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I downloaded a .tif raster file from opentopography.org. It's an Alos (AW3D30 ) topography file showing mountainous terrain in Sweden. On the very right the file contains terrain, and on the left a lake surface. The lake surfaces have values of -9999 for each cell.

Is there some way to interpolate these -9999 values into values which would somehow correspond to the lake surface elevation? For example, the elevation of the nearby shore/coast is around 300 something meters. Is there a way to replace all the -9999 values with 300 values in order to get a somewhat acceptable transition from shore/coast to lake surface?

The mentioned file can be downloaded from here: https://www.dropbox.com/s/kai6202uewas47j/no_value.tif?dl=0

Vince
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marco
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    For question 2: Have you tried setting -9999 to NoData (http://desktop.arcgis.com/en/arcmap/10.3/manage-data/raster-and-images/nodata-in-raster-datasets.htm) and setting any raster cells overlapping or in the vicinity of the shoreline to 300m and then interpolating between existing raster values and shoreline to create a new raster. You could start by creating point data from your raster and shoreline data after the NoData operation. The link above also explains how to assign NoData to cells. – ZrSiO4 Dec 26 '17 at 23:24
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    If you know the lake surface elevation you can reclassify these from -9999 to 300 (or whatever). You dont mention what GIS software you are using but see for example this question: https://gis.stackexchange.com/questions/17712/performing-raster-reclassification-in-qgis – BERA Dec 27 '17 at 09:15
  • Thank you for the replies both @ZrSiO4 and @BERA! BERA can you add a new reply? I can't label your comment as the solving one. – marco Dec 27 '17 at 19:03

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