I am planning to perform a least-cost path analysis in ArcGIS 10.1 (advanced license) by means of Path Distance tool. I am taking into account a large area, corresponding to the Mediterranean basin. I am planning to use wind direction as an horizontal factor in the estimation of anisotropic least-cost paths representing navigation routes across that basin. My question: is there any specific type of projection that should be preferentially used when dealing with such a large area and given the type of analysis involved?


When calculating least-cost paths, the best projection to use is one that preserves scale. One that might be preferable would be an Equidistant Conic Projection.

The projection has the useful property that distances along the meridians are proportionately correct, and distances are also correct along two standard parallels that the mapmaker has chosen. The two standard parallels are also free of distortion.

One such projection would be the Europe Lambert Conformal Conic which you can find in the ESRI Continental Projected coordinate systems.

Another one which I found on EPSG Registry is ETRS89 / LCC Europe (EPSG 3034).

ETRS89 / UTM (CRS codes 25828-37 or 3040-49) used for conformal mapping at scales larger than 1:500,000. ETRS89 / LAEA (CRS code 3035) used for statistical applications at any scale.

  • Thank you @Fezter for your useful reply. I have found a webpage which indicates (as indeed you did) that a conformal projection should be used "when the map's main purpose involves measuring angles, showing accurate local directions, or representing the shapes of features or contour lines" (geo.hunter.cuny.edu/~jochen/gtech201/lectures/lec6concepts/…).
    – NewAtGis
    May 22 '17 at 6:50
  • If this post answered your question, please accept it as per our help page. I also came across the same page.
    – Fezter
    May 22 '17 at 6:51
  • I am wondering why when I set on ArcMap the coordinate system as Europe Lambert Conformal Conic and I add a layer projected on UTM 33N (European Datum 1950), ArcMap doen not return any warning about the difference in coordinate system. I am just courious to know if there is any connection between the two. Apologies for what may prove a stupid question. I will more than happy to be redirected to any relevant source of information.
    – NewAtGis
    May 22 '17 at 6:54
  • Rather than ask a new question in the comments, you'll get a wider audience if you post a new question. However, this topic was covered recently in this post.
    – Fezter
    May 22 '17 at 6:57

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