Ole Rathmann

Hi Donitz, since the OWC-generator in WACA works with a pre-defined number of speed-bins I cannot rule out that the last speed-bin is treated in a little bit special way. Ole.

Hi Donitz, in the creation of and OWC the algorithm also distributes "an event" between two adjecent bins according to the speed-discretization width, ws. So you should imagine that a certain speed measurement "U" in fact covers a range [U-0.5ws ..U+0.5ws], and the distribute the fractions of the event according to how much of this intervals falls in the two bins involved. So, if practice this means that if U is just at the borde between two bins, then they will each get 0.5 count. Same principle applies to direction, this time of course using the direction-discretization. Clear?

Hi Madajavi, we have now updated the WAsP FAQ-page regarding all-sector wind speed distributions, containing in fact the equation for the emergent wind speed distribution. The page also contains a link to a very illustrative example, highlightening the special features of the emergent distribution. The page is: http://www.wasp.dk/Support/FAQ/WindDistribution.aspx .

Hi Neil, it is still a problem to get from closed-polygon land-surface (roughness) representation to the "network" representation we use in WAsP. In the Help-system of the Map editor, in the topical page "Line types | Roughness lines | Roughness area topology" you will see the principle of the latter demonstrated. So, in you case, in stead of having to split up the polygons in smaller segmements fitted together at node-points it would be easier to keep the polygons but sqeeze them slightly, to make sure there is a small space of, say, 3 m, betwee adjecent polygons. Then neither the map editor nor WAsP itself would register any crossing line-segments not overlapping roughness areas. Hope you may use this advice.

Hi all - the rejection of maps with negative elevations in the Map Editor was just introduced as a reaction to elevation outliers. The WAsP flow model can easily cope with negative elevations; it is the relative variation of terrain height that matters, not the absolute value. We will modify the Map Editor so it only reacts to extremely negative and positive elevations (say,+10 000m)

Hello "WAsP101", basically the answer to having a 10m ZDPH on a 300 plateau is using a "displaced" height contour of 310m. Please notice that the situation is more complicated if the forest is on a slope - in that case you should "clip" (use the clipping option) out the forest area, save that as a separet map file, increase all elevations by 10 m, save again; then reload the original map and use "Add and replace" the forest map into it. That should give you the forest area "lifted" by the displacement height.

Dear "Server", the answer is - unfortunately - simple: The Map Editor does not support 3D polylines in DXF, only 2D lines (3d lines only if each line has a fixed eelvation). So it is - in effect - 2D lines with an elevation as height contours, and 2D roughness change lines (in DXF input in a rather special way described in the Help-system) to describe areas with specific land-cover or roughness-length.

Hi Fernando, No, the wake model in WAsP is still based on the N.O.Jensen-model (1984), implemented according to the paper by I.Katic, J.Højstrup and N.O.Jensen (1986). The full references are given in the WAsP Help-system (Other information sources | References)