Glossary for Geospatial Science

  Technical vocabulary defined by MicroImages

book Glossary

flow direction:  In a raster-based watershed analysis, each cell is assumed to drain into one of its eight neighbors (left, right, up, down, plus the four diagonals).  The flow direction of a cell is expressed in degrees: up=0, right=90, down=180, left=270; and the diagonals: 45, 135, 225, 315.