LE 1

• Watershed Delineation

  -Creates a boundary that represents the contributing/catchment area for a particular pour point or outlet
• Uses topography to bound watersheds with ridges?

  Topographic divide
• Topographic watershed divides do not always

  correspond to the line that is effectively delimiting

  the groundwater? t/f

  true
• Geologic Divide

  • Also known as the phreatic divide or groundwater divide-
  • Subsurface flow affected by underlying impermeable

  geology
• Watershed boundary can be modified by artificial flow (e.g. artificial

  derivation, drinking and wastewater networks, roads, pumps,

  reservoirs).?

  artificial barriers
• what are the three divisions of watershed?

  topographic, geologic, artificial barrier
• what are the methods of delineation?

  automated DEM-based Delineation, manual topographic Map delineation
• what are the three kinds of automated DEM-based delineation?

  digital elevation model, digital surface model, digital terrain model
• General processes on Automated DEM-based delineation? (FFFDPW)

  fill, flow direction, flow accumulation, drainage processing, por point, watershed processing
• do automated DEM-based delineation is more accurate than manual topograpic map? t/f

  true
• Peaks

  – circles of high

  elevation
• Valleys

  – portions of contour that curve towards the peak
• Ridges

  – portions of contour that curve away from the peak
• in delineating a watershed, we should pass on ridges