry[0]

var = ["pr", "tmmn"]
dates = ("2000-01-01", "2000-06-30")

daily = gridmet.get_bygeom(geometry, dates, variables=var, snow=True)



If the input geometry (or coordinate) is in a CRS other than EPSG:4326, we should pass
it to the functions.
coords = (-1431147.7928, 318483.4618)
crs = 3542
dates = ("2000-01-01", "2006-12-31")
data = gridmet.get_bycoords(coords, dates, variables=var, loc_crs=crs)



Additionally, the get_bycoords function accepts a list of coordinates and by setting the
to_xarray flag to True it can return the results as a xarray.Dataset instead of
a pandas.DataFrame:
coords = [(-94.986, 29.973), (-95.478, 30.134)]
idx = ["P1", "P2"]
clm_ds = gridmet.get_bycoords(coords, range(2000, 2021), coords_id=idx, to_xarray=True)


Contributing
Contributions are very welcomed. Please read
CONTRIBUTING.rst
file for instructions.