revise surface elevation locally using observed data

[Lalith]

Hi,

I am trying to set up a groundwater model. I have DEM data that covers a large area (these are less accurate). In addition, I have more accurate measured ground surface elevation data (in X, Y and Z form) at several locations of interest given the discharge and pumping activities at these locations. There are observed ground water elevations at these locations which are expected to be used in model calibration.

I first used DEM data to establish ground elevation in the entire model domain and then imported the observed data at these locations of interest and interpolated in 2D. Problem is that ground surface elevations in entire modeling area changes when I load observed local data as 2D data set and interpolated. Since there are no observed data in the regions among observed data, ground elevation drastically changes to unrealistic values in the areas where there is no observation data. Simply, model remove elevations calculated from DEM and recalculate elevations based only using observed data.

Please let me know how I can first use DEM data to generate ground surface elevations in my entire model and revise ground elevations only locally using measured data without changing ground elevations in the entire domain.

Thank you,

Lalith

Edited January 16, 2017 by Lalith

[Alan Lemon]

It may be easiest to convert the raster (or a portion of the raster) to a scatter set. Delete the points that are in the area where your hi-res data is. Then merge the hi-res scatter with the lower-res scatter set by selecting both items in the project explorer, right clicking, and selecting the merge command.

[Lalith]

Thank you Allen. I will update you if I come across any issues.