Spanish painter Joaquin Mir (also called Joaquin Mir Trinxet or Joaquim Mir i Trinxet) was born in Barcelona and studied there at Escuela Oficial de Bellas Artes (the School of Fine Arts), He was active in the late 19th and early 20th centuries, and was known primarily for his landscapes.
He worked in a lush, painterly style, often with a bright color palette. Some of his compositions utilize Art Nouveau inspired design elements and others blend representation with elements of abstraction or even drip painting.
Though the biographical information I could find about him was limited, there are a number of sources of images on the web, in particular on Cuidad de la pintura, which has over 300 images of his works (about half of which are drawings or sketches).
Christie's Sold Lots (some zoomable)
Wikipedia bio (ES) - (Google Translate English)
ArtCyclopedia (museum links and other resources)