Fix CRS being WKT instead of PROJ.4 (#2715)

* Fix CRS being WKT instead of PROJ.4

See https://github.com/mapbox/rasterio/blob/master/CHANGES.txt#L7

* Fix rasterio usage for older rasterio without to_proj4

Co-Authored-By: djhoese <david.hoese@ssec.wisc.edu>

* Fix indentation on rasterio AttributeError check

* Add CRS WKT fix to whats-new

Author: djhoese

doc/whats-new.rst

@@ -79,6 +79,9 @@ Bug fixes
   :py:class:`CFTimeIndex` now results in a :py:class:`pandas.TimedeltaIndex`
   instead of raising a ``TypeError`` (:issue:`2671`).  By `Spencer Clark
   <https://github.com/spencerkclark>`_.
+- Fix ``open_rasterio`` creating a WKT CRS instead of PROJ.4 with
+  ``rasterio`` 1.0.14+ (:issue:`2715`).
+  By `David Hoese <https://github.com/djhoese`_.
 
 .. _whats-new.0.11.3:
 

xarray/backends/rasterio_.py

@@ -282,7 +282,10 @@ def open_rasterio(filename, parse_coordinates=None, chunks=None, cache=None,
         # CRS is a dict-like object specific to rasterio
         # If CRS is not None, we convert it back to a PROJ4 string using
         # rasterio itself
-        attrs['crs'] = riods.crs.to_string()
+        try:
+            attrs['crs'] = riods.crs.to_proj4()
+        except AttributeError:
+            attrs['crs'] = riods.crs.to_string()
     if hasattr(riods, 'res'):
         # (width, height) tuple of pixels in units of CRS
         attrs['res'] = riods.res