What’s GDAL? GDAL is the Geospatial Data Abstraction Library, it’s a library to transform raster and vector data and it’s the Swiss Knife of GIS. Topography and bathymetry digital elevation models can easily be handled using GDAL.
Last time we had the task to create mountain ranges polygons for the whole world. I prepared a small tutorial referred to that. Maybe you can find something interesting for you. It will show you a model on how to select defined regions, slicing raster, smoothing and also exporting desired features. Enjoy!